Abstract:To investigate the immunomodulatory effects of the combination of a probiotic complex and oligofructose on mice, an immunocompromised mouse model was successfully established by injecting cyclophosphamide according to the Methods for Testing and Evaluating the Functions of Health Foods (2023 Edition), thereby reducing the immune function of mice. The effects of low, medium, and high (6×106, 6×107, and 6×108 CFU each) doses of combined probiotic complex and oligofructose (1.5 mg/pc) on body weights, immune organ indices, and cellular, humoral, and nonspecific in immunocompromised mice were determined. The experimental results showed that the co-infusion of probiotic complex and oligofructose resulted in a significant increase in the body weight, thymic index, and splenic index of immunocompromised mice, with the latter two in the high-dose group increasing by 104.15% and 46.12%, respectively, suggesting an improvement in the pathological characteristics of the thymus and spleen. Moreover, in the high-dose group, the optical density difference value, foot plantar thickness, hemolytic empty spot number, half hemolytic value, phagocytic index α, phagocytic index, and NK cell activity increased by 83.87%, 94.12%, 51.49%, 31.83%, 46.53%, 54.29%, and 86.92%, respectively, compared with values in the model group, indicating significantly improved cellular, humoral, and non-specific immunity in immunocompromised mice. Levels of the serum cytokines IL-2, IL-6, and TNF-α also increased in a dose-dependent manner. These findings indicate that the administration of a probiotic complex and oligofructose to mice can enhance their immune function.

Abstract:To explore the protective effect of resveratrol on oxidative casein- induced learning impairments in mice and the possible underlying mechanism, thirty-six 7-week-old Kunming male mice were randomly divided into four groups: the blank control group (CT), oxidized casein group (CO), resveratrol low-dose group (LR), and resveratrol high-dose group (HR). The experimental results showed that after the resveratrol intervention, the learning and memory abilities of mice were improved, the latency of finding the platforms was shortened by 20.85% and 9.63%, respectively, for the low-dose group (LR) and the high-dose group (HR), the number of crossing the platforms increased by 53.63% and 47.57%, respectively, and the percentage of residence time in the target quadrant (where the platform was located) out of the total time increased by 103.69% and 53.68%, respectively. In addition, the body’s antioxidant capacity increased, the level of total antioxidant capacity (T-AOC) and the activities of antioxidant enzymes (SOD and CAT) significantly increased (P<0.01), whilst the content of malondialdehyde (MDA) decreased (P<0.05). The morphology of hippocampus and amygdala nerve cells were regular, the inflammatory aggregation state was ameliorated, the expressions of inflammation-related genes (IL-1β, IL-6, and TNF-α) were significantly down-regulated (P<0.05), and the expressions of learning and memory related genes (BDNF, TrkB, and CREB) were significantly up-regulated (P<0.01). In conclusion, resveratrol could effectively ameliorate the oxidized casein-induced learning and memory impairments in mice, and the underlying mechanism may be related to the activation of the BDNF/TrkB/CREB signaling pathway to improve the antioxidant and anti-inflammatory capabilities of the body.

Abstract:This study aimed to explore the protective effects and underlying mechanisms of black corn polysaccharide on renal injury in diabetic mice. A murine diabetes mellitus model was established using intraperitoneal streptozocin injection, followed by black corn polysaccharide intervention. Urine albumin content, urine albumin/creatinine ratio, serum creatinine (SCr), blood urea nitrogen (BUN), triglyceride (TG), total cholesterol (TC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and malondialdehyde (MDA) levels were measured using biochemical assay kits. Histopathological changes in kidney tissues were assessed through HE, PAS, and Masson staining. Enzyme-linked immunosorbent assay (ELISA) was employed to measure the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and interleukin-10 (IL-10). Western blot analysis was performed to determine the protein expression of phosphorylated p65 (p-p65), p65, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1). The results showed that compared with those in the model group, the levels of SCr, BUN, MDA, TG, and TC in the high-dose black corn polysaccharide group were reduced by 56.41%, 54.89%, 45.34%, 13.10%, and 11.85%, respectively. Additionally, the 24 h urinary protein content and UACR levels decreased (P<0.01), while the activities of SOD, GSH-Px, and CAT increased (P<0.01). The renal tubules were neatly arranged, and the degree of fibrosis and glycogen deposition in the kidney tissue was reduced. The serum levels of pro-inflammatory factors IL-1β, IL-6, and TNF-α were reduced by 36.85%, 30.77%, and 36.85%, respectively, while the level of the anti-inflammatory factor IL-10 was increased by 32.46% (P<0.01). The expression of Nrf2 and HO-1 was increased by 68.33% and 77.09%, respectively, while the expression of p-p65/p65 was decreased by 35.22%. These results indicate that black corn polysaccharide exerts a considerable protective effect on diabetic kidney damage, offering a scientific basis for the treatment of patients with clinical diabetic nephropathy.

