Diacetyl is one of the most important substances in dairy products and contributes to buttery flavor in cheese.Based on the biosynthesis pathway of diacetyl, 23 strains of lactic acid bacteria were screened according to the ability to produce diacetyl, activities of acetoin reductase, α-acetolactate decarboxylase, and diacetyl reductase for adjunct culture, the growth ability in ripening environment of cheddar cheese, and autolysis degree.The impact of the selected adjunct culture on the properties of cheddar cheese was evaluated with a rapid ripening model.The ripening experimental results showed that the addition of adjunct cultures did not result in significant difference in the physical and chemical indicators, proteolysis, and texture of cheddar cheese except the flavor profile.Compared to the other groups, diacetyl content and buttery flavor was higher in the cheddar cheese prepared with CCFM 601, and the decline of diacetyl was slower during ripening.Therefore, the addition of adjunct cultures in cheddar cheese with high production ability of diacetyl could enhance the milky flavor of cheddar cheese during ripening.

Ursolic acid, a pentacyclic triterpene compound with anti-inflammatory and antioxidant effects, has been widely applied in medicine, cosmetics, and various other fields.In this study, a “push-pull” metabolic engineering strategy was employed to increase the production of ursolic acid in Saccharomyces cerevisiae.Firstly, de novo biosynthesis of ursolic acid was achieved by heterologous expression and optimization of CADDS, CaCYP716A83, and HtCPR genes, resulting in 5.4 mg/L of ursolic acid.Subsequently, an expansion of the endoplasmic reticulum area was conducted to provide more adherent surface for membrane protease activity, obtaining 40.3 mg/L of ursolic acid.Due to multiple REDOX reactions was involved in the ursolic acid synthesis pathway, in which the NADPH was an essential cofactor.By enhancing the supply of NADPH, the ursolic acid titer was increased to 48.2 mg/L.Additionally, optimization of the electron transport chain and utilization of cytochrome b5 for efficient electron transfer to P450 enzyme further enhanced the electron supply, resulting in 74.6 mg/L of ursolic acid.Finally, by iteratively integrating these strategies including expanding endoplasmic reticulum area, enhancing NADPH availability, and electron transport efficiency and regulating the copy number of CaCYP716A83 and HtCPR genes, the ursoilc acid production was further enhanced to 84.3 mg/L.This study offers valuable insights for the development of efficient microbial cell factories for terpenoid synthesis, serving as a reference in the field.

Activated carbon and resin are commonly used in the Baijiu industry to remove odor and improve the quality of base liquor.In this study, the effects of activated carbon and macroporous resin treatments on the flavor of ZaoShao Baijiu were investigated using changes in physical and chemical indexes, sensory changes, and changes in the content of important flavor substances as indicators.Results revealed that, in terms of physical and chemical indicators, weakly alkaline macroporous resin showed the least loss of total acids and total esters, with 6.11% and 4.76%, respectively.In the aspect of sensory changes, there was a significant decrease in fruity aroma, distilled grain off-odor, and irritation in the activated carbon-treated samples, a significant decrease in fruity aroma, floral aroma, distilled grain off-odor, and irritation in the resin-treated samples, and different changes in grassy aroma and grain aroma after different resin treatments.In the sense of flavor substance changes, coconut shell activated carbon had the best retention effect on esters (52.89%-86.74%) and the lowest retention effect on aldehydes except for benzaldehyde and hexanal (<50%).Among the resins, weakly alkaline macroporous resins had the highest retention of esters (41.74%-90.73%) and the lowest retention of alcohols (32.82%-60.52%), and strongly basic macroporous resins had the lowest retention of aldehydes other than benzaldehyde (0%-54.17%).Based on the results of the indicators, weakly alkaline macroporous resin is a processing technique that could reduce the irritation and distilled grain off-odor in ZaoShao Baijiu while better retaining the original alcohol flavoring substance.The best dynamic absorption parameter of weakly alkalized porous resin was measured at 8 BV, and the flow rate was 5 BV/h.

Conjugated linoleic acid (CLA) is a geometric and positional isomer of linoleic acid with diverse physiological functions.Previous research mainly used free linoleic acid as a substrate to produce CLA.To access the abundant non-free linoleic acid in nature, this study investigated 22 strains of lactic acid bacteria to identify those capable of producing CLA from non-free linoleic acid.Results showed that 8 strains of lactic acid bacteria efficiently produced CLA from non-free linoleic acid, with Bifidobacterium breve CCFM683 exhibiting the highest conversion rate at 96%.To elucidate this phenomenon, two candidate genes, Lipase A and B, were selected from the genome of Bifidobacterium breve CCFM683 through sequence comparison and expressed in Escherichia coli BL21 for functional analysis.Results showed that Lipase B specifically hydrolyzed linoleic acid monoglyceride, and the strain initially hydrolyzed the monoglyceride into free linoleic acid, which was subsequently converted into CLA when used as a substrate.This study provides a valuable reference for future research on the utilization of non-free linoleic acid by lactic acid bacteria.

This paper studied taxonomic changes of Bacillus coagulans, previously reclassified as Weizmannia coagulans, which currently correct name is Heyndrickxia coagulans.The study was investigated by a genome-based taxonomic classification that included, in addition to re-evaluation of the 16S rRNA gene sequence of CICC 20138, determination of core genome multilocus sequence typing (cgMLST), average nucleotide identity (ANI), and digital DNA-DNA hybridization (dDDH) analysis to species level.The phenotypic information of CICC 20138 was obtained by morphological, physiological, and biochemical analysis.Based on the analysis for the similarities of 16S rRNA gene sequences, the highest similarity to Heyndrickxia coagulans and Heyndrickxia faecalis was 99.20%.The genome size of CICC 20138 (GCA_009936615.1) was 3 386 433 bp, containing 216 contigs, and the genomic DNA G+C content was 46.7 mol%.The cgMLST analysis showed the closest genetic relationship between CICC 20138 and Heyndrickxia coagulans clustered on the same branch with 100% support.The ANI value of CICC 20138 and Heyndrickxia coagulans ATCC 7050^T(GCA_000832905.1) was 98.16%, and the dDDH value was 87.1%.CICC 20138 could be identified as Heyndrickxia coagulans.ANI and dDDH analysis based on whole genome sequence should be an accurate and effective method for bacterial identification, thereby obtaining more accurate species classification information.For strains with potential significant value, whole genome sequence analysis is an important tool for understanding microbial evolution throughout classification and identification.

Heap fermentation is the most challenging step in Jiangxiangxing Baijiu production and also a window for environmental microorganisms to participate in fermentation.Fungal communities are considered to be the main contributors to the saccharification and fermentation of Jiangxiangxing Baijiu.This study aimed to examine the variability and origins of fungi in heap fermentation, offering a biological foundation for regulating and controlling heap fermentation.High-throughput sequencing technology was used to assess the fungal community, and the possible sources of fungi were further analyzed by three-phase diagram comparison and SourceTracker analysis.Results showed that fungal diversity significantly decreased over time, indicating a strong selection of fungi.The dominant fungi include Pichia (average relative abundance is 82.75%), Saccharomyces (5.75%), Thermoascus (2.75%), Aspergillus (2.25%), and Monascus (1.12%).Daqu (with an average contribution ratio of 33.14%) mainly contributed molds and other microorganisms, while the operating environment (with an average contribution ratio of 66.71%) mainly provided yeast.This study emphasized the enrichment effect of heap fermentation on core microorganisms, and both Daqu and the environment contributed to the source of functional microorganisms.This study contributes to a deeper understanding of the role of the accumulation environment of Jiangxiangxing Baijiu.

