Abstract:The therapeutic effects of mustard leaf extract, glucosinolate (GSL), on colon cancer were investigated. Total GSL content in mustard leaf was quantified using UV spectrophotometry. A colon cancer model associated with colitis was developed in Balb/c mice using azoxymethane and dextran sulfate sodium. The mice were divided into control, model, and low/high-dose mustard leaf GSL groups. After a 9-week trial, inflammatory cytokine levels and NF-κB p65/COX-2 and Wnt/JNK signaling pathway activities were analyzed. The gut microbiota was examined through high-throughput sequencing of 16S rRNA. Total GSL content in mustard leaf reached 127.11 μmol/g. Compared with the model group, the high-dose mustard leaf GSL group showed significant respective increases in weight and colon length (42.11% and 20.37%, respectively (P<0.05)), a significant reduction in the number of colon tumors (P<0.05), decreases in IL-6, TNF-α, and IL-17 expression in colon tissue by 46.88%, 70.22%, and 20.43% respectively, a 98.55% increase in IFN-γ expression, and significant decreases in NF-κB p65, COX-2, Wnt, and JNK protein expression by 60.91%, 15.57%, 63.31%, and 96.58%, respectively (P<0.05). The abundances of Bacteroides, Turicibacter, Ruminococcaceae UCG-014, Ruminiclostridium_5, Akkermansia, norank f Clostridiales vadinBB60 group, Prevotellaceae UCG-001, and Blautia were significantly altered by mustard leaf GSL, resulting in a restoration of a healthy microbial balance in the gut. In summary, leaf mustard GSL is a potential adjuvant therapy for colon cancer, as evidenced by its capacity to alleviate pathological conditions and modulate inflammatory cytokines, signaling pathways, and gut microbiota in mouse models of colon cancer.

Abstract:In this study, the effects of barley bran extract fermented by Lactiplantibacillus plantarum dy-1 (Lp. plantarum dy-1) (FBBE) on lipid deposition and oxidative stress were investigated through a HepG2 high-lipid cell model. The results showed that, the protein content of barley bran did not change significantly after the fermentation with Lp. plantarum dy-1, but the protein with a relatively high Mw (around 52 ku) in barley bran was basically completely hydrolyzed, with the protein of 20~35 ku increasing significantly. The total sugar content was reduced by about 28% and the total phenolic content increased by about 42%. The FBBE treatment at 50 μg/mL decreased the TG content by 20.30%, whilst the polyphenols in the FBBE (FBBE-PP) at 5, 10 or 15 μg/mL decreased the TG levels by 16.97%, 27.41% and 34.92%, respectively, while reducing significantly the number of lipid droplets in the cells, indicating that polyphenol constituents were the effective components to alleviate lipid deposition in cells. After the FBBE-PP treatment at 10 μg/mL, the intracellular ROS content decreased by 23.45% and the SOD activity increased by 40.80%, compared with the model group. The FBBEPP could up-regulate the expressions of ppar-α and cpt-1α, down-regulate the expressions of scd-1 and acc-1 to alleviate cell lipid deposition, while up-regulating the expressions of nrf-2, ho-1, sod1 and cat to enhance the antioxidative stress ability of cells. In conclusion, the fermentation with Lp. plantarum dy-1 could improve the lipid-lowering and antioxidant activities of barley bran, and its polyphenol components could significantly alleviate high-fat induced lipid deposition and oxidative stress in cells.

Abstract:The anti-fatigue mechanism of the active constituents of earthworm was clarified using ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry/mass spectrometry (UHPLC-Q-TOF-MS/MS and network pharmacology. UHPLC-Q-TOF-MS/MS was used to identify chemical constituents of earthworm extract. The targets of these constituents and fatigue and anti-fatigue associated genes were collected to identify the common targets. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. KEGG Mapper was utilized to preliminarily elucidate the anti-fatigue mechanism, and animal experiments were performed to verify the antifatigue efficacy of earthworm extract. Network analysis showed that the anti-fatigue effects of earthworm extract mainly function via positive regulation of phosphorylation, NF-κB signaling pathway, serotonergic synapse signaling, JAK-STAT pathway, and arginine and proline metabolic pathways. As shown in the results of animal experiments, the time of weight-bearing swimming in mice in the middle-dose earthworm extract group was 34.07 min, significantly longer than that (9.78 min) of the CK group (P<0.001). Hepatic glycogen content in the high-dose earthworm extract group was 2 591.21 mg/g, which was significantly higher than that in the CK group (P<0.001). Urea nitrogen and blood lactic acid contents in the high-dose earthworm extract group were 3.65 nmol/L and 182.21 nmol/L, respectively, which was significantly lower than those of the CK group (P<0.01). In conclusion, the antifatigue effect of earthworm extract was exerted through synergistic effects of multiple constituents, targets, and pathways, providing valuable insights and methods for further research into anti-fatigue mechanisms.

Abstract:The digestibility of goat milk, casein (CN), whey protein (WP), and a mixture of CN and WP with a ratio similar to that in human breast milk (40:60, m/m) were assessed through in vitro simulation of digestion in the gastrointestinal tracts of adults and infants. The digestibility of all four proteins gradually increased during adult and infant in vitro digestion simulations. Mixed protein digestibility reached a maximum of 20.28% after 120 min of simulated infant gastric digestion, significantly higher than that of goat milk (P<0.05), suggesting that the mixed protein with a higher CN proportion was more easily digested. The mixed protein released up to 58.0 mg/mL peptide after 30 min of simulated infant gastrointestinal co-digestion. Dipeptidyl peptidase-4 inhibitory activity was relatively strong at the endpoint for the simulated infant gastrointestinal co-digestion. CN demonstrated the highest antioxidant activity of 34.11% during simulated infant gastrointestinal co-digestion. The mixed protein presented the lowest immunogenicity in simulated infant gastrointestinal digestion, indicating that the mixed protein is less likely to cause allergic reactions. Hence, the mixed protein combining CN and WP in a ratio similar to that in human breast milk provides improved digestibility, increased peptide content, reduced immunogenicity, and specific antioxidant activities. These findings provide important data to aid in the optimization of protein sources and ratios in whole goat milk-based infant formulas.

Abstract:In order to promote the development and utilization of berry-related products in Northeast China, 9 kinds of berries widely cultivated and common in Northeast China were used as the research objects, the contents of total phenols, total flavonoids and total anthocyanins in were determined and analyzed. The types and contents of the phenolic monomers in these berries were determined by high performance liquid chromatography. The antioxidant activity and anti-inflammatory activity of the berries were evaluated by measuring DPPH• scavenging ability, ABTS+∙ scavenging ability, hyaluronidase inhibitory ability and albumin denaturation inhibitory ability, and correlation analysis was conducted. The results showed that the contents of total phenols, total flavonoids and total anthocyanins in blue honeysuckle and lingonberry were higher, which were 2.83 and 2.42 g GAE/100 g DW, 0.99 and 2.09 g Rutin/100 g DW, 104.33 and 414.73 mg/100 g DW, respectively. These two berries had strong antioxidant and anti-inflammatory activities. The correlation results showed that the total phenolic content determined the antioxidant and anti-inflammatory activities of the berries. 19 monomer phenols were identified and quantified in 9 berries, with chlorogenic acid, cryptochlorogenic acid, arbutin and baicalein all being detected in berries. Chlorogenic acid and cryptochlorogenic acid were the main phenolic monomers in most berries. Among them, the number of the type of monomer phenol species in lingonberry and the content of the monomer phenols in blue honeysuckle were the highest. This experiment provides a theoretical basis for the comprehensive utilization of berries in Northeast China.

