Governing Body: China Light Industry Council
Organizers: China National Research Institute of Food and Fermentation Industries
China Information Center of Food and Fermentation Industries
Editor-in-chief: Su Yao
Editor-in-charge: Yongjie Yao, Xin Li, Ye Li, Yawei Chen, Ling Dong, Xintian Wang
Editor: Guoxiao Sun, Yue Zheng
English Editor: Yawei Chen, Guoxiao Sun
Issuer: Fang Liu
Frequency of Publication: semimonthly
Place of Publication: Beijing
ISSN 0253-990X
CN 11-1802/TS
Constipation is a common gastrointestinal disease, and its incidence has obvious gender differences, in which women being more susceptible to constipation.Previous studies have found that the application of estrogen receptor β (ERβ) inhibitor (tamoxifen citrate) can successfully construct an animal model adapted to female constipation.Meanwhile, Bifidobacterium longum CCFM1240 has the effect of relieving female constipation, but the mechanism to exert its effect is still unknown.Based on that, this study intends to analyze the possible approaches of relieving female constipation from the perspective of repairing intestinal nerves and intestinal barriers.Results showed that compared with the model group, the intervention of B. longum CCFM1240 could significantly regulate the structure of intestinal microbiota (upregulate the relative abundance of Pediococcus, downregulate the relative abundance of Parabacterioids, Oscillibacter, Ruminococcus UGG-010, and Ruminiclostridium 9), increasing the content of six short chain fatty acids (especially acetic acid, butyric acid, and valeric acid), helping to restore the intestinal barriers and intestinal nervous system (promote the secretion of ACh by intestinal neurons, reduce the pro-inflammatory factor IL-6 and increase the proportion of Treg), and improving intestinal inflammatory response.This study demonstrates that B. longum CCFM1240 can balance the intestinal environment, repairing damaged intestinal barriers and intestinal nerves, thereby alleviate constipation in female rats induced by estrogen receptor beta inhibitors, and provide a new method to treat female constipation.
Lycopene is a natural antioxidant used in food and pharmaceuticals.The traditional methods of plant extraction and chemical synthesis of lycopene have the disadvantages of large environmental pollution, complicated steps and high production costs.Microbial synthesis of lycopene has attracted international attention because it can effectively avoid the above problems.In this study, the lycopene synthesis pathway was constructed and optimized in food-safe strain Bacillus subtilis.Firstly, the lycopene synthesis gene cluster was heterogeneously expressed in B.subtilis to achieve de novo synthesis of lycopene.By optimizing the ribosome binding sites (RBS) of each gene in the lycopene synthesis gene cluster, the titer of lycopene was increased to 0.57 mg/L.In addition, error-prone PCR was used to randomly mutate the RBS-optimized lycopene synthesis gene cluster, and a mutant with lycopene titer increased to 6.4 mg/L was obtained.Secondly, by screening the expression host of the lycopene synthesis gene cluster, the titer of lycopene was further increased to 15.5 mg/L.On this basis, the titer of lycopene reached 77.4 mg/L by strengthening the synthetic pathway and knocking out the competitive pathway.Finally, after fine-tuning fermentation conditions, the lycopene titer in shake flasks increased to 91.0 mg/L.This study laid a foundation for the synthesis of lycopene by microbial method.
7-chlorine-tryptophan (7-Cl-Trp) has important biological activities and is widely used in pharmaceutical, chemical and agricultural fields.In the previous study, a whole-cell catalyst was constructed to synthesize 7-Cl-Trp by expressing L-amino acid deaminase (L-AAD) and halogenase in E.coli.The amount of 7-Cl-Trp synthesis was increased by regulation of expression levels of L-AAD and halogenase and strengthening the coenzyme supply.However, 7-Cl-Trp synthesis is still limited by the substrate tryptophan degradation side reaction and the low catalytic efficiency of halogenase.In this study, tryptophan utilization was first improved by knocking down the gene, tnaA, which increased the 7-Cl-Trp synthesis by 15.8%.Then, by combination with directed evolution and site-directed mutagenesis, whole-cell-catalyzed amount of 7-Cl-Trp synthesis of the triple mutant was increased by 54.9%.Kinetic analysis showed that the three-point mutant increased Kcat by 50.0%, Km by 9.2%, and the overall catalytic efficiency by 65.2%.Finally, the whole-cell catalytic conditions were optimized to produce 105.7 mg/L of 7-Cl-Trp after 12 h (40 ℃, pH 7.4, 400 mg/L tryptophan, 10 μmol/L FAD).This study provides a new idea for whole-cell catalytic synthesis of halides.
Monacolin K (MK), a characteristic natural bioactive compound of Monascus spp., has a variety of physiological influence such as strong cholesterol-lowering and blood lipid-lowering, anti-hyperlipidemia etc.In this study, the MK yield of fermented coarse cereals was increased through screening of fermentation strains, substrates and optimization of fermentation technology by Monascus spp. Moreover, the quality of fermentation products was evaluated by detecting physicochemical indexes, active components and safety indexes.The aim of this study was to provide a theoretical basis for the development of coarse cereals fermented by Monascus spp. with high MK content.The results showed that the biomass of Monascus purpureus 3.462 9 was the highest(P<0.05).Among the four coarse cereals fermented with M.purpureus 3.462 9, Tartary buckwheat had the highest MK and pigment yields of 80.1 mg/kg and 299.20 U/g (P<0.05), respectively.The optimal fermentation technology was:solid-liquid ratio of 25∶10 (g∶mL), initial pH 4, inoculum amount of 8%, temperature of 30 ℃.Under the optimal condition, the MK content in fermented Tartary buckwheat reached 200.00 mg/kg, which was 150% higher than that before optimization (P<0.05).The fermented Tartary buckwheat has good physicochemical quality, and its content of total phenol and total flavone were 1.50 and 4.66 g/100 g, respectively (P<0.05).And the fermented Tartary buckwheat had excellent safety characteristics, microbiological indicators were below the requirements (QB/T 2847—2007), and its content of total biogenic amines, aflatoxin B1 and oryzanamycin were lower than the safety limit (T/ZZB 1452—2019).This optimal fermentation technology not only enriched the MK in Tartary buckwheat fermented by M.purpureus 3.4629, but also obtained the fermented products with good quality, which laid a theoretical foundation and provided data support for the research and development of coarse cereals fermented by Monascus spp.
Monensin, a polyether ionophore antibiotic, is extensively utilized across agricultural and pharmaceutical sectors.Streptomyces cinnamonensis, a key microorganism for monensin production, could potentially enhance monensin fermentation yields through strain breeding and selective addition of precursors.This study employed atmospheric room temperature plasma mutagenesis on an industrial monensin-producing strain 2110, successfully generating a high-yield mutant strain with a monensin titer of 7.56 g/L, marking a 10% increase.Further optimization of the fermentation medium for this mutant strain through single-factor and response surface methodology identified the primary components as 35.0 g/L glucose, 41.81 g/L soybean oil, 30.0 g/L soybean meal, 1.0 g/L sodium propionate, 0.25 g/L lysine, 0.12 g/L isoleucine, and 0.16 g/L valine, with soybean oil, isoleucine, and valine significantly impacting monensin production.Under these conditions, fed-batch fermentation in a 5 L bioreactor achieved a yield of 12.23 g/L, representing a 56.56% improvement.These findings offer valuable insights for the industrial production of monensin and demonstrate significant potential for industrial application.
Taking Sanghuangporus as the starting strain (SH-0), the “Long March 5B” carrier rocket was carried out space mutagenesis, and 30 mutant strains were obtained through liquid fermentation screening, after identification,there were 2 Poria, and the rest were Sanghuangporus spp.Taking the dry weight of SH-0 mycelium as the index, the formula of liquid fermentation medium was optimized by uniform design method.The results showed that the optimal formula of liquid fermentation medium of Sanghuangporus was 46.47 g Corn flour, 55.00 g glucose, 22.00 g peptone, 21.94 g soybean flour, 0.07 g potassium dihydrogen phosphate, 36.34 g bran, 0.01 g sodium chloride, 0.29 g magnesium sulfate in 1 l medium.The optimal liquid fermentation medium was used to screen 12 space mutagenic strains of Sanghuangporus and 1 commercially available Sanghuangporus (SH-S) whose mycelial dry weight was significantly greater than that of sh-0.Through multi-dimensional comprehensive comparison of the rescreening strains, the space mutagenic strain sh-68 of Sanghuangporus was finally screened, and its mycelial dry weight was 24.4 g/L;the crude polysaccharide content was 32.99 mg/g;total flavonoids 8.90 mg/g, the total polyphenol content was 7.76 mg/g, and the total antioxidant capacity was 53.9 μmol/g, The clearance rate of DPPH was 91.8%.After giving the corresponding weights to each index, its comprehensive score was 32.46, which was significantly improved on the basis of 22.56 points of the starting strain.