Abstract:To explore the physicochemical properties of Viola philippica Polysaccharide (VPP) and its effect on the exercise endurance in mice, the physicalcochemical properties of crude and purified polysaccharides were determined. The serum biochemical metabolism indexes and liver oxidative stress levels of mice were measured after exhaustive swimming experiments. The results showed that VPP could be separated and purified into two main components, VPP-A (55.45%) and VPP-B (45.32%), which were further purified to yield VPP-A1 and VPP-B1. The weight-average molecular weights of VPP-A1 and VPP-B1 were 2.532×106 and 5.843×105 g/mol, respectively. VPP-A1 was composed of mannose, glucose, and fucose in a molar ratio of 1.76:1.00:0.21, whilst VPP-B1 was composed of glucose, fucose, and glucuronic acid in a molar ratio of 1.00:1.160:1.73. Both VPP-A1 and VPP-B1 had certain water- and oil-holding properties, as well as good thermal stability. Compared with CON, the exhaustive swimming time of mice in the VPP, VPP-A1, and VPP-B1 groups increased significantly by 74.26%, 31.99%, and 45.83% (P<0.05), respectively, their hepatic glycogen and muscle glycogen contents significantly increased by 151.18%, 52.44%, 77.48%, and 117.26%, 50.53%, 74.53%, respectively (P<0.05), and their blood lactate and blood urea nitrogen levels were significantly reduced by 50.23%, 23.24%, 32.50% and 56.94%, 33.63%, 45.01%, respectively (P<0.05). Meanwhile, VPP, VPP-A1, and VPP-B1 all significantly improved the activities of antioxidant enzymes in the mice’s livers, reduced their contents of malondialdehyde, and alleviated oxidative stress damage to their livers. In summary, VPP had a significant improving effect on the exercise endurance of mice, and such an effect of the crude polysaccharide was greater than those of the purified polysaccharides. This study provides a research foundation for the indepth development of Viola philippica polysaccharide into sports functional foods.

Abstract:In this study, the protective effect and underlying mechanism of American Ginseng Polysaccharide (AGP) against H2O2-induced oxidative damage in HepG2 cells were investigated based on the Nuclear Factor-erythroid 2-related Factor 2 (Nrf2)/Heme Oxygenase-1 (HO-1) signaling pathway. H2O2 at a concentration of 300 μmol/L was selected for establishing an oxidative damage model of HepG2 cells (cell survival rate: 62.23%), and 320, 640 or 1 280 μg/mL of AGP was given for intervention, and the reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH), and malondialdehyde (MDA) levels in each group of cells were measured separately; the expressions of Nrf2, SOD1, SOD2, HO-1, and CAT proteins in the cells were analyzed by Western blot. The results showed that the AGP treatment had insignificant effect on the proliferation of HepG2 cells, and AGP at the three dose could significantly increase the survival rate of oxidatively damaged HepG2 cells, which were 89.36%, 91.42%, and 91.06%, respectively; The levels of ROS (15.74%, 20.71%, and 25.39%) and MDA content in oxidatively damaged cells were significantly reduced, and the levels of intracellular SOD, GSH, and CAT proteins were effectively elevated; Western blot results showed that AGP could significantly up-regulate the protein expression levels of Nrf2, SOD1, SOD2, HO-1, and CAT (P<0.05, P<0.01). In summary, AGP can ameliorate the oxidative damage in HepG2 cells by regulating the Nrf2/HO-1 signaling pathway. The results of this study can provide more data support for the further development and utilization of AGP.

Abstract:In this study, an animal model of obese mice was established by high-fat diet induction, and different doses of carnosic acid (50 or 100 mg/kg•bw) were used to intervene in mice on high-fat diet. After the intervention, the obesity indexes and body weights of mice in different groups were compared. Real-time fluorescence quantitative PCR was used to detect and analyze the liver and epididymal adipose tissue, and the differences in the expression levels of lipid metabolism-related genes in mice of different groups were compared. The results showed that the obesity rate of high-fat diet mice exceeded 20%. Carnosic acid could ameliorate the weight gain of high-fat diet mice and regulate the expression of lipid synthesis- and metabolism-related genes. Carnosic acid intervention could down-regulate the expression levels of PPAR-γ and FASN genes in the liver and epididymal adipose tissues of obese mice (P<0.05), whileup-regulating the expression levels of lipid decomposition-related genes. Among which, the relative expression levels of PPAR-α, HSL and CPT-1 genes in the liver of the mice in the high-dose carnosic acid intervention group were 2.36 times, 2.26 times and 1.47 times those of the highfat group, respectively. The intervention of carnosic acid could down-regulate the expression levels of the PPAR-γ and FASN genes in the liver of obese mice, as well as the expression levels of the PPAR-γ, FASN and SCD-1 genes in the epididymal adipose tissues, thereby inhibiting the differentiation of adipocytes and reduces the rate of adipogenesis. The intervention of carnosic acid could also up-regulate the expression levels of the PPAR-α, HSL and CPT-1 genes in the liver of obese mice, and the expression level of the HSL gene in the epididymal adipose tissues, thereby promoting triglyceride hydrolysis and mitochondrial thermogenesis, accelerating the oxidative decomposition of fat, and eventually inhibiting the accumulation of fat in the liver and adipose tissues. The above results indicate that the intervention of carnosic acid can ameliorate obesity by regulating the expression of genes related to lipid synthesis and decomposition.

