Diabetes is a chronic metabolic disease characterized by high blood glucose level. Since chemical hypoglycemic drugs tend to increase the burden on the liver and kidneys and the risk of cardiovascular disease, there is an urgent need for a method to control blood glucose levels with low side effects for patients with mild disease. Some researchers have indicated that Porphyra has the capacity to decrease postprandial blood glucose levels and has potential in the development of hypoglycemic drugs and functional foods. Bacillus subtilis, isolated from a seaweed culture base in Weihai, Shandong, was used in this work to ferment Porphyra yezoensis. The fermentation conditions of the fermentation products with α-glucosidase (GTase) inhibitory activity were investigated and optimized. The potential peptides with GTase inhibitory activity were separated and identified by gel chromatography and LC-MS/MS, and the active ingredients were verified by molecular docking simulation. The results showed that P. yezoensis fermented powder (PFPOB) formed a competitive inhibition of GTase. The IC₅₀ was 0.21 mg/mL, which was better than the positive control (Acarbose, IC₅₀=0.88 mg/mL). Ingredient analysis and molecular docking indicated that the inhibitory activity might originate from peptides GPGDFL and SPPPPPA. In this study, a functional food ingredient with an effect on GTase inhibition was prepared, and the primary active components were first identified. This indicated that Porphyra can be one of the sources of hypoglycemic functional foods and provided theoretical support for the high-value development and utilization.

As an iron source that can be utilized by organisms, heme is applied to the fields of food and pharmaceutical industry. The production of heme by microbial fermentation has industrial potentials but the yield is low. In this study, the synthetic level of heme in Escherichia coli were improved through metabolic engineering. The heme yield was increased by constructing tolC-deleted Escherichia coli (WTΔT), overexpressing hemA and hemH, and adding Fe²⁺ exogenously. The results showed that over-expression of hemA in the tolC-deleted strain resulted in the accumulation of porphyrins. When 80 μmol/L Fe²⁺ was added, the strain co-expressing hemA and hemH (WTΔT-AH) exhibited intracellular heme content of 40.18 μmol/L, 3.98-fold of that in WT. The above results provide a certain theoretical basis and value for improvement of heme yield by recombinant Escherichia coli.

Chemical degradation and enzymatic degradation are the common methods for the preparation of oligosaccharides by polysaccharide degradation. The products prepared by chemical methods are often complicated and difficult to obtain oligosaccharides with a single degree of polymerization. The enzymatic method has become an important issue in recent years because of its high specificity and high uniformity of target products. In this study, the technological conditions for producing gellan oligosaccharides by acid hydrolysis were optimized first, and the optimum acid hydrolysis conditions were as follows: substrate concentration 0.5%, HCl concentration 0.5 mol/L, and hydrolysis for 3 h. A strategy for one-step production of gellan oligosaccharides by Pichia pastoris fermentation coupled with polysaccharides degradation was proposed. The results showed that the optimal fermentation conditions for gellan lyase were 20 g/L yeast powder, 1% methanol, and pH 6.0; the optimal enzymatic degradation conditions were 2 g/L gellan gum at the initial fermentation and hydrolysis for 96 h. Finally, the products of the two degradation methods were compared by Fourier transform infrared spectrometer (FTIR) and matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Gellan oligosaccharides with polymerization degrees of 5, 8, and 12 were obtained after acid hydrolysis, and gellan oligosaccharide with a polymerization degree of four was obtained after enzymatic degradation. The structure of the acid hydrolysis product was not changed, and the CC could be observed in the enzymatic degradation product. This study provides a feasible way to prepare gellan oligosaccharides with a single degree of polymerization and explore their functional activities.

Fresh-cut lettuce is vulnerable to browning during storage and distribution, seriously affecting its commodity value. Effect of high pressure processing (HPP) treatment on enzymatic browning of fresh-cut lettuce was explored after treating with different pressure conditions (100, 200, and 400 MPa) and then storing at 4 ℃ for 8 d. The changes of color, browning index, weight loss rate, hardness, total phenolic content, flavonoid content, malondialdehyde (MDA) content, polyphenol oxidase (PPO) activity, peroxidase (POD) activity, and phenylalanine ammonia lyase (PAL) activity were measured during storage. Results showed that HPP treatment could effectively delay the browning of fresh-cut lettuce compared with CK group, the treated pressure is higher, and the suppression effect is more significant. 400 MPa treatment was the most effective for delaying the development of browning, which significantly inhibited the increase in the contents of total phenolic and flavonoids, and suppressed PPO, POD, PAL activity and the gene expressions levels of LsPPO, LsPOD and LsPAL. Therefore, HPP treatment evidently maintains the better color of fresh-cut lettuce during storage to effectively prolong the storage period.

The breeding of Saccharomyces cerevisiae CLNJ1 producing high γ-aminobutyric acid(GABA) will provide theoretical basis and technical support for applying to food and pharmaceutical industries. The CLNJ1 was bred by genome shuffling to improve yield of GABA, and then the safety of the fusion strain was evaluated. The CLNJ1 was identified as Saccharomyces cerevisiae, and its GABA yield was 1.72 g/L. The GABA yield of CLNJ1-Y breeding by LiCl₂ mutagenesis with CLNJ1 was 5.96 g/L, which was 247% as much as CLNJ1. The GABA yield of CLNJ1-YC breeding by genome shuffling with CLNJ1-Y was 12.28 g/L, which was 614% as much as CLNJ1. Hemolysis and antibiotic sensitivity tests were studied for CLNJ1-YC, and the result showed that CLNJ1-YC had no hemolytic activity and was sensitive to the most antibiotics. The S. cerevisiae CLNJ1 can improve the yield of GABA after genome shuffling, and which has good application prospects.

In this research, a fungus with high cellulase activity was screened from Cupei of Sichuan sun vinegar. Its physiological-biochemical characteristics were studied and analyzed by ITS sequence. The conditions of enzyme producing and enzymatic properties of the strain were investigated by single factor and orthogonal experiments. The strain was identified as Lichtheimia ramosa, the crude enzyme solution was extracted under the following conditions: 3.5×10⁶ CFU/mL of bacterial suspension, 1% of inoculation volume, 30 ℃, cultured for 24 h at 180 r/min, and the reaction was performed at 50 ℃ for 30 min. The max activities of endoglucanase and β-glucosidase were 95.92 U/mL and 47.57 U/mL at pH 5.0 and 6.0. This study revealed that endoglucanase and β-glucosidase were produced by L. ramosa during the fermentation of Cupei, and had well stability of pH and heat stress, which provided some reference value for the production of Sichuan sun vinegar.