This study aimed to clarify the causative organisms of diseases of postharvest passion fruit and the inhibitory activity of plant-derived bacteriostatic agents against the main pathogenic bacteria, providing a reference for the disease control of postharvest passion fruit.This study used the tissue isolation method to isolate and purify the pathogenic bacteria from naturally infected passion fruit, identified the pathogenic bacteria by morphological observation and biological analysis, screened for inhibitors with inhibitory effects on the pathogenic bacteria by using the mycelial growth rate method, and further investigated the inhibitory virulence of phytic acid, citral, and phenyl-lactic acid and their effects on malondialdehyde content, cell membrane integrity, nucleic acid and protein leakage of the primary pathogen.Results showed that the pathogenic bacteria causing postharvest passion fruit diseases were Fusarium, Colletotrichum, Alternaria, and Meyerozyma.Based on the pathogenicity test, Fusarium oxysporum was determined to be the primary pathogen.Phytic acid, citral, and benzyl lactic acid could significantly inhibit the mycelial growth and spore germination of Fusarium oxysporum and be able to destroy the integrity of the cell membrane.The EC50 of phytic acid, citral, and benzyl lactic acid was 0.082 4%, 0.293 9 μL/mL, and 2.277 0 g/L, respectively.The germination rates of 0.2% phytic acid, 0.8 μL/mL citral, and 5 g/L benzyl lactic acid were only 14.91%, 21.03%, and 20.32%, and propidium iodide staining rate was 66.85%, 84.73%, 84.46%.Moreover, studies showed that phytic acid, citral, and phenyl lactic acid treatments significantly increased nucleic acid and protein leakage and malondialdehyde content, with the concentration-dependent.All the above results indicate that phytic acid, citral, and benzyl lactic acid destroy the structure of the cell membrane of F. oxysporum, thus affecting the normal growth of the mycelium to achieve a better bacterial inhibition effect, which provides the theoretical foundation for the application in food preservation.
This study used network pharmacology and molecular docking technology to explore the inhibitory mechanism of apple polyphenols on Pseudomonas aeruginosa and its diseases.The active components of apple polyphenols were collected through references search, and the component targets were obtained through TCMSP platform, PubChem database, SwissTargetPrediction database, and Swiss ADME website.Genecards, OMIM, and TTD databases were searched for Pseudomonas aeruginosa related targets.The “bioinformatics” website was used to obtain intersection targets.The protein-protein interaction analysis of the intersection targets was performed using the STRING platform.Moreover, the GO functional enrichment analysis and KEGG pathway enrichment analysis were performed using the DAVID platform.Finally, molecular docking was performed using the AutoDockTools software to validate the experiment.After screening, 8 plant active components and 184 component targets were obtained, including 1 103 targets for inhibiting Pseudomonas aeruginosa and 52 intersection targets.Through protein-protein interaction analysis, a total of 51 key targets including EGFR, AKT1, BCL2, and HIF1A were predicted.Through GO and KEGG enrichment analysis, 387 entries and 93 pathways were found to be related to the inhibition of Pseudomonas aeruginosa, mainly affecting pathways such as EGFR tyrosine kinase inhibitor resistance, PI3K/AKT, and VEGF signaling pathways.Molecular docking showed that the four active components with the highest degree values could all bind to the targets.Overall experimental results showed that apple polyphenols can inhibit Pseudomonas aeruginosa and its diseases through multiple components, multiple targets, and multiple pathways.This study can provide a theoretical basis for the study of apple polyphenols in inhibiting Pseudomonas aeruginosa and its diseases.
JIANG Luyao, ZHOU Junhan, YAN Yang, CHEN Jie, DENG Xiaodong, SHU Xin, TANG Chongshao, LUO Yingxin, ZHAO Zhiwei, WEI Yuying, GAN Juli, DU Yanfeng, YAN Wenbo, ZHANG Weiwei
Traditional antibacterials are still widely used, but this has caused bacteria to develop considerable antibiotic resistance.One benefit of the new antibacterials that target the quorum sensing mechanism is that they don’t cause drug resistance in bacteria.This work offers theoretical justification for the creation of novel antibacterials from natural materials.Salmonella is the test strain used in this study.The MIC of two Dendrobium extracts against Salmonella was investigated.Using in swimming, growth curve, and biofilm experiments to investigate the impact of the extract on Salmonella motility, growth, and biofilm formation.Utilizing HPLC to examine the extract’s primary constituents.We employ the molecular docking simulation to investigate the mechanism of the extract on the Salmonella quorum sensing system.The MIC of Dendrobium officinale Kimura extracts on Salmonella is 8 mg/mL and the MIC of Dendrobium denneanum Kerr extracts on Salmonella is 4 mg/mL.The extracts exhibit concentration dependence and significantly restrict Salmonella’s ability to migrate, form biofilms, and swarm at subinhibitory doses.The HPLC analysis reveals the presence of isorhamnetin, hyperin, and quercetin in both Dendrobium extracts.Both LuxS proteins are able to bind to these active monomers.These findings suggest that via binding monomeric components to matching proteins, the extract inhibited the production of pathogenic factors, hence having an antibacterial impact.
Ziziphus jujuba Mill., a fruit characterized by its high nutritional and medicinal value originating from Shanxi, has garnered limited attention regarding the differential metabolites in its juice fermented by diverse microbial strains.Utilizing Lactiplantibacillus plantarum, Lactobacillus acidophilus, and a combined strain of the two for synergistic fermentation, this study conducted a non-targeted metabolomics analysis of the original and fermented jujube juices via liquid chromatography-mass spectrometry.Results revealed that the juice fermented by the combined bacterial strain exhibited superior effects.Between the original juice and the various fermented versions, six primary classes of differential metabolites were identified, including organic acids, organic bases, amino acids, sugars, phenols, and nucleosides.Further analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways demonstrated that only the major differential metabolites between the single-strain and combined-strain fermented juices exhibited non-overlapping metabolic pathways, especially in amino acid metabolism.This study offers insights into the metabolic differences between original and fermented jujube juices, as well as among the different fermented versions.The detected substances can serve as valuable data for further analysis of fermented jujube juice and corresponding biological function research.
The study combined intelligent sensory analysis technology with traditional sensory evaluation and used regression analysis and correlation analysis methods to explore consumer preference of Baijiu during different meal and wine pairings.It investigated the correlation between preference and brain waves and facial expressions emotions.It also examined changes in taste perceptions of consumers on dishes before and after meal and wine pairing, correlating with preferences for pairing, aroma, taste, overall liking, purchase intent, and level of recommendation.Results showed heterogeneous changes in taste intensity after different meal and wine pairings, and both elegant-flavor Baijiu and Chi-flavor Baijiu enhance taste intensity with sour, bitter, and spicy dishes.Greater umami intensity change leaded consumers to prefer recommending the Chi-flavor Baijiu.Higher sweetness intensity change correlated with a preference on sweet dishes paired with the Chi-flavor Baijiu.Highest consumer preference appeared when elegant-flavor Baijiu paired with sweet dishes and Chi-flavor Baijiu with salty dishes.Linear regression models yielded correlation coefficients (R) between 0.49 and 0.76, all with P-values below 0.05, indicating a good fit and demonstrating that combining intelligent sensory analysis with traditional sensory evaluation could effectively analyze consumer preference during different meal and wine pairings.This study establishes a scientific basis for enhancing meal and wine pairing preferences.