Listeria monocytogenes is a foodborne pathogen that can cause listeriosis, especially in fermented meat products. This study aimed to estimate the contamination rate of L.monocytogenes in fermented meat products in China using a meta-analysis of literature data.A total of 34 literatures from five databases were selected from 2011 to 2022.Based on the random effect model, the comprehensive prevalence rate of L.monocytogenes was estimated to be 4.1% (95% CI:2.3%-5.7%), of which L.monocytogenes comprehensive prevalence rates of fermented sausage, fermented ham, and Chinese style cured meat were 3.1% (95% CI:2.4%-3.9%), 5.9% (95% CI:4.2%-9.3%), and 3.9% (95% CI:2.2%-6.1%), respectively.Regionally, the highest prevalence of L.monocytogenes was 5.2% (95% CI:2.1%-9.3%) in Southwest China.The main serotypes of L.monocytogenes were 4b, 1/2a, 1/2b, and 1/2c.In terms of types of institutions, the vast majority of the included research samples were from the retail market.By understanding the differences in the prevalence levels of L.monocytogenes in fermented meat products, the potential risks to public health and safety could be clarified, which would help to control L.monocytogenes in fermented meat products and guide the competent authorities, industry, and other stakeholders to develop a more effective control method.

One prerequisite for probiotics is to exert beneficial effects by reaching the intestinal tract with a sufficient number of viable bacteria.Therefore, the number of viable bacteria and gastrointestinal tolerance are two important indicators for evaluating probiotic products.The main purpose of this study was to evaluate the initial activity and gastric digestion tolerance of commercial probiotic products and to explore the effects of different physiological factors on the activity of strains during gastric digestion.Firstly, the total bacteria and live bacteria content of the samples were determined by flow cytometry.Secondly, the samples were subjected to simulated digestion experiments under different conditions to determine the total number of live bacteria in the samples and calculate the survival rate.Results showed that the content of viable bacteria in 15 samples was different from the labelled values, but all products met international and domestic standards.In the simulated gastric digestion experiment, the pH value of gastric juice was the main factor affecting the activity of bacteria, while the simulated digestion speed and pepsin concentration were the secondary factors.In the same simulated gastric digestion experiment, the tolerance of different products was significantly differed.This study provides a basis for standardizing the market environment and formulating relevant standards and maintains important guiding significance for consumers to choose products and producers to improve product quality.

To achieve high-value utilization of grapefruit peel, grapefruit peel pectin (GPP) was extracted by ultra-high pressure assisted citric acid method.In this study, the pectin yield was investigated as an index, and the liquid-solid ratio, the value of pH, pressure, and holding pressure time were used as single factors.The extraction process was optimized based on the single-factor test using the Box-Behnken design with the response surface method.It was compared with the common acid-extracted grapefruit peel pectin (AGPP) in industry and commercial grapefruit peel pectin (CGPP) to study the characteristics of pectin extracted under optimal conditions.It was found that the optimal extraction process conditions for GPP were the liquid-solid ratio of 27∶1 (mL∶g), pH 1.9, pressure of 324 MPa, and holding pressure time of 5 min, under which the pectin yield could reach 21.56%.The resulting pectin had a moisture content of 9.49%, acid insoluble ash content of 0.42%, a galacturonic acid content of 80.06%, a solubility of 81.25%, a degree of esterification of 58.84%, and the total phenolic content of 24.70 mg GAE/g pectin.In addition, GPP had higher apparent viscosity and oxidation resistance compared to AGPP and CGPP.The study showed that extracted GPP by ultra-high pressure was of good quality and could be potentially utilized as a food ingredient in the food sector.

Staphylococcus saprophyticus is one of the specific spoilage bacteria in aquatic products.Polypeptide-zinc chelates have bacteriostatic potential, but there are few reports on their inhibition of Staphylococcus saprophyticus.In this study, the polypeptide-zinc chelates P2 and P3 of the Mandarin fish were prepared from the protein of the Mandarin fish by enzymatic hydrolysis, chelation reaction, centrifugal-alcohol precipitation, and finnally alcohol-precipitation centrifugation.The inhibitory cycle and minimal inhibitory concentration (MIC) of P2 and P3 against Staphylococcus saprophyticus were studied by Oxford cup method and double gradient dilution method.Through the bacterial growth curve, electrical conductivity, ultraviolet absorption, superoxide dismutase (SOD), and catalase (CAT) activity, and scanning electron microscope (SEM), the effects of P2 and P3 on Staphylococcus saprophyticus were evaluated.Results showed that the microbial circles produced by P2 and P3 against Staphylococcus saprophyticus were (17.89±3.06) mm and (21.39±2.46) mm, respectively, with MIC of 0.78 mg/mL for both P2 and P3.After the action of P2 and P3, bacterial growth was inhibited, cell membrane integrity was disrupted, and permeability increased, resulting in an increase in SOD activity and a decrease in CAT activity in the bacterial body.The SEM results showed that the surface of the bacterial cells treated with P2 and P3 was rough, wrinkled, twisted, and deformed, resulting in the destruction of the bacterial structure and ultimately leading to bacterial death.

Xanthoceras sorbifolium Bunge seeds meal is the main by-product in the production of Xanthoceras sorbifolium Bunge oil, which is rich in protein.In this study, the Xanthoceras sorbifolium Bunge seeds meal protein was extracted by the method of ultrasound-assisted alkali extraction and acid precipitation, and the effects of ultrasound amplitude, ultrasound time and pH on the extraction rate of Xanthoceras sorbifolium Bunge seeds meal protein were studied by single factor experiment, and the changes of structural and functional properties of Xanthoceras sorbifolium Bunge seeds meal protein after ultrasound treatment at different time were systematically analyzed.Results showed that the best technology for ultrasound-assisted extraction of Xanthoceras sorbifolium Bunge seeds meal protein was as follows:ultrasound amplitude of 40%, ultrasound time of 9-15 min, pH at 11, and extraction temperature of 45 ℃.Under this condition, the protein extraction rate was the highest, and the main protein molecular weights were 25 and 38 kDa.After 0-12 min ultrasound treatment, the particle size of Xanthoceras sorbifolium Bunge seeds meal protein decreased, its net negative charge increased and hydrophilicity increased.With 15 min ultrasound treatment, the solubility of Xanthoceras sorbifolium Bunge seeds meal protein reached the maximum value of (81.37±1.61)%.Under the same condition, the foaming capacity, emulsifying capacity, water-holding property, and oil-holding property of Xanthoceras sorbifolium Bunge seeds meal protein reached the maximum.Considering the extraction rate and functional properties, 12-15 min ultrasound treatment could be used to extract protein from Xanthoceras sorbifolium Bunge seeds meal, as well as improve its functional properties.The results could provide a basic reference for efficient extraction and property enhancement of Xanthoceras sorbifolium Bunge seeds meal protein.

A new whipped cream was prepared by using gelatin as the main protein in the emulsification system, and the effect of gelatin concentrations (0.5%-1.5%) on the stability of whipped cream was investigated in this study.Results indicated that gelatin was adsorbed at the oil-water interface with the emulsifier to reduce the interfacial tension and stabilize the pre-whipped emulsion, and the particle size of the emulsion significantly decreased by 33.69% with the increase of gelatin concentration.The samples with 0.5%-1% gelatin concentration had excellent overrun, and the overrun of 1.5% was low.CLSM results demonstrated that the cream with low gelatin concentration had low viscosity and was easy to whip and aerate, and the partial coalescence of fat was low, so the overrun was higher, but the cream with high gelatin concentration had higher viscosity and was difficult to whip.The short-term shape-retention ability and textural properties of whipped cream also improved significantly with the increase in gelatin concentration.Rheological results showed that whipped cream had a weak gel system, yield stress increased significantly with the increase of gelatin concentration, and the internal network of whipped cream became stronger, so the cream had better shape retention ability, hardness and viscosity.Therefore, the mechanism of gelatin to improve the quality of whipped cream is the interaction of gelatin in the continuous phase of cream forming a gelatin network structure, thus improving the whipping properties of cream.This provides a theoretical basis for the application of gelatin in whipped cream.