Abstract:Proteins recovered from surimi rinsing wastewater were used as raw materials to prepare protein hydrolysates with antioxidant and hypoglycemic activities. Single-factor experiments and orthogonal optimization analysis were conducted with five factors, namely substrate mass fraction, pH, enzymatic hydrolysis time, temperature, and enzyme dosage, to determine the optimal process conditions for the preparation of peptides recovered from surimi rinsing wastewater by hydrolysis with a compound protease. The amino acid composition and molecular weight distribution of the peptides were also analyzed. Results indicated that at a substrate mass fraction of 3%, the optimal enzymatic hydrolysis conditions were as follows: temperature: 45 ℃, pH: 8.0, time: 4 h, enzyme dosage: 4 000 U/g prot. Under these conditions, the degree of hydrolysis and peptide content of the obtained enzymatic hydrolysis product were 23.62% and 23.21 mg/mL, respectively. The prepared peptides had a total amino acid content of 58.40 g/100 g and a high hydrophobic amino acid content (22.84 g/100 g) that accounted for 39.11% of the total amino acid content. Molecular weights were mainly concentrated in the <1 kDa range (88.02% of all molecules). Results of in vitro antioxidant and hypoglycemic activity testing revealed that the peptides exerted good scavenging effects on OH• and DPPH• with semi-inhibitory concentrations (IC50) of 8.28 mg/mL and 2.54 mg/mL, respectively. The IC50 values for α-glucosidase and α-amylase were 22.82 mg/mL and 26.31 mg/mL, respectively. In conclusion, peptides prepared by enzymatic hydrolysis of proteins recovered from surimi rinsing wastewater demonstrated good in vitro antioxidant and hypoglycemic effects. The results of this study can potentially provide a novel approach to the high-value utilization of recovered proteins.

Abstract:The gene encoding the carbon metabolism control protein, ccpA, plays a critical role in the utilization of carbon sources and environmental adaptation of lactic acid bacteria. The ccpA gene of Lacticaseibacillus rhamnosus hsryfm 1301 was completely deleted using an in-frame, marker-free method. The growth status of L. rhamnosus hsryfm 1301 and its ccpA deficient strain were compared under different conditions. The use of glucose, fructose, mannose, galactose, or lactose as the sole carbon source resulted in the wild-type strain reaching the stationary phase 4~5 h faster than the ccpA mutant. At low mass fraction of mixed carbon sources (0.2%) and the presence of non-preferred carbon sources, the wild-type strain exhibited a secondary growth phase. In contrast, the mutant strain did not exhibit the secondary growth phase but entered the stationary phase earlier than the wild-type strain. Under low-carbon source conditions, the biomass of the ccpA mutant was greater (approximately 0.3 of OD600) than that of the wild-type strain. The ccpA gene enhanced the growth rate of L. rhamnosus, but it inhibited growth under low carbon source conditions. The effects of the ccpA gene on the growth of L. rhamnosus varied across different environments, conferring a growth advantage to the strain under conditions with ample carbon sources.

Abstract:Ginkgo biloba L. seed (GBS) is a traditional Chinese medicinal and food resource, and its use as a raw material to brew fruit vinegar can provide a new direction for the utilization of abundant GBS resources. However, balancing ginkgotoxin degradation, active ingredient retention, and bitter flavor attenuation represents a bottleneck in the ginkgo vinegar brewing process. In this study, six strains of Aspergillus oryzae were isolated from naturally fermented soybean paste blocks and identified using multiphase taxonomy methods. Among them, strain A. oryzae SSC3-6 had the fastest growth rate and the best coverage effect for preparing ginkgo koji, and its amylase, glycosylase, and cellulase activities were all the highest, with values of 8.35, 4.17, and 7.89 U/mL, respectively. When comparing enzymatic hydrolysis rates, ginkgo vinegar produced using A. oryzae SSC3-6 has a faster production rate, and the MPN content in the vinegar decreased significantly from 84.65 to 24.30 μg/mL (P<0.05). The contents of γ-aminobutyric acid and flavonoids increased significantly from 0.15 mg/mL and 83.00 mg/L to 1.08 mg/mL and 133.96 mg/L, respectively (P<0.05). Furthermore, the A. oryzae ginkgo vinegar exhibited obvious aromas of raw GBS, with a sweet aftertaste. Moreover, the composition of volatile components was more diverse and balanced, with a lower abundance. Therefore, the use of A. oryzae in the brewing of ginkgo vinegar can effectively control MPN content, maintain or even increase the content of active substances, and improve the unique bitter flavor of ginkgo fruit. The results of this study represent an important reference for the high-quality and non-toxic brewing of ginkgo vinegar in China.

Abstract:The preparation of food-derived peptides with angiotensin transferase (ACE)-inhibitory activity from yak milk casein was explored. One strain with the potential to produce ACE-inhibitory peptides was screened from sour yak milk using the skimmed milk plate and Lowry methods and was combined with five proteases to hydrolyze yak milk casein. Hydrolysis degree, ACE inhibition rate, peptide concentration, and pH were used as indices to determine the optimal proteases, and the hydrolysis process was optimized via bacteria-enzyme cofermentation and hydrolysis using an orthogonal test. An ACE-inhibitory peptide from yak milk casein was isolated and purified using ultrafiltration and dextran gel G-15, and its amino acid sequence was determined using liquid chromatography tandem mass spectrometry (LC-MS/MS). The effect of temperature, pH, and a buffer salt system on its stability was determined. The potential strain Lactobacillus fermentum 187 with 43.29% ACE inhibition was screened, and the optimal protease was alkaline protease, with optimal enzyme preparation process parameters including an enzyme-to-substrate ratio of 767 U/g, 5% lactobacillus inoculation, an enzyme digestion time of 10 h, an enzyme digestion temperature of 37 ℃, and a substrate pH of 7.0. The G2 peptide fraction (IC50=0.28 mg/mL) was separated via ultrafiltration and dextran gel G-15 and exhibited a promising antihypertensive effect; the G2 peptide fraction also has good thermal, acid-base, and salt stability. In addition, a total of nine peptide sequences were identified by LC-MS/MS. The results of this study provide a theoretical reference for the development and utilization of bacterial and enzymatic co-fermentation and the hydrolysis of yak casein to produce antihypertensive peptides.