The unique climate of the production area has created the non replicability of high-quality Maotai flavor Baijiu.Taking the Daqu Kunsha sauce wine produced in Renhuai City as the research object, analyze the influence of regional climate on the flavor of base wine in 1-7 rounds of brewing.The results indicated that the climate differences in core production areas from 2021 to 2023 mainly lie in temperature, Air quality index (AQI), and precipitation.There was no significant difference in the alcohol content of base liquor produced in different climates (P>0.05).The difference in total acid content was concentrated in rounds 1 and 2.The difference in total ester content was between the 4th and 6th rounds, with the base wine reaching its peak in 2021, with a total ester content of 6.87 g/L and 6.30 g/L in the 4th and 6th rounds, respectively, which was 12.42% and 38.97% higher than the same period in 2022, and 47.15% and 62.64% higher than in 2023, respectively.Through the analysis of odor activity value (OAV), it was found that 10 flavor substances such as acetaldehyde, furfural, acetal, ethyl lactate, n-propanol, etc.play an important role in the aroma characteristics of the base wine.Among them, the OAV of ethyl lactate in the base wine brewed in 2023 was higher than that in 2021 and 2022 (P<0.05).The application of least squares discriminant analysis can effectively distinguish the aroma components of base wines from different brewing climates, and 12 flavor substances with important distinguishing contributions, namely ethyl heptanate, octanoic acid, ethyl butyrate, ethyl acetate, isobutanol, etc., can be determined based on VIP values>1.This study elucidates the impact of climate characteristics on the flavor of soy sauce wine, providing reference for optimizing actual production time.
Research on the differences in liquor production through separate fermentation of piled-up fermented grains from different parts of the third, fourth, fifth and sixth rounds of Jiangxiang Baijiu in Shennongjia Ecological Liquor Industry.The bottom center of the piled fermented grains was taken as the origin for layering.From the inside to the outside, it was divided into four parts:the bottom layer (0-60 cm), the middle layer (60-160 cm), the outer layer (160-210 cm), and the surface layer (210-230 cm).The piled fermented grains of the four parts were separated for separate fermentation and wine production, and the physicochemical differences of the fermented grains and the differences in wine production were compared.The results showed that the physicochemical differences between different parts of the accumulated fermented grains in the same round were significant, and there were also significant changes in the same part of the accumulated fermented grains in different rounds.Among the accumulated fermented grains that were fermented separately, the middle and inner layers produced the best quality wine, with the best sensory characteristics of soy sauce flavor, flower and fruit aroma, sweetness, and cottony texture, as well as the best overall sensory characteristics.The highest content of tetramethyl pyrazine was produced by fermentation of surface grains alone, and the astringency, off-flavor, burnt taste and other off-flavor of the wine produced by surface and outer grains were the most obvious to the senses.The content of propanetriol was the highest in the middle layer of stacked spirits, the content of xylitol was the highest in the inner layer of stacked spirits, and the content of erythritol in different parts of the stacked spirits was less different overall.This study can provide a reference for the optimisation of the stacking process and the improvement of wine quality of soy sauce-type white wine production.
To investigate the dynamic changes in flavor compounds during the fermentation of ice wine, this study analyzed the monomeric phenols and aromatic components in Vidal ice wine samples fermented by Hanseniaspora uvarum (Hu) and Saccharomycopsis crataegensis (Sc).Results showed that the total polyphenol content in the Hu fermentation group consistently exceeded that of the Sc group, peaking on the third day of fermentation (53.23 mg/L).Aromatic component analysis indicated that the total content of aroma substances with odor activity values greater than 1 in the Hu group was significantly higher than in the Sc group, also reaching its maximum on the third day (5.34 mg/L).Principal component analysis demonstrated significant changes in aroma compounds in the Hu group during the early stages of fermentation, particularly in isoamyl acetate, isobutyl acetate, and phenylethyl acetate, with volatile compounds stabilizing during the mid to late fermentation stages.In contrast, the Sc group primarily produced alcohols during the early fermentation stages and esters during the late stages.Furthermore, orthogonal partial least squares discriminant analysis identified seven differential aromatic components between Hu and Sc fermentations, with isoamyl acetate, which imparts a fruity aroma, having the highest variable importance projection value.Overall, H. uvarum demonstrated superior flavor enhancement in the fermentation of ice wine, providing valuable insights for optimizing ice wine fermentation processes.
To make the regulation results of benzothiadiazole (BTH) on grape quality reflected in wine, for this study, ‘Cabernet Gernischt’ grape was used as test material, and the cell wall changes of grape treated with BTH were observed.Optimized impregnation process, effects of impregnation, BTH treatment on phenolics, and color and aroma composition of grape mash were investigated.Results showed that compared with the control (CK), the cell wall thickness of grape skin in the BTH treatment of berry enlargement stage (PD), veraison (ZS), and ripening (CS) increased by 2.79 times, 62.83%, and 1.60 times, respectively, and the treatment at the enlargement stage had the greatest effect on the cell wall of the peel.The optimized impregnation process of BTH treated grapes was 36 mg/L pectin compound enzyme that impregnated at 23 ℃ for 46 h.The total phenols, flavonoids, aroma concentration, and color quality of BTH treated grape mash in the optimized impregnation process were higher than those of CK.Interactive RDA and PLS-DA analysis showed that the increase of aroma concentration and the improvement of color quality of BTH treated samples mainly depended on the variation total phenols and flavonoids.The optimized impregnation process had the greatest effect on the release of linear aliphatic, terpenes, and branched-chain aliphatic aroma compounds.In summary, BTH treatment can significantly improve the accumulation of phenolic substances in grape mash, the quality of color, and aroma, thereby improve the quality of wine.The research results can provide scientific theory and practical reference for the application and promotion of BTH in regulating the quality of Cabernet Gernischt wine.
To improve the quality of raw materials for sweet red wine, this study conducted roasting treatments on Merlot grapes under different conditions.These roasted grapes were then used to produce sweet red wine.By measuring the physicochemical components, antioxidant properties, and color indicators of different wine samples, along with sensory evaluation, the impact of roasting treatment on wine quality was explored.Results showed that as the roasting temperature or degree of roasting increased, there was a significant increase in the total sugar, total acidity, total phenolic compounds, antioxidant properties, and color quality of the resulting wine.Sensory evaluation indicated that the optimal roasting condition for Merlot grapes was a 45 ℃ roasting temperature with 40% weight loss.Under these conditions, the resulting wine showed a 152.1% increase in total sugar, a 47.7% increase in total acidity, a 38.6% increase in total phenolic compounds, and an increase in antioxidant properties by 38.1%.The color indicators showed that L* decreased by 9.79%, a*increased by 45.2%, and b* increased by 5.8%.This study demonstrated that appropriate roasting treatment of Merlot grapes could enhance the color quality and antioxidant properties of the wine, resulting in a smoother, richer taste and more intense aroma.This research provides a practical and effective method for improving the raw material quality for sweet red wine production and offers theoretical and practical support for the development of wine-making technology.
Dendrobium devonianum is a unique medicinal and edible plants in Longling, Yunnan Province.Polysaccharides with high content is its main effective component.D.devonianum soaking wine is a local specialty product, but there exists some problems, such as low solubility of polysaccharides in the wine and unclear functional ingredients.In this paper, cellulase, glucanase and β-mannanase were used to hydrolyze polysaccharides of D.devonianum.Further, the enzymatic hydrolysate of D.devonianum was used to be fermented as the main raw material mixed with fruit of Morus alba, Lycium chinense Miller and Dimocarpus longan Lour.The contents of total polysaccharides, organic acids, total phenols and flavonoids in D.devonianum wine were determined.The antioxidant activities were then investigated.The results showed that the average molecular weight of polysaccharides decreased from 7 880 Da to 501 Da after hydrolysis by cellulase.The polysaccharides in the enzymatic hydrolysate can be retained in the wine below 15% (volume fraction), even in 50% of the wine, the polysaccharides content of the enzymatic hydrolysate is 5.30 times of the original polysaccharides solution.The alcohol content of the compound fermented D.devonianum wine was 10.9%vol, the contents of total polysaccharides, flavonoids and total phenols were 11.18, 0.53 and 0.58 g/L, respectively.Additionally, the organic acids such as citric acid, malic acid, succinic acid and acetic acid were also contained.The scavenging rate of DPPH free radicals, ABTS cationic radicals and hydroxyl radicals were better.These results laid a foundation for the further development of the compound fermented D.devonianum wine.