To analyze the effect of biological deodorization on the main volatile components of Carassius auratus var.Dongting soup and clarify the biological deodorization mechanism, yeast fermentation and mixed strains (yeast+Lactobacillus plantarum JYLP-002) fermentation, combined with ozone pretreatment, were used for deodorization.The volatile flavor components were analyzed by headspace-solid phase micro-extraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and identified by odor activity value (OAV) and orthogonal partial least squares-discriminant analysis (OPLS-DA).Results showed that ozone treatment could significantly reduce the content of hexanal, (E)-2-octenal, 10-undecenal, (E,E)-2,4-decadienal, and (E,E)-2,4-heptandienal, which reducing fishy and greasy odors.The contents of hexanal, nonanal, (E,E)-2,4-decanedienal, (E,E)-2,4-nonadienal, and other odor-producing substances were further significantly reduced by biological deodorization, indicating the efficiency of deodorization.Among them, vinyl caproate, ethyl oleate, ethyl linoleate, and other volatile flavor compounds with pleasant odors such as floral and fruity aroma were produced in mixed strains treated group, which showed better effect of deodorization combined with aroma enhancement.

Based on peptidomics combined with molecular docking technology, active peptides with antithrombotic effects were screened from Holothuria leucospilota. LC-MS/MS technology was used to characterize the full peptide spectrum of the enzymatic hydrolysate of sea cucumber, and a small-scale candidate peptide library was established through simple separation and purification.At the same time, bioinformatics software was used to analyze the physicochemical properties of the peptide library and evaluate the feasibility of the anti-thrombotic activity screening method.Using Discovery Studio software to screen potential antithrombotic peptide sequences by molecular docking based on the binding mode of recombinant hirudin fragment (HIRV2) and thrombin, the antithrombotic activity of artificially synthesized peptides was evaluated using four indicators, including activated partial thromboplatin time, prothrombin time, thrombin time, and thrombin inhibition rate.Results showed that the enzymatic hydrolysate of sea cucumber contained 1 795 peptide sequences.116 peptide sequences with a relative molecular weight of 1-3 kDa were selected to establish a candidate peptide library.Six potential antithrombotic active peptides (CDOCKER ENERGY was higher than HIRV2) were screened through molecular docking.SCp-1 and SCp-2 were closely bound to the 10 amino acid residues of thrombin, indicating that they were potential antithrombotic peptides.In vitro activity showed that both SCp-1 and SCp-2 exhibited (P＜0.05) a dose-dependent endogenous anticoagulant activity and a common pathway anticoagulant activity.Compared to the two, SCp-1 exhibited stronger anticoagulant activity in the endogenous pathway, while SCp-2 exhibited better anticoagulant activity in the common pathway.In summary, two novel foodborne antithrombotic peptides were successfully screened from the enzymatic hydrolysis products of sea cucumber through peptide omics combined with molecular docking.

To broaden the resources of pigment-producing microorganisms, strains with the ability to produce red pigment were screened and identified from traditional brewing Pixian Douban.The red pigments were purified and characterized by silica gel column chromatography, ultraviolet visible spectrophotometry (UV-Vis), high performance liquid chromatography (HPLC), fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance (NMR), and high resolution mass spectrum (HRMS).Additionally, the antibacterial activity of the red pigment produced by the strain was preliminarily analyzed.Results showed that a red pigment-producing strain GH-2 was screened from Pixian Douban, and it was identified as Serratia marcescens by morphological, physiological, and biochemical characteristics and 16S rRNA gene sequence analysis.The structure of red pigment produced by S.marcescens GH-2 was identified as 2-methyl-3-pentyl prodigiosin.The prodigiosin produced by S.marcescens GH-2 has a significant inhibitory effect on Vibrio parahaemolyticus and has a certain inhibitory effect on Staphylococcus aureus.

This study focused on the preparation and flavor properties of oyster meat hydrolysate through a composite enzymatic process involving protease and amylase, with oysters as the subject of investigation.Sensory evaluation and head-space solid-phase micro-extraction and gas chromatography-mass spectrometer (HS-SPME-GC-MS) were employed to analyze the changes of volatile compounds in oyster meat before and after enzymatic hydrolysis.The objective was to identify the key flavor compounds and main fishy components in both oyster meat and its enzymatic hydrolysate.Furthermore, the relative odor activity value (ROAV) was utilized to quantify the contribution of each component to the flavor of oyster meat enzymatic hydrolysate.The addition of amylase could break down glycogen present in oyster meat into small molecule monosaccharides which subsequently promoted Maillard reactions within the enzymatic hydrolysate at specific temperatures.As a result, compounds with pleasant flavors were generated to mask the fishy taste associated with oysters.The findings revealed a decrease in substances such as (E, E) -2,4-heptadienal, hexanal, heptaldehyde, and nonanal, which exhibited a fishy and hala taste after enzymatic hydrolysis.Moreover, this process also resulted in the formation of substances with strong fruit and grass flavors, such as 2-pentylfuran, benzaldehyde, and hexadecaldehyde, which could also eliminate the fishy taste present in oyster meat.Finally, through synergistic interactions among various volatile compounds involved, an overall coordinated aroma profile was achieved resulting in a long-lasting flavor experience.

The different whole wheat proportions doughs fermented for 12 hours under cold and normal temperature were studied.The effects of fermentation temperature on the quality of the dough for different whole wheat proportions could provide references for improving the quality of whole wheat dough and its cold fermentation.The pH, total acidity, water holding rate, water activity, number of viable yeast, fermentation volume, dough skin color, texture, and sensory evaluation of cold (C group) and normal temperature (NT group) fermented doughs with different whole wheat ratios were measured.Results showed that the pH, dough skin color, and fermentation volume of C group were significantly higher than those of NT group (P<0.05), while the acidity was significantly lower than NT group (P<0.05).The viable yeast number of 75% and 100% whole wheat ratio of C groups were more than 1.5 times than that of the same proportions of NT groups.The water activity of 50% whole wheat ratio of C group was extremely significant higher than that of the same proportion of NT groups (P<0.001).The water holding rate of 50% whole wheat ratio in C group and the hardness, cohesion, springiness, gumminess, and chewiness of 25% whole wheat ratio of C group had no difference with those of the same proportion in NT group (P>0.05).However, the hardness and chewiness of 50%-100% whole wheat ratio in C groups were extremely significant higher than that of NT groups (P<0.001).Results showed the number of viable yeast, fermentation volume, and water activity with different proportion of whole wheat doughs fermented at cold temperature had significant increased, which could improve the hardness, chewiness and sensory evaluation of whole wheat dough, providing reference for the quality of whole wheat dough and its products.

To investigate the dynamic changes of physical and chemical quality and volatile components during the growth process of pomelo fruits, five characteristic pomelo fruits (Dongfengzao pomelo, Changshou Shatian pomelo, Liangping pomelo, Long′an pomelo, and Fengdu Hongxin pomelo) from southwest China were selected.The main physical and chemical quality and volatile components in the five mature stages were analyzed.For the external quality, the weight and horizontal and vertical diameter of pomelo fruit were in direct proportion to maturity, while the peel thickness was in inverse proportion.For the internal quality, the juice yield, edible rate, and soluble solid contents of pomelo fruit all increased, and the titratable acid content decreased significantly.With the extension of maturity, vitamin C content increased first and then decreased.A total of 52 volatile components were detected in the fruits of 5 varieties of pomelo, including 20 terpenes (10 monoterpenes and 10 sesquiterpenes), 9 alcohols, 10 aldehydes, 8 esters, 2 ketones, and 3 others.As the maturity period prolonged, the total amount of volatile substances followed the pattern:commercial maturity period>mature color transition period>growth and expansion period>young fruit period>expansion period.As the maturity period extended, the proportion of terpenes remained the highest, ranging from 82.8% to 96.4%.Limonene was the most abundant terpene substance, accounting for 67.7%-90.1% of terpenes.Its variation pattern was consistent with that of terpenes and total volatile compounds.Myrcene, β-pinene and α-pinene were relatively abundant monoterpene substances.α-Caryophyllene, germacrene D, and β-caryophyllene were also relatively abundant sesquiterpene substances.Alcohols and aldehydes were volatile substances second only to terpenes, accounting for 1.6%-13.4% and 0.3%-6.8%, respectively.In addition, a small amount of esters, ketones, and other substances were also present in pomelo fruits.This article provides a basis for exploring the nutritional quality characteristics of pomelo fruits in China and also provides data support for the processing and utilization of pomelo fruit resources.