Abstract:In order to promote the development and utilization of the products related to the ethanolic extract of Tricholoma matsutake (T. matsutake), aqueous ethanolic solutions with different volume fractions of ethanol were used to extract T. matsutake. The contents of polysaccharides, polyphenols and total flavonoids were measured, and the scavenging abilities of T. matsutake ethanolic extracts towards DPPH, hydroxyl, and ABTS+ radicals and the inhibitory effect against α-glucosidase were determined. The inhibition types and mechanisms of the extracts were examined by enzyme kinetic analysis, UV spectroscopy, fluorescence spectroscopy and infrared spectroscopy. The results showed that the content of the polysaccharides in the ethanolic extract obtained with 70% (V/V) ethanol was the highest (46.45%). The contents of polyphenols and total flavonoids in the water extract were the highest (13.92% and 1.03%, respectively). The scavenging abilities of the T. matsutake ethanolic extracts for DPPH, hydroxyl and ABTS free radicals showed a dose-dependent manner, with the IC50 values being 1.03, 0.49 and 0.87 mg/mL, respectively. The ethanolic extract obtained with 70% (V/V) ethanol exhibited the greatest inhibitory effect against α-glucosidase, with the inhibition rate being 28.93% at an extract mass concentration of 0.2 mg/mL. The ethanolic extracts obtained from the study all had good antioxidant and α-glucosidase inhibitory activities, and inhibited enzyme activity in the form of anti-competitive mixed-type enzyme inhibition, thereby affecting the microenvironment of the enzyme and changing its secondary structure. The ethanolic extracts can be used for the development of natural antioxidants and hypoglycemic agents. This research provides a reference for in-depth studies on T. matsutake ethanol extracts.

Abstract:The authentic Hubei Chinese medicinal and edible herb Fubaiju, Chrysanthemum morifolium, is rich in flavonoids. An evaluation method based on an in vitro chemical antioxidant assay and an in vivo C. elegans model was proposed to investigate the antioxidant capacities of flavone compounds, using the free-radical-scavenging rate, antioxidant enzyme activity, and nematode fluorescence intensity as indicators. The common peaks indicated in the spectral fingerprints of flavonoids from 15 different brands of Fubaiju Chrysanthemum were assessed to investigate the spectrum-effect relationship between Fubaiju Chrysanthemum flavonoids and their antioxidant activities. The maximum DPPH and the ABTS+ free-radical-scavenging rates of the flavonoid extract of Fubaiju were 83.14% and 75.32%, respectively. Moreover, the flavonoid extract significantly improved the antioxidant enzyme activity in nematodes and enhanced their oxidative stress resistance. Eight characteristic common peaks in the flavonoid spectral fingerprint profile all showed a certain correlation with antioxidant activity, especially peak 3, which had the most significant correlation and may represent luteolin-7-O-β-Dglucoside. Peak 4 showed the most significant correlation with ABTS+ free-radical scavenging and may represent luteolin-7-O-β-D-glucuronide. The flavonoid extract from Fubaiju Chrysanthemum exhibited promising antioxidant activity, providing a reference for the subsequent derivation and development of antioxidants.

Abstract:In the processing of foods containing polyphenols and whey protein, both components interact, which has a great influence on the foam properties of whey protein itself. Using whey protein isolation (WPI) and tea polyphenols (TP) as raw materials, the interactions of TP with WPI and heated WPI (HWPI) were investigated, and the effects of the TP concentration, pH, salt ions, and temperature on the foam properties of the resulting TP/WPI and TP/HWPI complexes were evaluated. The interaction between TP and HWPI was stronger than that of the former with WPI. Insoluble complexes were formed between TP and WPI (or HWPI) when TP was present at a high concentration (7.5 mg/mL). At TP concentrations of 2.5 and 1.25 mg/mL, respectively, TP/WPI and TP/HWPI both exhibited the best foam properties, with a corresponding foam capacity of 94.51% and 95.11%, and foam stability of 272.32% and 276.70%. At pH 5.0 and 4.0, respectively, TP/WPI and TP/HWPI both showed the best foam properties, with a corresponding foam capacity of 92.50% and 97.82%, and foam stability of 276.73% and 298.33%. The foaming properties of TP/WPI and TP/HWPI degraded with increasing salt (ion) concentration, but those of TP/HWPI were less affected. Compared with TP/WPI, temperature had less effect on the foaming ability of TP/HWPI. Therefore, the addition of TP at a low concentration could form TP/HWPI complexes with good foam properties. This study provides a reference for processing milk-protein-related foamed food.

Abstract:Due to the tendency of refrigerated sword prawn (Parapenaeopsis hardwickii) to spoil quickly, affecting both muscle quality and microbial community characteristics in the shrimp heads, intact and headless sword prawn were used as the research object. To explore relevant changes, muscle physicochemical indexes and high-throughput sequencing results of two shrimp types were assessed after 0, 2, 4, and 6 d of chilled storage at 0 ℃. The results showed that the moisture content, water activity, L* values, and a* values in the muscle of both groups significantly decreased (P<0.05), while b* values increased (P<0.05) with the extension of chilled storage. The muscle fibers of fresh shrimp were closely and orderly arranged, while the gaps between myofibrils increased after chilled storage, as indicated by hematoxylin and eosin (H&E) staining and transmission electron microscopy. During chilled storage, the moisture content, water activity, and L*, a*, and b* values of headless shrimp were higher than those of intact shrimp, and the degree of myofibrillar fiber damage was lower. The microbial richness and diversity in shrimp muscle was the highest at the early stage of storage and diminished gradually. Proteobacteria were dominant at the phylum level (89.23%~99.82%). Delftia, Pseudoalteromonas, and Psychrobacter were dominant in the early and late stages of chilled storage at the genus level, respectively. The β diversity analysis revealed that two first principal coordinates accounted for 89.36% of the variance, and the bacteria community composition in headless shrimp after 2 d of chilled storage significantly differed from that in the other sample groups. In conclusion, head removal before sword prawn storage can effectively reduce the rate of muscle deterioration and microbial richness. These findings provide a theoretical basis for clarifying the changes in the muscle quality of sword prawn.