To explore the linkage and differences between the protease gene characteristics and phenotypes of three strains of Lacticaseibacillus paracasei BDⅡ, J4, and J17, three strains of Lacticaseibacillus paracasei with high protease viability were screened by using the clear circle method and the Folin method, and then they were subjected to whole-genome sequencing, and combined with the comparative genome analyses of 15 publicly available strains of Lacticaseibacillus paracasei and Lactobacillus johannes, with emphasis on key genes affecting the protease-producing ability of Lacticaseibacillus paracasei.Results showed that BDⅡ, J4, and J17 had relatively high protease activity, with BDⅡ having the highest protease activity of 22.017 U/mL.Whole-genome sequencing analysis indicated that the GC content of the three strains ranged from 46.14% to 46.64%, and the genome sizes were located between 2.3 Mb and 3.2 Mb.By CAZys annotation, BDⅡ was found to contain the unique protein family GT51 (indirectly involved in the regulation of protein hydrolysis) and the unique peptidase pepX (catabolic peptide), which were closely related to the synthesis of the bacterial cell wall, and therefore it was hypothesized that the presence of peptidases pepX and GT51 was responsible for the highest protease activity of BDⅡ.This study screened a strain of Lacticaseibacillus paracasei BDⅡ with high protease production by a combined phenotypic and genomic approach, elucidated the mechanism of protein hydrolysis and the regulation of protein hydrolysis-related genes, and found that BDⅡ has a great potential for application in functional dairy products.
This study used naturally fermented sour meat as the target lactic acid bacteria donor to find lactic acid bacteria that are suitable for animal-derived matrix fermentation and have strong growth ability, good tolerance and strong fermentation properties.After screening, separation and purification, three lactic acid bacteria were obtained, namely Lactiplantibacillus plantarum, Pediococcus pentosaceus and Pediococcus acidilactici.Taking naturally fermented sour meat as the target lactic acid bacteria donor, three types of lactic acid bacteria were obtained by screening, separation and purification, namely L. plantarum, P. pentosaceus and P. acidilactici.The strain’s growth ability, acid production ability, tolerance, protein degradation ability and fat hydrolysis ability were tested.The results showed that the maximum number of viable bacteria of the three lactic acid bacteria strains were 7.8×1010 CFU for L. plantarum, 3.5×1010 CFU for P. pentosaceus, and 3.8×1010 CFU for P. acidilactici;The maximum time periods of acid production were 3-14 h for L. plantarum, 3-10 h for P. pentosaceus and P. acidilactici;The maximum high temperature tolerance of the three strains was 65 ℃;The highest tolerance NaCl addition was 6%;The maximum tolerable NaNO2 content was 100 mg/kg;The minimum pH tolerance was 4.0;They all had the ability to degrade glucose and protein;P. pentosaceus and P. acidilactici had more obvious fat hydrolysis ability;There was no antagonism between the three strains and they could be cultured synergistically.Therefore, the three types of lactic acid bacteria can not only provide a good antibacterial environment for the fermentation of meat products, but also enrich its flavor characteristics, providing a reference for the subsequent development and quality research of fermented meat products.
This study investigates the probiotic properties and cholesterol-lowering abilities of fermentation bacteria, by isolating and purifying four strains of lactic acid bacteria from traditional fermented mare’s milk.The morphological, physiological, and biochemical characteristics of these strains were assessed, along with their growth curves, tolerance to bile salts and artificial gastric fluid, and susceptibility to antibiotics.Additionally, qualitative assays were conducted for bile salt hydrolase activity and cholesterol oxidase to evaluate their cholesterol scavenging potential.The strains were ultimately identified using 16S rRNA gene sequencing.The findings reveal that the isolated strains exhibited strong tolerance to high concentrations of bile salts (3.0 g/L) and artificial gastric fluid (pH 2.0) while remaining sensitive to the majority of the eight antibiotics tested.Distinct white precipitation zones around the filter paper disks of each strain indicated the presence of bile salt hydrolase activity.The cholesterol scavenging rates for single and composite strains in the culture medium ranged from (76.46±1.26)% to (87.96±0.43)%, with the composite strain demonstrating superior capacity for cholesterol compared to individual strains.These strains had been identified as Lactiplantibacillus plantarum.This study suggests that the four isolated strains possess fundamental probiotic attributes and a high safety profile, along with notable cholesterol-lowering capabilities in vitro, which warrant further explored in vivo.
The MRS, blueberry and whey protein were used as the medium of lactic acid bacteria.The different protective agents were added after fermentation to explore the effects of spray drying process on the survival rate of bacteria cultured in different medium.The results showed that the mixed culture medium of blueberry whey protein could promote the growth of Lactiplantibacillus plantarum 67 and Lacticaseibacillus paracasei grx701, and the number of viable bacteria was 5×108 CFU/mL which was higher than that of MRS Medium.Blueberry whey protein mixed fermentation sample plus protective agent which was skim milk powder 12%, sodium glutamate 1.5%, trehalose 4%, glycerin 4%.The protection effect on lactic acid bacteria is good, which the survival rate is 91% at the inlet temperature of 120 ℃ and outlet temperature of 60 ℃.At the inlet temperature of 150 ℃ and 180 ℃, the number of viable bacteria can also reach 107 CFU/mL.When the inlet temperature was 150 ℃, the dispersion of blueberry whey protein mixed fermentation powder was better than 120 ℃ and 180 ℃.The bacterial powder surface was smooth.The infrared spectrum showed that the heat resistance of the bacteria was improved by the interaction between the bacteria, whey protein and anthocyanin of blueberry during the fermentation of blueberry mixed whey protein.
Methods such as confocal laser scanning microscopy, SDS-PAGE, size exclusion chromatography and ELISA were employed to compare the effects of 1.4 μm pore size microfiltration and pasteurization at 72 ℃ for 15 s on the in vitro gastrointestinal digestion of camel skim milk under simulated infant conditions.The results showed that the structure and moisture content of gastric clots, percentages of remaining caseins, releasing amounts free amino groups, and molecular weight distribution of protein hydrolysate for microfiltered camel milk in simulated gastric fluids were closer to raw camel milk, while pasteurization reduced the degradation rate of casein of camel milk in simulated gastric fluids, suggesting that pasteurization increased the resistance of casein to digestive enzyme.Additionally, microfiltration retained immunoglobulin G in camel skim milk to a larger extent, and also retained more immunoglobulin G and insulin during digestion.Microfiltered camel milk has gastrointestinal digestion characteristics and bioactive component retention similar to raw camel skim milk.This study provides a theoretical basis for the production of camel milk products with high-bioactivity.
Processed cheese is produced by blending various natural cheeses at different stages of maturation with emulsifying salts and other additives.The mixture undergoes heating, melting, and continuous emulsification to achieve a homogeneous product.In this study, the physicochemical properties and microstructure of processed cheese using texture analysis, rheometry, and scanning electron microscopy (SEM) were characterized to investigate the influence of phospholipids on its quality characteristics.The findings indicated that phospholipids notably enhanced the melting properties, hardness, and chewiness of reconstituted cheese by modifying the emulsification process (P<0.05).Phospholipids and proteins could reduce the elasticity and viscosity of cheese through hydrogen bonding and hydrophobic interactions.Microstructurally, phospholipids decreased the formation of protein voids and promoted a more uniform dispersion of fat globules, resulting in a dense mesh structure that alters the water distribution within the cheese.In conclusion, the addition of phospholipids to processed cheese significantly impacts its emulsification properties, functional attributes, and microstructure.These findings offer valuable insights for optimizing the production process of processed cheese and enhancing overall product quality.
Proteins and polyphenols can interact in reversible or irreversible ways, thus affect the sensory, texture and nutritional properties of foods.To investigate the types of non-covalent interactions between anthocyanins (centaurin-3-O-glucoside (C3G)) and bovine serum albumin (BSA) and their effects on BSA protein properties, multispectral techniques and molecular docking methods were used.The effects of C3G on the properties of BSA protein were also studied.First, Fourier infrared spectroscopy showed that the amide I and A bands were redshifted and their peak intensities weakened after C3G combined with BSA.The results of circular dichroism spectrum showed that the structure of BSA protein became loose and the secondary structure of BSA was changed in the presence of C3G.The α-helix content decreased from 31.8% to 31.1%, and the β-fold content increased from 18.1% to 18.5%.Next, the fluorescence spectra confirmed that the quenching of BSA by C3G is a static quenching caused by the formation of ground state complex.Thermodynamic and molecular docking results showed that the force between BSA and C3G is mainly contributed by electrostatic attraction and hydrogen bond, and C3G entered the BSA cavity structure.Finally, the study on the physical properties of BSA showed that the addition of C3G could expand the BSA domain and increase the particle size from 244.75 nm to 644.70 nm.Interestingly, C3G significantly enhanced the solubility, water holding capacity and oil holding capacity of BSA, as well as improved foam properties and emulsification properties.This study provides an important experimental and theoretical basis for understanding the effects of C3G on the conformation and protein properties of BSA, and provides a theoretical basis and reference for the application of protein-anthocyanin complexes.