Abstract:The effects of buffalo milk fermented with Lactiplantibacillus plantarum B (LPB) and yogurt starter on blood pressure and gut microbiota structure and function were assessed using pregnant rats. The rats (10 weeks old) were randomly divided into a fermented buffalo milk group (YT), labetalol hydrochloride positive control group (PC), and negative control group (NC), with five rats per group. Starting from the 1st day of pregnancy, the rats in groups YT, PC, and NC were respectively gavaged with 10 mL of 20 mg/kg fermented buffalo milk, 10 mL of 4 mg/kg labetalol hydrochloride, and 10 mL of normal saline once a day for 21 days. Modeling was initiated on day 15 of pregnancy, with daily injections of N-nitro-Larginine methyl ester hydrochloride (L-NAME, 125 mg/kg) until delivery, and blood pressure and microbial composition of colonic contents were measured daily. Blood pressure in group YT was significantly reduced by induction with L-NAME and was significantly lower than that in the post-induced group NC (P<0.05) but was not significantly different from that of group YT or group PC (P>0.05). Compared with group NC, group YT exhibited lower abundance of Firmicutes and higher abundance of Rothia, Bifidobacterium, Bacteroides, and Parabacteroides (P<0.05), and the ratio of Firmicutes to Bacteroidetes was reduced from 10.46 to 3.74. Fermented milk intake also significantly promoted folate and sphingolipid biosynthesis while significantly increasing the levels of acetic acid and isovaleric acid. This study demonstrates that buffalo milk fermented with LPB can aid in stabilizing blood pressure in pregnant rats by improving their gut microbiota structure, indicating great potential as a new functional food to improve prenatal health.

Abstract:To explore the regulation and mechanism of Lilium davidii var. willmottiae (LD) on the liver circadian clock gene Clock-Bmal1 and glucose and lipid metabolism in rats on a high-fat diet. The model was established by feeding rats with high-fat diet for 8 weeks. The high-fat rats were randomly divided into the model group, metformin group, melatonin group, low-dose LD group, medium-dose LD group, high-dose LD group, combination group, with the normal group being fed with an ordinary diet. Intragastric intervention was carried out for 4 weeks. Fasting blood glucose (FPG), abdominal circumference, body length, and liver weight were measured. Lee's index and liver wet weight index were calculated. Total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) in the serum and liver were detected by the microplate method. The level of glycosylated hemoglobin (Hb Alc) was detected by ELISA. The mRNA and protein expression levels of the Clock and Bmal1 genes in the liver were detected by RT qPCR and Western blot. The results showed that compared with the model group, the LD intervention group could improve the body posture of high-fat rats, regulate the blood lipid levels, reduce Hb Alc, and upregulate the mRNA and protein expression of Clock and Bmal1 (P<0.05). The abdominal circumference and Lee's index of the medium-dose LD group decreased (8.61%, 5.04%), with their serum TC, TG and LDL-C decreasing (36.59%, 29.73%, 34.04%), Hb Alc decreasing by 24.37%, Clock and Bmal1mRNA expression increasing (159.17%, 228.58%) and protein expression increasing (52.09%, 151.33%). In conclusion, LD alleviated glucose and lipid metabolism disorders caused by a high-fat diet, which might be achieved through the upregulation of the liver Clock and Bmal1 gene expression. The results of this study provide a theoretical basis for using LD in the prevention and treatment of metabolic diseases and the development and utilization of functional health foods.

Abstract:A hyperuricemia (HUA) mouse model was developed through intraperitoneal injection of potassium oxonate for 7 days to investigate the potential of CJP in alleviating hyperuricemic renal injury by regulating uric acid transporters. After intervention in the HUA model using freeze-dried cherry juice powder (CJP), benzbromarone, and allopurinol, serum uric acid (UA), creatinine (Cr), and blood urea nitrogen (BUN) were detected using commercially available kits. Pathological changes in the liver and kidney were determined using hematoxylin-eosin (HE) staining. Expression of uric acid transporters in mouse kidney was assessed using western blot and immunohistochemistry. The UA level in the high-dose CJP group decreased from 191.99 to 113.12 μmol/L (P<0.01), remaining 25% higher than the normal level, whereas the Cr level decreased from 16.09 to 7.40 μmol/L (P<0.01), and the BUN level decreased from 8.24 to 4.73 mmol/L (P<0.01). The latter two indicators reached normal levels, demonstrating a substantial alleviation of renal tissue injury. CJP downregulated the expression of two uric acid-reabsorbing proteins, urate transporter 1 and glucose transporter 9, while upregulating the protein expression of three uric acid-secreting proteins, ATP-binding cassette superfamily G member 2, anion transporter 1, and anion transporter 3, with no obvious liver toxicity. CJP thus alleviates hyperuricemic renal injury by regulating uric acid transporters. This study can serve as a scientific basis for the development of health products derived from cherry for preventing and treating hyperuricemic renal injury.

Abstract:A mouse model of lipopolysaccharide (LPS)-induced RAW264.7 cell inflammation was developed to investigate the in vitro anti-inflammatory mechanism of saikosaponin d (SSd). SSd demonstrated a significant inhibition of nitric oxide release from RAW264.7 cells at a concentration of 8 μmol/L (P<0.01) and suppressed mRNA level expression of inflammation-related genes, including inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), interleukin-6, and tumor necrosis factor-α, in a dose-dependent manner at concentrations of 4 and 8 μmol/L (P<0.01). Western blot analysis revealed that SSd effectively reduced the protein level expression of iNOS and COX-2. SEM images confirmed that SSd alleviated LPS-induced morphological changes in RAW264.7 cells. Additionally, SSd inhibited the expression and phosphorylation levels of key proteins involved in inflammation-related signaling pathways, including toll-like receptor 4 (TLR4), IκB kinase, nuclear factor κB (NF-κB), and glycogen synthase kinase-3β (GSK3β). These findings indicate that SSd strongly inhibits LPS-induced RAW264.7 cell inflammation by targeting the TLR4/NF-κB and GSK3β signaling pathways. These findings contribute to our enhanced understanding of the anti-inflammatory effects of SSd.

Abstract:In order to study the effects of Saussurea laniceps polysaccharides (SLPs) on the expression of inflammatory factors and antimicrobial peptide LL-37 in UVB-induced keratinocytes, SLPs were extracted by the ethanol thermal reflux method, and SLPs at different concentrations were used to examine the inhibitory effect of COX-2 (a key mediator of inflammatory pathway). A cell model of UVB irradiation-induced inflammation was established to determine the influence of SLPs on prostaglandin E2 (PGE-2), TNF-α and IL-1β inflammatory factors, as well as the relationships of SLPs with LL-37 expression. An enzyme-linked immunosorbent assay (ELISA) and western blot analysis were used to detect the production of inflammatory factors and LL-37 antimicrobial peptide. The results showed that the inhibition rate of COX-2 was 82.41% at 1 000 μg/mL, and the expression of PGE-2, TNF-α and IL-1β inflammatory factors in HaCaT cells was significantly downregulated at 100 μg/mL (P<0.01). In addition, SLPs at 50 μg/mL and 100 μg/mL concentrations enhanced the expression of LL-37 antimicrobial peptide (P<0.01), thereby down-regulating the expression of TNF-α and IL-1β inflammatory factors, then reducing skin inflammation. Conclusion: SLP can significantly inhibit the inflammatory response induced by UVB, and can further slow down the damage caused by inflammation to the skin by regulating LL-37 antimicrobial peptides, which has the potential to prevent skin inflammatory damage caused by UVB irradiation.