Abstract:In this study, the "France" variety was used as the experimental material, which was stored in an environment with O2 concentration in the range of 2%~3% and CO2 concentration ranging in 0%~3%, 3%~6% and 6%~9%, respectively, to study the storages’ effects on fruit firmness, soluble solids content, titratable acid content, ascorbic acid content, weight loss rate, peel color change, respiratory intensity, and cell membrane permeability. The CO2 concentration suitable for plum fruit controlled atmosphere was screened to provide a reference for the research and development of plum fruit storage and preservation technology. The results showed that compared with the control (CK), the controlled atmosphere treatment inhibited to a certain extent the decreases of fruit firmness, titrable acid content and ascorbic acid content, delayed the darkening of fruit skin color and the increase of weight loss rate, reduced fruit respiration intensity, inhibited the increase of cell membrane permeability, and extended the shelf life. After 90 days of storage, the 6%~9% CO2 treatment group could maintain fruit firmness more effectively, which was 53.88% higher than that of the CK group; the mass fractions of soluble solid and titratable acid were 18.61% and 0.132%, respectively, which were 10.58% and 42.42% higher than that of the CK group, respectively; the weight loss rate was 2.32% lower than that of the CK group. In addition, the 6%~9% CO2 treatment group significantly reduced the respiration intensity and delayed the color darkening of plum fruit. Therefore, controlled atmosphere storage could maintain plum fruit quality and prolong storage period, and the CO2 concentration suitable for prune storage was 6%~9%. The research results provide a scientific basis for the research and development of storage and preservation technology for plum fruit.

Abstract:High-purity litchi γ-aminobutyric acid (GABA) was prepared via separation and refinement through sequential alcohol precipitation, resin column chromatography, and crystallization. Through a static adsorption experiment, the 732 cation exchange resin was screened from nine different types of resins, where its adsorption and desorption rates reached 81.56% and 88.26%, respectively. Evaluation of the static adsorption kinetics indicated that adsorption on the resin was primarily controlled by liquid-film diffusion, and was also influenced by the combined effects of multiple diffusion processes, such as intraparticle diffusion and adsorption-desorption on the internal surfaces of the particles. A dynamic elution experiment revealed that the highest raw material utilization rate was achieved at a sample loading of 8.25 mg/g. By taking the purification efficiency and cost into comprehensive consideration, the optimal elution conditions were determined as follows: sample concentration: 1.0 mg/mL, sample loading flow rate: 1.0 mL/min, sample pH value: 4, eluent concentration: 1.5 mol/L, elution flow rate: 1.0 mL/min. Under these optimized conditions, the purity and yield of the obtained litchi GABA were 77.40% and 92.05%, respectively. By crystallization from the purified sample solution, the purity increased to 95.35%, and the structure of the obtained crystal was identified as GABA through nuclear magnetic resonance analysis. In conclusion, the present study demonstrated that a combination of alcohol precipitation, ion exchange column chromatography, and crystallization processes enabled the recovery of GABA from litchi at a purity of >95%. The results of this study can serve as a valuable technical reference for the development and utilization of litchi GABA.

Abstract:Silver nanoparticles (AgNPs) were synthesized by a green method employing macadamia green peel polyphenol, and the effects of the mass concentration of macadamia green peel polyphenol and reaction time on the synthesis of the silver nanoparticles were evaluated. The synthesized AgNPs were structurally characterized by Fourier-transform infrared spectroscopy, nanoparticle size and zeta potential analyses, as well as transmission electron microscopy. The conditions for the synthesis of the AgNPs using macadamia green peel polyphenol were as follows: mass concentration of macadamia green peel polyphenol: 2.0 mg/mL (m/V), molar concentration of AgNO3 solution: 0.1 mmol/L, reaction time: 48 h, volume ratio of polyphenol solution to AgNO3 solution=1:9. Fourier-transform infrared spectroscopy revealed that the -OH on the benzene ring participated in the synthesis of the AgNPs. The nanoparticle size and zeta potential analyses indicated that the synthesized AgNPs showed good dispersion with a small particle size (70~130 nm) and negative charge. The transmission electron microscopy images and energy dispersive spectra demonstrated that the synthesized AgNPs were nearly spherical in shape, and Ag was closely surrounded by C and O with a proportion of 62.31%. Importantly, macadamia green peel polyphenol can be used as a natural reducing agent and stabilizer in the green synthesis of AgNPs, and the synthesized AgNPs display good dispersibility, which provides a new concept for the comprehensive utilization of macadamia green peel.

