Abstract:To investigate the impact of dietary arsenic exposure on hepatic lipid metabolism and its underlying molecular mechanisms, C57BL/6 mice were chronically fed arsenic-containing chow, and an arsenic-exposed HepG2 cell model was used. Mouse liver structure was examined with transmission electron microscopy, and lipid metabolism indicators in HepG2 cells were analyzed through immunoblotting and assay kits. Results showed a significant reduction in both the number and size of lipid droplets in the livers of the arsenic-exposed group. In vitro experiments revealed decreased expression of Sterol Regulatory Element Binding Protein-1c (SREBP-1c) and Fatty Acid Synthesis (FASN) proteins in HepG2 cells exposed to arsenic concentrations ranging from 10 to 40 μmol/L (SREBP-1c: 0.73, 0.60, 0.54, 0.40; FASN: 0.88, 0.77, 0.75, 0.82). Levels of triglycerides (TG) and total cholesterol (TC) also declined (TG: 0.94, 0.78, 0.78, 0.73; TC: 0.95, 0.73, 0.70, 0.57), indicating arsenic-induced lipid metabolism disruption. Additionally, phosphorylated Extracellular Signal-Regulated Kinase (ERK) expression increased significantly following arsenic exposure (5.72, 23.78, 33.20, 47.17), suggesting ERK pathway activation. Pre-treatment with PD98059, an ERK activation inhibitor, led to increased SREBP-1c and FASN expression in arsenicexposed HepG2 cells (SREBP-1c: 1.2; FASN: 1.3), as well as elevated TG and TC levels (TG: 1.2; TC: 1.2). These findings provide a theoretical basis for the role of ERK signaling in arsenic-induced lipid metabolism disorders in HepG2 cells.

Abstract:The mechanism of action of deoxynivalenol (DON) on oxidative stress in human renal tubular epithelial cells (Human Kidney-2, HK2) was explored in this article. DON cytotoxicity was assessed using the MTT assay, and the expression levels of apoptosis-regulating proteins-including Bax, Bcl-2, Caspase-2, Caspase-3, Caspase-6, Caspase-8, and Caspase-9-was measured by Western blotting. Transcriptome sequencing (RNA-seq) analyzed the genome-wide expression profile of HK2 cells following 24-hour DON exposure. DON exposure elevated LDH, MDA, and ROS levels in HK2 cells, while reducing antioxidant indicators such as SOD and GSH and increasing inflammatory markers IL-6, IL-1β, and TNF-α. Bax and caspase protein expressions were upregulated, while Bcl-2 protein expression was downregulated. Transcriptome analysis identified 5 962 differentially expressed genes after exposure to 40 μmol/L DON, with 2 813 upregulated and 3 149 downregulated. Protein levels aligned with gene expression profiles. DON induces oxidative stress and nephrotoxicity in HK2 cells, affecting renal function and metabolism through signaling pathways, including Caspase, MAPK, and PI3K-Akt. These findings offer a theoretical basis for the regulation of DON-induced nephrotoxicity.

Abstract:Sports nutrition emphasizes not only the diversity of nutrients, but also their timing intake. Protein supplements are important sources for the requirements of sports nutrition. Currently, the leading products on the market are mainly protein powders, although some liquid beverages are available. However, no previous studies have reported their gastrointestinal digestive behavior and protein hydrolysis profiles. In this paper, five commercially available high-protein sport supplements and three high-protein foods were selected based on protein type and formulations. Their gastrointestinal digestive behavior and protein hydrolysis were evaluated using an in vitro digestion model. The results showed that the water dispersion of powder products had large particle size and were apt to form sediments. All products were sensitive to pH, but they showed different buffering capacity against pH reduction during the in vitro gastric digestion. Products with higher casein content showed a slower pH reduction. All samples tended to form aggregates in the simulating stomach environment. During gastric digestion, the viscoelasticity of the liquid products increased rapidly and decreased or reached a plateau, while the rheological properties of powder products remained constant. One of the liquid products had the highest protein hydrolysis degree (approximately 29%) after 30 min of mimicked gastric digestion, which was 1.5, 1.4, and 1.4 times higher than that of the selected powder products. At the end of gastrointestinal digestion, the protein hydrolysis of each product was in the range of 60%~80%. The hydrolysis degree of proteins in these sports supplements was higher than that in chicken and beef. In conclusion, protein types and product formulations affect the hydrolysis of high-protein sport supplements. The application of liquid formulation and concentrated milk protein might be more favorable for protein absorption than powders. The results in this study may provide data support for the precise design and development of high-protein sport supplements.

Abstract:A stable and reliable method for the rapid analysis of the chemical components of the new resource food of Inula nervosa Wall. was established. The digestion-promoting functions were compared across diverse solvents (water and oil) for I. nervosa. The chemical components of the new resource food I. nervosa were analyzed using UPLC-Q-TOF-MS/MS. According to the principles of functional food, the distance of ink movement in the small intestine, GAS, and MTL in mice, body weight, food intake, food efficiency ratio, secretion amount of pepsin, and pepsin activity were evaluated. The results revealed 18 relevant compounds. The small intestine motility of mice in the high-dose water extract group, low, medium, and high-dose volatile oil groups increased by 58.61%, 49.27%, 61.88%, and 83.78% (P<0.05, P<0.05, P<0.01, P<0.000 1), respectively. These results notably led to an increase in the secretion of GAS and MTL (P<0.05). Food intake in the low, medium, and high-dose water extract groups increased by 6.05%, 6.99%, and 8.91% (P<0.05, P<0.01, P<0.000 1) and in medium and high-dose volatile oil groups by 6.72% and 8.74% (P<0.01, P<0.001), respectively. All extraction methods greatly enhanced pepsin activity (P<0.01). However, there was a notable difference between high-dose volatile oil and highdose water extract (P<0.01). Pepsin secretions significantly increased in both groups (P<0.05); water extract and volatile oil exhibited digestion-enhancing effects, with volatile oil exhibiting superior effects compared to the water extract.

Abstract:Different deer skin gelatin samples of amino acid compositions were investigated and its drug-food homologous prescription was used to study immunomodulatory effects on immune-suppressed mice. Amino acid composition was comprehensively analyzed using an amino acid analyzer. Various parameters, including body weight, immune organ indices, immune factor levels, delayed-type hypersensitivity, serum hemolysin, carbon clearance assay, peritoneal macrophage phagocytosis of chicken red blood cells, and jejunal histopathological changes, were observed in different mouse groups. The results revealed that deer skin gelatin contains 17 amino acids, with a total content ranging from 68.47 to 69.82 g/100 g. Glycine had the highest content (17~18 g/100 g), while cysteine had the lowest (0.15~0.3 g/100 g), with sample 3 scoring the highest. Different doses of deer skin gelatin (0.7, 1.4, and 2.8 g/kg) in traditional medicine formulations significantly increased the thymus index (2.36, 2.47, and 2.51 mg/g), spleen index (5.43, 5.84, and 5.94 mg/g), carbon particle clearance (5.22, 5.30, and 5.66), serum hemolysin levels (47.87, 50.6, and 53.4), macrophage phagocytosis index (0.34, 0.35, and 0.36), phagocytosis rate (43.20%, 44.57%, and 44.87%), and immunological factors IgA (133.40,134.34, and 146.81 pg/mL), IgG (121.83,129.83, and 133.58 pg/mL), IgM (200.44, 204.58, and 214.4 pg/mL), IFN-γ (109.55, 110, and 113.75 pg/mL), TNF-α (173.80,176.79, 179.14 pg/mL), and IL-4 (164.26, 172.04, and 208.85 pg/mL). Meanwhile, ear swelling degree significantly decreased (5.91, 5.46, and 5.55 mg), and ileal mucosal barrier damage was improved. In conclusion, deer skin gelatin possesses rich amino acid content, and its traditional medicine formulations exhibit immunomodulatory effects, which provides new ideas for the development of healthy food.