Abstract:Lipopolysaccharide (LPS), a key component on the outer side of the outer membrane (OM) of Gramnegative bacteria, is an important virulence factor affecting the characteristics of the outer cell membrane of pathogenic bacteria. However, at present, there is a lack of in-depth research on the pathogenic mechanism of bacterial LPS. In this study, differential lipidomic studies were carried out for the first time on the wild Escherichia coli strain W3110 and its LPS structural mutants ΔwaaC and Δ(lpxL lpxM lpxP), and the effects of LPS structural changes on lipidome. The results indicated that the loss of LPS-related structure in E. coli significantly altered the type and relative content of cell lipids, which was closely related to the change of OM characteristics. Compared with W3110, the permeability of ΔwaaC and Δ(lpxL lpxM lpxP) increased by 13.59% to 19.00%, and the fluidity of the OM decreased by 23.71% to 32.84%. Differential lipidomics revealed that 416 lipids of 22 subclasses were identified in W3110. The types of lipid species of the two mutant strains were reduced, while new lipids such as CL(14:0/14:0/15:0/12:0)-H, CL(17:3/15:0/12:0/14:0)-H, and CL(18:3/12:0/14:0/15:0)-H appeared in both mutants. In addition, most of the lipid contents of the two mutant strains changed significantly, in particular, the monounsaturated PE decreased by 3.07%~9.02%, and the monounsaturated CL increased by 1.11%~1.73%. There were also large differences in lipidome between ΔwaaC and Δ(lpxL lpxM lpxP). This study revealed that the structural changes of LPS resulted in significant alterations in lipid type and relative strength, which was an important factor for the change in the OM characteristics of E. coli.

Abstract:Laccase is widely used in the textile industry for dye decolorization, fabric surface modification, and textile bleaching. Screening for a laccase that is alkaline stable and suitable for textile dye decolorization is challenging. A novel alkaline laccase (LacNC) was obtained from Neobacillus cucumis and expressed in Escherichia coli. LacNC is a monomeric protein with a molecular weight of 58 ku. The optimum pH values for LacNC were 6.0, 7.0, and 8.0 when 2,6-dimethoxyphenol, syringaldazine (SGZ), and guaiacol, respectively, were used as substrates. The optimal temperature for LacNC was 55 ℃ for the guaiacol substrate. The activity of LacNC remained more than 85% in the pH range of 5.0~11.0. After incubation at 40 ℃ for 1 h, the activity of LacNC was still higher than 80%. In addition, the decolorization rates of indigo carmine and malachite green by LacNC were more than 90% and 80% in 3 h, respectively, and the decolorization rate of reactive black B by LacNC reached 85% in 24 h. In this study, a new alkaline laccase demonstrating high decolorization efficiency for synthetic dyes under alkaline conditions was obtained. Hence, this laccase is an environmentally friendly candidate for treating wastewater in the textile industry.

Abstract:High-throughput sequencing was used to analyze bacterial diversity in 15 samples of white cashmere goat milk and its dairy products collected from Alxa, Inner Mongolia. The samples differed significantly in bacterial diversity and richness (P<0.05). Processing goat milk into traditional dairy products greatly alters the dominant bacterial phyla and genera and introduces many unclassified bacteria. Additionally, the relative abundances of foodborne pathogens, including Enterobacter, Enterococcus, Raoultella, and Pseudomonas, were greatly reduced in the traditional dairy products. At the operational taxonomic unit level, Shurmeg had the richest composition of bacterial species and the highest number of unique bacterial species. According to PICRUSt2-based prediction of gene function, the main metabolic gene functions of bacteria in goat milk and its dairy products included global and overview maps, carbohydrate metabolism, and amino acid metabolism. The results of this study clarify the bacterial diversity in white cashmere goat milk and its dairy products collected in Alxa, Inner Mongolia, providing a basis for comparison of bacterial microbiota, prediction of functional genes, and safety evaluation of goat milk and its dairy products.

Abstract:The purpose of this study was to prepare silkworm pupa protein glycopeptides by transglutaminase-induced glycosylation, and explore their umami taste-enhancing effect and hazardous substances. On the basis of single factor experiments, the conditions of TGase enzymatic reaction were optimized by the response surface methodology with sensory score and grafting degree as the evaluation indexes. Then, the differences in taste and hazardous substances between the high temperature Maillard reaction products (HMP) and low-temperature enzymatic glycosylation reaction products (LEP) were compared. The results showed that the optimum conditions for low-temperature enzymatic reaction were as follows: peptide/sugar ratio, 2.2:1; protein peptide mass fraction, 6.5%; initial pH of the reaction, 6.9; reaction temperature, 50 ℃. mass faction of TGase enzyme, 3%; reaction time, 4 h. At the same concentration and degree of glycosylation, the contents of acrylamide, 5-hydroxymethylfurfural and furfural were 113.3 μg/mL, 3.0 μg/mL and 1.76 μg/mL in HMP, respectively. However, in LEP, the contents of acrylamide, 5-hydroxymethylfurfural and furfural were reduced to 64.05 μg/mL, 1.96 μg/mL and 0.01 μg/mL, respectively. The contents of the three major hazards of LEP were significantly lower than those of HMP, indicating that the low-temperature enzymatic reaction was superior to the Maillard reaction. The sensory results showed that there was insignificant difference in the taste between HMP and LEP. Compared with the control group, the sensory score of LEP was significantly increased, indicating that the low-temperature enzymatic reaction can be used as another effective approach for increasing the umaminess of silkworm pupa protein peptide components. The results showed that the lowtemperature enzymatic reaction could enhance the umaminess and reduce the formation of hazard substances in silkworm pupa protein peptide fractions on the basis of the hazard and sensory analyses.

Abstract:To reveal the structural characteristics of fucoidan (FUC) and its interactions with the gut microbiota, weak acid degradation products (AFUC) and oxidative degradation products (OFUC) of fucoidan were prepared and the regulatory effects of fucoidan and its degradation products on gut microbiota were investigated through in vitro human fecal fermentation. The relative molecular mass of AFUC obtained from the degradation of FUC was determined to be 7.4 kDa, with a sulfate group content of 3.12% and a monosaccharide composition ratio of Fuc:Gal=24.83:75.22. The relative molecular mass of OFUC decreased to 19.6 kDa. Compared with FUC and OFUC, treatment using AFUC, which contains a low sulfate group content, significantly increased the contents of acetic acid, propionic acid, butyric acid, and valeric acid in the fermentation broth by 34.96%, 135.41%, 13.45%, and 16.92%, respectively, whereas it significantly decreased isovaleric acid content (24.55%), which was not affected by FUC and OFUC treatments. In addition, AFUC significantly promoted the enrichment of Bacteroidetes (38.54%), decreased the relative abundance of Firmicutes (17.71%), and considerably inhibited the proliferation of Proteobacteria (46.88%). This study suggests that fucoidan sulfate group content may play a crucial role in influencing regulatory effects on the gut microbiota. The results of this study serve as a valuable resource for fucoidanbased product development aimed at improving intestinal health.