Brassica rapa L. is an edible and medicinal plant that grows on the Tibetan plateau. It has anti-hypoxia and anti-fatigue effects. To study the functional activity and the protective effect on muscle homeostasis of B. rapa extract, its antioxidant activity of it was determined by in vitro free radical scavenging assay first. Then the long-term exercise-induced fatigue mice were used, and the blank group, exercise group, and low and high-dose groups were set up respectively. Firstly, the protective effect on muscle injury was determined by histological observation. Then, the related biomarkers assays and real-time fluorescence quantitative PCR experiments were utilized to analyze the skeletal muscle. It was found that the B. rapa extract could increase the NAD+/NADH ratio and promote ATP synthesis. It also could modulate the SIRT1/PGC-1α/TFAM pathway to enhance mitochondrial function. Then, the Nrf2/HO-1 pathway was regulated and the anti-oxidative stress defense system was enhanced. Finally, it could alleviate muscle injury and promote muscle regeneration by regulating the acta1 and titin-related genes. In conclusion, B. rapa could enhance energy metabolism, maintain the stability of mitochondrial function, improve the ability of antioxidant defense, relieve muscle injury, and promote muscle regeneration, thus playing a role in protecting muscle homeostasis.

There are bound sialoglycans in dietary mucin from animals, which may have an impact on human nutrition and health. In this work, a sialic acid-rich mucin, edible bird’s nest (EBN) was chosen as the research target. Also, the terminal sialic acid of EBN glycoprotein was removed through acidic treatment, forming acidolysis bird’s nest (ABN) and subject to in vitro digestion separately. The effects of these two types of bird’s nest and N-acetylneuraminic acid on the growth of probiotics and the fecal bacteria of pregnant women in vitro were investigated. Compared with the ABN, EBN and N-Acetylneuraminic acid could improve the growth of Lactobacillus and Bifidobacterium and increase the production of short chain fatty acids. EBN can significantly promote the growth of Akkermansia muciniphila. EBN can also increase the production of acetic acid, propionic acid, and butyric acid within 24 h during the in vitro fermentation of fecal bacteria of healthy women and late pregnant women, especially for the increase of propionic acid. Meanwhile, EBN can also reduce the relative abundance of potential pathogenic bacteria such as Escherichia coli-Shigella, Enterobacter, and Klebsiella, and increase the relative abundance of potential probiotics such as Bacteroides, Faecalibacterium and Coprococuus. EBN had more remarkable effect than ABN in reducing the abundance of pathogenic bacteria and increasing the abundance of probiotics. Therefore, the integrity of bound sialic acid of EBN plays an important role in its biological function.

In this study, red ginseng, Polygonatum odoratum, Portulaca oleracea, wolfberry, pomelo, pumpkin, ginger, celery, and yam were used as raw materials to prepare Jiaosu. The optimal conditions for Jiaosu preparation were determined by single-factor and central composite design-response surface tests, and the glycemic regulatory functions of the Jiaosu were investigated by α-amylase and α-glucosidase inhibition tests and rat tests. The optimal condition were: 49.5 h, 37℃, and inoculation size of compound lactic acid bacteria 0.1%. The addition of oligofructose didn’t have significant effect on the α-amylase inhibition rate (P＞0.05). The IC₅₀ values of Jiaosu on α-amylase and α-glucosidase were (16.54±0.40) and (46.54±6.50) mL/L, under the concentration of 33.3 mL/L Jiaosu, the α-amylase activity could be completely inhibited. The rat test showed that the Jiaosu significantly improved the fasting blood glucose of diabetic rats. In this study, the optimal fermentation process of the compound plant Jiaosu was determined, and the effect of the Jiaosu on regulating blood glucose was confirmed by the inhibition of enzyme activity and reduction of fasting blood glucose in rats, which provides a theoretical basis for the development of the compound plant Jiaosu with the effect of regulating blood glucose.

Panax ginseng and Panax quinquefolium are commonly used as precious traditional Chinese medicines in China. Because they are related species of Panax ginseng, they are similar in morphology and chemical composition. However, the medicinal properties and efficacy of Panax ginseng and Panax quinquefolium are quite different, and they cannot be mixed in clinical practice, so it is particularly important to identify them. In this study, a large number of G-quadruplex-containing double-stranded DNA was amplified by PCR (polymerase chain reaction) with primers at the 5′ end of the specific snp site on the genomic DNA of Panax ginseng and Panax quinquefolium, which was denatured and combined with hemin to form a DNA enzyme with peroxidase activity (DNAzyme), catalyzed H₂O₂ and 2,2′-azino-bis (3-ethylbenzothiazoline-6sulfonic acid) diamine (ABTS) changes in color. Through the optimization of the PCR system and color development system, this study could quickly and simply identify Panax ginseng from Panax quinquefolium with a sensitivity of 0.1 ng/μL. A visual discrimination method of PCR and G-quadruplex for the identification of Panax ginseng and Panax quinquefolium was established, which provided a new way for human participation in the identification of Panax ginseng and Panax quinquefolium.

The headspace solid-phase microextraction combined with gas chromatography-mass spectrometry(HS-SPME-GC-MS) and high-throughput sequencing were used to investigate the relationship between Scopulibacillus and Daqu flavor. The results showed that the abundance of Scopulibacillus increased significantly with the deepening color of Daqu, and Scopulibacillus had a significantly positive correlation with six flavor compounds. A pure strain of Scopulibacillus daqui LBM32026 was isolated from the black Daqu, and the growth characteristics and flavor metabolism of the strain were analyzed at different temperatures. It was found that it grew rapidly at 50 and 60 ℃, but grew slowly or even inhibited at 30 ℃ and 40 ℃. A total of 40 volatile compounds, including 8 alcohols, 2 esters, 3 acids, 8 nitrogenous, 7 aromatics, 4 phenols, 5 aldehydes, 1 ketone, 1 lactone and 1 other compound, were detected in the solid-state fermentation of monobacteria. This research contributes to the study of thermophilic microorganisms in high-temperature Daqu and provides a theoretical basis for their future production application in the Daqu production process.

Culturomics technology was used to screen and identify culturable bacteria in strong-flavor Baijiu cellars on a large scale and focus on breakthrough in the isolation and screening of anaerobic bacteria, by designing and optimizing screening medium, combined with MALDI-TOF MS and 16S rRNA gene identification technology. The results showed that a total of 124 bacteria strains from 44 species and 21 genera, including 9 potential novel species, were isolated from strong-flavor Baijiu cellars using 5 specific anaerobic medium and 2 aerobic medium. Among them, 100 strains were isolated under anaerobic conditions and 24 strains were isolated under aerobic conditions; 60 strains were isolated from pit mud samples and 64 strains were isolated from fermented grains samples. Bacillus sp. and Clostridium sp. were the dominant strains isolated from cellar samples. According to the species and abundance of culturable bacteria from different screening conditions and isolation habitat, six characteristic strains from strong-flavor Baijiu cellars were identified, and their biological characteristics were analyzed. This study laid a foundation for the excavation of potential novel species in strong-flavor Baijiu cellars, the directional screening of characteristic strain resources, the analysis of interaction mechanism, functional research and development, and industrial application.