Yak milk cheese casein bitter peptides have multiple beneficial bioactivities, including ACE inhibitory activity, antibacterial activity, and anti-glycation activity.HMG-CoA reductase is one of the primary targets for treating hypercholesterolemia (HC) and is the key rate-limiting enzyme in the body’s cholesterol biosynthesis.This study focuses on the yak milk cheese bitter peptides RPKHPIK (RK7) and KVLPVPQ (KQ7) as the research subjects, using atorvastatin, simvastatin, rosuvastatin, and pravastatin as control samples.Using bioinformatics tools, we studied the physicochemical properties of KQ7 and RK7, employed molecular docking and molecular dynamics simulations to reveal the mechanism of HMG-CoA reductase inhibition, and measured the inhibitory activity of RK7 and KQ7 on HMG-CoA reductase through in vitro experiments. The results indicated that the molecular weights of RK7 and KQ7 are 874.90 Da and 779.50 Da, respectively.Both RK7 and KQ7, as well as the four statin drugs, could form ligand-receptor complex conformations with HMG-CoA reductase.After comparing RK7 and KQ7 with the inhibitory peptides in the HMG-CoA reductase peptide database, it was found that KQ7 had a 75% similarity with known inhibitory peptides, and RK7 is a novel inhibitory peptide for HMG-CoA reductase.In vitro experiments showed that the IC50 values of RK7 and KQ7 for HMG-CoA reductase were 1.045 mg/mL and 1.228 mg/mL, respectively. This study efficiently and rapidly identified yak milk-derived HMG-CoA reductase inhibitory peptides through bioinformatics platforms and in vitro validation experiments.It also explored the mechanisms of molecular interactions through molecular docking and molecular dynamics simulations, providing new insights into HMG-CoA reductase inhibitory peptides.
Traditional fermented sufu is a daily condiment and appetizer, acting as a good source of plant-derived protein and bioactive peptides.To explore the angiotensin converting enzyme (ACE) inhibitory tetrapeptide and investigate the structure-activity relationships, the peptides of oil sufu were isolated using ultrafiltration and solid-phase extraction, and identified using Nano-LC-MS/MS.The potential ACE inhibitory peptides were preliminarily screened by online database, and then the peptides with high ACE inhibitory activity potential were further screened and analyzed using molecular docking, quantum chemical calculation, and quantitative structure activity relationship modeling.Their binding modes, distribution of the frontier molecular orbital, active sites, and inhibitory activities were analyzed.The results showed that peptides with molecular weight <3 kDa had the highest inhibitory activity [IC50=(489.6±26.69) μg/mL], and a total of seven high-potential ACE-inhibitory tetrapeptides were screened after sequences identification.The molecular docking results showed that all seven peptides bound tightly to the receptor through hydrogen bonding, hydrophobic, electrostatic, and metal bonding interactions to exert their inhibitory effects.Quantum chemical results showed that the highest occupied molecular orbitals of the tetrapeptide were mainly distributed on the two-terminal proline (P), and they had a high electronegativity and was easy to become an active site;FALP, GWPT and EGWP had lower energy gap and higher molecular reactivity.The results of quantitative structure activity relationship modeling showed that the parametric characteristics of the amino acid residues at two-terminal of the tetrapeptide had a more significant effect on the IC50 value;the smaller hydrophobicity and stereotropism of the amino acid, and larger electrical properties, the stronger the activity of the peptides.In conclusion, computer-assisted screening of ACE inhibitory peptides in furu was feasible, and the electrical properties of the two-terminal and proline were important to its inhibitory activity, which will provide a reference for the subsequent rapid screening of ACE inhibitory peptides and the study of structure-activity relationship.
To investigate the synergistic inhibitory effect of food flavorings alone and in combination with other inhibitors on acrolein (ACR), seven compounds, including disodium 5′-guanylate (GMP), disodium 5′-inosinate (IMP), quercetin (QUE), curcumin (CUR), theanine (THE), propyl gallate (PG) and monosodium glutamate (MSG) were screened from flavor compounds and food additives.The inhibitory effect on ACR at high temperatures was determined by high-performance liquid chromatography-diode array detection, and then the synergistic inhibitory effect of these compounds on ACR was analyzed by using CompuSyn software according to the Chou-Talalay method, the combination with good synergistic inhibitory effect was used in roasted pork patties to verified the inhibitory effect on ACR generated during processing.Our results showed that all seven inhibitors had the ACR-scavenging ability;Secondly, GMP combined with THE, MSG, and QUE in a constant IC50 ratio had a good synergistic inhibitory effect on ACR within a certain concentration range;Thirdly, by adding its compound combination to the actual system of roasted pork patties, it was found that the GMP+THE compound had the best synergistic effect, with an inhibition rate of 62.23% on ACR in roasted pork patties, which was about 1.6 times that of using it alone, in addition, the inhibitory effect of using straw mushrooms containing an equal amount of GMP instead of the combination of GMP and THE in roasted pork cake on ACR is comparable to that of the GMP+THE group.On this basis, the adducts of GMP and THE with ACR, including GMP-ACR, THE-ACR, THE-2ACR-1, and THE-2ACR-2, were detected in pork patties using LC-MS/MS.This indicated that their synergistic inhibition of ACR is due to the formation of their respective adducts, and also proved the feasibility of using mushrooms to replace GMP pure products in food.This article selected the combination of flavor agents GMP and THE, which could synergistically inhibit ACR generated during food processing.This study provided a scientific basis for the development of high-temperature resistant ACR inhibitors, reducing the chemical hazard of ACR in food processing, improving food safety, and preventing chronic diseases caused by ACR.
The primary objective of this study was to delve into the influence of varying concentrations of octenyl succinic anhydride (OSA) on the emulsifying proficiency and stability of tamarind seed polysaccharide (TSP) subsequent to esterification.To accomplish this, TSP and its esterified derivatives underwent rigorous characterization utilizing infrared spectroscopy, scanning electron microscopy, and thermal analysis techniques.Furthermore, the emulsifying potential, emulsion stability, and rheological attributes of OSA-modified TSP were meticulously analyzed.The results indicated that the higher the degree of OSA esterification, the smaller the emulsion particle size becomes, accompanied by an increased absolute value of zeta potential, ultimately enhancing emulsion stability.Optical microscopy analysis underscores that TSP and OSA-TSP emulsions with three specific substitution levels exhibit optimal stability in a pH 7 environment, with stability diminishing as either the pH or substitution degree decreases.This study involved the esterification of tamarind polysaccharide with octenyl succinic anhydride, enabling a comparative assessment of the structural characteristics, emulsifying capacity, and emulsification stability between TSP and OSA-TSP samples with varying degrees of esterification.The outcomes presented herein offer valuable insights and serve as a reference for the modification of novel polysaccharides and their potential industrial applications.
This study presents a low-cost and environmentally friendly method for the green synthesis of silver nanoparticles (AgNPs) using Forsythia suspensa leaf extract as a reducing agent.The optimal green synthesis process was determined through single-factor and orthogonal experiments;The structural characterization of AgNPs was conducted using UV-Vis spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction;The catalytic degradation activity of AgNPs on organic pollutants such as p-nitrophenol (4-NP), methyl orange, methylene blue, and rhodamine B was evaluated;The antibacterial activity against Escherichia coli (E.coli) was preliminarily assessed;The antioxidant activity was evaluated by determining the DPPH radical scavenging ability, with vitamin C used as a positive control.The results showed that the optimal conditions for green synthesis were 40% ethanol concentration, 70 minutes reaction time, and 4 mL of Forsythia suspensa leaf extract. Under these conditions, the synthesized AgNPs had particle sizes mainly ranging from 40 to 70 nm with good crystallinity.The degradation rates of 4-NP, methylene blue, methyl orange, and rhodamine B by AgNPs were 91.08%, 90.03%, 94.64%, and 93.00%, respectively.The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNPs against E.coli were determined to be 0.140 6 mg/mL and 0.281 3 mg/mL, respectively;The DPPH radical scavenging rate was 93.5% at an AgNP concentration of 0.55 mg/mL.In summary, AgNPs synthesized using Forsythia suspensa leaf extract demonstrated high catalytic degradation, antibacterial, and antioxidant activities, suggesting their potential applications in wastewater treatment, medical bioactive materials, and other fields.