Abstract:The extraction process for green radish polysaccharide (GRP) was optimized to improve the extraction yield of GRP by varying the enzyme activity, enzymatic hydrolysis time and temperature, and solid-solvent ratio in singlefactor experiments using response surface methodology. The optimal GRP extraction process involved an enzyme activity of 285 U/g, an enzymatic hydrolysis temperature of 48 ℃, an enzymatic hydrolysis time of 59 min, and a solid-solvent ratio of 1:21. The average yield of GRP extracted using this process was 5.34%. GRP was composed primarily of ten monosaccharides with a molar ratio of mannose: ribose: rhamnose: glucuronic acid: galacturonic acid: glucose: galactose: xylose: arabinose: fuc ose = 0.827: 0.365: 1.216: 1.519: 2.853: 66.215: 17.425: 0.295: 8.713: 0.574. Additionally, GRP presented excellent antioxidant capacity, and its scavenging rates for 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) radical, hydroxyl radical, and 1,1-diphenyl-2-trinitrophenylhydrazine radical were 91.14%, 85.31%, and 62.73%, respectively, with half-maximal inhibitory concentrations of 10.78, 8.42, and 17.40 mg/mL, respectively. The optimal GRP extraction process, monosaccharide composition and structure of GPR, and excellent antioxidant activity of GPR were determined, providing a reference for further research on the physiological activity of GRP and development of relevant health food.

Abstract:The traditional mud-packing method for preparing salted sea duck eggs has drawbacks of long pickling time, high salt content, and inconsistent quality. This study improved the traditional mud-packing method and clarified the change patterns of the physicochemical properties and quality of sea duck eggs during pickling. The results showed that mature salted sea duck eggs prepared using the improved mud-packing method exhibited a mass change rate of 1%~3% and salt content of 3.0%~3.4% in egg white, which were much lower than those (2%~-6% and 4.4%) of mature salted sea duck eggs prepared using the traditional mud-packing method. Additionally, the mass change rate of duck eggs significantly increased when using a pickling solution with a salt mass fraction below 20% (P<0.05). The two methods did not differ much in the decreasing trend of water content in egg white during pickling, whereas the traditional and improved methods decreased the water content of egg yolk from 45% to 22% and 17%, respectively. The salt contents of egg white and yolk increased from 0.2% to 3%~4% and 0.9%~1.2%, respectively, indicating that the salt content increased more significantly for egg white. Furthermore, the salt mass fraction significantly impacted water removal and salt infiltration (P<0.05). On day 25 of pickling, the improved method resulted in an oil yield and sandiness exceeding 65% and 90%, respectively, and the yolk texture properties reached the level of those on day 40 when using the traditional method. Moreover, the yolk particle structure became loose, and the formation rate of the hard inner core in yolks was obviously reduced. On day 40 of pickling, the improved method resulted in a salt content in egg white below 4% and a salt content in egg yolk over 0.9%. Therefore, compared with the traditional method, the improved mud-packing method reduced the saltiness of mature salted duck eggs without lowering their oily, loose, and sandy quality. This study can provide a theoretical basis for improving the traditional mud-packing method and optimizing the quality of salted duck eggs.

Abstract:To investigate the effect of storage temperature on the quality and fungal community structure of fresh black Gastrodia elata, fresh Gastrodia elata tubers were stored at different temperatures (1~3 ℃, 3~5 ℃, and 5~7 ℃; relative humidity: 85%~95%) for 30 days. The changes in quality, functional components, and fungal diversity were analyzed. The results of post-harvest quality analysis revealed that, compared with the treatments at 1~3 ℃ and 5~7 ℃, the treatment at 3~5 ℃ maintained a higher energy charge in the fruiting body of the sample (1~3 ℃: 0.26; 3~5 ℃: 0.40; 5~7 ℃: 0.32); inhibited the accumulation of malondialdehyde and proline contents (1~3 ℃: 12.04 mmol/g and 19.56 μg/g; 3~5 ℃: 9.61 mmol/g and 16.44 μg/g; 5~7 ℃: 10.79 mmol/g and 17.79 μg/g), and slowed down the increase of rot rate (1~3 ℃: 96.67%; 3~5 ℃: 8.33%; 5~7 ℃: 63.66%). The hardness of the samples at 3~5 ℃ (11.84 N) was insignificantly different from that of the group at 5~7 ℃ (11.67 N), but significantly lower than that of the group at 1~3 ℃ (19.86 N). The analysis results of functional components indicated that the treatment at 3~5 ℃ effectively delayed the decline of gastrodin, p-hydroxybenzaldehyde, p-hydroxybenzyl alcohol, adenosine, and total amino acids content. The results of fungal diversity analysis showed that the treatment at 3~5 ℃ inhibited more effectively the increase in relative abundance of Cladosporium, Penicillium and Ilyonectria as well as the overall change in fungal diversity on the surface of fresh black Gastrodia elata. In conclusion, 3~5 ℃ was the suitable storage temperature for fresh black Gastrodia elata, and this study provides a theoretical basis for maintaining the storage quality of fresh black Gastrodia elata.

Abstract:This study investigated the inhibitory effect of tea tree essential oil on Listeria monocytogenes and its application in the preservation of chilled fresh pork. The minimum inhibitory concentration (MIC) of tea tree essential oil against Listeria monocytogenes was determined, and the bacterial growth curve and the changes in cell microstructure were observed. The changes in the total bacterial count, total volatile basic nitrogen content, thiobarbituric acid reactive substances content, pH, color, and texture of the pork treated with the tea tree essential oil during refrigeration were analyzed. The results showed that the MIC of tea tree essential oil against Listeria monocytogenes was 4.0 mg/mL, and different treatments with tea tree essential oil exhibited a significant inhibitory effect on Listeria monocytogenes. The tea tree essential oil damaged the structural integrity of the cell membranes and cell walls of Listeria monocytogenes, causing the release of internal cellular contents and ultimately the death of bacteria. Compared with the control group, the total colony number of MIC, 2MIC and 4MIC of the tea tree essential oil treatment groups decreased by 1.18, 1.37 and 1.56 log CFU/g, respectively, and the values of TVB-N and TBARS did not exceed the maximum threshold during storage (0~12 days). Therefore, tea tree essential oil effectively inhibited the growth of microorganisms in pork, delayed the degradation of nitrogen-containing compounds, fat oxidation, color and quality changes in the pork. The results showed that tea tree essential oil could inhibit the growth of Listeria monocytogenes and extend the shelf life of chilled fresh pork for about 3 days, and can be used as a preservative for chilled pork.

Abstract:Vacuum cooling often results in the penetration of pathogenic bacteria into the stomata of vegetables, hindering their removal using conventional washing methods. A control group (CK) was washed with a cleaning agent alone, whereas experimental groups were subjected to ultrasonic (US) or vacuum-ultrasonic (VC-US) treatment combined with washing with a leaning agent to eliminate Escherichia coli that penetrated the stomata of lettuce after vacuum cooling. The E. coli removal efficiency of these treatments and their impact on lettuce quality during storage were evaluated via measuring bacterial colony counts and key physicochemical indicators before and after treatment. The number of E. coli in the lettuce decreased from 4.33 to 1.97 log CFU/cm² after VC-US treatment, indicating higher removal efficiency than that of the US and CK groups (to 3.03 and 2.85 log CFU/cm², respectively; P<0.05). After two days of storage, the VC-US group had a significantly higher L* value but considerably lower a* and b* values than the CK and US groups (P<0.05). The chlorophyll and vitamin C contents in the VC-US group were slightly, but not significantly, lower than those in the CK and US groups, (P>0.05). Additionally, the weight loss rate in the VC-US group (-18.56%) was significantly lower than those in the CK (0.79%) and US (0.16%) groups (P<0.05). In conclusion, VC-US treatment, as a composite method, effectively removes E. coli from within lettuce and does not significant affect lettuce quality. This study provides a theoretical basis and practical insights for the removal of pathogenic bacteria from within vegetables.