In this experiment, liquid-liquid microextraction and headspace-solid-phase microextraction combined with GC-MS were used to study the changes of the important aroma compounds of light-flavor Baijiu during storage in clay jars. And the changes of critical aroma compounds in light-flavor Baijiu were analyzed by the principal component analysis based on quantitative data combined with sensory evaluation and physicochemical indexes. The results showed that with the extension of aging time, the content of organic acids increased with the esters mostly decreased, the aldehydes, ketones, and phenols had obvious changes, as the alcohols did not change significantly. After 5 years of aging, the light-flavor Baijiu presented a more pleasant flavor, and the critical aroma compounds basically tended to stabilize. This study clarified the effect of pithos storage on the aging process of light-flavor Baijiu, which has some guiding implications for the aging techniques and product development of light-flavor Baijiu.

Enzymatic extrusion has great application potential in fermentation because of its outstanding advantages in treating and degrading natural macromolecules. Applying it to the pretreatment of Apios fortunei to brew Huangjiu may be a good method to increase the added value of the products of A. fortunei. In this study, the parameters of enzymatic extrusion were optimized, and the temperature of final zone was 104.9℃, the moisture was 50.06%, the screw speed was 96 r/min, and the amount of enzyme added was 1.40‰ (0.168 KNU/g, starch dry basis). The highest gelatinization degree (98.89%) and reducing sugar content (20.69%) were obtained under this condition. Then, the optimum conditions were used to pretreat A. fortunei to brew Huangjiu. The A. fortunei Huangjiu was obtained, with the alcohol content of 9.4%, total acid of 7.15 g/L, total sugar of 2.7 g/L, furthermore, the high non-sugar soluble solids content (50.02 g/L), γ-aminobutyric acid (0.47 mg/L), and high antioxidant activity of A. fortunei Huangjiu proved that it had high nutritional value. The sensory evaluation results showed that its overall acceptance was good with unique flavor. In summary, it was proved that A. fortunei Huangjiu pretreated by enzymatic extrusion had certain potential in expanding the category of Huangjiu. Further analysis by GC-MS and odor activity value showed that linalool, myrcene, etc in A. fortunei Huangjiu may be the source of its special flavor.

Phenols are one of the key factors affecting the quality of wine grapes, and they also have an important impact on the quality of wine, so people attach great importance to them. In this paper, the Cabernet Gernischet grape was used as the raw material to study the changes of phenolic compounds in grape fruit under different pressure (100, 200, 300, 400, 500 MPa) and time (5, 15, 25, 35, 45 min). Results showed that 400 MPa pressure treatment and 25 min time treatment had the best effect. After ultra-high pressure treatment, the contents of total anthocyanins, total flavonoids, total phenols, flavonols, flavanols, unacylated, and acetylated anthocyanins in the treated samples significantly increased compared with the control, which resulted in the decrease of L^* value and the increase of a^* value, C^*_ab value, b^* value, and h^*_ab value of the color parameters, resulting in the color change of the treated samples to deep red. The results of this study can provide some data reference for the improvement of grape and wine quality by ultra-high pressure technology.

Nomads in Central and East Asian countries have a history and tradition of drinking koumiss and use it for health care. In order to understand the species diversity of lactic acid bacteria in yogurt koumiss in Central and East Asia and to screen out strains with potential probiotic characteristics, 44 samples of koumiss collected from China, Mongolia, Kyrgyzstan, Uzbekistan, and other regions were isolated and identified, and their tolerance to artificial gastrointestinal juice in vitro and milk fermentation characteristics were analyzed. The results showed that a total of 264 strains of lactic acid bacteria were isolated and identified in 44 koumiss samples, and the isolation rate of Lactobacillus kefiranofaciens was higher in the samples of Central Asia and Xilingol region in China, while Lactobacillus helveticus was the dominant strain in the samples of Mongolia, and Xinjiang province in China. L. helveticus Q27-6, Lactiplantibacillus plantarum Q18-3, and Lactobacillus paracasei Q18-5, were screened from curd fermented by skim milk, using acid production ability and tolerance in artificial gastrointestinal fluid as indexes. The selected strains had potential probiotic properties, and their temperature adaptability also suggested that they were more suitable for the fermentation and production of low-temperature fermentation dairy products such as koumiss.

In order to screen Monascus strains suitable for use as cheese starter, the traditional monascus fermented food was cultured for enrichment, and the preliminary screening was carried out using the plate streaking method. The preliminary screened strains were used to prepare cheese by a new short-term ripening process, and the second screening was conducted by flavor evaluation. Six fungi with good flavor were screened and suspected to be Monascus, and they were confirmed to be Monascus through DNA sequence comparison. The cheese samples were prepared by the six Monascus strains with short-term ripening process, and the safety, functionality, physicochemical parameters, texture and antioxidant properties were tested to analyze their effects on the quality of cheese. The results showed that Monascus strains BC20 and ZX-99 had both food safety and cheese ripening ability. At the end of cheese ripening, the citrinin content in cheese samples was 20 μg/kg, lower than the national standard detection limit and far lower than the quantitative limit of 80 μg/kg. The pH 4.6 soluble nitrogen content of the two samples was (40.99±0.90)% and (26.05±0.56)%, respectively. This study screened two Monascus strains which were suitable for making mature cheese, and provided a new short-term ripening process for preparing Monascus cheese. In addition, this study also provides a basis for optimizing the quality of Monascus cheese, shortening the cheese ripening time and reducing the production cost.

Bacterial soft rot is one of the main diseases of postharvest pepper. This study aimed to explore the application potential of antagonistic lactic acid bacteria to control soft rot of postharvest pepper. Pathogenicity analysis of Pectobacterium carotovorum subsp. carotovorum CBJ3 (Pcc CBJ3) showed that storage at 25 ℃ (≥3 lg CFU/mL) and 4 ℃ (8 lg CFU/mL) could cause pepper soft rot rate of 100%. It indicated that Pcc CBJ3 had strong pathogenicity. An antagonistic strain LAB2 with strong antibacterial activity against Pcc CBJ3 was screened from pepper and identified to be Lactobacillus plantarum by 16S rDNA. The bacteriocin and cell-free fermentation supernatant (CFS) of L. plantarum LAB2 had antibacterial activity against Pcc CBJ3 in vitro. Four bacteriocins, plantaricin_E, plantaricin_F, plantaricin_N, and plantaricin_J, were identified by database comparison using draft genome sequences. The result of disease control in vivo showed that bacteriocin and CFS of L. plantarum LAB2 both had disease control effect on pepper soft rot, and CFS performed better, which significantly reduced the disease incidence and the lesion diameter of soft rot (P<0.05). Scanning electron microscopy showed that CFS could maintain the integrity of pepper epidermis structure. Microbial counting result showed that CFS significantly reduced the number of pathogens in pepper (P<0.05). Further studies showed that CFS could delay the firmness decrease, water loss, soluble solid content loss, and malondialdehyde accumulation of pepper during storage. This study provides a reference for the application of biological control technology in storage and preservation of postharvest pepper.