Heterocyclic amines, a class of mutagenic and carcinogenic polycyclic aromatic compounds, are harmful substances generated from the thermal processing of high-protein foods.This study investigated the effects of mango peel, an industrial by-product, and its main active ingredients, pectin and mangiferin, on the formation of main heterocyclic amines 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PHIP) and 2-amino-3,8-dimethyl-imidazo[4,5-f] quinoxaline (MeIQx) in both chemical model systems and food systems (roasted beef patties).The study also explored the efficacy of these ingredients under different compounding conditions and investigates the impact of the mangiferin-pectin compound on the sensory and nutritional qualities of roasted beef patties.The study used solid-phase microextraction technology (Oasis MCX column) to extract heterocyclic amines from roasted beef patty samples, and used high-performance liquid chromatography mass spectrometry to determine the content of heterocyclic amines and analyze them.Sensory and nutritional indicators were assessed using reagent kits, texture analyzers, and colorimeters.The results indicate that when mangiferin and pectin were added to beef patties at different amounts (1%, 2%, 3%,on weight basis), they could significantly inhibit the formation of PhIP and MeIQx in roasted beef samples (P<0.05).The combination of the two has a better inhibitory effect.When the optimal combination ratio was 2∶1, the inhibition rate reached nearly 50%, and the optimal treatment was 3%.In conclusion, mango peel and its main components could significantly inhibit the generation of heterocyclic amines during food thermal processing, and had multiple effects on improving the sensory and nutritional quality of food.This result can provide experimental ideas and theoretical basis for the development of natural additives with multiple effects such as improving food safety and nutrition.
The aim of this study was to investigate the effects of steam explosion (SE) on the structural, physicochemical and functional properties of soluble dietary fiber (SDF) in pomegranate peel.Taken the extraction rate of SDF as index, the optimal technology of SE modification was as follows:the particle size of pomegranate peel residue was 60 mesh, the pressure was 0.60 MPa, and the maintenance pressure time was 140 s.Under these conditions, the extraction rate of SDF was (13.42±0.12)%, which was (5.91±0.04)% higher than that before modification.The analysis of Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy showed that more chemical groups were exposed, the intermolecular hydrogen bonding was strengthened, and the crystallinity was decreased after SE.The structure of SDF was also changed, and the surface was poriferous, rough and collapsed.The water-holding capacity, oil-holding capacity and swelling capacity of modified SDF were increased to (1.19±0.09) times, (1.60±0.16) times and (1.95±0.03) times of those before SE, respectively.In addition, SE improved the glucose adsorption capacity, alpha-amylase inhibition ability, cholesterol adsorption capacity and antioxidant ability of SDF in pomegranate peel residue.In conclusion, SE technology can effectively improve the physicochemical and functional properties of SDF from pomegranate peel residue, which provides a theoretical basis for the extraction and application of SDF from pomegranate peel residue.
The relationship between changes in volatile compounds and lipid and protein oxidation of chilled beef storage at superchilled temperature (-1.5, -2.5 ℃) was studied.Gas chromatography-mass spectrometry and stoichiometric analysis showed that the main flavor substances of beef samples in superchilled groups were n-hexaldehyde, nonylaldehyde, undecylaldehyde, and dodecylaldehyde.The contents of dimethyl disulfide and 3-methylthiopropionaldehyde which were significantly negatively correlated with odor sensory scores and positively correlated with protein carbonyl content (P<0.001) were relatively high in the control groups (4.0, 0.0 ℃).Beef samples in superchilled groups had a higher content of nonylaldehyde and undecylaldehyde, which were positively correlated with the scores of odor sensory and significantly negatively correlated with the hydrogen peroxide value (P<0.05).No dimethyl disulfide and 3-methylthiopropionaldehyde were detected in -1.5 ℃ (SC1) and -2.5 ℃ (SC2) groups, and the concentration of nonylaldehyde and undecylaldehyde was higher in SC2 group than in SC1 group.During storage period, the carbonyl of beef in superchilled groups was significantly lower than that in control groups, and the active sulfhydryl content was significantly higher than that in control groups (P<0.05).The carbonyl content of beef in SC2 and SC1 groups was only 2.04 and 2.09 nmol/mg on the 24th day, while the active sulfhydryl group content was still 28.94 and 31.24 nmol/mg.The content of hydroperoxide in SC2 group was the lowest only 0.082 g/100 g and had a higher odor perception (3.63 still maintained the normal odor of beef), that was, the -2.5 ℃ (SC2) superchilled group had a better storage effect, indicating that superchilled storage may maintain the good volatile flavor of beef by inhibiting the oxidation of lipid and protein.The research results provide theoretical and data support for the application of superchilled in the storage and preservation of chilled beef.
In this study, deep eutectic solvents (DESs) were used to extract tuna skin collagen (TSCO).Firstly, the TSCO extraction rate and the integrity of the advanced structure were used as evaluation indexes to select the solvent combinations with better extraction effect.Subsequently, the effects of different extraction conditions were discussed, including the proportion of components, extraction speed, temperature and time, and finally the crude extracted TSCO was purified by column chromatography.The extracted collagen was analyzed using Fourier transform infrared spectroscopy, SDS-polyacrylamide gel electrophoresis and scanning electron microscopy.The results showed that the extraction rate of collagen could reach 98.74% under the conditions of 2∶1∶30 molar ratio of betaine, citric acid and water, extraction temperature of 60 ℃, rotational speed of 1 000 r/min and extraction time of 180 min.After purification by column chromatography its purity was 91.4%, which was higher than that of the collagen standard (80.4%).Structural analysis showed that the extracted TSCO maintained an intact triple-helical structure with uniform molecular weight distribution and good microscopic morphology, indicating that DESs could efficiently extract TSCO without destroying its structural integrity.This study demonstrated the high efficiency and feasibility of DESs in TSCO extraction, which can provide a reference for promoting the high-value utilization of tuna skin.
As an emerging processing method, 3D printing has great potential for application in the food industry.The pseudo-plastic fluid behavior of the starch paste makes it easy to extrude from the 3D printing nozzle and quickly deposit into molding.In this paper, the microstructure, gelatinization, rheology, and 3D printing properties of pectin-sweet potato starch flocculation system were studied by adding different contents of pectin (0%, 1%, 3%, 5%, 7%) with sweet potato starch as the main raw material.Results showed that all the samples exhibited elastic gel-like properties and solid-like characteristics, which were conducive to the shape preservation of the samples after 3D printing.Pectin content had significant effects on gelatinization, rheology, texture, and microstructure of sweet potato starch gel (P<0.05).Compared with natural sweet potato starch, the viscosity value, recovery value, and disintegration value of pectin sweet potato starch flocculation system decreased, and the gelatinization temperature increased.Among them, the mixed gel with 3% pectin content had the best printing effect, and the hardness, elasticity, water holding, and adhesive properties are (82.35±3.08) g, 0.98±0.01, (0.79±0.04) g/g, and 58.38±0.02, respectively.Moreover, the network structure was regular and the thermal stability was good.The mixed gel with 7% starch gel and pectin content of raw sweet potato had poor printing effect.In summary, adding a certain amount of pectin could improve the gel characteristics of the coagulation system and improve the 3D printing effect of sweet potato starch gel, so that sweet potato starch has a broader application prospect in the field of 3D printing.
Corn flour was firstly fermented by lactic acid and followed by hydrolyzed using cellulose, and the effects of the compound modification on the rheological properties of corn flour batter were investigated, and its influence on the baking, texture and sensory characteristics of the prepared chiffon cake were also evaluated.The results showed that the modification endows significant improvements in the elastic modulus, viscous modulus, and apparent viscosity of the corn flour dough.Compared with the unmodified corn flour, the weight loss rate of composite modified corn cake was reduced;and the adhesiveness, gumminess, hardness and chewiness of the prepared chiffon cake were decreased by 30.77%, 57.42%, 58.82%, and 60.88%, respectively;The sensory evaluation score also increased by 33.3 points;and the cohesion had no significant changes.In addition, the elasticity of the chiffon cake prepared with compound modified corn flour reached 95.05%, which was similar to the value of the cake prepared by wheat flour chiffon;the quality characteristics of chiffon cake produced by the compound modified corn flour was significantly improved.The results obtained could provide support for the feasibility of applying modified corn flour in chiffon cake.