To investigate the inhibitory ability of strains X3-2B and 37X-3 on xanthine oxidase(XOD)and their alleviating effect on hyperuricemia (HUA) in mice, this study used HPLC to determine the content of xanthine and uric acid (UA) in the medium.The strains were cultured in a medium containing xanthine and XOD for different durations (20, 40, 60, 80 and 100 min).This study also adjusted the pH and bile salt concentration of the medium to study the inhibitory ability of XOD and the acid and alkali resistance of strains X3-2B and 37X-3 in vitro.In addition, sixty KM mice were divided into five groups, including control group (Group C), model group (Group M), X3-2B group (Group X), 37X-3 group (Group L), and allopurinol group (Group P).All groups, except for Group C, were fed high-purine chow.The mice were fed for 4 weeks, and the corresponding doses of strains X3-2B, 37X-3, and allopurinol were administered to groups X, L, and P respectively.This study investigated the mitigating effects of strains X3-2B and 37X-3 on HUA in mice by analyzing physiological and biochemical indexes, renal pathology sections, and intestinal tissues of the mice for XOD activity.Results showed that strains X3-2B and 37X-3 effectively inhibited XOD-catalyzed xanthine production of UA.At pH 2 and bile salt addition of 0.3%, the viable bacterial counts of X3-2B and 37X-3 were 6.4×10⁷ CFU/g (X3-2B), 9.3×10⁷ CFU/g (37X-3), and 2.1×10⁶ CFU/g (X3-2B), 2.8×10⁶ CFU/g (37X-3) respectively.After four weeks of feeding, there was a significant decrease in serum levels of UA, BUN, and Cr in mice in groups X and L (P<0.05).The renal units were structurally intact, and the activity of XOD in intestinal tissues was inhibited (P<0.05).The study concluded that strains X3-2B and 37X-3 were able to effectively inhibit XOD activity and reduce UA production.Furthermore, these strains were found to exert XOD inhibition function in the intestinal tract of HUA mice and alleviate HUA in mice.

κ-Carrageenan is a macromolecular polysaccharide substance with galactose and dehydrated galactose as the main chain.It is also one of the most important edible gums.It can be used to prepare composite hydrogel with other hydrophilic polymers and has important application potential in the field of medical materials.To improve the application performance of κ-carrageenan hydrogel, in this paper, oxidized κ-carrageenan (OKC) was prepared by TEMPO/NaClO/NaBr reaction system using κ-carrageenan (KC) as the material, and then the oxidized κ-carrageenan/polyacrylamide hydrogel was prepared by chemical crosslinking method using OKC and polyacrylamide (PAM) in different mass ratio.The effect of oxidized κ-carrageenan on the application properties of hydrogel was investigated by measuring moisture content, water solubility, swelling rate, mechanical properties, infrared spectroscopy, and microstructure of hydrogel.Results showed that OKC could significantly increase the swelling rate, tensile strength, and elongation at break, and decrease the water solubility of the composite hydrogel (P<0.05), and when the ratio of OKC/PAM was 3∶4, the performance index of the composite hydrogel reached the optimal value, the moisture content of OKC₃/PAM₄ was 82.7%, the water solubility was 12.2%, the swelling rate was 887%, the tensile strength reached 0.223 MPa, and the elongation at break reached 448%.Infrared spectroscopy analysis showed that the C-6 alcohol hydroxyl group in κ-carrageenan was oxidized to the C-6 carboxyl group, and hydrogen bonding existed between the components of the oxidized κ-carrageenan/polyacrylamide hydrogel.Scanning electron microscope showed that the OKC/PAM hydrogel had a dense porous three-dimensional network structure with uniform and regular pore size.Therefore, OKC and PAM can be compounded to prepare hydrogel with good performance, which will provide a theoretical basis for the development of carrageenan hydrogel medical dressing.

To investigate the quality characteristics of lamb meat prepared by various cooking methods, such as steaming, boiling, stir-frying, roasting, and hot pot, the nutritional quality and palatability of lamb meat cooked by different methods were comprehensively determined and analyzed by partial least squares discriminant analysis (PLS-DA).Results indicated that there were significant differences in the quality characteristics of lamb meat among different cooking methods.In terms of nutritional quality, instant-boiled lamb meat had the highest moisture content, roasted lamb meat had the highest protein content, and stir-fried lamb meat had the highest fat content and the highest total free amino acid content.In terms of eating quality, boiled lamb meat had the highest pH value and stir-fried and roasted lamb meat had the worst water retention.Stir-fried and instant-boiled lamb meat had high L^* values, while roasted lamb had the highest a^* value.Instant-boiled lamb meat had the best tenderness and steamed and boiled lamb meat had the highest chewiness.The electronic nose sensors W1C, W3C, W5C, and W2W, showed the highest response values for roasted lamb meat, indicating that roasted lamb meat had a higher content of aromatic volatile flavor compounds.The electronic tongue sensors CTS, NMS, and CPS presented larger response values for boiled lamb meat, indicating that boiled lamb meat had a richer flavor.The PLS-DA analyses revealed a distinct separation among lamb meat samples from the five cooking methods, highlighting significant quality variation.Elasticity, SCS sensor, chewiness, ANS sensor, W3C sensor, and hardness emerged as the primary indicators of quality differences across cooking methods.The research aims to provide a basis for an in-depth investigation of the quality characteristics of lamb meat after cooking by data support.

This experiment aimed to improve the extraction methods of antioxidant peptides using membrane separation technology, with a focus on enhancing their application potential in the food industry and health sector, and to support in-depth research into the bioactivity of these antioxidant peptides.Initially, antioxidant peptides were extracted from dried cured beef using the hydrochloric acid extraction method, and their antioxidant capacities at different concentrations (0.2, 0.4, 0.6, 0.8, 1 mg/mL) were tested.It was found that their antioxidant ability increased with concentration.Subsequently, membrane separation technology was employed to purify the antioxidant peptides from beef.Different microporous membranes (PTFE, CA, PVDF, CN-CA, PES, and mixed membranes) were used for separation, and their DPPH free radical and hydroxyl radical scavenging rates were tested.Among them, the CN-CA aqueous mixed fiber microporous membrane showed the best scavenging rates, reaching 77.45% and 51.06%, respectively.The optimized conditions for the preparation of the BTESE/CN-CA composite membrane were 15 g/L solution concentration, 7.5 min heat treatment time, 150 ℃ heat treatment temperature, and 1.25 MPa.Through peptide scoring and half-life analysis, the separated peptide Phe-Asp-Gly-Asp-Phe (FDGDF) was hypothesized to have the strongest activity.Quantum chemical simulations analyzed the binding sites and force fields between FDGDF and superoxide dismutase.This study demonstrates that membrane separation technology can significantly enhance the antioxidant activity of beef peptides, providing valuable insights for research in the fields of food and nutrition.

Wheat, as a raw material for starter-making, its crushing degree is particularly important to the quality of high- temperature Daqu.Based on the preliminary small-scale experiments, in this study, wheat with a crushing degree of 55%, 60% and 65%, which did not pass the 20-mesh sieve, were used for the fermentation of high temperature Daqu, and the fermentative process was monitored.The physicochemical results were analyzed by correlation analysis, principal component analysis, and cluster analysis.The evolution of volatile flavor compounds in Daqu was analyzed by headspace solid phase microextraction combined with gas chromatography and mass spectrometry.The correlation analysis of physicochemical and flavor substances was carried out by partial least squares regression method.Results showed that the high-temperature Daqu produced with 55% wheat crushing degree had the best water retention.The crushing degree of 65% was conducive to the acid production, the release of ferulic acid in wheat bark, and the formation of guaiacol.At the end of fermentation, the proportions of pyrazines, phenols, and ketones in three kinds of Daqu, in descending order, corresponded to the wheat crushing degree of 65%, 60% and 55%, respectively.The highest proportion of aldehydes occurred when the crushing degree was 55%.The advantageous flavor substances mainly included isovaleric acid, phenyl ethanol, isoamyl alcohol, furfural, 3-furfural, 2, 4-di-tert-butylphenol, guaiacol, tetramethylpyrazine, trimethylpyrazine, dimethyl trisulfide, etc.The sensory results indicated that using coarse crushed wheat was beneficial for improving the baking and sauce flavor of high-temperature Daqu.The study provided solid theoretical and practical support for optimizing the starter-making techniques of high-temperature Daqu.