An aroma-producing yeast is isolated and screened from natural fermented Zha-chili by the olfactory method combined with the content of total ester, which is identified and classified as Pichia kudriavzevii Y50. To explore quality improvement of Zha-chili produced by mixed fermentation, Y50 and Lactobacillus plantarum fermentation Zha-chili (C), natural fermentation Zha-chili (A), and L. plantarum fermented Zha-chili (B) for research object, the basic physical and chemical indexes of three kinds of Zha-chili, capsaicin, organic acids and volatile components were comparatively analyzed. The results showed that the pH values, total acid, nitrite and carotene contents of three kinds of Zha-chili were similar, but the organic acid content of Zha-chili C was (25.46±0.32) g/kg, which was 57.8% and 32.2% higher than that of Zha-chili A and B, respectively. 90, 67 and 72 volatile flavor substances were detected from Zha-chili A, B and C, among which the volatile substance content of Zha-chili C was the highest of (10 101.11±99.04) μg/kg, and the volatile substance content of esters, alcohols, aldehydes, and acids had improved, compared to A and B, respectively by 75%, 358%, 106%, 23% and 102%, 59%, 68%, 51%, making the Zha-chili stronger ester, floral and fruit scent, which indicated that aroma-producing yeast Y50 could improve the overall flavor quality of Zha-chili. Through the calculation of odor activity value (OAV), 22 aroma compounds with OAV>1 were detected. These key aroma compounds gave Zha-chili unique aroma characteristics, among which β-ionone, 2-methylbutyrate, caproate, n-heptanol, (+) -limonene, heptanal and guaiacol were the key ingredients of Zha-chili C flavor. The results showed that Y50 had application potential in Zha-chili production.

In order to explore the types of amine-producing bacteria and their characteristics, eight strains of biogenic amines-producing bacteria were isolated from white sufu post-fermentation process and their growth characteristics and ability to produce biogenic amines (BAs) were studied. Furthermore, the determination of 16S rDNA of eight strains showed that the four strains were identified to be Bacillus paramycoides and others were found to be Bacillus tropicus, Enterococcus faecium, Bacillus amyloliquefaciens, and Bacillus subtilis. The BAs in the fermentation broth of these strains were detected and analyzed by ultra performance liquid chromatography (UPLC). The results indicated that they produced different kinds of BAs. All strains had the ability to produce putrescine, cadaverine and tyramine, of which the content of tyramine was the highest, ranging from 0.45 to 87.31 mg/L. Among them, Enterococcus faecium S5 produced the largest amount of total BAs (106.34 mg/L) and tyramine (87.31 mg/L). Moreover, amine-producing characteristics of strain S5 were analyzed, indicating that the content of total BAs increased with the increase of temperature (15-35 ℃), but total BAs and tyramine production can be inhibited under given conditions (temperature＜15 ℃, or alcohol volumn fraction＞15%, or mass fraction of amine acids＜0.5%, or pH＞7.5, or mass fraction of NaCl＞6.0%). The present study provides reference for controlling the production of BAs during sufu post-fermentation process.

The higher tea saponin content has been a key factor limiting the comprehensive utilization of Camellia oleifera cake (COC), and the existing mainstream microbial fermentation method for degrading tea saponin has the disadvantages of long liquid fermentation cycle and high cost for large batch operations. It is expected to develop a new idea for large-scale production of solid-state fermented COC based on the Bacillus subtilis strain that effectively degrades tea saponin obtained in the early screening. This study used the degradation rate of tea saponin as the primary indicator to optimize the conditions of solid-state fermentation using single-factor and response surface experiments, and then to determine and analyze the nutrient composition of COC before and after fermentation. The results showed that the optimal fermentation conditions were determined as follows: initial water content 83.7%, fermentation temperature 36.3 ℃, inoculum amount 10.5%, and fermentation time 60.0 h. Under this condition, the degradation rate of tea saponin in COC reached 72.18%. Through the analysis of composition, it was found that fermentation made significant differences in the components of COC, including tea saponin, tannins and other anti-nutritional factors significantly reduced; crude protein, reducing sugars, essential amino acids and other nutrients significantly increased; the main active ingredients polyphenols, flavonoids content significantly increased, while polysaccharides, total sugars significantly reduced as they were consumed by the strain as a carbon source. This study provides some theoretical support for the comprehensive utilization of COC in China.

Hyperuricemia is a group of heterogeneous disease with tissue injury that is caused by long-term purine metabolism disorder and continuous high concentration of blood uric acid, it might also induce gout when getting serious. Probiotics have potential treatment function. The purpose of this study was to explore the potential of a novel Lactobacillus fermentum F40-4 in yogurt production. The results indicated that L. fermentum F40-4 had no suppression on growth of Streptococcus thermophilus and Lactobacillus bulgaricus, which were the main culture of yogurt starter. Compared with the control group, L. fermentum F40-4 had little influence on the pH, and acidity indexes during fermentation, the 1∶1 inoculation of L. fermentum F40-4 and starter culture could delay the pH drop process and reduce the whey precipitation during cold storage. The flavor analysis results showed that the yogurt added L. fermentum F40-4 had more abundant volatile flavor compounds, mainly containing esters, aldehydes, alcohols, ketones, acids, and hydrocarbons, among which esters and aldehydes had the highest content. This study suggested that L. fermentum F40-4 could be used as an auxiliary culture for yogurt production, which provided a theoretical basis for the further development of the probiotic yogurt with uric acid-lowering function.

The mixed cultures of Lactobacillus casei and Lactobacillus plantarum, L. casei and Lactobacillus rhamnosus, L. plantarum and L. rhamnosus were inoculated into jujube pulp for fermentation. The viable lactic acid bacteria count was measured during the fermentation of jujube pulp, and the changes in pH value, total titratable acid, total phenolics, total flavonoids, polysaccharides, ascorbic acid, organic acids, antioxidant capacity, and color were compared before and after fermentation. The results showed that the jujube pulp was rich in nutrients, and all the above mixture starters grew well in jujube pulp. After 24 h of fermentation, the viable counts exceeded 9.4 lg CFU/mL, while the color of jujube pulp fermented with the mixture of L. plantarum and L. rhamnosus was closer to that of the unfermented group. The mixed fermentation of L. plantarum and L. rhamnosus was also superior to the other two fermentation groups in terms of total phenolic, total flavonoid, polysaccharide contents, and antioxidant activities. In conclusion, the mixed fermentation of L. plantarum and L. rhamnosus should be suitable for jujube pulp.