Abstract:The anti-inflammatory effects and mechanisms of the mycelial polysaccharide ISP-80 from the Isaria cicada Miquel C1 was investigated in a mouse monocyte-macrophage RAW264.7 inflammation model, induced by lipopolysaccharide (LPS). The polysaccharide (ISP-80) was obtained through hot water extraction from the Isaria cidada C1 mycelium. The toxic effects of ISP-80 on RAW264.7 cells were evaluated using the CCK-8 assay, and the impact of ISP-80 on the secretion of TNF-α, IL-1β, and IL-6 cytokines was measured using ELISA. Furthermore, the mechanism of ISP-80 was analyzed using western blotting to detect the relevant proteins in the MAPK/NF-κB pathways. The findings indicated that the extraction rate of ISP-80 was 10.42% and it was composed of three polysaccharide fractions, each containing Glc, Man, and Gal monosaccharides, in a molar ratio of 1.00:5.03:1.55. Adding ISP-80 at 0.01~1.00 mg/mL exerted no cytotoxic effects and promoted cell proliferation (P<0.000 1). The 0.25 mg/mL ISP-80 treatment significantly decreased the secretion of pro-inflammatory cytokines IL-1β (P<0.001) and IL-6 (P<0.05), reaching 0.59- and 0.88-times those of the LPS group, respectively, and inhibited cell differentiation while restoring cell morphology. The anti-inflammatory action of ISP-80 acted via the MAPK/NF-κB pathways. ISP-80 inhibited the MAPK pathway by blocking p-p38 and p-JNK, which decreased by 0.20 and 0.41, respectively (P<0.001). Furthermore, the NF-κB pathway was inhibited by blocking IκBα and p65, which decreased by 0.43 (P<0.01) and 0.24 (P<0.001), respectively. These results indicate that ISP-80 can be a natural and safe antiinflammatory agent for the prevention and treatment of inflammatory diseases.

Abstract:The inhibitory effect of erianin extracted from Dendrobium officinale on the growth of human esophageal cancer KYSE-150 cells was investigated. The CCK-8 kit, microscope, scratch test, and flow cytometry were used to determine the inhibitory effect, morphological changes, cell migration, cell apoptosis, and cycle arrest of erianin on the activity of KYSE-150 cells. Western blot analysis was used to detect the expression levels of Bax, Bcl-2, Vimentin, Akt, P-Akt, PI3K, P-PI3K, N-cadherin, and E-cadherin proteins. The results of cell experiments showed that the IC50 of erianin for inhibiting the growth of KYSE-150 cells at 24, 48, and 72 h was 357.30, 120.20, and 57.43 nmol/L, respectively. The cells exhibited reduced migration capability and demonstrated shrinkage and aggregation during growth. After treatment with 40, 80, and 120 nmol/L for 24 h, the percentage of apoptosis was found to be 27.57%, 35.38%, and 61.97%, respectively, compared with the control group. The proportion of cells in the G1 phase in the treatment group significantly decreased from 56.64 % to 2.80%, whereas the proportion of cells in the G2 phase significantly increased from 16.82% to 86.98%. The western blot results showed that the expression of Bax and E-cadherin increased, whereas the expression of Bcl-2, Vimentin, P-Akt, PI3K, P-PI3K, and N-cadherin decreased, indicating that erianin has the potential to induce apoptosis and inhibit cell migration. In summary, erianin from D. officinale has the capability to inhibit cell migration through the inhibition of the EMT pathway and KYSE-150 cell proliferation and induce apoptosis via regulation of the PI3K/Akt signaling pathway.

Abstract:Using commercial calf rennet as the control, fresh cheese was processed with milk-clotting enzyme from germinated moringa seed. The sensory attributes, nutritient components, functional properties (stretchability, melting, oil precipitation), total color difference, free fatty acids and other indicators were compared and analyzed. The results showed that there was no significant difference in sensory attributes, yield, protein content and total color difference ΔE value between the two processed cheeses (P>0.05). The fat content of the cheese processed with milk-clotting enzyme from germinated moringa seed was 17.71%, which was significantly lower than that of processed cheese with calf rennet (P<0.05). The meltability and tensile length of the processed cheese obtained with milk-clotting enzyme from germinated moringa seed were 14.50 mm and 30.40 cm, respectively, which were significantly better than those of calf rennet processed cheese (P<0.05). There was no significant difference in the total content of free fatty acids between the two types of processed cheese (P>0.05). The mass fraction of linoleic acid in the processed cheese prepared with milk-clotting enzyme from germinated moringa seed was 1.68%, which was significantly higher than that of the processed cheese prepared with calf rennet. This study showed that the milk-clotting enzyme from germinated moringa seed can replace calf rennet to a certain extent in the processing of fresh cheese, which provides an important reference value for the application of milk-clotting enzyme from germinated moringa seed in cheese processing.

Abstract:We investigated the effects of different environmental factors, namely, culture time and temperature, pH, and NaCl concentration, on autoinducer (AI-2) activity and biofilm formation of the foodborne pathogen Listeria monocytogenes. The results revealed that during the logarithmic growth period, the AI-2 activity of L. monocytogenes was initially enhanced with an increase in cell density, although on reaching the stable growth period, the activity showed a subsequent declining trend. The highest values for growth, biofilm biomass, and AI-2 activity were recorded when L. monocytogenes was cultured in polystyrene culture plates at 37 ℃ for 24 h, which were 7.65-, 11.14-, and 4.40-fold higher than the values obtained at 4 ℃, respectively. Listeria monocytogenes showed similar growth performance in response to the addition of 0.5-9.0 wt.% NaCl, with AI-2 activity peaking at a NaCl mass fraction of 3.0% and a relative fluorescence intensity of 6.159. The lowest values of biofilm biomass and AI-2 activity were recorded at an NaCl mass fraction of 9.0%. Moreover, at pH value 5 and pH value 9, AI-2 activities were 0.11- and 0.13-fold compared to the control group (pH value 7.4), respectively, indicating a significant inhibition of activity at both low and high pH values. Collectively, these findings indicate that AI-2 activity and biofilm formation of L. monocytogenes are influenced by environmental factors. These findings will provide a reference for further research on the regulation of biofilm formation by the LuxS/AI-2 quorum sensing system and its quenching.