Abstract:Fresh Aralia cordata Thunb was dried by three different methods (vacuum freeze-drying, vacuum drying, and hot-air drying) and the effects of the different drying methods on the quality and Maillard reaction products were evaluated. The physical properties, main chemical components, polysaccharide and amino acid compositions, Maillard reaction products, protein oxidation products, and the antioxidant activity of Aralia cordata Thunb in vitro were determined. The optimal tissue structure; highest rehydration ratio, closest color to that of the fresh sample (ΔE=6.39); highest protein content (6.99 g/100 g); total sugar (68.25 g/100 g), reducing sugar (7.13 g/100 g), and total amino acid content (197.90 mg/g); highest DPPH radical scavenging (83.12%), ABTS+ radical scavenging (73.51%), and total antioxidant capacity (7.49 mmol FeSO4/g) were obtained by vacuum freeze-drying. The vacuum drying method yielded the highest content of ligustilide in Aralia cordata Thunb. (10.81 mg/g). However, this method also resulted in a significant color difference (ΔE=16.28) and elevated levels of Maillard reaction products. The content of ferulic acid, ligustilide, Maillard reaction products, and protein oxidation products in Aralia cordata Thunb, subjected to hot-air drying, gradually increased with increasing temperature. Aralia cordata Thunb, subjected to hot-air drying at 60 ℃, had a high content of ferulic acid (49.82 μg/g), ligustilide (7.24 mg/g), and amino acid (193.82 mg/g), and the anti-oxidation ability was second only to that of the vacuum freeze-dried sample. In conclusion, vacuum drying required an extended drying time and resulted in lower overall quality. Vacuum freeze-drying resulted in the best quality of Aralia cordata Thunb, but its application cost was higher. Among the methods, hot-air drying at 60 ℃ is the preferred method of drying Aralia cordata Thunb for practical production applications.

Abstract:The thawing of quick-frozen litchis in air and still-water environments was analyzed via numerical simulation and experimental verification by monitoring the internal temperature changes and thawing time. The thermal properties of litchis during thawing, especially the ice-water phase transition, were mainly influenced by the moisture content. The temperature changes of litchi during the thawing period could be accurately predicted using the numerical model. The root mean square error (RMSE) for the air-thawed group and the still-water-thawed group was 2.02 and 1.79 ℃, respectively. The measured and simulated thawing times for the two groups had deviations of 2.32% and 1.50%, respectively. Compared with air thawing, the thawing time of litchi peel, pulp, and core in the still-water environment was shortened by 93.33%, 74.94%, and 69.25%, respectively. The larger the horizontal and vertical diameters of litchi, the higher the temperature and heat transfer coefficient of the thawing medium, and the shorter the thawing completion time, whereas the internal temperature was less uniform. The thawing rate of litchi depends not only on the heat exchange efficiency between the thawing medium and the fruit, but also on the internal thermal conductivity of the litchi fruit. In summary, after determining the chemical composition and thermal properties of litchi, the thawing of frozen litchi was effectively analyzed through numerical simulation. Thawing is also affected by the horizontal and vertical diameters of litchi and the temperature and heat transfer coefficient of the thawing medium.

Abstract:On the basis of exploring the influence of addition of whole purple potato flour on the dough characteristics of whole purple potato flour-wheat flour mixed dough, the starch digestion characteristics, bioaccessibility of anthocyanosides and antioxidant activities of purple potato breads with different addition amounts of whole purple potato flour were compared. The results showed that the addition of purple sweet potato flour reduced the water absorption of mixed flour, shortened dough formation time, reduced dough’s stability, but delayed dough aging. With an increase in the addition amount of purple sweet potato flour, the resistant starch (RS) content in the starch of purple sweet potato bread increased, the glycemic index decreased, the antioxidant activity increased, and the bioavailability of total anthocyanins and anthocyanin monomers decreased. When the addition amount of purple sweet potato flour was 50%, the RS content in purple sweet potato bread’s starch was 39.60%, the glycemic index was 71.86, the total reducing capacity was 13.24 mg Vc/g, and the total anthocyanin bioavailability was only 2.64%. Ten anthocyanin monomers were detected. The bioaccessibility of delphinidin-3,5-diglucoside was the highest, followed by paeoniflorin 3-O-acyl glycoside monomer, with cyanidin 3-O-acyl glycoside monomer having the lowest bioaccessibility. The addition of whole purple sweet potato flour can prolong the shelf life of bread, delay starch digestion, improve its antioxidant activity, which meet consumers' demand for nutritious and healthy staple food products.

Abstract:Ultrasound-assisted deep eutectic solvent extraction technology was employed to extract the active ingredient, Schisantherin A (SCA), from Schisandra sphenanthera. The optimal extraction solvent was determined, and the influences of water content, extraction temperature, liquid–solid ratio, sonication time, and sonication power on SCA extraction yield were investigated. Response surface methodology was adopted for optimization of the extraction process, and the optimized process was compared with extraction using conventional organic solvents. The results indicated that the optimal extracting agent was a combination of choline chloride and levulinic acid (molar ratio of 2:3), and the optimal process conditions for extraction were as follows: 20% water content of the solvent (volume fraction), 63 ℃ extraction temperature, 21:1 liquid-solid ratio (mL/g), 63 min sonication time, and 150 W sonication power. The SCA extraction yield under these conditions was 10.12 mg/g, which was close to the predicted value and demonstrated the effectiveness of the model in predicting the optimal process conditions for SCA extraction. In addition, the extraction yield was 1.98- and 3.30-fold that of the yields obtained by extraction using 80 vol% dimethyl sulfoxide and 95 vol% ethanol, respectively. Good bacteriostatic effects were exhibited when Escherichia coli was subjected to 24 hours of intervention with SCA at a mass concentration of 2.25~4.50 mg/mL. The results of this study can serve as reference for high-efficiency and green extraction of SCA and its development and application in bacteriostasis.