Water chestnut starch is rich in resources, but its application is limited by the shortcomings of natural starch, such as poor thermal stability and easy aging.High hydrostatic pressure technology is a green and efficient means of starch modification and has a better application prospect.To investigate the effect of high hydrostatic pressure treatment on the properties of water chestnut starch, water chestnut starch was treated at a pressure of 200-600 MPa for 20 min, and the changes in the physicochemical, structural, and in vitro digestive properties of water chestnut starch were investigated after treatment at different pressures.Results showed that the solubility, swelling force, and viscosity of water chestnut starch decreased with the increase of treatment pressure, and decreased by 83.73%, 48.32%, and 78.12% at 600 MPa, respectively.The energy storage modulus and loss modulus of water chestnut starch increased by high hydrostatic pressure treatment, and the gel strength, hardness, and adhesion of water chestnut starch were most improved by 400 MPa treatment, and increased by 47.07%, 45.45%, and 25.34%, respectively.The granular morphology of water chestnut starch disappeared after 500-600 MPa treatment, its crystalline type changed from A-type to B-type, and the crystallinity and short-range ordering were significantly reduced (P<0.05).The in vitro digestion results showed that the high hydrostatic pressure treatment decreased the relative content of fast-digested starch and increased the relative content of slow-digested starch in water chestnut starch.The high hydrostatic pressure treatment as a method of nonthermal modification of water chestnut starch can broaden its application in food production.

Chili oils were prepared from seven rapeseed oils with different levels of concomitants, and flavor differences of the chili oils were comprehensively compared by determining volatile compositions and sensory characteristics.Physicochemical indexes of different rapeseed oils, such as chemical characteristics (acid value, iodine value, peroxide value and total antioxidant property), fatty acid compositions, lipid concomitants and volatile compositions, were determined.Correlation between the physicochemical indexes of rapeseed oils and the increment of aroma-active compounds of chili oils was analyzed.Results showed that with increasing levels of concomitants in rapeseed oils, the number of volatile components in chili oils first decreased and then increased, and the volatile component content increased significantly in No.4 chili oil.According to the correlation with the increment of volatile components of chili oil, the indexes related to the chemical characteristic value, fatty acid composition and lipid concomitant level of rapeseed oil can be divided into two categories, which affected differently the increment of nitriles, sulfur-containing components, aromatic hydrocarbons, esters, acids or phenols.Heterocyclic substances were positively correlated with oil flavor and negatively correlated with chili flavor and choking sensation, and many aldehydes were positively correlated with overall flavor harmonization.No.5 chili oil had the highest sensory preference score, which was related to its rich volatile components and may also be related to the coordination between oil flavor and chili flavor.

Research has shown that nutrition and diet play a key role in improving cognitive decline and reducing the risk of dementia.This study aimed to investigate the effect of walnut oil on scopolamine-induced cognitive impairment in rats based on the BDNF/TrkB/ CREB signaling pathway.24 SD rats were randomly divided into a control group, a model group, and a walnut oil group.First, walnut oil was gavaged for 30 days, and the other two groups were treated with equal volume of saline.On the 31 st day, the model group and walnut oil group were intraperitoneally injected with 3 mg/(kg·d) of scopolamine daily for 5 days.The learning and memory abilities were tested through new object recognition experiments and Morris water maze tests.HE staining was used to observe the pathological morphology of the hippocampus.The acetylcholine (ACh) content and acetylcholinesterase (AChE) activity in the brain tissue were detected using a reagent kit.Western blot was used to detect synaptophysin (SYN), postsynaptic density-95 (PSD-95), brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB), and cAMP-response element binding protein (CREB) expression levels in the hippocampus.It found that walnut oil could improve the learning and memory ability of rats in the scopolamine-induced cognitive impairment model, as well as neuronal cell arrangement, and structural integrity.It could also decrease the activity of AChE, increase the level of ACh, and significantly elevate the expression of target proteins in hippocampal tissues.This suggests that walnut oil has an effect on cognitive function in scopolamine-induced cognitive impairment and its possible mechanism is related to the activation of the BDNF/TrkB/CREB signaling pathway to regulate synaptic plasticity.

To investigate the changes in metabolites and antioxidant activity of fresh roses before and after fermentation, the processing technology of rose a uniform design test optimised black tea.The main components of dried rose petal water extract (RWE) and rose black tea aqueous extract (RBTE) were determined before and after fermentation.Their antioxidant capacity was evaluated in vitro.Non-targeted metabolomics was also used to analyse changes in metabolites.Results showed that the optimum processing technology of rose black tea was the withering time of 22 h, fermentation temperature of 31 ℃, and fermentation time of 8 h.RBTE contents of total polyphenols and polysaccharides were significantly higher than that of RWE.Contents of anthocyanins and free amino acids were significantly lower than that of RWE (P<0.05).Non-targeted metabolomics analysis identified 2 028 metabolites in rose extracts before and after fermentation.A total of 24 significantly different metabolites were screened.It was found that the contents of chicory, inosine, and harmine increased after rose fermentation, which gave rose black tea a unique flavour, physiological regulation, antioxidant, and anti-inflammatory functions.The KEGG enrichment analysis of differential metabolites revealed that the processing of rose black tea had a significant impact on amino acids, affecting the taste quality of the tea.At the same time, it was found that RBTE showed strong DPPH free radical and hydroxyl radical scavenging ability, indicating that fermentation helped enhance the antioxidant activity of roses.The results can provide a theoretical basis for rose black tea′s functional activity research and product development.

Soybean yogurt is a new plant-based yogurt with healthy nutrition.In this study, soybean whey, 7S and 11S protein components were isolated and purified from soybean by salting-out isoelectric point precipitation method.The dynamic changes of pH value, acidity, lactic acid bacteria proliferation, protein hydrolysis degree, and particle size of different components during fermentation were investigated, as well as the differences in rheological properties, microstructure, volatile compounds, and sensory characteristics of fermentation products, to clarify the contribution of different protein components to the texture and flavor formation of soybean yogurt.Results showed that with the increase of fermentation time, the pH value of 11S protein fermentation products decreased significantly (P<0.05), and the acidity, the lactic acid bacteria number, the protein hydrolysis degree, and the average particle size increased significantly (P<0.05).At the same time, the rheological results showed that the 11S protein fermentation products had the highest viscosity, and the microstructure showed rough granular and more compact and uniform protein aggregation.In addition, GC-MS and electronic nose results confirmed that 7S protein could produce a large number of yogurt aroma compounds such as 2-hexanone, 2-octanone, 2-nonanone, 2,3-butanedione, 2,3-pentanedione, and acetoin after fermentation, while 11S protein produced more beany flavor compounds such as hexanal, pentanal, (E)-2-heptenal, (E)-2-hexenal, 1-hexanol, 1-pentanol, 1-octen-3-ol, benzaldehyde, acetic acid, and 2-pentylfuran, with low sensory acceptance.Results showed that 11S protein was the key component of the yogurt texture formation, and it was also the main component of the interaction with beany flavor compounds.This study would provide a theoretical reference for the quality optimization and flavor improvement of soybean yogurt products.

Runner dehumidification cold air-drying technology is a new type of food drying technology, which is an energy-saving drying method with an independent heat pump and dehumidification depth.To explore the specific effects of different rotor dehumidification and cold air-drying conditions on the drying process of apple slices, the drying characteristics and quality analysis of apple slices under different supply air temperatures (10, 20, 30 ℃), regeneration temperatures (90, 100, 110 ℃) and slice thickness (3, 4, 5 mm) were studied.Fick’s second law was used to calculate that the moisture diffusion coefficient under each working condition ranged from 6.03E-9-3.00E-8 m²/min.Six thin-layer drying models were proposed, and it was found that the Page model could better predict the cold air-drying process of apple slices.Results showed that the rotor dehumidification drying had a lower color difference value than other traditional drying methods, and the hardness of apple slices dried by cold air decreases with the increase of air supply temperature, mainly because the softening degree of slices would change with the change of moisture content, and the crispness would increase with the increase of temperature.With the increase in thickness, the hardness and brittleness also increased, and the regeneration temperature had little effect on the hardness and brittleness, and the chewiness was positively correlated with the hardness.Overall, cold-air-dried apple slices have a softer texture than hot air but have a lower crispness than hot-air-dried.