In this study, cassava starch was used as raw material to improve the 3D printing formability and quality characteristics of the xanthan gum-cassava starch coagulation system by adding different proportions (0%, 2%, 4%, 6%, 8%, and 10%) of xanthan gum.Results showed that the addition of xanthan gum increased the G′, G″, and tanδ values of the starch system, indicating that it had obvious elastic behavior, which was beneficial to the shape stability of the printed object after 3D printing.The amylose content, retrogradation value, relaxation time, and water fluidity of the starch system were reduced.The amylose content was reduced by 4.47 g at most, the retrogradation value was reduced by 339 mPa·s at most, and the relaxation time was reduced by 164.74 ms at most, which made the texture of the 3D printed sample clearer, improved the accuracy of the sample, and further promoted the extrusion smoothness of the starch sample and the smoothness of the printed sample surface.When the addition amount of 8% xanthan gum was 14 min, it showed a good printing appearance and printing height.At this time, the starch gel system had a suitable fluidity and mechanical strength to maintain the sample shape and maintain the sample height.In summary, when the addition amount of xanthan gum was 8%, the starch coagulation system showed the best printing characteristics.
To prolong the shelf life and solve the problem of the sales limitations of fresh wet jelly, the four packaging materials of cast polypropylene (CPP), polyethylene (PE), polyamide/polyethylene (PA/PE), and polyester/polyethylene (PET/PE) were vacuum-packed with fresh wet jelly in this experiment, to investigate the effect of package skin degree on the water loss and freshness preservation quality of fresh wet jelly.Results showed that the package skin degree of the four materials was PE>CPP>PA/PE>PET/PE.PA/PE and PET/PE, due to the poor flexibility of the material, the degree of adhesion after the vacuum was not enough, easily making the fresh wet jelly damage, exacerbating the loss of water, and further promoting the reaggregation of amylopectin during storage.The formation of microcrystals changed the conformation of starch and the retrogradation increased with the prolongation of storage time.CPP and PE were more flexible, which could achieve a high degree of adhesion with the fresh wet jelly, and maintain its high moisture content, thus hindering the recrystallization of amylopectin, inhibiting retrogradation to a certain extent, thereby delaying the increase of hardness, chewiness, relative crystallinity, and ordered structure of starch, inhibiting the decline of the L* value, to keep the color bright and the sensory quality better.Among them, PE had the best preservation effect.Therefore, the PE packaging material with high fitness could effectively control the water loss of the fresh wet jelly, so that it showed better texture and sensory quality during the 15-day storage period.However, due to the highest oxygen permeability rate of PE, the amount of gas penetrating from the outside to the inside of the packaging was the largest, resulting in the weakening of the skin degree after the 9th day of storage.Although the fresh wet jelly could still maintain the highest moisture content, its decline was significantly increased.Other methods need to be further studied to improve it.
To explore the drying effects of four drying methods, namely microwave vacuum puffing drying (MVPD), hot air drying (HD), microwave-assisted hot air drying (MD-HD), and vacuum freeze drying (VFD), on jujube crisps, a systematic evaluation was conducted on the impact of different drying methods on the texture, microstructure, puffing degree, rehydration ratio, energy consumption, sensory score, color, browning degree, vitamin C, total acid, total phenol, flavonoid, total sugar, and soluble solids of jujube crisps.The results showed that jujube crisps dried by MVPD performed the best in terms of hardness [(1 684.66±49.53) g], crispness [(1 552.16±52.51) g], puffing degree [(33.86±0.45)%], rehydration ratio (2.06±0.09), energy consumption [(0.22±0.01) kW·h/kg], and sensory score (86.93±1.49).It also had a higher retention rate of vitamin C (17.62 mg/100 g), total phenol (1.25 mg GAE/g DW), and flavonoid (1.83 mg rutin/g DW), and increased the total sugar content (685.66 mg/g).Jujube crisps dried by VFD retained better color and nutritional components, but had a longer drying time [16.55±0.51) h] and higher energy consumption [(13.24±0.56) kW·h/kg].Jujube crisps dried by HD and MD-HD had darker color, weaker aroma, and poorer taste due to high-temperature treatment.Microstructural analysis showed that jujube crisps treated by MVPD had a uniform cell structure, high porosity, and less cell wall damage.In conclusion, MVPD has a higher retention rate of nutritional components and lower energy consumption while ensuring the nutritional quality of jujube crisps, making it suitable for industrial production.The research results can provide a theoretical basis for the selection of drying processing techniques for jujube crisps.
In this study, “Bingtian” Phyllanthus emblica L.was used as raw material,the effects of membrane concentration, freeze-thaw concentration and vacuum concentration on physicochemical properties, antioxidant activity, and stability of P.emblica juice were analyzed.The results showed that the thickening times of membrane concentration, freeze-thaw concentration and vacuum concentration were 3.67 times, 5.19 times, and 8.61 times, respectively.The content of vitamin C in membrane concentrated recovery juice, freeze-thaw concentrated recovery juice and vacuum concentrated recovery juice were 86.21%, 94.88%, and 71.69% of the original juice, and the content of total phenol was 70.64%, 91.51%, and 49.61% of the original juice, respectively.The scavenging ability of freeze-thaw concentrated recovery juice on DPPH and ABTS free radicals was obviously stronger than that of vacuum concentrated recovery juice and membrane concentrated recovery juice.The absolute potential of freeze-thaw concentrated recovery juice was the largest, the particle size and polydispersity index were the smallest, and the juice system was the most stable.There were 32 kinds, 22 kinds, 29 kinds and 19 kinds of volatile components in raw juice and three kinds of concentrated restorative juice, mainly esters, aldehydes, and alcohols.
The study investigated the impact of different drying methods, including hot air drying at 40 ℃ (HAD 40 ℃), hot air drying at 50 ℃ (HAD 50 ℃), hot air drying at 60 ℃ (HAD 60 ℃), microwave vacuum drying (MVD), vacuum freeze drying (VFD), and natural air drying, on the drying kinetics and volatile compositions of Strobilanthes tonkinensis Leaves.The drying processes of the six drying methods were simulated using a thin-layer drying model.The impact of these different drying methods on the volatile components was assessed through the utilization of an electronic nose (E-nose) in conjunction with headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS).Additionally, organoleptic evaluations were conducted to determine the most suitable drying method for S. tonkinensis leaves.The results showed that the drying rate was highest for MVD and lowest for natural drying, with the Page model demonstrating the best fit for simulating the drying kinetics of S. tonkinensis leaves.Significant variations were observed in the types and concentrations of volatile components among different drying methods, aligning closely with the outcomes obtained from the electronic nose analysis.A total of 61 volatile components across 9 types were identified in the six drying methods, with 42, 27, 28, 25, 38, and 49 components detected in HAD 40 ℃, HAD 50 ℃, HAD 60 ℃, MVD, VFD, and natural drying, respectively.Significant losses of volatile components were observed in HAD 50 ℃, HAD 60 ℃, and MVD.HAD 50 ℃, MVD, VFD, and natural drying methods exhibited better preservation of alcohols and ketones.HAD 40 ℃ had the highest nitrogen compound content.In sensory evaluation, HAD 40 ℃ received the highest total sensory score, displaying a bright yellow-green color in the tea broth, a pure aroma with a distinct glutinous rice note, a mellow taste, and a lingering aftertaste.PLS-DA identified 20 distinct volatile components, enabling effective differentiation among the various drying methods applied to S. tonkinensis leaves.The study offers a theoretical foundation for the optimized drying and processing of S. tonkinensis leaves.
The physicochemical indexes and volatile components of Luzhou flavor Baijiu head aged 50, 30, 10, and 7 years were analyzed based on gas chromatography-ion mobility spectrometry (GC-IMS).The physical and chemical analysis results showed that the higher the cellar age, the higher the total acid and ester content of the Luzhou flavor Baijiu head.The GC-IMS analysis results showed that 52 volatile components were identified in 4 Luzhou flavor Baijiu heads with different cellar ages, including 24 esters, 9 alcohols, 9 aldehydes, 5 ketones, 2 furans, 1 acid, 1 sulfide, and 1 aromatic hydrocarbon, of which esters and alcohols were the main contribution components to the liquor body.After partial least squares discrimination analysis, 12 key differential compounds except ethanol were identified to distinguish Luzhou flavour Baijiu head samples of different cellar ages.The head of Luzhou flavor Baijiu was reboiled by seven-tower tower distillation equipment.When the optimal removal amount of distillate was 2 L (the total amount of head entering the tower was 15 L), the head quality of Luzhou flavor Baijiu could be significantly improved, the use standard of Luzhou flavor base liquor could be reached, and the utilization rate of the head could be increased.