Abstract:Selenium nanoparticles (SeNPs) are widely used in the fields such as materials, food, and agriculture, due to their large specific surface area, antioxidant properties, and antibacterial capabilities. In this study, SeNPs were synthesized via the mediation by a hot watermelon peel leaching solution. The formation of SeNPs was confirmed and their apparent characteristics were analyzed using scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy (FT-IR). The antioxidant activity of the SeNPs was evaluated by measuring their scavenging capacities for ABTS+ and DPPH free radicals. The findings revealed that the SeNPs synthesized via the mediation by the hot watermelon peel leaching solution were spherical granular with an average particle size of 211.4 nm, and a selenium content of 22.66% as determined by energy dispersive X-ray spectroscopy. The X-ray diffraction pattern lacked sharp Bragg reflections, indicating that the SeNPs were amorphous. FT-IR spectroscopy analysis indicated the presence of substances such as macromolecular proteins, phenols, alcohols on the surface of the SeNPs, which might contribute to their stability and dispersion. Additionally, the results of antioxidant activity tests demonstrated that at a mass concentration of 500 μg/mL, the SeNPs exhibited free radical scavenging rates of 83.80% for ABTS+ and 94.34% for DPPH. In conclusion, spherical SeNPs with an average particle size of 211.4 nm and notable antioxidant activity were successfully synthesized through the mediation by the hot watermelon peel leaching solution. This research provides a theoretical reference for the biosynthesis of SeNPs and application of their antioxidant properties.

Abstract:Sheep liver is a by-product of lamb or mutton production, which is rich in various nutrients and has high research value. However, the fishy smell of sheep liver, which is difficult to remove, restricts its further processing and utilization. To promote the development and utilization of this by-product, lamb liver was used as a raw material to produce lamb liver powder, which was characterized through sensory evaluation, as an indicator, and the removal of the fishy smell of lamb liver powder was assessed. Six factors were evaluated using single-factor experiments: the rinsing frequency, rinsing time, cooking time, concentration of additives, drying time, and drying temperature. Based on the single-factor experiment, the Box Behnken response surface design method was used to optimize the process for removing the fishy smell from sheep liver powder. Secondly, gas chromatography-ion mobility spectroscopy (GC-IMS) was used to analyze the optimal deodorization process and the volatile substances in sheep liver that had not been deodorized, to determine the effectiveness of the treatment process. The sensory score for removing the fishy smell from sheep liver powder was the highest when the process was conducted by rinsing at 40 ℃, rinsing 5 times, adding 4% (m/m) excipient, cooking for 50 min, and drying for four hours at 65 ℃. The GC-IMS results indicate that through the optimal deodorization process, various undesirable flavors and a large number of volatile aroma compounds such as aldehydes, ketones, and alcohols can be removed. The deodorization effect is significant, and the flavor improvement is good. The results provide a theoretical basis and reference parameters for optimizing the deodorization of lamb and its by-products.

Abstract:Soluble solids content (SSC) and firmness index (FI) are key factors that affect the taste of strawberries. Accordingly, a general predictive model was established for strawberry quality parameters, SSC and FI, based on common features. First, spectral features were extracted using competitive adaptive reweighted sampling (CARS), the successive projection algorithm (SPA), and uniformative variable elimination (UVE). Subsequently, decision models were constructed using partial least squares regression (PLSR), extreme learning machine (ELM), and least squares support vector machine (LS-SVM). The whale optimization algorithm (WOA) was used to optimize the parameters of the LS-SVM model to ultimately establish a general predictive model based on the common features of SSC and FI. The results indicated that spectral noise can be effectively reduced using the Savitzky-Golay (SG) convolution smoothing technique for preprocessing. The CARS-LS-SVM model exhibited the best single-indicator predictive performance for SSC and FI, with correlation coefficients of 0.937 and 0.898 and residual predictive deviations of 2.87 and 2.28, respectively. The SSC and FI features extracted using the UVE method had the highest overlap rate. The LS-SVM dual-indicator model that was established based on common features achieved effective predictions of SSC and FI, with correlation coefficients of 0.922 and 0.871 and residual predictive deviations of 2.58 and 2.04, respectively. Near-infrared spectroscopy could simultaneously predict the SSC and FI of strawberries. The results of this study can serve as a theoretical reference for the development of general predictive models capable of determining multiple strawberry quality parameters.

Abstract:To investigate the influence of varying storage temperatures on the postharvest quality and flavor of ‘Nanhong Pear’, harvested ‘Nanhong Pear’ fruits were separately stored in constant-temperature boxes at 0, 10, 20 and 30 ℃. Sensory and nutritional indicators of the fruits were measured at seven-day intervals, and changes in flavor were determined using gas chromatography-ion mobility spectrometry. The results indicated that ‘Nanhong Pear’ fruits stored at 0 ℃ exhibited no discernible change in color or evidence of rotting and browning during the storage period. At this temperature, fruit ripening was also inhibited, leading to the maintenance of a relatively astringent flavor in the fruits. ‘Nanhong Pear’ fruits stored at 10 ℃ exhibited soft, golden-yellow flesh, and a hardness of 3.47 kg/cm2 after 21 days of storage. Their flavor became unpleasant after 28 days. In pear fruits stored at 20 ℃ and 30 ℃, yellowing and softening of the flesh occurred after 7 days of storage, while rotting, browning, and an unpleasant flavor developed after 14 days. The findings of this study indicate that temperature exerts an important influence on the postharvest quality and flavor changes of ‘Nanhong Pear’. Specifically, a temperature of 0 ℃ is optimal for long-term storage and transportation of ‘Nanhong Pear’ fruits, while 10 ℃ is suitable for short-term storage and on-shelf sales. Fruits are best consumed at 14~21 days of storage. ‘Nanhong Pear’ fruits stored at 20 ℃ and 30 ℃ suffer quality deterioration after 7 days of storage, indicating that fruits stored at these temperatures are only suitable for short-term sales after harvesting.