To comprehensively evaluate and analyze the chemical composition and antioxidant activity of Physalis peruviana L., which was the most widely cultivated plant in Physalis genus in China, the contents of total phenols and total flavonoids of extracts from leaf, calyx, and fruit of P.peruviana L.were determined using UV spectrophotometry, the compounds were identified by ultra-high performance liquid chromatography-mass spectrometry and the main compounds were detected.In vitro antioxidant activity was tested using DPPH free radical, ABTS cationic free radical, ·OH free radical scavenging method, and iron ion reduction method.Results indicated that the total phenolic content (8.15 mg GAE/g DW) and total flavonoid content (30.43 mg RT/g DW) of the extract from the leaf of P.peruviana L.were the highest, followed by the extract from the calyx, and the total content of the fruit extract was the lowest.A total of 4 flavonoids, 3 fatty acids, 1 withanolide, 1 dibenzofuran, and 1 hydroxycinnamic acid were identified from the three parts.The types of compounds extracted from the leaf and calyx were abundant, the content of astragalin (492.03 μg/g DW) in the leaf extract was the highest, while the content of hyperoside (162.10 μg/g DW) in the calyx extract was the highest and only ferulic acid-4′-O-glucoside compounds were detected in the fruit extracts (137.37 μg/g DW).The leaf extract had good hydroxyl radical scavenging activity (SC₅₀=0.61 mg/mL), while the calyx extract had the best ability to scavenge DPPH radicals (SC₅₀=0.19 mg/mL), ABTS cationic radicals (0.13 mmol TE/g), and iron ion reduction (0.16 mmol Fe²⁺/g).The research results have enriched the secondary metabolites data of P.peruviana L., providing a scientific basis for fully utilizing the resources of P.peruviana L.and developing natural antioxidant products.

Three commercial Hongqu (L, G, J) were selected for the fermentation of Baijiu.The volatile flavor components of Baijiu were analyzed by GC-MS.To thoroughly investigate the effects of different kinds of Hongqu and different Hongqu content additions on the volatile flavor components of brewed liquor, 47 volatile flavor components in the wine were qualitatively quantified, and multivariable statistical analysis was applied to compare the differences in volatile flavor components among the samples.Results showed that the addition of Hongqu L, as well as the high content of Hongqu J, had a significant effect on the reduction of the total higher alcohol content in the wine samples (25.9%-29.5%), mainly on the reduction of isobutyl alcohol and isoamyl alcohol, and the addition of Hongqu L, J, and G had a significant effect on the reduction of the content of ethyl lactate (68.5%-244.4%), ethyl acetate (24.85%-50.89%), and ethyl hexanoate (23.35%-145.17%) contents were enhanced significantly.The different kinds of Hongqu, different additive amounts, and the generation of senior alcohols and esters had a certain regulatory effect, and the volatile flavor components of the brewed Baijiu had significant differences.The difference was mainly reflected in the reduction of the type of esters and higher alcohol content.These factors had a contributing role in the improvement of the quality of the Baijiu.

The volatile substances in light flavor Baijiu were analyzed qualitatively and quantitatively by using various technical strategies, and the differences of sensory characteristics and flavor substances between single-grain and multi-grain light flavor Baijiu were analyzed.Based on the quantitative results of volatile substances and aroma activity value (OAV) in light flavor Baijiu, a 36 important compounds (OAV≥1) that have significant aroma contributions to single-grain and multi-grain light flavor Baijiu were screened out, and the significant difference compounds between single-grain and multi-grain light flavor Baijiu were mined by chemometrics technology (P<0.05).It mainly included ethyl octanoate, ethyl lactate, isoamyl acetate, 1-octen-3-one, 3-hydroxy-2-butanone, acetal, n-butanol, 2-pentylfuran, etc.Among them, the content of 2-pentylfuran was higher in single-grain light flavor Baijiu, and other compounds were higher in multi-grain light flavor Baijiu.Furthermore, sensory quantitative description and analysis showed that multi-grain light flavor Baijiu had richer fruit and grain flavors, and the mellow and sweet feelings of liquor body were stronger than those of single-grain liquor body.Combined with the content of ethyl acetate, the main aroma substance of light aroma Baijiu, and the total amount of flavor substances, the analysis further explained that the light aroma of single-grain light aroma Baijiu was pure, while the aroma and taste of multi-grain light aroma Baijiu were more reasonable, which provided a theoretical basis for the process optimization of light aroma Baijiu and the regulation of product flavor.

Ara h 2 is one of the major peanut allergens.This study aimed to develop a rapid detection method for Ara h 2 allergens in food and reduce the occurrence of peanut allergy caused by accidental eating.In this study, a mouse monoclonal antibody was used as a capture antibody and a rabbit polyclonal antibody as a detecting antibody, and the working concentration of antibodies was optimized by the checkerboard method.An indirect double-antibody sandwich chemiluminescence enzyme immunoassay for the detection of peanut allergen Ara h 2 was established, and the sensitivity, accuracy, precision, and specificity of the method were evaluated.The detection limit of the method was 1.085 ng/mL, the linear range was 3.12-200 ng/mL, the recovery rate was 78.30%-94.39%, both intra-batch and inter-batch coefficients of variation remained below 10%, and the method demonstrated excellent specificity by exhibiting no cross-reactivity with other prevalent food allergens.In a comparative analysis with an indirect double-antibody sandwich ELISA method employing the same antibodies, this method displayed distinct advantages in terms of sensitivity.The chemiluminescent enzyme-linked immunosorbent assay developed in this study offers dependable technical support for the evaluation of Ara h 2 allergen components during peanut food production processes and prior to consumption.

This study aimed to compare the content of 10 phenylethanoid glycosides in different processed Cistanches Herba from different hosts using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QQQ-MS).The dried Cistanches Herba was crushed, sieved through a 60-mesh sieve, and extracted by ultrasound with 50% methanol.Separation was performed on an Agilent Eclipse Plus C18 column (2.1 mm×150 mm, 1.8 μm) using gradient elution with mobile phase A (0.1% formic acid aqueous solution) and B (acetonitrile).Detection was carried out in dynamic multiple reaction monitoring mode using an electrospray ionization source in UPLC-QQQ-MS.Results showed that significant variations were observed in the composition of 10 phenylethanoid glycosides among Cistanches Herba cultivated on different hosts and subjected to various drying treatments.Freeze-dried Cistanches Herba showed the highest content of these compounds for both host plants, followed by drying at 80 ℃.Although freeze-drying preserved the maximum content of 10 phenylethanoid glycosides in Cistanches Herba, drying at 80 ℃ was more cost-effective for large-scale production.

An electrochemical immunosensor based on glassy carbon electrode-modified gold nanoparticles/graphene oxide composite film was developed and applied to detect marbofloxacin residues in fresh meat.Gold nanoparticles/graphene oxide composite film was synthesized on the electrode surface by an electrodeposition method, and then the graphene oxide of composite film was reduced by an electrochemical method.The antibody was finally immobilized.The modified process of the electrode was characterized by cyclic voltammetry.The electrochemical detection conditions of immunosensor were optimized by differential pulse voltammetry.Under the optimum conditions, marbofloxacin was quantitatively determined.The change of peak current was linearly related to the concentration of marbofloxacin in the range of 0.5-400 ng/mL with a detection limit of 0.05 ng/mL.The detection limits in pork, chicken and beef samples were 0.09, 0.10, and 0.09 μg/kg respectively, and the recovery rates ranged from 82.81% to 101.99%.These results obtained are consistent with that of ultra-high performance liquid chromatography-tandem mass spectrometry.The results showed that the fabricated electrochemical immunosensor could be applied for the detection of marbofloxacin residues in real samples.