To improve the processing and edible quality, whole wheat bread was prepared with whole wheat sourdough which was fermented by seven strains of lactic acid bacteria. The effects of different fermentation types of lactic acid bacteria on the baking quality, aging characteristics, and nutritional value of whole wheat bread were investigated. The results showed that compared with naturally fermented sourdough, the specific volume of whole wheat bread prepared with sourdough fermented with facultatively heterofermentative (FHe-type) Lactobacillus plantarum increased by 4.3%, while the baking loss, hardness, and aging rate decreased by 10.1%, 17.2% and 44.11%, respectively. At the same time, it also has positive effects on bacteriostasis and shelf-life extension. The total amino acid content increased by 5.51%, and protein chemical score was the highest. The antioxidant capacity was strong, increased by 70.69% compared to the control group. Therefore, the whole wheat sourdough which can be used as starter culture agent, fermented by FHe-type L. plantarum, can significantly improve the quality of whole wheat bread, and provide theoretical basis and production guidance for the subsequent industrial production of whole wheat bread.

Germination can improve the nutritional composition and reduce the content of anti-nutritional factors in black beans. In order to test the effects of chitooligosaccharides with different molecular weight and dosage on the quality of black bean sprouts, black beans were soaked in chitooligosaccharides with molecular weight of 1 500 Da and 3 000 Da in the concentration of 0.001, 0.01, 0.1 and 1 μg/mL, respectively. The production performance of black bean sprouts was measured, and the nutritional composition and antioxidant activity of black bean sprouts were determined by spectrophotometry and liquid chromatography. The results showed that chitooligosaccharides could stimulate the germination of black beans and increase the yield of black bean sprouts. The formation of soluble protein was enhanced after chitooligosaccharides treatments. Meanwhile, the content of phytic acid, which is an antinutrient factor, was reduced in black bean sprouts. In addition, the contents of vitamin C, total polyphenols, total flavonoids, as well as components of polyphenols and flavonoids were increased. As a result, the antioxidant capacity (DPPH, ·OH and H₂O₂ scavenging rates) of black bean sprouts was enhanced after chitooligosaccharides treatments. Among them, the chitooligosaccharides with molecular weight of 1 500 Da in 0.01 μg/mL had the best effect, and the quality of black bean sprouts obtained was the highest. This study provides theoretical support for the application of chitooligosaccharides as germination additives in the production of black bean sprouts.

Single factor test and response surface method were used to optimize the preparation of cinnamon essential oil liposomes, and the particle size, potential, micromorphology, thermal stability, infrared spectrum, in vitro release, antibacterial properties and composition were studied. Results showed that the optimal preparation conditions were that mass ratio of phospholipid to cholesterol was 4.09∶1 (phospholipid 10.23 mg/mL, cholesterol 2.5 mg/mL), cinnamon essential oil was 2.46 mg/mL, tween 80 was 2.99 mg/mL, and dosage of phosphate-buffered saline (PBS) was 40 mL (0.01 mol/L, pH 7.2). Under these conditions, the embedding efficiency of cinnamon essential oil liposomes was 81.95%. The particle size of the liposomes was 94.21 nm, the polydispersity index (PDI) was 0.133, and the zeta potential was -40.4 mV, which had nanometer size and good stability. Microstructural analysis showed that cinnamon essential oil liposomes were monolayer vesicles. Thermal stability analysis showed that the thermal stability of cinnamon essential oil liposomes was slightly decreased compared with blank liposomes. Infrared spectrum results showed that cinnamon essential oil formed hydrogen bonds with the non-polar head in liposomes. In addition, the cumulative release rate in 24 h was 79.23% in the in vitro release experiment, which confirmed that the product had slow-release properties. The results of the antibacterial performance analysis confirmed that cinnamon essential oil liposomes had long-term antibacterial effects on Escherichia coli and Staphylococcus aureus. In this study, cinnamon oil liposomes with stronger stability, higher embedding rate, and better sustained-release effect were obtained, which could provide technical support for the development and application of cinnamon essential oil in the field of functional food.

In this study, a new extraction method mediated by organic solvent and salt was developed to simultaneously extract phycocyanin and lipids from the unbroken Spirulina platensis. To obtain the maximum co-production extraction performance, the process parameters of the developed extraction method with n-hexane and calcium chloride were optimized. After optimization, the optimal conditions to extract phycocyanin and oil from unbroken Spirulina platensis using the n-hexane and calcium chloride-mediated method were that calcium chloride concentration was 3%, the volume ratio of n-hexane to suspension was 2:1, the ratio of algal biomass to liquid was 1:60 (g:mL), and extraction time was 3 h. Under the optimized conditions, the maximum extraction rates of phycocyanin and oil by the exploited extraction method were 71.06% and 26.19%, respectively. Based on these obtained results, the novel developed extraction method not only enables the co-production extraction of phycocyanin and lipids from Spirulina platensis but also has the function to separate the extracted phycocyanin and lipids, which provides important practical details to extract the desired bioactive substances from Spirulina platensis through Spirulina-derived deep processing.

In this study, the emulsion was prepared with the porcine skin protein powder (PSPP) as an emulsifier and soybean oil as the oil phase, and then the PSPP-based emulsion gel was formed by heat induction. The effects of PSPP concentration, heating time and times on emulsion stability, emulsion gel texture, and water-holding capacity were researched. Results showed that with the increase in PSPP concentration, after heat treatment, the precipitated water layer of the emulsion was gradually decreased and the emulsion structure remained more complete, resulting in a significant reduction in droplet size variation. Moreover, the apparent viscosity of the emulsion was increased. The analysis of texture and water-holding capacity indicated that the hardness, cohesion, and water-holding power of the emulsion gel were significantly enhanced with the increase in PSPP concentration. The laser confocal microscopy revealed that with the increase of PSPP concentration, the diameter of the emulsion gel was notably decreased, and the protein coverage at the oil-water interface was increased. Furthermore, when the concentration of PSPP was 30 g/L, the texture characteristics of the emulsion gel changed slightly with the increase in heat treatment time and times, which indicated that the PSPP-based emulsion gel could tolerate long-term and repeated heat treatment.