Abstract:In this study, it’s the effect of Cycle (Leu-Pro) on the growth of Lactobacillus plantarum was investigated. Lactobacillus Plantarum T1 was used as the research object, and high-performance liquid chromatography (HPLC) was used to preliminarily characterize and quantify the Cyclo (Leu-Pro) in the fermentation broth of Lactobacillus Plantarum T1. Lactobacillus Plantarum T1 was respectively inoculated in the MRS broth medium without or with different mass concentrations (0.5, 1, 5, 10 μg/mL) of Cyclo (Leu-Pro) for 18 h. The growth curves and viable bacterial counts of Lactobacillus plantarum T1 under different culture conditions were determined by the 96-well method and plate counting method. The results showed that Cyclo (Leu-Pro) at different mass concentrations had significant growth-promoting effects on the growth of Lactobacillus plantarum T1, among which, 1 μg /mL Cyclo (Leu-Pro) had the greatest growth-promoting effect and could increase the viable counts to 8.73×1010 CFU/mL, which was an order of magnitude higher than the control. Under different stress conditions, 1 μg/mL Cyclo (Leu-Pro) could shorten the lag period and increase the growth rate of Lactobacillus plantarum T1, and its viable count and biomass increased significantly (P<0.05). In summary, Cyclo (Leu-Pro) promoted the growth of Lactobacillus plantarum T1 and enhanced its stress resistance. This will favor the application of Lactobacillus plantarum T1 as a starter in the field of food fermentation.

Abstract:In order to study the composition of caproic acid-producing bacterial community in Medium/high-temperature Daqu, four different medium/high-temperature Daqu in Sichuan were used as the research objects. After the enrichment with the enrichment medium, the metagenomic DNA of Daqu and Daqu enrichment liquid samples were subjected to high-throughput sequencing with 16S rRNA gene amplicons, and the composition of caproic acid-producing bacterial community in Daqu was analyzed. The results showed that the diversity and abundance of the potential caproic acid-producing bacterial community in Daqu increased after the enrichment. The potential dominant caproic acid-producing bacteria (relative abundance >1%) in Daqu included Clostridium_sensu_stricto_18 (2.19%~69.00%), Clostridium_sensu_stricto_15 (1.76%~7.65%) and a small amount of Clostridium_sensu_stricto_12, Clostridium_sensu_stricto_1, Clostridium_sensu_stricto_10, Clostridium_sensu_stricto_7 and Caproiciproducens. Among them, in terms of the main potential caproic acid-producing bacterial community, Q1 Daqu was dominant with Clostridium_sensu_stricto_18, and Clostridium_sensu_stricto_15; Q2 Daqu was dominant with Clostridium_sensu_stricto_1, Caproiciproducens, and Clostridium_sensu_stricto_18; Q3 Daqu was dominant with Clostridium_sensu_stricto_18, and Caproiciproducens; Q4 Daqu was dominant with Clostridium_sensu_stricto_18, and Clostridium_sensu_stricto_1. The results showed that there were differences in the composition of caproic acid-producing bacterial communities in different medium/high-temperature Daqu in Sichuan. The preliminary analysis was carried out to provide a theoretical basis for the directional study of caproic acid-producing bacteria in Daqu, and also provide a direction for the preparation of high-quality Daqu to promote the quality improvement of Nongxiangxing liquor.

Abstract:Distiller' grains are one of the by-products of the winemaking process, and rich in a variety of natural active substances. In this research, the ACE inhibition rate of the crude extract obtained by water extraction from the rice distiller's grains was 42.93%, which was 21.25% lower than that (64.52%) of the commercially available antihypertensive peptide (measured at the same time). Subsequently, the crude extracted was treated with the ethanol (90% volume fraction). Then, the resulting supernatant was filtered by ceramic membrane and nanofiltration membrane, then extracted with petroleum ether. The extracted samples were separated by 3, 0.2 μm and 5 000 u ultrafiltration membranes. The ACE inhibition rate of the 5 000 u permeate was 46.00%, which was higher than that (39.57%) of the commercially available antihypertensive peptide (difference: 6.43%). Finally, LTQ Orbitrap Velos Pro was used, with the aid of Compound Discovery software, to analyze the possible bioactive peptides. Eleven active short peptides were identified, including Val-Val-Val, Ile-Ser-Val, Val-Pro-Leu, Leu-Ser-Glu, Ph-Tyr, and Val-Arg. These peptides contained hydrophobic or aromatic amino acids that have been shown to be involved in ACE inhibition mechanism, such as Val, Phe and Tyr. The experimental results showed that the above separation methods could improve the ACE inhibition effect of the polypeptide mixture. The separation of polypeptide mixtures with high ACE inhibition activities from distiller' grains provides a theoretical basis for the processing and utilization of distiller's grains.

Abstract:Sheep placenta was used as the raw material to extract proteins and peptides. The protein content and MTT tumor inhibitory activity were used as the evaluation indexes to screen the extraction and fractions of sheep placenta with anti-tumor activity. The results showed that the stirred extraction method mixed phosphate buffer solution could be used to prepare sheep placenta extracts with inhibitory activity against a colon cancer cell lines. The specific conditions were as follows: mixed phosphate buffer solution (containing 0.15 mol/L NaCl solution, 50 mmol/L conventional PBS solution, and 0.5~1 mmol/L phenylmethylsulfonyl fluoride) at pH value 7.4, extraction temperature of 4~10 ℃, and extraction for 2 h. The total extract yield and the protein content were 37.91 and 55.62%, respectively. The results of antitumor activity showed that the inhibition rate was 56.88 and 53.07% in HT-29 and HCT-116 cells, respectively, when the concentration of the extract was 2 mg/mL. The total extract was isolated and purified using a Sephadex-G-25 gel column chromatography to obtain F2 and F3 fractions with good inhibitory activity against HT-29 and HCT-116 cells; the IC50 of F2 was 0.328 and 0.183 mg/mL, respectively, and the IC50 of F3 was 0.213 and 0.095 mg/mL, respectively. In conclusion, the active fractions obtained from the gel column chromatography of the mixed phosphate extract of sheep placenta had good inhibitory activity against colon cancer cell lines. The results provide theoretical and technical support for the effective development and comprehensive utilization of sheep placenta waste.

Abstract:In this study, the effects of ultra-low temperature freezing and frozen storage on the quality of mussels during frozen storage were explored by taking the freezing method and frozen storage temperature as variables. During the 6-week freezing process, compared with the slow freezing in the refrigerator and the freezing at -20 ℃, the mussels were quickly frozen in liquid nitrogen and thawed at -30 ℃, resulting in a loss of 22.58%, a higher moisture content (76.61%) as compared with the other groups, and the best sensory scoring while maintaining good elasticity (0.52 mm) and chewiness (5.64 mJ). During the frozen storage period, the TVB-N value and total bacterial count of the mussels continued to increase, whilst the pH continued to decrease. After rapid freezing in liquid nitrogen and frozen storage below -30 ℃ , the TVB-N value of mussels was 12.2 mg/100 g, and the total bacterial count was 32 CFU/g, which were significantly lower than those of the other three groups (P<0.05). The pH value (7.32) and color L* value (66.18) of mussels were higher than those of the other three groups. Compared with the other groups, the Ca2+-ATPase (345.21 IU/L) activity of the myofibrillar protein in the mussels frozen at -20 ℃ after rapid freezing in liquid nitrogen was the highest, with higher elasticity (0.59 mm) and chewiness (6.86 mJ). In summary, using liquid nitrogen for quick freezing of mussels can effectively improve the quality of frozen mussels, and a lower storage temperatures can improve the quality of frozen mussels to a certain extent, which will provide theoretical support for ultra-low temperature preservation of mussels.