In this paper, the sensory score and catechin content prediction models of multi-variety Wuyuan green tea were established based on near-infrared (NIR) spectral nondestructive testing technology with different varieties and quality grades of Wuyuan green tea as research objects, and the effects of different pretreatment algorithms, variable screening methods, and modelling methods on the prediction accuracy were compared.First, the raw spectra were pre-processed and principal component analysis (PCA) was used to reduce the dimensionality.The characteristic wavelengths related to sensory scores and catechin content were subsequently screened by competitive adaptive reweighted sampling (CARS), shuffled frog leading algorithm (SFLA), and variable iterative space shrinkage approach (VISSA).The linear partial least squares regression (PLS) and random forest algorithm (RF) prediction models were developed.Results showed that the best preprocessing and variable screening algorithms for sensory scores were standard normal variate (SNV) and CARS, respectively, and the best preprocessing and variable screening algorithms for catechin content were min-max normalization (Min-max) and CARS, respectively.The nonlinear RF model based on variable screening was the best, and the prediction accuracy of sensory scores and catechin content reached 0.927 and 0.939, respectively, and the relative standard deviation (RSD) values of the prediction models were greater than 2, indicating that the model has better prediction performance and better robustness.The study indicates that NIR spectroscopy can be used for sensory scoring and rapid prediction of the catechin content of Wuyuan green tea of different quality grades.

To investigate the effects of different medical-food homologous treatments on the quality of low-temperature air-dried mutton, fresh local lamb hind leg meat was taken as raw materials, marinated with lotus leaves and pueraria root homologous extracts and antioxidants, and air-dried at low temperature [(8±1) ℃, the humidity of 50%-70%, wind speed of 2 m/s].Sensory evaluation and gas chromatography-ion mobility chromatography combined with multivariate statistical methods were used to analyze the volatile compounds characteristics of air-dried lamb leg treated with different homologous extracts of medicine and food.Results showed that a total of 52 volatile organic components (including monomers and dimers) were identified from four kinds of low-temperature air-dried mutton, including 16 alcohols, 11 aldehydes, 9 ketones, 9 esters, 3 acids, 1 olefin, 1 pyrazine, and 2 nitriles.Fingerprint analysis showed that there were significant differences in the characteristic volatile organic substances of four different treatments of low-temperature air-dried mutton.Principal component analysis showed that different treatment methods could significantly change the characteristic flavor of low-temperature air-dried mutton, and the results were consistent with the results of sensory evaluation.The results of fingerprint and principal component analysis were directly verified by cluster heat map analysis.The results provided a scientific basis for improving the taste and flavor of low-temperature air-dried mutton and producing high-quality air-dried mutton.

In this study, liquid chromatography-mass spectrometry (LC-MS) combined with the UNIFI screening platform was used to quickly and qualitatively analyze the chemical components in grape seed extract, and establish a method for the determination of effective components in grape seed extract.Firstly, the mass spectrum data of grape seed extract were collected by ultra-performance liquid chromatography-quadrupole-time-of-flight high-resolution mass spectrometry (UPLC-Q-TOF-MS/MS).According to the matching results of the database built by UNIFI software, combined with the retention time of control substance, characteristic fragment ions and related literature, 20 chemical constituents were identified from grape seed extract, including 7 polyphenols, 1 triterpene, 1 flavonol, 1 unsaturated fatty acid, 1 polyhydroxylamine, 3 phenolic acids, and 6 amino acids.In addition, the four active components (catechin, epicatechin, proanthocyanidin B2 and proanthocyanidin C1) in grape seed extract were determined simultaneously by ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QqQ-MS/MS).The linear relationship was good in their respective ranges (r≥0.998), and the average sample recovery was 96.7%-102.6%.This study provides a rapid, simple, and accurate method for qualitative and quantitative analysis of chemical components in grape seed extract, providing an important theoretical reference for its quality evaluation and basic research of pharmacodynamic substances.

Temperature accelerated storage experiment was employed to simulate the aroma deterioration process of white tea beverage during shelf life in this study, quantitative descriptive analysis combined with gas chromatography-ion mobility spectroscopy (GC-IMS) and gas chromatography-mass spectrometry (GC-MS) was used to analyze the dynamic changes of aroma sensory and volatile compounds of white tea beverage during storage.The quantitative descriptive analysis results showed that during high-temperature storage, the floral, fragrant, and sweet properties of white tea beverages were weakened, while the medicinal, sour, musty, and watery properties were gradually increased.The results of GC-MS analysis showed that the content of alcohol compounds first increased briefly and then decreased significantly, aldehyde compounds decreased first, then increased, and then decreased again, and ketone compounds increased significantly and then fluctuated.The changes in compounds such as linalool, benzaldehyde, geraniol, and β-ionone, which had a relatively high content, were more pronounced.The compounds detected by GC-IMS were mainly aldehydes, and their content gradually decreased during storage, and the contents of ketones gradually increased, which was consistent with the results of GC-MS analysis.The overall trend of the GC-IMS analysis results showed a gradual decrease in compounds with pleasant aroma attributes and an increase in compounds with unpleasant aroma attributes.

High-gravity brewing is a commonly used technique in beer production duo to its high economic efficiency.During high-gravity brewing, brewer’s yeast is subjected to different environmental stresses in different brewing stages.Proline is considered as an important stress-protective agent in brewer’s yeast, which endows brewer’s yeast with better tolerance ability against stresses in high-gravity brewing.Since the intracellular concentration of proline can be used as a reference for screening of brewing yeast with good environmental tolerance ability, the establishment of a method capable of rapidly detecting the concentration of intracellular proline in brewing yeast is required.This study developed a novel fluorescent microplate method (FMM) for the detection of intracellular proline concentration in brewing yeasts based on sodium hypochlorite oxidation and o-phthalaldehyde (OPA)/n-acetyl-l-cysteine (NAC) fluorescence methods combined with the optimization of cells disruption technique.The linear ranges and the recovery rate of the novel method were 5-40 μmol/L (0.58-4.6 mg/L) and 73.33%-105.5%, respectively.Compared to the high-performance liquid chromatography method, the FMM assay had no significantly different absolute quantification of intracellular proline in brewing yeasts, but the procedures in the FMM assay were much faster and more convenient.Therefore, the novel FMM method proposed in this study not only proposes a new solution for the detection of intracellular proline in brewing yeasts, but also provides a new strategy for screening the proline-accumulating brewer’s yeasts with better adaptation to stresses in high-gravity brewing.

Zang-flavor Baijiu is a kind of liquor with “Fen and Luzhou” flavor characteristics, which is made from highland barley, inherits the traditional brewing technology of Zang-style Mingxi Baijiu, and uses Zangqu for fermentation.To clarify the aroma components and sensory characteristics of Zang-flavor Baijiu, the volatile compounds in four kinds of Zang-flavor Baijiu (Jixiang, Jiabin, Zangsheng and Liangyuang) were analyzed by sensory quantitative description analysis and headspace solid-phase microextraction/liquid-liquid extraction combined with gas chromatography-mass spectrometry.The characteristic volatile compounds were filtered out by odor activity value analysis.The correlation between sensory characteristics and characteristic flavor compounds was further revealed by partial least squares and correlation analysis.Results showed that the characteristics of Fen-flavor in the four types of Zang-flavor Baijiu were gradually weakened, while the characteristics of Luzhou-flavor were gradually enhanced.A total of 58 aroma compounds were identified in all samples, of which esters and acids were rich in species and relatively high in content.There were 28 characteristic compounds with aroma contribution to Zang-flavor Baijiu, among which ethyl hexanoate and ethyl octanoate had the largest contribution.There was a positive correlation between hexanal and herbaceous incense.Ethyl caproate, ethyl butyrate, ethyl decanoate, ethyl octanoate, hexanoic acid, and ethyl linoleic acid ester had good correlation with cellar aroma, fruit aroma, grain aroma, flower aroma, acid aroma, and empty-cup aroma respectively.This study revealed the flavor structure characteristics of Zang-flavor Baijiu and provided references for quality evaluation and quality improvement for Zang-flavor Baijiu.