To solve the issue of slow penetration of salt in traditional meat curing methods, improve the curing technology, and ensure the quality of meat products, the research selected beef, which is commonly used as raw material for sauced and braised meat products in China as the research object and applied a novel non-thermal technology, pulsed electric field (PEF) for the pretreatment of beef. The effects of different pulse electric field intensities (1.00, 2.25, 3.50 kV/cm) and pulse numbers (50, 100, 150, 200, 250) on the curing effect and edible quality of beef were explored. Results showed that pulsed electric field pretreatment could effectively increase the curing absorption and sodium chloride content of beef, which revealed that PEF treatment could accelerate the curing process of beef. The sodium chloride content was the highest when the pulse number and pulse electric field intensity were 100 kV/cm and 2.25 kV/cm, respectively, which indicated that the promoting effect of curing was optimal. Besides, PEF pretreatment did not affect the L^*, a^*, b^*, pH, pressure loss, and springiness of cured beef within a range of electric field intensity and pulse number, revealing that PEF treatment had no adverse effect on the quality of cured beef. In addition, the hardness, adhesiveness, and chewiness of beef reduced when these two parameters were 100 kV/cm and 2.25 kV/cm or 3.50 kV/cm, respectively, and the pulsed electric field intensity of 2.25 kV/cm and pulse number of 150 were also acceptable, which revealed that PEF treatment significantly improved the texture of beef. In conclusion, for the processing industry of sauced and braised meat products, PEF technology is an excellent novel curing-assisted technology, which could provide some references for the development of sauced and braised meat products.

In this study, Litopenaeus vannamei was used as raw material and dried at different hot air-drying temperatures until the moisture content was about 20%. The content changes of trimethylamine (TMA), trimethylamine oxide (TMAO), dimethylamine (DMA), and formaldehyde (FA) were measured respectively. The changes in moisture content, total volatile base nitrogen (TVB-N), total reducing power value, pH value, TMA, TMAO, FA, and DMA during hot-air-drying of shrimp at 85 ℃ were further explored. At the same time, the reaction characteristics of TMAO decomposition in shrimp meat supernatant under different reaction time, temperature, and pH conditions to produce TMA were studied to verify the similarity of the formation rule and the whole of TMA in shrimp meat supernatant. With increasing hot-air-drying temperature, non-enzymatic thermal decomposition of TMAO in white shrimp was observed, leading to a significant increase in the levels of endogenous TMA, DMA, and FA. Moreover, with the increase in drying time, the moisture content of shrimp decreased, TVB-N value, total reducing power, and pH value increased, TMAO content showed a significant downward trend, and endogenous TMA, DMA, and FA content increased significantly in the later drying period. Endogenous TMA increased significantly from the initial 29.36 mg/kg to 565.11 mg/kg (P<0.01). The supernatant of shrimp meat contains substances that produce TMA, and the formation of TMA was consistent with the formation of TMA in dried shrimp during hot air drying. The higher the temperature and the longer the heating time, the more TMA was produced. The formation law of endogenous TMA in the hot-air-drying process of shrimp provides a theoretical basis for the processing and production of dried shrimp products, to provide a basic reference for controlling the content of TMA in dried shrimp.

Cod skin collagen peptide and three different configurations of carrageenan (κ-, ι-, and λ-) were used to make Maillard products prepared by dry heat method with different reaction time. The structure of the reaction products was characterized by infrared spectrum, browning degree, grafting degree, fluorescence intensity, and surface hydrophobicity. Maillard products were added to Spanish mackerel surimi, and the influence mechanism of carrageenan configuration on it and the optimal ratio to improve the quality of surimi products was analyzed. Results showed that with the increase of incubation time, the grafting rate and browning degree of the three Maillard products gradually increased, the fluorescence intensity reached the maximum after the reaction 4 days, and the surface hydrophobicity decreased with the extension of time. All the Maillard products added to Spanish mackerel surimi could improve the gel strength and hardness of the surimi. Among them, the surimi which added κ-carrageenan Maillard product with a reaction time of 6 days got the highest gel strength (1 825.48 g·mm) and hardness (31.31 N). Hence, the peptides modified by Maillard reaction with carrageenan could enhance the gel strength and the hardness of surimi, and κ-carrageenan Maillard product with 6 days reaction time made the gel strength and hardness of surimi maximized.

This study aimed to compare the different drying processes of kiwifruit powder and provide a basis for the improvement of processing technology and development of kiwifruit. The effects of hot air drying (HAD), vacuum drying (VD), and vacuum freeze-drying (FD) methods on the quality of kiwifruit powder were assessed. Principal component analysis (PCA) was used to evaluate the quality of the different kiwifruit powders. Results showed that FD kiwifruit powder had bright green color and better hydration ability and oil absorption, due to the porous and uneven surface. But FD kiwifruit powder was easy to be agglomerated because of the poor fluidity. In addition, FD kiwifruit powder had the lowest moisture and highest ascorbic acid content (111.50 mg/100 g). HAD kiwifruit powder was considered to have a coke yellow color, while it had the largest packing density (the lowest packaging cost) because of the smallest gap between particles. The VD kiwifruit powder had a smooth surface, which caused the worst hydration ability and oil absorption. According to the results of PCA models, FD kiwifruit powder had the highest comprehensive principal component score and the best quality. In conclusion, the quality of kiwifruit powder obtained by different drying processes had its own characteristics. Comprehensively, the freeze-drying kiwifruit powder had the best quality.

At present, apricot juice production and processing are often pretreated by crushing, enzymatic liquefaction, hot scalding, etc., which has some adverse effects on the color and flavor of apricot juice. During the alternating freezing and thawing process of apricot fruit, the mechanical effects caused by ice crystal growth and recrystallization damage the cell wall, cell membrane, and other structures, it increased the dissolution of intracellular juices. The physicochemical indexes of apricot fruit and two kinds of apricot juice treated by different processes were studied and their volatile substances were analyzed and identified. Results showed that the contents of total sugar, soluble solid, soluble pectin, and soluble protein in apricot juice pressed at low temperature were higher than those in apricot fruit and pectinase juice, and the contents of clarification, L^* value, and browning index in apricot juice pressed at low temperature were better than those in apricot juice cured by pectinase. A total of 118 volatile substances were detected in apricot fruit, low-temperature pressed apricot juice, and pectinase juice, among which 56 volatile substances were detected in apricot fruit with a content of 28.60 mg/mL, while 72 volatile substances were detected in low-temperature pressed apricot juice and 63 volatile substances were detected in apricot juice with the content of 79.11 mg/mL and 62.93 mg/mL, respectively. The physicochemical indexes and volatile substance contents of apricot juice pressed at low temperature were better than those of apricot fruit and pectinase.