Using high-throughput sequencing technology and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), this study analyzed the microbial diversity and volatile flavor components of Xizang yak yogurt.On this basis, the correlation between microbial community structure and flavor substances, as well as related metabolic functions, was explored.The results showed that the dominant bacteria in Xizang yak yogurt were Lactobacillus,Streptococcus, Enterococcus, and Lactococcus, while the dominant fungi were Geotrichum, Kluyveromyces, and Pichia.In the analysis of volatile flavor components, a total of 37 volatile flavor compounds were detected in Xizang yak yogurt.The main flavor substances were ethyl hexanoate, ethyl L-lactate, ethyl octanoate, ethyl decanoate, isoamyl alcohol, 2,3-butanediol, phenylethyl alcohol, 2-methylhexanoic acid, and 2-nonanone.Correlation analysis indicated that Lactobacillus, Streptococcus, Geotrichum, and Pichia were the microorganisms most significantly associated with volatile flavor components. Lactobacillus and Streptococcus showed a positive correlation with most metabolic products.This study explored the correlation between volatile flavor substances in Xizang yak yogurt and microbial community structure, providing a theoretical basis for improving the quality and taste of Xizang yak yogurt。
Temperature is the most critical factor affecting fish preservation.As an emerging preservation technology, superchilling storage has become highly research-worthy in the field of aquatic product preservation due to its ability to effectively delay the quality deterioration of fish.This study aimed to investigate the effects of superchilling storage on the quality of the northern pike (Esox lucius).Sensory evaluation, pH, total viable counts, total volatile base nitrogen (TVB-N), water-holding capacity, and volatile compounds were analyzed as quality indicators during different storage periods.The results showed that sensory scores and water-holding capacity decreased with prolonged storage time, with the sensory score dropping to (51.60±2.16) on the 15th day.TVB-N values and total viable counts increased over time, although TVB-N remained within acceptable limits, while total viable counts reached (8.20±0.14) lg CFU/g by 15 days.The pH values initially decreased and then gradually increased.Analysis of volatile compounds revealed that propanal, hexanal, (E)-2-heptenal, 3-methyl-1-butanol, and 1-octen-3-ol were present in relatively high concentrations during storage.Based on variable importance in projection values and relative odor activity values, seven key differential compounds-ethyl hexanoate, 3-methyl-1-butanol, heptanal, 1-butanol, ethyl propionate, 2-butanone, propanal, and 2,3-pentanedione were identified as potential markers for quality changes during superchilling storage.A comprehensive analysis of all indicators indicated that the fish became inedible by the 15th day of superchilling storage.This study provides a valuable reference for the application of preservation techniques in aquatic products.
High-temperature Daqu is a commonly used saccharification starter in the production of sauce-flavor Baijiu, which provides raw materials and a variety of enzymes, functional microorganisms, flavor substances, and their precursors for Baijiu fermentation.Its quality directly affects the quality and yield of Baijiu.In this study, a detailed explanation of high-temperature Daqu of three different colors, including black, yellow, and white, was provided.The factors that may lead to the formation of these different colors were summarized, clarifying the influence of the production environment, manufacturing processes, non-enzymatic browning, enzymatic browning, and the functional microorganisms on the color of Daqu.The study offered guidance for the production regulation of high-temperature Daqu of different colors.Additionally, it analyzed the differences in physical and chemical properties, enzyme activities, microbial compositions, and flavor profiles among the high-temperature Daqu ofdifferent colors.This further enriched and enhanced the understanding of high-temperature Daqu and carries significant implications for the development of traditional brewing techniques.
Plant meal is an agricultural byproduct of oil extraction from oilseeds, containing nutrients such as protein and polysaccharides, as well as functional components such as flavones, polyphenols, and active peptides.However, plant meal contains anti nutritional factors, and the oil extraction process may lead to protein denaturation and cause imbalance in amino acid content.In addition, it is easy to be contaminated by Aspergillus flavus if the plant meal is not stored properly.These issues have greatly affected the full utilization of plant meal resources.By utilizing the metabolic characteristics of microorganisms, the nutritional value and utilization rate of plant meal resources can be significantly improved through the fermentation process, promoting the high-value utilization of plant meal.Therefore, this article reviews the research and application progress of microbial fermentation to enhance the nutritional value, flavor, and functional characteristics of plant meal, in order to provide reference for the research and application of microbial fermentation of plant meal.
Black beans contain abundant polyphenolic compounds such as anthocyanins.The inflammatory response is one of the mechanisms of self-protection in the body, used to promote wound healing.A large number of studies have confirmed that anthocyanin extracts from black bean have strong preventive and therapeutic effects against inflammatory diseases, such as anti-obesity, anti-diabetes, anti-fatty liver, anti Alzheimer’s disease, anti inflammatory bowel disease, and neuroprotective effects.In this paper,the extraction of anthocyanins from black beans, the pathways and mechanism of anti-inflammatory effect were summarized, and the future hot spots and applications of black beans’ anti-inflammatory effect were prospected, in order to provide a reference for the development of functional foods based on black bean anthocyanins.
The taste substances present in meat products are mainly water-soluble entities, including free amino acids, nucleotides, organic acids, polypeptides, and inorganic salts.When meat products enter the oral cavity, they are released and perceived through the action of taste receptors on the tongue, the mechanical action of teeth, the secretion of saliva, and the act of swallowing.This process enables the taste substances to interact with the taste receptors in the mouth, initiating a signal cascade that ultimately activates the taste cortex in the brain, resulting in a taste response.The identification of taste substances in meat products can be accomplished through molecular docking technology, which calculates the intensity of interaction between taste receptors and taste-active peptides, thereby selecting peptides with specific taste attributes.This article mainly summarized the formation pathways and influencing factors of taste substances in meat products, further investigates the release and perception of taste during the oral processing of these products, and employs molecular docking technology to explore the enhancement of meat taste and the mechanism of saltiness enhancement based on taste-active peptides.This research provides theoretical references for the regulation of flavor quality and the innovation of sensory technology in meat products.
Selenium polysaccharide (Se-polysaccharide) is a combination of selenium and polysaccharide, which is more easily absorbed and utilized by the body than inorganic selenium.It possesses a variety of biological activities, including antioxidant, anti-tumor, antiviral, immune enhancement and other aspects.Scientific studies suggest that Se-polysaccharide has the potential for future development in the fields of drug research and nutraceutical development.Through combining the relevant studies on selenium polysaccharide domestic and foreign, this article summarizes the synthetic methods and pharmacological activities of Se-polysaccharide, and hope to provide a valuable reference for the in-depth research of selenium polysaccharide.
Litchi, as a popular summer fruit, is highly susceptible to peel browning and fruit rot after harvesting, which severely affects its storage life.Currently, most litchi freshness packaging on the market uses traditional packaging technologies such as foam boxes, cartons, and films, which can solve the aforementioned problems to some extent.However, in recent years, with the continuous development of packaging technology and the growing needs of people for a better life, higher standards have been set for the appearance, freshness, quality, and shelf life of litchis post-harvest.Therefore, this paper sequentially discusses the research and application of traditional freshness packaging, release-activated packaging, and intelligent packaging in the field of litchi freshness, comprehensively analyzes the current status, limitations, and challenges of litchi freshness technology, and aims to provide a direction for future research, with the expectation of supporting the high-quality development of the litchi industry.
As global food safety issues become more severe, the development of rapid and sensitive detection technologies has become increasingly critical.Characterized by efficiency, speed, and simplicity, nucleic acid isothermal amplification technologies are playing an increasingly vital role in the field of food safety detection.This paper systematically explores the applications of various nucleic acid isothermal amplification methods in food safety detection, including loop-mediated isothermal amplification (LAMP), rolling circle amplification (RCA), recombinase polymerase amplification (RPA), enzymatic recombinase amplification (ERA), strand displacement amplification (SDA), and nucleic acid multi-arm primers and circular optimization technologies.The discussion encompasses the main types, basic principles, specific applications, advantages of combining these methods with other technologies, and future development trends.By analyzing recent research advancements, this study aims to provide new perspectives and references in the field of food safety detection.It further seeks to promote the development and application of these emerging technologies.