Abstract:The aim of this study was to investigate the effect of light-emitting diode (LED) irradiation treatment on the storage quality of fresh-cut strawberries. In this experiment,‘Benihope’ strawberry was used as the experimental material, the fresh-cut ‘Benihope’ strawberries were stored at (4.0±1.0) ℃ and a relative humidity of 85%~90% and treated with blue LED light (light intensity: 36 μmol/(m2.s); time: 36 h), which served as the experimental group, and the fresh-cut fruits stored at dark were used as the control group. Regular assessments were conducted to measure various quality indicators of freshcut strawberries, such as firmness, colour, content of soluble solids, titratable acidity, ascorbic acid content, soluble protein content, soluble sugar content, total phenolic content, and content of anthocyanins, and the activities of polyphenol oxidase (PPO) and peroxidase (POD). The results showed that the blue light treatment effectively delayed the decline in firmness and contents of soluble solids, titratable acid, soluble protein, soluble sugar and ascorbic acid in fresh-cut strawberries. In the control group, no significant change was observed in anthocyanin content, whilst a trend of initial increase following deccrease was observed in its total phenol content and POD and PPO activities. Notably, the blue light treatment increased significantly the anthocyanin and total phenolic contents and POD activity while inhibiting the PPO activity. At the end of storage, the blue light treatment of fresh-cut strawberries made the total phenolic, anthocyanin, and ascorbic acid contents becoming1.39-, 1.54-, and 1.24-fold, respectively, those of the control strawberries. Thus, blue LED light treatment could effectively maintain the quality of fresh-cut strawberries, which provides a certain theoretical basis for the preservation of fresh-cut strawberries.

Abstract:Storage time has a crucial effect on the quality of cabbage. Identifying the optimal storage time mainly relies on manual experience, which is not accurate and reliable. This study aimed to establish a stoichiometric recognition model based on Raman spectrum to calculate the storage time of cabbage. The Raman spectra corresponding to different storage times of cabbage heart were evaluated. Principal component analysis (PCA), support vector machine (SVM), and linear discriminant analysis (LDA) were established by testing the Raman spectra of cabbage heart every 48 h after harvest. The results showed that soluble sugars, cellulose, soluble proteins, and carotenoids were the main components affecting the storage quality of cabbage. The classification accuracy of linear and polynomial functions of the SVM model and verification set were 97.75 and 97.34%, respectively, and the classification accuracy of the SVM model and verification set were 97.50% and 96.00%, respectively. The classification accuracy of the LDA quadratic function model and the verification set were 99.00% and 97.00%, respectively. Both SVM and LDA models based on Raman spectrum effectively identified different optimal storage times of cabbage. Thus, this study provides reference and technical support for the identification of cabbage freshness based on storage time.

Abstract:In this study, ‘golden’ passion fruit was used as the experiment material, and different doses of UV-C treatment (0, 2.02, 4.04, and 6.06 kJ/m2; the sample subjected to 0 kJ/m2 UV-C as the control) were used to treat the fruits before they were stored at 20 ℃ for 18 d. Compared with the control, on the 9th day of storage, the UV-C treatment led to significant suppression on the decrease of L* value, the increase of b* value (P<0.05), and the decrease of titratable acid (TA) and flavonoid contents (P<0.05), while maintaining a* values as negative values and reducing the decay index and shrinkage index; The vitamin C contents of the fruits treated by UV-C at 2.02 or 4.04 kJ/m2 were 2.66 and 2.11 mg/100 g, respectively, which were higher than that of the control; The respiration rates of the fruits treated by UV-C at 2.02 or 6.06 kJ/m2 were 7.84 and 16.96 mg CO2/g FW h, respectively, which were lower than that of the control, although there was no significant effect on the content of total soluble solids, total phenolic content and firmness value (P<0.05); The UV-C treatment at 6.06 kJ/m2 increased cell membrane permeability and decreased total phenolic content. In general, the effect of the UV-C treatment at 2.02 kJ/m2 was better than those of the control and other UV-C treatments, thus can be used as an effective treatment to provide some theoretical guidance for the application of UV-C on postharvest passion fruit.

Abstract:To analyze the quality change of eel meat during frozen storage, eel slices (4×5 cm) were frozen at -18 ℃, and their changes of structure and properties were monitored for 6 months. The results showed that with the increase of frozen storage time, the values of L*, b*, and a* showed a downward trend. The content of oxygenated myoglobin decreased by 19.91%, and the content of high methemoglobin increased by 21.92%. The structure of muscle fibers after 6 months was loose, the arrangement was chaotic, the gap between muscle bundles was enlarged, and the integrity of muscle tissue was destroyed. The water holding capacity and shear force decreased by 8.73 and 65.42%, respectively. The pH value decreased by 18.5% (P<0.05) in the first month, and then increased gradually with the frozen storage time. The lipids of eel meat during frozen storage oxidized and the protein was degraded. The TBARS value increased from 0.73 to 1.62 nmol/mg protein, whereas the TVB-N value increased from 7.69 to 20.24 mg/100 g. Thus, the color and edible quality of frozen eel meat gradually deteriorated. This study provides a theoretical basis for the freezing and preservation of eel, as well as the quality control, storage and transportation of its prefabricated products.

Abstract:In order to solve the problems of short shelf life and easy spoilage of instant rice noodles, fresh wet rice noodles were used as the target, the influences of multiple preservation factors on the fresh-keeping effect and quality of fresh wet rice noodles were studied using the fencing technology. The experimental results showed that the shelf life of fresh wet rice noodles could be prolonged to 19 d through adding 0.8 g/kg sodium dehydroacetate and 0.05 g/kg ε-poly-lysine hydrochloride; after this treatment combined with 1% (v/v) lactic acid for 90 s, the shelf life could be further extended to more than 30 d. The process conditions were optimized by adding the fencing factors. The shelf-life of instant rice noodles could reach 90 d via pasteurization combined with lactic acid treatment (i.e. acid soaking with 1.0% (v/v) lactic acid for 60 s and heat sterilization at 90 ℃ for 30 min). The above results showed that the preservatives-acid soaking and pasteurization acid soaking preservation technologies can effectively extend the shelf life of fresh wet rice noodles and ensure the quality of the product. The research results provide a practical solution for solving the storage problem that fresh wet instant rice noodles are difficult to be preserved.

Abstract:To comprehensively use Antarctic krill resources, four acidic deep eutectic solvents were prepared for astaxanthin extraction. The optimization of the extraction considered the recycling of solvents and stability and antioxidant capacity of the extraction solution. Moreover, the extraction residue was used as a biosorbent. The enhancement of the acidity of deep eutectic solvents significantly increased the extraction efficiency of astaxanthin. The content of astaxanthin obtained by the deep eutectic solvent DL-menthol: acetic acid (MAA) under optimized conditions [extraction temperature: 25℃; extraction time: 1 h; solid-liquid ratio 1:10 (g/mL)] was 222.96 mg/kg, with good solvent recycling and antioxidant ability. The DL-menthol: caprylic acid (MOA) extract showed favorable color and concentration stability at 4 ℃. A strong positive correlation (average R2>0.9) was identified between the chromatism values observed in the deep eutectic solvent extracts and the corresponding astaxanthin concentrations during storage. The extraction residue was rough and porous, and the adsorption rate of the anionic dye Congo red reached 70%. This study provides valuable technical details for the selection and design of solvents for the extraction of natural astaxanthin and the efficient utilization of Antarctic krill.