To study the quality change of Gracilariopsis lemaneiformis with different moisture contents (12%, 25%, 35%, 45%, 55%) and storage temperatures (10, 20, 30, 40, 50 ℃). In this experiment, the changes in the agar extraction yield, gel strength, algal reducing sugar content, agarase activity, and colonies number of G. lemaneiformis were studied. Results showed that within 7 days of storage, the extraction yield and gel strength of G. lemaneiformis agar decreased with the increase of moisture content, storage temperature and storage time. Under the condition of low moisture content and low temperature storage, the G. lemaneiformis could maintain good processing quality, the growth and reproduction of microorganisms were relatively slow, the reducing sugar content in algae was less, the agarase activity was lower, the agar extraction yield was higher, and the gel strength was also more stable. This study provides data support and theoretical guidance for rational drying and storage of G. lemaneiformis and guaranteeing the quality of agar, which is of great significance for the high-value utilization of G. lemaneiformis and even promoting the development of the agar industry.

This paper aimed to explore the changes in instant solubility and physicochemical properties of Euryale ferox powder after extrusion. High-quality Euryale ferox was treated by a twin-screw extruder, and its structure was characterized by an optical microscope, scanning electron microscope, colorimeter, rheometer, Fourier transform infrared spectrometer, differential scanning calorimeter, and other precision instruments. Through the research and analysis of the quick solubility and the content changes of main components, the internal correlation between the structural properties of Euryale ferox powder after extrusion and the changes in its internal composition was discussed. Results showed that the instant solubility of Euryale ferox after extrusion was improved, the caking rate decreased from 11.40% to 6.61%, and the solubility, water solubility index, and water absorption index increased from 1.81%, 0.47%, 218.99%, and 33.87% to 53.05%, 53.95%, 224.16%, and 91.30%. The results of powder characteristics showed that the scattering property and friction property of gorgon fruit increased after extrusion treatment, and the angle of repose and sliding angle decreased from 41.6 and 44 to 35 and 35.5. The bulk density and tap density increased from 0.44 g/mL and 0.55 g/mL to 0.51 g/mL and 0.65 g/mL. Results showed that, on the one hand, the crystal structure of Euryale ferox was destroyed by extrusion, the crystallinity and gelatinization enthalpy of the powder decreased, and the hydrophilic ability increased. On the other hand, the extruded Euryale ferox paste was a “non-Newtonian fluid”, and its dynamic viscoelasticity, shear viscosity, and fluidity were enhanced. Extrusion increased the reducing sugar content of Euryale ferox powder but decreased the starch and amylopectin content.

This study aimed to establish a method for qualitative identification of adulterated camellia seed oil by gas chromatography-mass spectrometry (GC-MS) combined with gas chromatography (GC). A GC-MS method was established for the rapid detection of the content of β-amyrin in vegetable oil, to realize the batch initial screening of vegetable oil samples. On this basis, the results were confirmed by combining with GC determination of fatty acid content. Results showed that the determination of β-amyrin was rapid, the detection period was short, and the linear relationship was good. The average recoveries at low, medium, and high levels were 82.6%-111.5%, and the relative standard deviations (RSD) were all lower than 5.36%. The method could be used for batch screening of vegetable oil samples. In addition, combined with GC determination of fatty acid content to confirm the results, oleic acid and linoleic acid could be used as the identification index of camellia seed oil adulteration. The method is suitable for the qualitative identification of camellia seed oil mixed with one or several other vegetable oils (peanut oil, corn oil, rapeseed oil, and soybean oil), and the adulteration detection limit is 10%.

To explore the dynamic changes and content differences of flavonoids, phenolic acids, limonoids, alkaloids, and coumarins during the development of kumquat fruit, the content changes and differences of five bioactive components in the whole fruit of 8 kumquat varieties at different growth stages were analyzed by ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry. Results showed that from September to December, 85 bioactive components were detected in 8 varieties of kumquat fruits, including 48 flavonoids (mainly flavonoids and polymethoxyflavones), 9 phenolic acids (mainly chlorogenic acid and erucic acid), 3 limonin (mainly limonin), 5 biogenic bases (mainly N-methyl tyramine and tyramine), and 20 coumarins (mainly artemisinin). With the fruit expansion, the total contents of flavonoids, limonoids, and alkaloids in kumquat fruit decreased sharply with the increase of maturity 35-125 days after anthesis and tended to be flat about 95 days after anthesis. The contents of phenolic acid and coumarin in kumquat fruits varied significantly during development. Among the eight kumquat varieties, the content of total flavonoids in kumquat hybrids was the highest, but the content of kumquat glycosides was very small. The content of total flavonoids in the other seven kumquat varieties was mainly kumquat glycosides, accounting for 26.08%-79.08% of the total flavonoids. In this study, the detection method of kumquat glycosides was established, and the results confirmed the differences in bioactive components in kumquat fruit at different growth stages, which provided data support for the comprehensive utilization of kumquat fruit resources and the development of health products.

Three organic varieties of blueberry wine cultivated in Majiang County, Guizhou Province, were selected to analyze the flavor characteristics using headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and gas chromatography-ion mobility spectrometry (HS-GC-IMS). Seventeen esters, seven alcohols, four acids, three ketones, one terpene, and three heterocyclic compounds were identified by GC-MS. In three blueberry wine samples, the results of odor activity value analysis showed that the content of ethyl acetate, ethyl caprylate, ethyl caproate, and ethyl 3-methylbutyrate were higher. GC-IMS was used to analyze 35 flavor compounds, of which 15 flavor compounds were also identified by HS-SPME-GC-MS. Remarkable differences were found in the fingerprint spectrum of the flavor compounds among the three samples. Principal component analysis effectively recognized each sample. The synergistic analysis using two methodologies could obtain more comprehensive information about the flavor characteristics of blueberry wine. The research results provide the basis for improving the flavor characteristics of blueberry wine.

A method was established for 23 veterinary drugs residues in pork by direct analysis in real-time mass spectrometry. At the same time, the methodological evaluation of matrix effect, detection limit, and precision. The pork was ground, extracted with acetonitrile, and then purified. Real-time fast direct analysis was performed using direct analysis in real-time (DART) in situ ionization source combined with triple quadrupole mass spectrometry (DART-QQQ) for detection, multiple reaction monitoring (MRM) mode detection, and an external standard method for quantification. Results showed that the matrix effect in DART of the molecular structure of veterinary drugs included two aspects, which were competitive adsorption and competitive ionization. The competitive adsorption effect of quinolones and the competitive ionization effect of sulfonamides and nitroimidazole were dominant. The detection limits of 23 veterinary drug residues in the three pretreatment methods were all 10 μg/L. The relative standard deviation (RSD) of the overall precision of the method was 36.25%-112.36%. In the detection of quinolones in meat by real-time rapid and direct analysis, the RSD of extracts from the purification column were significantly lower than those of other substrates. Therefore, better precision could be obtained by using a purification column for the detection of quinolones in meat. For sulfonamides and nitroimidazoles, increasing the purification degree has no obvious improvement in the precision. The method is accurate and sensitive, and is suitable for the simultaneous and rapid screening of 23 unqualified veterinary drugs in pork.