Abstract:As a non-thermal sterilization method, pulsed electric field has been widely studied for its ability to control microbial contamination. The inactivation effects of moderate-intensity pulsed electric field (MIPEF) on Escherichia coli were clarified by using different media solutions (sodium chloride, phosphate-buffered saline, and peptone), mass fractions of sodium chloride (0.85%, 0.10%, 0.20%, and 0.30%), electric field intensities (0.16, 0.20, and 0.24 kV/cm), treatment times (20, 40, 60, 80, and 100 min), and bacterial densities (103, 105, 107, and 109). The morphological changes, intracellular macromolecules, and intracellular enzyme activities of E. coli treated with MIPEF were examined. The inactivation effect of MIPEF on E. coli differed under different conditions. The treatment time was positively correlated with the inactivation effect of MIPEF, and the microbial count was reduced by 3.08 lg CFU/mL after 100 min of treatment, with a temperature differential of 2.10 ℃. The bactericidal effect of MIPEF on E. coli was different in various media solutions. The inactivation effect of MIPEF on E. coli decreased significantly as the mass fraction of sodium chloride increased. MIPEF had a greater bactericidal effect when the bacterial density was lower. The results of field emission scanning electron microscopy and transmission electron microscopy demonstrated that cell integrity was compromised following MIPEF treatment. Macromolecular constituents, including proteins and DNA, were significantly reduced following MIPEF treatment. Furthermore, the activities of adenosine triphosphatase (ATPase), succinate dehydrogenase (SDH), and pyruvate kinase (PK) were significantly diminished (P<0.05) in the samples treated with MIPEF for 100 min compared with those in control samples. Furthermore, the activities of Na+K+-ATPase, Ca2+Mg2+-ATPase, and SDH were reduced by 34.21%, 32.26%, and 86.93%, respectively, whereas the activity of PK was reduced by 88.93 U/g prot. This study provides a reference for application of non-thermal sterilization technology in the food industry and clarifies the sterilization mechanism of MIPEF.

Abstract:The patterns of changes in the quality and flavor of fresh mutton over time under different storage conditions (room temperature: 25~30 ℃; refrigerated storage temperature: 4~8 ℃; and near-ice temperature: 0~1±1 ℃) were clarified by monitoring the quality indicators and volatile compounds of fresh mutton using traditional physicochemical analysis and gas chromatography-ion mobility migration (GC-IMS). The results showed that when fresh mutton was stored at room temperature for 22 h, the total volatile base nitrogen (TVB-N) and total bacterial count reached 15.28 mg/100 g and 6.38 lg CFU/g, respectively, both exceeding the standard thresholds. Meanwhile, six characteristic volatile compounds appeared, including 6-methyl-5-hepten-2-ol, 1,4-dioxane, isoamyl alcohol, ethyl acetate, ethanol, and N-nitrosodimethylamine. When fresh mutton was stored at refrigerated storage temperature for 6 d, the TVB-N and total bacterial count were 15.16 mg/100 g and 6.15 lg CFU/g, respectively, and seven characteristic compounds appeared, including tert-amyl ethyl ether, methyl 2-butenoate, methanethiol, 1,4-dioxane, 2-heptanone, 1-heptanol, and octanal. When fresh mutton was stored at near-ice temperature for 19 d, the TVB-N and total bacterial count reached 15.67 mg/100 g and 6.36 lg CFU/g, respectively, and six characteristic volatile compounds emerged, including 3-octanone, octanal, 1-heptanol, heptanal, butanal, and hexanal. The shelf lives of fresh mutton stored at room temperature, refrigerated storage temperature, and near-ice temperature were 22 h, 6 d, and 19 d, respectively. The finding can serve as a theoretical basis and data support for the circulation, sales, and safe consumption of fresh mutton.

Abstract:The optimal conditions for ultrasonic-assisted cellulase extraction of bioactive polysaccharides from alpiniae oxyphylla fructus (AOF) were clarified using response surface methodology and artificial neural network coupled with genetic algorithm. The optimized conditions were a solvent-to-solid ratio of 20 mL/g, cellulase mass fraction of 4%, and ultrasonic power of 300 W for 20 min, which yielded a total polysaccharide extraction of 4.20%. Fourier transform infrared spectra revealed that the extracted sample had polysaccharide characteristic absorption peaks containing uronic acid and pyranose rings. The results of in vitro antioxidant assays showed that the total antioxidant capacity of AOF polysaccharides was 80.76 μmol TE/mL at 300 μg/mL and the ferric reducing antioxidant power was 133.6 μmol FeE/mL. To further evaluate the biological activity of AOF polysaccharides, a zebrafish colitis model was established using 2,4,6-trinitrobenzene sulfonic acid. The results showed that AOF polysaccharides prepared via ultrasonic-assisted cellulase extraction significantly promoted the total antioxidant activity, decreased the expression of the proinflammatory factor interferon-γ, increased the expression of the anti-inflammatory factor interleukin-10, and decreased the production of nitric oxide in zebrafish with colitis. These results indicate that the AOF polysaccharides have anti-inflammatory and antioxidant effects, providing a theoretical basis for the development of AOF products.

Abstract:To clarify the quality characteristics of yak red viscera, four kinds of red viscera, including yak heart, liver, lungs, and kidneys, were used as the raw materials to analyze the discrepancies in shear force, pH, cooking loss, color difference, texture, nutrient composition, gel property, emulsifying property, foaming property and microstructure of various red viscera, and then the correlation analysis, principal component analysis, and cluster analysis were carried out. The results showed that the protein content, emulsifying property, foaming and gel properties of the heart were significantly higher than those of other red organs (P<0.05). The tenderness of the liver was better than that of other red organs (P<0.05). The flesh color and water-retenting capacity of the lung were better than those of other red organs (P<0.05). The water and fat contents of the kidney were significantly higher than those of other red organs (P<0.05); from the perspective of microstructure: the myocardial fibers of the yak heart were arranged densely and evenly; the liver tissue structure was clear and neatly arranged; the lung tissue was loosely arranged; the kidney tissue structure was clear and closely arranged. Three principal component factors were extracted, including nutritional factor PC1 (35.38%), texture factor PC2 (27.17%), and emulsifying factor PC3 (22.64%). Combined with the results of cluster analysis, it can be concluded that the lungs were suitable for steam cooking; the heart and kidneys were suitable for processing into minced meat products; the liver was suitable for stir-frying. In summary, t yak red viscera products have their own characteristics. The results of this study provide a theoretical basis and data support for deep processing of yak red viscera.

Abstract:To improve the quality and efficiency of single-batch mass drying of wolfberry, a room-temperature vacuum drying system was designed and manufactured to have a capacity to dry 1 125 kg of fresh wolfberry fruits per batch. On the basis of no-load test results, the drying efficiency of the system for wolfberry was studied by side pumping, end pumping, and combined pumping. The vacuum capacity and heating capacity of the system were experimentally proved to meet the design requirements. During vacuum drying at room temperature, the water loss rate of wolfberry peaked at 4 kg/h and then gradually decreased to 1.5 kg/h with drying time. Compared with end pumping and combined pumping, side pumping resulted in a shorter drying time (7.00% and 3.13% less, respectively) and a higher dehumidification efficiency (29.27% and 19.23% higher, respectively). As the drying temperature decreased (from 60 to 53 ℃), the proportion of high-quality dried wolfberry fruits gradually increased (from 54% to 79%), and the proportion of air-filled wolfberry fruits gradually decreased. Local temperature and humidity uniformity in the drying oven is an important factor affecting these proportions in the final dried wolfberry products. The research results lay a foundation for the development of a room-temperature vacuum-drying system with a capacity to dry 4 tons of fresh wolfberry fruits per batch, while providing a reference for the development of these systems for fruits, vegetables, and Chinese herbs as well as for optimizing the final vacuum-dried products of wolfberry.