Abstract:The effects of chickpea protein powder incorporation in mass fractions of 0, 2, 4, 6, 8, and 10% on steamed bread quality were examined. In particular, its effects on the farinograph index, water distribution, rheological properties, and secondary structure content of the dough, and the steamed bread’s quality were investigated. When less than 4% chickpea protein powder is added, the dough’s water absorption rate, formation time, stability time, and farinograph index increase, while the degree of weakening decreases. Weakly bound water in the dough gradually separates into bound and free water pools. Rheological results reveal that addition of <6% chickpea protein powder improves the elasticity and viscosity moduli of the dough, but the dough’s structural strength is reduced when added powder exceeds 6%. Secondary structure analysis shows that, with 2% chickpea protein powder, the β-sheet content peaks at 37.76%, effectively enabling formation of a more stable gluten network, thereby enhancing dough quality. As the chickpea protein powder content gradually increases, the steamed bread becomes darker, and its specific volume and width-to-height ratio decrease. Notably, the hardness, adhesiveness, and chewiness increase, while elasticity, cohesiveness, and resilience decline. At a chickpea protein powder mass fraction of 2%, the steamed bread achieves its highest specific volume (2.52 mL/g) and optimal textural properties (hardness: 3 182.46 g, chewiness: 2 493.15 g, and resilience: 0.46 mm). Gas retention in the dough increased, and the highest sensory score (83.71) was achieved. In short, adding appropriate amounts of chickpea protein powder to steamed bread dough can improve the bread quality. These findings provide references for the application of chickpea protein powder in pasta and bakery products.

Abstract:An optimal method for removing the acerbic taste of Humboldt squid (Dosidicus gigas) that will be safe, reliable, energy-minimizing, standardizable, and quantifiable was developed. The specific acerbic taste of Humboldt squid exerts a serious adverse impact on its texture and flavor. To comprehensively assess the nutritional content of Humboldt squid, a mixture of four sodium salt reagents (sodium hexametaphosphate, sodium carbonate, sodium pyrophosphate, and sodium citrate) was used for performing deacidification treatment of the squid under ultrasound-assisted conditions. Using metabolomics technology, the deacidification effect was evaluated through indicators such as organic acid content, total acidity, effective acidity, volatile acids, and carboxyl functional groups. The treatment reduced the mass fraction of organic acids and their derivatives from 16.00% to 9.78%. Total acidity, effective acidity, and volatile acid content decreased from 15.80, 3.55, and 12.20 mol/L to 8.47, 0.63, and 7.84 mol/L, respectively. The mass concentrations of lactic acid, citric acid, and succinic acid decreased from 8.46, 1.65, and 1.45 mg/mL to 1.13, 0.31, and 0.00 mg/mL, respectively. The pH value increased from 6.23 to 8.29. Sulfhydryl group content increased from 22.50 μmol/L to 31.07 μmol/L, then decreased to 23.57 μmol/L. The color of squid became whiter and brighter, while reducing hardness, viscoelasticity, and chewiness to a certain extent. Although total volatile basic nitrogen content increased to 23.94 mg/100 g, the freshness of the squid was maintained. These findings indicate that the mixture of four sodium salt reagents exerts a significant deacidification effect. This study provides theoretical data for the quantification and standardization of acerbic taste perception.

Abstract:To explore the differences in meat quality and nutrient contents in the ribeye meat and sirloin meat of Dulong bull (DB) and its hybrid bull (HB), the meat quality characteristics and nutrient components of ribeye meat and sirloin meat were determined and compared between DB and HB. The results showed that the L* value of hybrid bull ribeye meat was 34.30, which was 7.23 higher than that of DB (P<0.01). The shear force values of HB’s ribeye meat and sirloin meat were 4.38 kg/cm2 and 4.72 kg/cm2, respectively, which were 0.79 kg/cm2 and 1.15 kg/cm2 higher than those of DB’s ribeye meat and sirloin meat (P>0.05), respectively).The tenderness of DB was better compared with HB. The water loss rate of HB’s ribeye meat was 28.23%, which was 7.49 lower than that of DB (P<0.05). The protein and ash contents of HB’s sirloin meat were 23.25% and 1.27%, respectively, which were 2.20% and 0.07% higher than those of their ribeye meat (P<0.01), with HB’s ash content being significantly higher than that of DB (by 0.02%; P<0.05). The contents of total amino acid, umami amino acid, sweet amino acid, and bitter amino acid of HB’s sirloin meat were 20.154%, 5.47%, 4.73%, and 9.81%, respectively, which were 1.986% (P<0.01), 0.52% (P<0.05), 0.40% (P<0.05), and 1.07% (P<0.01), respectively, higher than those of its ribeye meat. The first-limiting amino acid included methionine plus cysteine, with scores ranging from 56.74% to 57.66%, the scores of threonine, valine, isoleucine, leucine, phenylalanine plus tyrosine, and lysine were all over 100%, indicating high-quality protein meat. This study showed that for the same breed cattle, the meat quality characteristics and nutritional value of the sirloin meat were better than those of the ribeye meat The meat color, water retention, fat deposition, mineral nutrition and flavor of the hybrid cattle were significantly improved. This study provides a scientific basis for the development of characteristic beef products through innovative utilization of interspecies hybridization.

Abstract:The visceral fat of Tibetan sheep fat was used as the raw material. Tibetan sheep fat was prepared by five different extraction methods, i.e. dry simmering, wet simmering, water enzymatic method, ultrasonic-assisted enzymatic hydrolysis and Soxhlet extraction. The effects of the five extraction methods on the quality of Tibetan sheep fat were investigated by taking the physicochemical properties, fatty acid composition and oxidative stability as the indexes. The results showed that the peroxide value of the Tibetan sheep fat extracted by the ultrasonic enzyme-assisted method was the lowest (0.02 g/100 g), and the saponification value was the highest (227.08 mg/g); the oxidative stability of the Tibetan sheep fat obtained by the ultrasonic-assisted enzyme hydrolysis method was superior to that of the Tibetan sheep fat extracted by the other four methods; the results of fatty acid analysis showed that a total of 36 fatty acids were detected in the Tibetan sheep fats obtained by the five different extraction methods , among which stearic acid (34.75%), palmitic acid (34.03%), and oleic acid (63.88%) were the fatty acids with the highest content percentages in the Tibetan sheep fats prepared by the five different extraction methods. Among the fat-soluble vitamins, the content of VA was the highest in the five types of Tibetan sheep fats, with an average content as high as (131 389±17 903.49) ng/g, and the contents of VE were higher (P<0.05) in the Tibetan sheep fats obtained by the dry simmering (5 079.79 ng/g) and ultrasound-assisted enzymatic hydrolysis (4 911.25 ng/g) methods. Based on the comprehensive comparison, the ultrasound-assisted enzymatic hydrolysis method led to a Tibetan sheep fat product with a higher yield and the best fat quality, which laid a theoretical foundation for the development and utilization of Tibetan sheep fat.