In recent years, food safety problems caused by the contamination of pork products with Listeria monocytogenes have occurred frequently, which poses a serious threat to public health. The virulence of L. monocytogenes in pork products should be controlled to curb the occurrence of social public health problem. First, this paper summarizes the pollution status of L. monocytogenes in pork in recent years. Then, the pathogenicity of L. monocytogenes is reviewed subsequently, and analyzed the feasibility of controlling the pathogenicity of L. monocytogenes by intervened the growth, resistance and virulence of L. monocytogenes. Finally, hurdle technology is proposed to inhibit L. monocytogenes from different aspects and to enhance the microbiological safety of pork.

The fermentation process of high-salt liquid soy sauce is accompanied by complex microbial activities. The proliferation and metabolism of various microorganisms in the multi-species fermentation system form the unique sensory flavor of soy sauce. Yeast plays an important role in the formation of soy sauce flavor during the long fermentation cycle which is one of the important microorganisms driving soy sauce fermentation. In this review, we summarize the characteristic flavor compounds of soy sauce reported in recent years, and focus on the main types of salt-tolerant yeast species in sauce mash which has ability to enhance the flavor of soy sauce. Additionally, we discuss the process of soy sauce fermentation by intervening the yeast community to improve the product quality, and prospect the future for the industrialization development of the fermentation of traditional seasoning.

Yeast polysaccharides are vital macromolecules in wine, originating from the release of yeast during the fermentation and autolysis during the aging with lees. A growing number of researchers and winemakers are focusing on its effects on wine quality. The molecular structure of yeast polysaccharides is complex. Therefore, it is essential to improve the wine quality by investigating the mechanism of their interaction with the wine matrices. In this paper, we systematically review the effects of yeast polysaccharides on wine taste, color, aroma and stability. At the same time, we have described the changes of wine quality after the addition of exogenous yeast polysaccharides, especially its effects on the astringency of wine. Finally, it also provided an outlook on future research priorities, in order to provide a reference for improving wine quality.

Renewable energy and environmental issues are attracting global attention due to the crisis of energy shortage and food waste. Anaerobic digestion is an energy saving biotechnology that combines sustainable waste disposal and renewable energy production. Kitchen waste can be converted into clean energy such as methane and hydrogen through anaerobic digestion. In recent years, considerable progress has been made in the anaerobic digestion of kitchen waste, but there are still some difficulties such as low marsh rate and long digestion time. Firstly, the status quo of anaerobic digestion of kitchen waste is summarized, through the analysis of existing problems in domestic and foreign studies, the multi-means optimization of anaerobic digestion process of kitchen waste to improve the methane production rate is comprehensively described. Thus, theoretical basis is provided for improving the utilization rate of anaerobic digestion and biogas rate of kitchen waste in the future.

Fermented fruits and vegetables use lactic acid bacteria or yeasts as the starter. During fermentation, microorganisms trigger complex bioconversion which improve the flavor of fruits and vegetables and release the multiple metabolic compounds with healthy benefits. Previous studies suggested that fermented fruits and vegetables could provide many positive impacts, such as regulating intestinal health, immunoregulation, hepatoprotective, anti-oxidant, anti-diabetic, anti-cholesterol, and anti-obesity. This review elaborates the nutritional components variation of different fruits and vegetables during fermentation, clarifies the benefits and mechanisms of fermented fruits and vegetables, and discusses several existing problems and development prospects. This article may contribute to a deeper understanding of fermented fruits and vegetables products, hoping to provide valuable references for the research and industrialization development of fruits and vegetables fermentation.

The stimulus-responsive hydrogel active components delivery system has been widely used in food, medicine, and other fields because of its unique swelling and degradation characteristics in different environments. However, some hydrogels have some problems such as low active components loading rate and low targeting release efficiency when they are used as active components delivery carriers. Based on the characteristics of high surface area and porous structure, metal nanoparticles can enhance the active component loading capacity of stimulus-responsive hydrogels. The composites prepared by the hybrid of metal nanoparticles and stimulus-responsive hydrogels have been widely studied in the field of environmentally responsive active components delivery and controlled release. This paper mainly reviewed the characteristics, types, and preparation methods of metal nanoparticles-stimulus-responsive hydrogel composites, summarized their applications in the field of active components delivery, and prospected their future development as the delivery system.

With the changes in people’s lifestyles and dietary structures, the prevalence of metabolic diseases such as fatty liver, diabetes, and obesity has increased significantly, seriously endangering the physical and mental health of residents. Research on healthy, universal, and scientific dietary patterns has become a key topic of concern in the current society. Time-restricted eating (TRE) is a dietary pattern that restricts the daily eating time, usually limiting the daily eating time to 4-12 h to extend the time in the fasting state. This pattern is widely praised for its benefits in weight loss, glucose tolerance improvement, and metabolic disorder regulation. Therefore, this paper searched and sorted the relevant literature from the official websites of China National Knowledge Infrastructure (CNKI), PubMed, Web of Science, the World Health Organization, and other relevant databases, analyzed the clinical evidence and potential mechanism of TRE in promoting metabolic health, and put forward prospects, to provide a certain reference for the application of TRE in the prevention and treatment of metabolic diseases.

Maturity, as a key factor to measure fruit quality, is closely related to fruit picking, packaging, storage, transportation, and other operations, and is also one of the decisive factors for its yield and quality. The existing artificial experience analysis method and physical and chemical experimental methods are too subjective, have low detection efficiency, cumbersome operation, and other shortcomings, which are difficult to achieve the requirements of nondestructive testing of fruit maturity in large quantities. Nondestructive testing technology has been widely studied and explored in the field of fruit maturity detection with its advantages of being fast and efficient. In this paper, the latest research progress on the basic characteristics of electricity and acoustics, intelligent sensory bionic technology such as the electronic nose and machine vision, near-infrared spectroscopy and hyperspectral imaging technology in fruit maturity detection at home and abroad in recent years were reviewed. The existing problems and future development prospects of various technologies were analyzed and prospected to provide a reference for agricultural product planting and automatic picking in China.

Blended teaching is an important direction of teaching mode reform in colleges and universities in the future. Food Toxicology is the core course of food quality and safety major, and also an important carrier for implementing the ideological and political teaching of the specialty course. The course team has constructed a five-stage advanced blended teaching mode. The practice showed that through teaching activities, students’ subjectivity and autonomy in learning had been fully developed, students’ collaborative learning and autonomous learning abilities have been developed, students’ vision has been expanded, and a new learning community of teachers and students has been constructed. The organic integration of curriculum ideological and political education and online and offline blended teaching is of great significance to improve the cultivation of college students’ professional knowledge and professional confidence.