The quality of pit mud is closely related to the yield and quality of Luzhou flavor Baijiu.Scientific pit mud quality grading method can provide a theoretical basis for the optimization of new pit mud formula and the maintenance of old pits.However, the current quality standards for pit mud still mainly rely on sensory evaluation, physical and chemical indicators, and simple microbial indicators (total bacterial count and spore count), which cannot comprehensively and objectively reflect the quality of pit mud.This study used multiple detection techniques to detect the physicochemical indicators and flavor substances of pit mud with different quality grades and established an accurate and reliable pit mud classification method based on partial least squares (PLS).This article used physical and chemical analysis, inductively coupled plasma mass spectrometry (ICP-MS), and gas chromatography-mass spectrometry (GC-MS) techniques to analyze pit mud with different quality grades based on sensory analysis and corresponding wine quality grading.PLS was utilized to analyze the detection results, and a total of 27 potential markers related to the quality grade of pit mud were selected, including sodium, water, ammonia nitrogen, potassium, calcium, hexanoic acid, ethyl hexanoate, 4-methylphenol, etc.A fast prediction model for pit mud grade was established based on these 27 potential markers using a training set.Pit mud with different grades were completely separated in the PLS score map, and the model was validated using training and validation set data.Results showed that the model was stable, reliable, and had a high prediction accuracy.This method has high accuracy in the classification of pit mud quality and can be used for analyzing and predicting pit mud grades.

As a by-product of oat processing, oat bran is rich in dietary fiber as well as protein, polyphenols, and other nutrients, which has a variety of health functions such as lowering postprandial glucose response, maintaining normal cholesterol level, regulating intestinal flora, and the like.At present, oat bran has not been fully utilized in our country.To further enhance the processing and utilization value of oat bran, different modification methods are usually adopted to improve its physicochemical properties and nutritional functions.This paper reviewed the heat treatment modification, non-heat treatment modification, and bioprocessing modification techniques of oat bran, compared the improvement effects of different modification techniques, and analyzed the potential of their application in cereal beverages, with a view to providing certain reference for the high value-added utilization of oat bran and the development of high fiber-based cereal beverages.

Ginger (Zingiber officinale Roscoe) is a medicinal and food plant,it is rich in various bioactive components and has a unique flavor.However,fresh harvested ginger contains high moisture content which is susceptible to spoilage,makes it difficult to transportation for long distance and store for a long time.These characteristics limit the deep processing of ginger, makes it important to study the drying of ginger.Pretreatment and drying methods are important steps in the drying of ginger, which not only remove excess moisture and improve the shelf life but also cause changes in the active components and flavor of ginger.Based on these, this study reviewed the effects of different pretreatment and drying methods on the quality and flavor of ginger, aimed to provide a theoretical reference for the drying technology of ginger and promote the high-quality development of the ginger processing industry.

Microbial contamination is the main trigger for vinegar deterioration.Developing detection and prevention methods for microbial pollutants can effectively address such issue.Herein, vinegar spoilage cases together with their causes, major responsible microbes, detection methods, as well as measures for control and prevention were reviewed.Study found that links including opening fermentation, pipeline transportation and tank storage were vulnerable to microbial contamination, such as Bacillus, Lactococcus and Gluconacetobacter, which results in swollen, precipitation, turbidity, stink, and biofilm.Traditional detection method was widely employed towards vinegar-contaminated microorganisms.Molecular biology techniques such as PCR technology and High-throughput sequencing represented as promising alternatives.Moreover, measures for addressing different contaminants were proposed.

Edible bird′s nest (EBN) is a prized natural substance served as both medicinal and food purposes, which possesses the activities of immune regulation, anti-inflammation, offspring intelligence development promotion, neuroprotection, intestinal flora regulation, and so on.However, the specific ingredients and mechanisms that contribute to neuroprotective properties of EBN remained obscure.This review delved into the fundamental composition and bioactive ingredients of EBN, as well as its neuroprotective effects and mechanisms.The findings indicated that the bioactive ingredients in EBN, including salivary acids, proteins, and polysaccharides, would confer its neuroprotective benefits through the modulation of neurotrophic effect, oxidative stress, and inflammatory responses.This review further illuminated the gut-brain axis as a potential pathway for the neuroprotective effects of EBN considering its digestion and absorption characteristics.Finally, a forward-looking perspective on EBN research was provided, which would facilitate the further research and high-value utilization of EBN in neuroprotection.

Plant proteins offer abundant resources, excellent nutritional value, low cost, and minimal environmental impact, making them become a type of high-quality raw material for food processing.However, their poor water solubility often results in poor product stability and taste defects when applied to water-based food products, limiting their use in actual production and processing applications.The plant protein deep processing industry is underdeveloped, resulting in a significant amount of protein resources being used solely as feed or fertiliser.This situation not only leads to a great waste of resources but also enhances environmental pollution.Currently, as plant-based products continue to develop, research on the solubility of plant proteins and solubilisation technology has become a popular topic and has made significant progress.However, there have been fewer comprehensive discussions on the related content and research results.The purpose of this paper was to review the internal and external factors affecting the solubility of plant proteins and to collate the relevant technologies to improve solubility.This study will provide theoretical references for the research and development of plant protein solubilisation technology and plant protein products.

Yam is an important medicinal source and traditional food for wellbeing and health preservation.Browning is the key obstacle in yam storage, transportation, and process.Yam browning is closely related to the levels and varieties of polyphenolics, the activities of polyphenol oxidase (PPO) and peroxidase (POD), the exposure timing of raw materials to oxygen, the levels and varieties of carbonyl compound and amino compound, and the processing temperature and duration.Currently, three techniques are used to prevent yam browning, including physical techniques, such as lowering the storing and processing temperature, precooking, high pressure, oxygen isolation, and irradiation, etc., chemical techniques, to immerse or fumigate yam slices with chemical inhibitors, and biological techniques including coating the yam slices with biological extracts, etc.To reduce the yam browning as much as possible and to get more yam processed products with high quantity and quality, further studies should focus on mechanisms in yam browning, selecting and breeding of yam varieties with less browning or no browning, techniques to prevent nutrients loss and maintain the sensory properties while decreasing browning index, and selection of suitable processing technologies to decrease yam browning.

Plant Jiaosu is a product obtained by fermenting fruits and vegetables under microorganisms.They have garnered considerable consumer interest in recent years owing to their substantial market worth.Although there has been various research on plant Jiaosu, analyzing its manufacturing process, composition, function, potential safety hazards, and controlling strategies was still needed.Hence, this review aimed to demonstrate the categories of plant Jiaosu, their primary active substances, flavor, production methods, functions, potential safety risks, and improvement strategies.Plant Jiaosu comprised probiotics, enzymes, organic acids, amino acids, and polyphenols.These chemicals contributed to the distinctive flavor of the plant Jiaosu.Plant Jiaosu had many functions, such as enhancing antioxidant capabilities, treating chronic illnesses, regulating gut microbiota, antibacterial/anti-inflammatory activities, mitigating obesity, and protecting the liver.Nevertheless, foodborne pathogens, methanol, and biogenic amines in plant Jiaosu raised safety issues.These issues can be reduced by using appropriate sterilization methods and designed fermentation processes.This research provides significant insights on the development of plant enzyme products.

Hesperidin, a flavonoid found mainly in citrus fruits, has a variety of physiological functions to prevent and ameliorate health problems such as oxidative stress, inflammation, and lipid accumulation.In recent years, the role of hesperidin in the field of sports has gradually attracted the attention of researchers.Studies have shown that hesperidin supplementation has potential benefits in improving physical characteristics and exercise performance, but there is no research on its application effect and mechanism in China.According to previous studies, hesperidin supplementation can reduce body fat, increase muscle mass, improve body shape to a certain extent, improve the body's aerobic and anaerobic capacity, and enhence muscle strength.Hesperidin has positive effects on the body mainly by activating or inhibiting some signaling pathways, improving vascular endothelial function, reducing oxidative stress and inflammation, and improving mitochondrial biogenesis.However, there are still few relevant studies, and its mechanism of action needs to be further studied, as well as different populations, doses, cycles, and training methods need to be further explored to develop personalized and scientific hesperidin supplementation strategies.