Abstract:The effects of color and crispness preservation pretreatments on frozen-thawed litchi pericarp were investigated in this study, including the effects on phenolase oxidation, cell integrity, browning, and other quality attributes. The results show that the color and shine of the litchi pretreated with 8% C6H8O7 + 0.5% Vc + 1% CaCl2 closely resemble those of fresh litchi. Compared to those of the control group, the relative electrolyte exudation rate and the juice loss rate of litchi after this pretreatment are decreased by 18.71 and 0.92%, respectively. In addition, the hardness retention rate is increased by 14.17%, while the residual enzyme activities of polyphenol oxidase and peroxidase are decreased by 158.18 and 342.14%, respectively. Meanwhile, the contents of polyphenols and anthocyanins and the antioxidant capacity retention rate increased by 9.79, 27.11, and 10.21%, respectively. Citric acid is found to be more effective in color preservation than Vc, while CaCl2 plays a critical role in maintaining crispness. Synergistic effects are noted among the three color- and crispness-preserving agents. In particular, the protective effects of Vc on cell integrity are observed only in the presence of CaCl2. The combination of 0.5% (m/V) Vc with citric acid and CaCl2 synergistically show enhanced color preservation and texture protection against enzymes. Hardness is better preserved at higher citric acid concentrations. In conclusion, pretreatment with 8% C6H8O7 + 0.5% Vc + 1% CaCl2 can be considered as a suitable solution for color and crispness preservation of frozen litchi. The results of this study can provide technical support for the preservation and processing of litchi.

Abstract:Polygonatum cyrtonema Hua was used as the test material to establish the HPLC fingerprint and extract its characteristic fingerprint information. Similarity evaluation, cluster analysis, and orthogonal partial least squares discriminant analysis (OPLS-DA) methods were employed to comprehensively analyze the irradiation of Polygonatum cyrtonema Hua with different doses of electron beams and screen for differential marker substances. The antioxidant activity of Polygonatum cyrtonema Hua was evaluated through DPPH and ABTS+ free radical scavenging rates. The spectrum-effect relationship between the fingerprint and antioxidant activity was explored using partial least squares regression analysis (PLSR).The results indicated that the similarity of HPLC fingerprints of Polygonatum cyrtonema Hua ranged from 0.972 to 0.994 at different doses, with 19 common peaks identified. Peak 2 was identified as rutin, peak 9 as quercetin, and peak 10 as liquiritin. OPLS-DA identified nine landmark differential substances before and after irradiation, including rutin, liquiritin, and quercetin. Spectrum-effect analysis demonstrated that 13 components were positively correlated with antioxidant activity, with Peak 1, Peak 6, and rutin identified as strong antioxidant substances in Polygonatum cyrtonema Hua. This study reflected the differences in composition and free radical scavenging ability with different doses of electron beam irradiation of Polygonatum cyrtonema Hua, providing effective data for quality monitoring of electron beam irradiation of Polygonatum cyrtonema Hua.

Abstract:To enhance the Maillard reaction during the film formation process and improve their functional properties, whey protein isolate (WPI), sodium caseinate (NaCas), and pullulan polysaccharide (PUL) were used as film-forming substrates. Under alkaline conditions with a pH value of 7.0~12.0, wet heating (90 ℃) was used to synergistically trigger the Maillard reaction. The degree of carbonyl-ammonia reaction was determined by parameters such as changes in the content of free amino acids and reducing sugars in the film-forming solution and degree of browning. The structural changes, barrier properties, thermal stability and antioxidant activity of the modified films were investigated. These films were also applied to the packaging and storage of coconut oil. The results show that alkaline conditions significantly accelerate and enhance the Maillard reaction of the thermotropic film-forming solution and improve the functional properties of films. Furthermore, the performance and properties of films significantly improved at pH value 11.0. Oxygen transmittance, water vapor transmittance, and tensile strength reached 0.045 cm3/(m2•d), 5.680×10-12 g•cm/(cm2•s•Pa), and 3.61 MPa high barrier and high strength, respectively; DPPH radical scavenging ability and reducing power reached 95.07% and 1.83, respectively, achieving outstanding antioxidant activities. In the accelerated storage experiment at 50 ℃, the acid and peroxide values of coconut oil were 0.27 mg/g and 0.12 g/100 g, respectively, after 20 days. The films significantly inhibited the oxidative rancidity of coconut oil and extended its shelf life. The results provide new applications of Maillard reaction modified films to prolong the shelf life of oils and fats.

Abstract:To use polyphenols from sorghum bran, this study employed ultrasonic-assisted deep eutectic solvent (DES) extraction method. The most efficient DES system for extracting polyphenols from sorghum bran was selected from 16 candidates. Subsequently, based on the results of single-factor experiments, the optimal extraction conditions for sorghum bran polyphenols were determined using the response surface methodology. Finally, the antioxidant activity of the extracted polyphenols for sorghum bran was assessed. The results indicate that the optimal solvent for extracting polyphenols from sorghum bran was 1,3-butylene glycol-malonic acid with a solvent molar ratio of 1:1 and water content of 20% (V/V). Under the conditions of solid-liquid ratio of 1:26 g/mL, ultrasonic temperature of 47 ℃ , and ultrasonic time of 50 min, the extraction yield of sorghum bran polyphenols was 19.47 mg/g, which was 2.21 and 1.68 times higher than that obtained by 70% (V/V) ethanol and 70% (V/V) methanol, respectively. The half maximal inhibitory concentration (IC50) values of DES extract against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) cation radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, superoxide anion, and hydroxyl radical were 105.85, 122.94, 145.42, and 146.29 g/mL, respectively, which were significantly lower than those of the 70% (V/V) ethanol and 70% (V/V) methanol extracts (P<0.05). At equivalent polyphenol concentrations, the ferric reducing ability of plasma (FRAP) value of the DES extract was significantly higher than that of the 70% (V/V) ethanol and 70% (V/V) methanol extracts (P<0.05). These results indicate that the ultrasonicassisted DES extraction method effectively extracts polyphenols from sorghum bran with high antioxidant activity. This research contributes to the green, efficient extraction and high-value application of polyphenols from sorghum bran.

Abstract:Headspace solid-phase microextraction-gas chromatography-mass spectrometry combined with orthogonal partial least squares discriminant analysis was used to explore key aroma components of three different varieties of processed black tea in Wuzhishan tea region. Relative odor activity value screening and sensory evaluation were used to analyze and screen the key aroma components of three kinds of black tea. A total of 62 volatile components were identified, mainly alcohols, esters, and aldehydes; 15 volatile components such as linalool (29.59%~40.90%), phenylacetaldehyde (2.62%~4.12%), and geraniol (1.25%~5.93%) had relatively high relative contents. Orthogonal partial least squares discriminant results showed that 20 kinds of volatile components, such as phenylethanol, α-terpineol, and leucinol, differed among the three kinds of black tea. Relative odor activity value analysis showed that methyl salicylate, decanal, linalool, nerol, and geraniol greatly contributed to the formation of honey aroma in the three kinds of black tea: carvacrol, thymol, 1-octen-3-ol, linalool, and leucinol were important contributors to the formation of “spicy aroma” and “flower and fruit aroma” in Zijuan black tea, and β-ionone, α-ionone, and β-cyclocitral were the key aroma components for the formation of “sweet potato aroma” in Hainan large-leaf variety black tea and “flower aroma” in Yunnan large-leaf variety black tea. In summary, the characteristic aroma of the three kinds of black tea in Wuzhishan tea region is honey aroma, flower aroma, and fruit aroma. Zijuan has better black tea trial production performance after being introduced to Hainan.