Abstract:The quality of fresh Gastrodia elata Blume (G. elata) processed and dried by using different methods was compared to clarify the effects of different drying methods on the quality of dried G. elata. Specifically, the G. elata samples were unprocessed (NGB) or steam-processed (PGB) before undergoing natural air drying, hot air drying, vacuum freeze drying (CFD), or vacuum microwave drying (VMD). The quality of the dried samples was then evaluated in terms of microstructure, contents of eight functional components (such as gastrodin and p-hydroxybenzyl alcohol), and in vitro antioxidant and antihypertensive activity. The results showed that the processing and drying methods significantly impacted the morphology and functional component contents of dried G. elata. The PGB-CFD group had the highest total functional component content of 42.71 mg/g, followed by the NGB-VMD group, at 30.98 mg/g. The NGB-CFD group exhibited the highest antioxidant capacity, with the total antioxidant capacity, DPPH free radical-scavenging capacity, and ABTS+ free radical-scavenging capacity reaching 68.54%, 50.86%, and 41.05%, respectively. The PGB-CFD group showed the highest ACE inhibition rate of 82.50%. In conclusion, the NGB-CFD method is the optimal drying method for G. elata slices. This study provides reference methods and basic data for further precise processing of fresh G. elata.

Abstract:Samples of longissimus dorsi muscle of pigs were subjected to static magnetic field-assisted superchilling (at -2 ℃ and magnetic field strengths of 1, 2, 3, 4, and 5 mT) and conventional superchilling (at -2 ℃) without applying a magnetic field. The freezing curves, total number of colonies, storage loss rates, cooking loss rates, pH values, color, shear force values, fat oxidation, and microstructures of the samples after storage for 0, 5, 10, 15, 20, and 25 days were determined to reveal the effects of static magnetic field-assisted superchilling on the freezing and thawing quality of pork. The results show that the ice crystals formed by static magnetic field assisted-superchilling at 3, 4, and 5 mT were small and uniform, and the damage to the internal muscle fiber structures of the meat samples was relatively small, indicating that the original quality of the meat samples was better maintained. Meanwhile, on the 25th day of storage, the total number of colonies, fat oxidation, and b* value in the 3 mT magnetic field-assisted superchilling group were 5.58 lg CFU/g, 0.24 mg/kg, and 10.94, respectively, which were significantly lower than those in the control group (superchilling without a static magnetic field) (P <0.05). These results indicate that the storage and preservation performances were improved. In conclusion, static magnetic field-assisted superchilling can help alleviate the reduction in pork quality caused by ice crystals, delay the deterioration of pork quality during storage, improve the quality of thawed meat, and extend the shelf life of pork. In particular, 3 mT magnetic field-assisted superchilling exhibited the best effects on pork storage and preservation. This study provides new ideas for the development of low-temperature storage and preservation technology for pork.

Abstract:To compare the effects of different modification methods on the structures and free radical scavenging abilities of Laminaria japonica polysaccharides, carboxymethylation, sulfation and phosphorylation methods were used to modify chemically Laminaria japonica polysaccharides. Ultraviolet spectroscopy, Fourier transform infrared spectroscopy, Congo red experiment, periodate oxidation and free radical scavenging ability experiments were used to compare the differences in the structure and DPPH•, •OH and O2-• scavenging abilities of Laminaria japonica polysaccharides before and after modification. The results showed that -OH was transformed into -COO, O-S and P-OH, respectively, indicating that carboxymethylation, sulfation and phosphorylation of Laminaria japonica polysaccharides were successful in the modification of Laminaria japonica polysaccharides. Compared with the polysaccharide before modification, the threestrand helix structure disappeared after modification. There were significant differences in the bond types of glycosidic bonds before and after modification: the glycosidic bond types of the Laminaria japonica polysaccharides and the phosphorylated Laminaria japonica polysaccharides were (1→6), (1→2, 1→4), (1→3), with their molar ratios being 0.04:0.05:0.91 and 0.03:0.05:0.92, respectively. The glycosidic bond types of carboxymethylated Laminaria japonica polysaccharide and sulfated Laminaria japonica polysaccharide were (1→2, 1→4) and (1→3), with their molar ratios being 0.02:0.98 and 0.10:0.90, respectively. The scavenging rates of carboxymethylated Laminaria japonica polysaccharide and phosphorylated Laminaria japonica polysaccharide against DPPH•, •OH and O2-• increased by 7.38%, 12.17% and 0.78%, and 9.12%, 40.22% and 14.52%, respectively. The scavenging rates of sulfated Laminaria japonica polysaccharides against DPPH• and O2-• increased by 24.48% and 5.16%, respectively, whilst the scavenging ability against •OH was weakened, with the scavenging rate being reduced by 34.82%. The analysis of comprehensive scores revealed that the half-maximal inhibitory concentrations (IC50 values) of the carboxymethylated, sulfated and phosphorylated Laminaria japonica polysaccharides were 2.53, 4.03 and 1.66 mg/mL, respectively, indicating that phosphorylation modification was superior to carboxymethylation modification and sulfation modification in improving the free radical scavenging ability of Laminaria japonica polysaccharide.

Abstract:Spectrum-effect correlation was used to screen antioxidant active components from the stems and leaves of Astragalus membranaceus. A total of 19 batches of ethyl acetate extracts from the stems and leaves of A. membranaceus with different geographical origins were used as test samples. High-performance liquid chromatography fingerprints of the samples were established using the similarity evaluation system of chromatographic fingerprints of traditional Chinese medicine, and the in vitro antioxidant activities of different samples were investigated. The correlation between common peaks of the stems and leaves of A. membranaceus and their antioxidant activity indices was clarified using Pearson correlation analysis, partial least squares regression, and grey correlation analysis. The results showed that 13 common peaks (F1~F13) were calibrated from the fingerprints of the 19 batches of samples. The similarity values between samples from each batch and the control fingerprint were 0.912~0.997. Ethyl acetate fractions from the stems and leaves of A. membranaceus with different geographical origins had significantly different antioxidant capacities (P<0.05). Further spectrum-effect correlation analysis showed that F3, F5, F7, F8, F10, and F12 were the main characteristic peaks reflecting the antioxidant activity of the stems and leaves of A. membranaceus. Among them, F5, F10, and F12 were respectively identified as quercitrin, calycosin, and kaempferol through comparison with the reference. This study provides an important theoretical foundation for further development of antioxidant products from the stems and leaves of A. membranaceus.

Abstract:Vacuum cooling often results in the penetration of pathogenic bacteria into the stomata of vegetables, hindering their removal using conventional washing methods. A control group (CK) was washed with a cleaning agent alone, whereas experimental groups wer

Abstract:Different proportions (10%, 20% and 50%) of highland barley flour (HBF) were added to wheat dough to clarify the effect of HBF proportion on the network structure of wheat gluten. The measured thermomechanical properties of the dough samples showed that when the HBF proportion increased, the mixed dough samples showed a significant increasing trend (P<0.05) in water absorption rate, formation time, and protein-weakening degree (C2), but an overall decreasing trend in gelatinization degree, stability, and starch retrogradation value. This indicates that the protein-weakening and gelatinization degrees of starch in mixed dough were significantly affected by HBF addition. Scanning electron microscopy and confocal laser scanning microscopy images revealed that adding a higher proportion of HBF hindered the gluten-starch interaction, thus disrupting the network structure of gluten. Raman and FT-IR spectra indicated that the protein spatial structure was altered and that the disulfide bonds were transformed from a relatively stable g-g-g configuration into an unstable t-g-t configuration. The disulfide bond content was found to be the highest (14.41 μmol/g) in the control group and 21.44% less than that of the control group when 50% HBF was added. In summary, the stability and spatial structure of wheat gluten were disrupted by the addition of HBF in any proportion. This study provides a theoretical foundation and practical reference for the development of cakes with HBF.