Abstract:To explore the differences of aroma components of mulberry leaf tea from different raw materials using headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS) combined with partial least squares discriminant analysis (PLS-DA). The aroma components of five different mulberry leaf teas, including spring shoots, buds, one bud and one leaf, tender leaves, and mature leaves were analyzed. The results showed that 25 volatile components were identified by GC-MS, whereas 62 volatile components were identified by GC-IMS, respectively. Through PLS-DA, clear differences between different mulberry leaf teas made of spring shoots, buds, one bud and one leaf, tender leaves, and mature leaves were identified. The variable importance in projection (VIP) of predictors was calculated, and 17 characteristic aroma components were screened: Cedrol, (z)-5-Tridecene, 2-Pentylfuran, 2-6-Dimethylcyclohexanol, Benzoyl isothiocyanate, Phenylacetaldehyde, Octanol, 1-Heptene, 2-Butanone, 2-Heptanone, Methyl acetate, Acetic acid, 2-Hexenal, Ethyl acetate, Methional, 2-Hexanone, and 3-Hydroxy-2-butanone. These characteristic aroma substances mainly present sensory characteristics such as fruit, soybean, butter, spicy, wood incense, and nuts. This study provides support for the selection of mulberry leaf tea raw materials.

Abstract:To compare the changing trends of the flavor compounds of pork meatballs obtained over different frying time periods, deep-fried pork meatballs were used in this study. Solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) was employed to separate and analyze the volatile flavor compounds of the deep-fried pork meatballs. Moreover, discriminant analysis was conducted by chemometric methods and sensory evaluations. The results revealed a total of 55 compounds belonging to nine categories, alcohols, aldehydes, alkanes, esters, acids, ketones, olefins, ethers and others, were detected, among which aldehydes had the highest content. Through Odor Activity Value (OAV) calculations and Partial Least Squares-Discriminant Analysis (PLS-DA), differences caused by the variations in frying time were distinguished. Nine volatile flavor compounds, namely hexanal, nonanal, β-myrcene, 1-pentanol, sabinene, β-pinene, butyl lactate, isoamyl alcohol, and lauricene, were preliminarily identified as the characteristic flavor compounds of deepfried pork meatballs. The flavor abundance was the highest when the frying time was 12 min. This research provides a theoretical basis for the development of high-quality pork meatballs and a reference for the industrial production of ballshaped foods like “lion's head” and “beef meatballs” and the flavor research of prefabricated dishes.

Abstract:A non-destructive detection method to identify damage caused by Conopomorpha sinensis in litchi fruit was examined with the help of multiple spectral techniques. The visible/near-infrared spectra, hyperspectral images, and X-ray imaging data of litchi were collected. Multiplicative scatter correction and standard normal variate transform were adopted to preprocess the spectra. Subsequently, characteristic wavelengths were obtained from the spectra using the successive projections algorithm (SPA). After that, partial least squares regression (PLSR) and support vector regression (SVR) were performed on the three spectral methods individually and the proposed multi-spectral fusion method. The results suggest that when one single method is used for detection, the MSC+SPA+SVR model established based on the visible/near-infrared spectra of litchi gives the best results. The performance indicators of the training set are R2=0.84 and RMSE=0.20, while those of the test set are R2=0.79 and RMSE=0.23. SVR modeling results of different combinations of spectral techniques demonstrate that combining visible/near-infrared spectra with X-ray imaging data provides optimal detection results. The performance indicators of the training set are R2=0.90 and RMSE=0.15, and those of the test set equal R2=0.84 and RMSE=0.19, with a detection accuracy of 95.00%. Therefore, multi-spectral fusion of visible/near-infrared spectra and X-ray imaging data enables better detection results for damage caused by Conopomorpha sinensis in litchi fruit. These findings give insights to future research on the development of related equipment.

Abstract:Biscuits are a type of baked food popular among consumers. However, recent studies have found that the associated hazards of monochloropropanediol esters (MCPDEs) and glycidyl esters (GEs) are widely present in biscuits, potentially threatening human health. In this study, L-cysteine, a bread quality improver used in food, was selected as an additive to inhibit the formation of MCPDEs and GEs in biscuits. Its addition effectively reduced the contents of 3-MCPDEs, 2-MCPDEs, and GEs in biscuits, and its inhibition efficiency increased with the its amount. The inhibition efficiencies of 3-MCPDEs, 2-MCPDEs, and GEs in biscuits when the mass fraction was 0.08% were 35.89, 33.97, and 30.98%, showing higher inhibition efficiency than that of TBHQ. The addition of L-cysteine enhanced the antioxidant activity, improved surface brightness, and increased crispiness of the biscuit. Furthermore, its addition affected the flavors of biscuits, wherein the contents of volatile aldehydes, ketones, acids, alkanes, and olefins decreased, but the contents of esters, aromatic hydrocarbons, and pyrazines increased. This study provides new ideas for the development of new low-hazardous substance biscuits.

Abstract:In this study, a new and reliable analytical method was established for the evaluation of 14 kinds of acidic herbicides residues in livestock meat through optimizing the pH value of the extraction solution, dispersing solid-phase extractant and concentrated sulfuric acid-methanol solution, in combination with gas chromatography-mass spectrometry (GC-MS). The samples were extracted by acetonitrile, the pH of the extraction solution was adjusted to ≤ 3, the fat was removed by n-hexane saturated with acetonitrile, and purified by dispersed solid-phase extractor C18, dried with nitrogen, derivatized by adding concentrated sulfuric acid-methanol solution for 2 min, extracted with n-hexane, t purified by saturated sodium chloride solvent, and determined by EI source-gas chromatography -mass spectrometry and the matrix external standard method. The results showed that the 14 kinds of acid herbicides displayed a good linearity in the concentration range of 0.01~0.5 μg/mL, with all the correlation coefficients being greater than 0.999, the limit of detection in the range of 0.001~0.003 mg/kg and the limit of quantification in the range of 0.003~0.01 mg/kg. At the spiking levels (0.01, 0.05, 0.1 mg/kg), the average recoveries of blank samples were in the range of 88.21%~110.0%, with the relative standard deviations (n=6) ranging between 1.02% and 8.32%. The advantages of this method include short derivatization time, less consumption of pretreatment reagents, convenient method and high sensitivity, which can be used for the determination of 14 kinds of acidic herbicides residues in livestock meat.

Abstract:The competition method was used to couple a monoclonal antibody against chlorothalonil with the rare earth europium florescent nanospheres to synthesize a fluorescent labeled immune probe. This probe was used with a highly sensitive and rapid lanthanide fluorescent immunochromatography card for the rapid quantification of chlorothalonil in vegetables and fruits through an immunoassay. In this study, a high sensitivity and specificity chlorothalonil antigen was selected, and the labelling conditions of fluorescent nanospheres and chlorothalonicin, coating concentration of flufenicomumab antigen on NC membrane, and proportion of diluted complex solution were optimized. The fluorescence test strip developed in this study was used in conjunction with a fluorescence detector and pre-treatment with low-dosage organic solvent. Herein, the optimum experimental conditions were the concentration of antigen was 0.05 mg/mL, and the concentration of antibody was 0.8 mg/mL, the pH of PBS working buffer was 7.2 (8% methanol). A standard curve was established, and the linear range of the method was 2~100 ng/mL with a detection limit of 0.2 mg/kg. The strip detection of chlorothalonil had strong specificity without any cross reaction observed in certain pesticides. The recovery rate of thiamethoxam was 85~98%, the intra-batch precision was 8%~12%, and the inter-batch precision was 11%~17%. There was no significant difference between the results of actual samples and the national standard method. The rapid time-resolved fluorescence assay developed in this study is fast, accurate, highly sensitive, and green and environmentally friendly, making it suitable for rapid and quantitative screening of chlorothalonil in food of plant origin.

Abstract:A high performance liquid chromatography-photodiode array detection (HPLC-PDA) method was established for detecting 14 chemical drugs illegally added to health products and Chinese patent medicines for sexual enhancement. The detected compounds comprised 11 phosphodiesterase inhibitors that met the supplementary test criteria, as well as three typical serotonin reuptake inhibitors. The samples were extracted with acetonitrile and then separated using an Agilent 5 HC-C18 (2) chromatographic column (250 mm×4.6 mm, 5 μm) through gradient elution with a mobile phase consisting of acetonitrile, methanol, ammonium, and acetate. The mobile phase pH was 5.0 and 7.0, flow velocity was 1.0 mL/min, column temperature was 30 ℃, sample size was 10 μL, PDA detector scanning range was 190~400 nm, monitoring was conducted at 254 and 238 nm, and the compounds were quantified using an external standard. The separation of 14 chemical drugs was adequate, the linear relationship was good within a certain concentration range, and the correlation coefficient r was >0.999 9. The average recoveries (n = 9) of low, medium, and high concentrations were 99.9%~101.0% with RSD <2%, and the detection limit was 0.016~0.201 μg/mL. A total of seven positive samples were detected in 91 batches of marketed products; the addition of three compounds was illegal. The method is simple, accurate, specific, and sensitive; therefore, it is suitable for daily supervision and inspection.

Abstract:Surimi is a concentrate of myofibrillar protein that has become one of the primary products in aquatic processing due to its rich nutritional value, smooth texture, convenience, and affordability. To maintain the quality and extend the shelf life of surimi, it is commonly preserved by freezing. However, the texture and gelatinization properties of surimi deteriorate during frozen storage, which in turn affects its application in food processing and preservation. This paper reviews the freezing denaturation mechanisms and influencing factors of surimi, as well as the types of antifreeze agents and their mechanisms. The molecular properties, applications, and functions of konjac glucomannan as a natural polysaccharide, along with its effects on the structural and functional properties of surimi proteins, are discussed in the context of its use as an antifreeze agent for surimi.

Abstract:Staphylococcus aureus is an emerging foodborne pathogen implicated in a substantial number of cases of staphylococcal food poisoning (SFP), primarily due to its ability to produce staphylococcal enterotoxins. Recently, due to the rising use of antibiotics, there have been increases in the frequency and severity of foodborne S. aureus drug resistance. Furthermore, there has been a rise in the emergence of multidrug-resistant strains, particularly in livestock and poultry production, as well as in aquaculture; this has garnered considerable attention and raised widespread concern globally. Therefore, it is particularly important to elucidate the underlying drug resistance mechanisms and develop effective methods for detecting drug resistance in S. aureus. To date, extensive research has been conducted on the drug resistance mechanisms of S. aureus, with clear descriptions provided for most of these, which can be divided into three types, namely, the inactivation of antibiotics, efflux pumps, and ribosomal protection. To rapidly and accurately determine the drug resistance phenotypes and related molecular characteristics of S. aureus, as well as to enhance the identification of new resistance genes and examination of new resistance mechanisms, a range of methods for resistance detection or prediction have been developed. These include traditional methods for detecting resistance phenotypes, targeted detection of related genes and their expression levels, and bioinformatics-based approaches that use omics data from strains to predict resistance. In this review, several common mechanisms underlying S. aureus drug resistance are described, followed by an evaluation of existing approaches.

Abstract:The quality and safety of edible vegetable oils are crucial for the development of the vegetable oil industry and the protection of human health. This paper provides a comprehensive review of potential safety risk substances in edible vegetable oils, including pollution sources pollution status and detection techniques of heavy metals, mycotoxins, pesticide residues, and other harmful substances. In the meantime, this paper describes in detail the potential impact of each safety risk substance on human health, in order to enhance the practical significance of the research. It is recommended that China's food safety regulatory authorities should revise the category, scope and limit requirements for safety risk substances in edible vegetable oil through evaluating the development of edible vegetable oil industry and the risk level of safety risk substances. Furthermore, food testing institutions are encouraged to develop and establish rapid detection methods for safety risk substances in edible vegetable oils, so as to provide support for the monitoring and control of safety risk substances in edible vegetable oils.

Abstract:Responsive food packaging is a major research direction of new food packaging. Unlike traditional packaging, responsive food packaging is incorporated with stimulus-responsive materials that respond to the food itself or external stimuli (e.g., light, temperature, humidity, pH value). When there are changes in the internal or external conditions of food packaging, the packaging material undergoes observable changes in color or internal structure, so that the internal and external changes in the packaging can be visualized or the active substances inside the packaging material are released, thereby realizing the monitoring and improvement of food quality. Based on the domestic and international research progress, this paper classifies stimuli-responsive food packaging into four categories according to the type of stimuli: physically responsive type (light, temperature, humidity), chemically responsive type (pH value, volatile sulfide), biological impact type (microorganisms and enzymes), and multi-responsive type. Moreover, the research advances of different kinds of responsive food packaging are also presented. Finally, this paper analyzes comprehensively the problems and challenges faced by the responsive food packaging during industrial manufacturing from production, marketing, safety and other aspects o, as well as the development potential of responsive food packaging in the future.

Abstract:Liupao tea is a unique dark tea product in Guangxi, China. Its distinctive local characteristics and unique health benefits have created broad market prospects. In recent years, the Liupao tea industry has been flourishing, and the related research has also gradually deepened. Liupao tea has the quality characteristics of ‘vibrant redness, thickness, aging aroma, and purity’, and the aroma and taste components play important roles in the flavor formation of the Liupao tea. This article overviews the relevant results of the current research on the quality characteristics of Liupao tea, and summarizes the evaluation methods of its aroma and taste components, elaborates the important compounds in the studies investigating its aroma, and sorts out the roles of different taste components in the taste formation of Liupao tea. In the meantime, this article summarizes the problems of current research and presents prospects for future research, in order to provide theoretical basis for the evaluation of Liupao tea’s quality characteristics and the improvement of its aroma and taste quality.