Abstract:Acanthopanax aculeatus fruit can be used as medicine and food. To improve the fruit utilization rate, Acanthopanax enzyme jelly samples were prepared. The jelly samples were assessed for texture properties, sensory score, and syneresis rate, and the optimal content of each raw material was determined using single-factor tests. The jelly formula was optimized by response surface experiments. Compound thickener, Acanthopanax enzyme, and steviol glycoside contents significantly impacted jelly quality. The optimal formula includes 2.0% pectin, 1.0% konjac gum, 45% Acanthopanax enzyme, 1.0% steviol glycoside, 2.0% citric acid, and 49% purified water. Jelly samples prepared according to this formula achieved a sensory score of 89.6 and a syneresis rate of 2.14%, which were better than those of other tested combinations. The structural properties (springiness: 16.68 mm, resilience: 0.46, firmness: 22.86 N, and chewiness: 34.95 mJ) of these jelly samples were comparable with those of commercially available jelly. Additionally, these jelly samples were bright purplish red, uniform in color, glossy, and translucent, with a strong Acanthopanax enzyme flavor, no objectionable odor, a springy and chewy mouthfeel, moderate sour and sweet taste, uniform texture, and firm structure. These samples thus achieved high sensory scores and excellent texture properties. This study provides insights and references for further processing of Acanthopanax fruits and development of Acanthopanax health foods.

Abstract:Whole Gentiana scabra bunge plants were subjected to extraction using an aqueous solvent, combined with heating and stirring, to obtain gentiopicroside. Optimal extraction conditions were determined using a nine-run, four-factor, three-level orthogonal test. The G. scabra bunge extract was purified using an AB-8 macroporous adsorption resin. Optimal purification conditions were determined by single-factor experiments, and the antioxidant, antibacterial, and anti-inflammatory activities of gentiopicroside were examined. The optimal extraction process required a solid:solvent ratio of 1:15, extraction temperature of 85 ℃ , stirring extraction duration of 1 h, and three extraction cycles. The extraction yield of gentiopicroside was 88.77%. The purities before and after purification were 5.70% and 13.34%, respectively. The optimal purification process involved a wet resin:medicinal material ratio of 2.5:1, loading liquid concentration of 0.15 g/mL, loading volume of 2.67 BV, loading flow rate of 1 BV/h, volume of 3 BV, and elution flow rate of 2 BV/h for pure water, and a volume of 4 BV and elution flow rate of 3 BV/h for 30% (V/V) ethanol. The corresponding elution rate and purity of gentiopicroside were 82.14% and 50.63%, respectively. The purified gentiopicroside exhibited a scavenging rate of 93.36% for DPPH radical, inhibitory zone diameter of 15.50 mm for Malassezia, and inhibition rates of 97.67%, 93.50%, and 97.03% for NO, TNF-α, and IL-1α, respectively. Gentiopicroside significantly inhibited ear swelling in mice, resulting in a reduction of the ear swelling rate to 126.88%. Using the optimized techniques for gentiopicroside extraction and purification resulted in an increase in the purity of the active substance by approximately 8 fold. The antioxidant, antibacterial, and anti-inflammatory activities of gentiopicroside were preliminarily assessed. It was speculated that gentiopicroside activity could be enhanced by improving its purity through optimization of the extraction and purification processes. This study clarified that gentiopicroside exhibits excellent antioxidant, antibacterial, and anti-inflammatory effects, establishing a crucial foundation for the rational development and utilization of G. scabra bunge.

Abstract:The dynamic sensory characteristics and flavor components of different spicy strip products were identified, and their relationships with consumer preferences were clarified to provide a reference for optimizing the taste and flavor quality of spicy strip products. Through sensory evaluation of 12 commercially available spicy strip products, four products with representative differences in texture and flavor were selected as the research objects. Temporal dominance of sensation, texture analysis, oil-distribution analysis, electronic nose, and headspace solid-phase microextraction-gas chromatographymass spectrometry were used to distinguish and compare the volatile compounds in the four products. The results showed that the spicy strip product B had a firm texture, rich oil content, and uniform oil distribution. Among the volatile compounds detected in the products, the amounts of linalool (12.58%) and anethole (12.71%), which are characteristic volatile substances in pepper and fennel, were relatively high in spicy strip product B, imparting more prominent flavor characteristics. Therefore, product B was more popular with consumers than the other brands of spicy strips tested. Among the 52 volatile compounds detected, pyrazines, alcohols, olefins, and esters were the main volatile compounds in spicy strip products. Particularly, linalyl acetate (6.71%~14.11%), γ-terpinene (6.58%~10.75%), and linalool (3.78%~12.58%) were relatively abundant in the samples. This study can provide a theoretical reference for the development and quality control of new spicy strip products.

Abstract:The black tea processed from ‘Gougunao No. 2’ (GGN), a new cultivar developed in Jiangxi Province, has a unique aroma. To clarify the aroma composition of this tea, the aromas of black teas processed from GGN and other main tea cultivars in Jiangxi province-including ‘Fudingdabai’ (FD), ‘Yingshuang’ (YS), and ‘Quntizhong’ (QTZ)-were analyzed through sensory evaluation, electronic nose, and gas chromatography-mass spectrometry (GC-MS). The sensory evaluation data showed that GGN black tea, which possessed a rich honey- and orchid-like aroma, had the highest aroma score (95.33), followed by YS black tea (floral aroma, 92.33), FD black tea (sweet potato-like aroma, 91.00), and QTZ black tea (sweet aroma, 89.33). The electronic nose identified aroma differences among the black teas processed from different cultivars. GC-MS analysis showed that the contents of total volatiles, alcohols, aldehydes, esters, and heterocyclic compounds in GGN black tea were significantly higher than those in other cultivars. Compared with GGN black tea, 333, 294, and 240 differential components were screened in YS, QTZ, and FD black tea, respectively, including 92 common differential components. As revealed by odor activity value analysis, 4,5-dimethyl-3-hydroxy-2,5-dihydrofuran-2-one, 1-octen-3-one, methyl salicylate, (E,E)-2,4-nonadienal, trans-2,4-decadienal, octen-3-ol, 2-pentylfuran, p-cresol, hexanal, and benzaldehyde contribute remarkably to the honey- and orchid-like aroma of GGN black tea. The results are of great significance for guiding the production of high-quality Jiangxi black tea.

Abstract:Procambarus clarkii from two distinct aquaculture areas (Xiantao and Qianjiang in Hubei Province) were examined to clarify flavor differences between raw and steamed P. clarkia meat. The contents of flavor-contributing nucleotides, organic acids, free amino acids, and inorganic ions in P. clarkii meat were quantitatively determined. The flavor intensities of taste substances were assessed with taste activity values and equivalent umami concentrations, and an electronic tongue was employed for taste and odor analyses. Thermal processing revealed adenosine monophosphate (AMP) to be the predominant taste nucleotide, with respective AMP concentrations in P. clarkii meat from Xiantao (denoted as AX-1) and that from Qianjiang (denoted as AX-2) of 2.914 and 2.751 mg/g contributing significantly to the umami taste of the meat. Glycine and alanine were identified as primary contributors to sweet taste, and valine and histidine were associated with bitter taste. Notably, thermal processing increased respective glycine and alanine contents in AX-1 by approximately 50.79% and 3.79%. These values were approximately 67.03% and 28.82%, respectively, in AX-2. Interestingly, the concentration of bitter amino acids in AX-1 also rose substantially after thermal processing, thereby influencing the overall taste. The equivalent umami concentrations demonstrated an upward trend. The contents of inorganic ions, the taste analysis via electronic tongue, and the sensory evaluations aligned with the observations about nucleotides and amino acids. The findings of this study indicate that there are pronounced differences in the taste attributes of P. clarkii meat sourced from various aquacultural regions. In a comprehensive evaluation, the flavor of thermally processed AX-2 was deemed best.

Abstract:To investigate the dynamic changes in the aroma components of Rucheng Baimao (Camellia pubescens) black tea, gas chromatography-mass spectrometry (GC-MS) technology was used to detect the volatile components in fresh tea leaves, withered tea, rolled tea, fermented tea, and dried tea. The results showed that a total of 129 volatile components were detected, which could be divided into alcohols, aldehydes, esters, ketones, alkanes, alkenes, and other seven categories. Among them, alcohols accounted for 23.26% (30 types), esters accounted for 27.13% (35 types), and alkanes accounted for 23.26% (30 types), which were the main categories of volatile components in the processing process. The five volatile components with rOAV>1 in the dry tea, linalool, phenethyl alcohol, geraniol, 2-phenylethanal, and β-ionone, are important contributors to the aroma quality of Rucheng Baimao (Camellia pubescens) black tea. The relative contents of linalool, phenethyl alcohol, geraniol, 2-phenylethanal, and β-ionone all increased first and then decreased during the processing process. Linalool reached the highest content (154.80 μg/kg) during the withering stage, whilst geraniol, 2-phenylethanal, and β-ionone had the highest levels during the fermentation stage (28.41, 10.75 and 4.09 μg/kg, respectively). The relative content of phenethyl alcohol showed a fluctuating trend during the processing process, and reached the highest value (10.66 μg/kg) during the fermentation stage. The metabolic pathways these five volatile components were involved were mainly the MVA and MEP pathways, the phenylalanine metabolism pathway, and the carotenoid degradation pathway for volatile terpenoids biosynthesis. The results of this study can provide a theoretical reference basis for the regulation of aroma quality of Rucheng Baimao (Camellia pubescens) black tea.

Abstract:Based on the droplet digital PCR technology, a quantitative duplex droplet digital PCR detection method for genetically modified maize MON87411 was established. The results showed that only the maize MON87411 could be specifically detected by this method, with no amplification reaction being observed in other samples. In the amplification stability test, the copy number RSD of endogenous and exogenous genes in three parallel amplifications were 0.56% and 3.93%, respectively, which met the requirement of RSD less than 25%.The linear correlation curve showed that when the mass concentration of template DNA was between 50 ng/μL and 0.08 ng/μL, there was a good linear relationship between the copy number of target genes and the template DNA concentration, with correlation coefficients R2 greater than 0.99. The quantitative linear range of MON87411-specific gene was between 26.6 and 17 086.6 copies with the limit of quantification (LOQ) being 1.34 copies/μL. In the accuracy test, the average copy number content at the five different template DNA mass concentrations were 52.14%, 63.09%, 66.08%, 60.50% and 52.16%, respectively, which were all within the theoretical copy number content range. In summary, the quantitative duplex droplet digital PCR detection method established in this study had high specificity, good stability, wide quantification range, high sensitivity and accuracy, thus can be used for the quantitative detection of genetically modified maize MON87411.

Abstract:Food safety issues impact individual physical health and regional economic development. Efficient and convenient detection methods are key to achieving relevant risk assessment and safety regulation. Traditional detection techniques are cumbersome and time-consuming, and fail to meet the market demand for rapid detection. Loop-mediated isothermal amplification (LAMP) is a promising candidate method for commercial applications in food safety inspection owing to its high speed, high sensitivity, strong specificity, and low cost. This study reviews the principle, classification, and product detection methods of LAMP, with a focus on analyzing the application of colorimetry in LAMP, and summarizes progress made in food safety inspection in the past five years, aiming to provide a reference for developing fast, on-site, lowcost methods for food safety inspection.

Abstract:Sacha inchi (Plukenetia volubilis Linneo, also known as South American oil vine) is native to the Peruvian Amazon and widely cultivated in Yunnan, China. Sacha inchi has been recognized as a sustainable crop worldwide, and has been widely used in food and daily necessities, thus has wide application prospects. The main active components in different parts of Sacha inchi vary. Its seeds are rich in active components such as polyunsaturated fatty acids, active proteins/peptides and polysaccharides, whilst the leaves and shells of Sacha inchi contain mainly phenolic compounds, such as flavonoids. These active components endow Sacha inchi with various biological activities, including antioxidant, anti-inflammatory, memory-improving, vision-improving, blood pressure-lowering, and blood lipid-reducing effects. However, there is a lack of systematic summary of the active components and efficacies of different parts of Sacha inchi. This article summarizes the primary active components and efficacies of different parts of Sacha inchi, including seeds, shells, and leaves, with a focus on the mechanisms underlying the lipid-lowering, blood sugar-reducing, and uric acid-lowering effects of Sacha inchi's active components, in order to provide a scientific foundation for the high-quality development of Sacha inchi industry.

Abstract:Minimally Processed (MP) fruits and vegetables are fresh fruits and vegetables that remain fresh after graded washing, peeling and cutting, preservation and packaging. Baby carrots are representatives of fresh-cut carrots, which have the characteristics of being small in size, crisp, sweet, and convenient to be consumed. However, baby carrots are susceptible to microbial contamination, tissue whitening, and water loss during peeling, cutting, and storage, which decreases the edible quality and easily causes contamination by foodborne pathogenic bacteria. In this paper, we reviewed the preservation technologies for the inhibition of bacteria and white-blush of Baby carrot as a representative of fresh-cut carrots, including chemical disinfectant treatment, use of organic acid and/or ethylene inhibitor, coating treatment, steam and hot water treatment, microwave treatment, low-temperature treatment, cold plasma, irradiation, high-pressure carbon dioxide, and combination of treatment techniques. Finally, the research direction of Baby carrot preservation is prospected, to provide a reference for the storage and preservation of similar fresh-cut fruits and vegetables.

Abstract:Food packaging plays a key role in maintaining food quality and extending shelf life. However, the traditional plastic packaging has environmental pollution and sustainability problems, so seeking sustainable and environmentally friendly alternative materials has become a hot spot of current research. Compared with single-layer bio-based films, multi-layer bio-based films show better mechanical properties, barrier properties, etc. Since the multi-layer packaging materials have a more complex internal structure and larger interlayer spaces between the layers (which makes them more suitable for the introduction of active substances), these materials have attracted extensive attention and research in recent years. In this paper, the construction methods of multilayer bio-based films and their applications in the field of packaged foods are reviewed. The classification of biobased packaging materials is discussed, and the preparation methods of multi-layer biobased films, including layer self-assembly technology (LbL), electrodynamic method, co-extrusion method and solvent casting method, as well as their advantages and disadvantages are introduced. The recent research progress of multi-layer biobased packaging in the field of food are comprehensively analyzed and summarized. The future research direction and development trend of bio-based multilayer films are proposed.