Abstract:In order to quickly find out the odor characteristic components of Amomum tsao-ko from different origins, their differential odor compounds were analyzed by gas-phase electronic nose technology combined with chemometric model, and the metabolic pathways of the main aroma compounds were analyzed by combining with the Kyoto Encyclopedia of Genes and Genomes (Kyoto Encyclopedia of Genes and Genomes, KEGG) pathway. The results of relative odor activity value (ROAV) showed that 4-ethyl-2-methoxyphenol,3-methylnonane-2,4-dione and (2E,4E)-deca-2,4-dienal (1≤ROAV≤100) were the key compounds affecting the odor of Amomum tsao-ko. For the first time 4-ethyl-2-methoxyphenol (ROAV=100) was found to be the greatest contributor to the odor of Amomum tsao-ko in Honghe and Xishuangbanna, Yunnan Province, whilst 3-methylnonane-2,4-dione (ROAV=100) was the greatest contributor to the odor of Amomum tsao-ko in other regions. The identification index of the established principal component analysis (PCA) model was 89, and the cumulative discrimination index of the discriminant factor analysis (DFA) model was 87.02%, which could effectively distinguish the origins of Amomum tsao-ko. The results of KEGG pathway analysis (P<0.05) showed that the monoterpene biosynthesis pathway and limonene degradation pathway may be beneficial to the aroma formation of Amomum tsao-ko. The experimental method of ultra-fast gas-phase electronic nose technology combined with chemometric model can provide a useful reference for the traceability and identification of the origin of Amomum tsao-ko as a medicine and food dual-use fruit.

Abstract:The differences in the flavor components of fermented rice wine varieties (Yichang, Wuxi, Suizhou, and Nanning local koji) were compared by optimizing the process for the fermentation of koji from four regions using an orthogonal test, and the basic physical and chemical indexes of the four kinds of fermented rice wine were determined. An electronic tongue was used to analyze the flavor characteristics of the four kinds of rice wine, and the differences in the flavor characteristics were compared by principal component analysis. The volatile flavor components of the four kinds of rice wine were determined by headspace solid-phase microextraction (HS-SPME-GC-MS). The optimum brewing temperature, time, and inoculum amount of koji for Yichang, Wuxi, Suizhou, and Nanning were 32 ℃, 60 h, 0.2%; 28 ℃, 60 h, 0.4%; 28 ℃, 60 h, 0.6%; and 32 ℃, 48 h, 0.6%, respectively. The pH of the four kinds of fermented rice wine was in the range of 3.88~4.01, where the difference was not significant. Yichang rice wine had the highest content of reducing sugar (431.53 mg/mL), where the content differed significantly among the four kinds of rice wine (P<0.05). There were significant differences in the flavor of the rice wine produced from koji in different regions, among which Nanning rice wine had the best flavor, with moderate acidity and sweetness and a rich taste. This wine had the most types of ester flavor compounds and the highest relative content, and had a rich and mellow flavor. Wuxi rice wine and Suizhou rice wine were different in color, flavor, taste, and organizational state, and the overall flavor was also different. Compared with the other three kinds of sweet rice wine, Yichang rice wine has the highest sweetness, but its taste and flavor were relatively simple. This study distinguished the unique flavor characteristics of koji fermented rice wine from different regions and provides a reference for improving the quality of traditional rice wine and maintaining the regional characteristics.

Abstract:According to the notice of the State Administration for Market Regulation, pesticide residues have become the primary factor affecting food safety, and how to strengthen the detection of pesticide residues in food has become the focus of social attention. Cyromazine is the pesticide with the highest number of reported pesticide residues exceeding the standard. The abuse of cyromazine poses a serious threat to food safety and human health. This review provides an overview of the current methods and technologies applied to detecting the cyromazine in food, including high-performance liquid chromatography, liquid chromatography-mass spectrometry, immunosensing technology, chemical sensor technology and aptamer-based sensor technology, in order to provide research ideas for improving the detection efficiency of cyromazine.

Abstract:The abundance, composition, and distribution of fungal contaminants in packaged drinking water production systems and environments were systematically investigated in both flood and drought hydrological seasons. The risk of fungal contamination in each water treatment process and the effectiveness of fungal removal were also evaluated. Raw water, water treatment processing materials, and the production environment were found to be contaminated by fungi to varying degrees during both the flood and drought periods. Notably, the highest level of fungal contamination was observed in raw water during the flood period, reaching 0.51 CFU/mL. The study revealed that using 100 μm and 0.2 μm filter membranes effectively removed fungi, with removal rates reaching 34.78% and 83.33%, respectively. Furthermore, Penicillium and Aspergillus were identified as the primary dominant fungal genera in the packaged drinking water production system. The contamination rates of Penicillium and Aspergillus were 28.99% and 37.68%, respectively, during the flood period and 18.87% and 50.94%, respectively, during the drought period. The analysis results indicated that raw water serves as the primary source of fungal contamination in the packaged drinking water treatment process. Production materials, including bottle blanks, caps, and bottles, were also identified as contributors to fungal contamination. These findings provide valuable data for the identification of fungal risks in packaged drinking water production systems and for the implementation of traceability, prevention, and control measures in the water treatment process.

Abstract:A triple-quadrupole liquid chromatography-tandem mass spectrometry (TQ LC-MS/MS) method was established to determine the contents of 14 phenolic compounds in Chaenomeles fructus grown in different regions. Its antioxidant activity was subsequently assessed by measuring the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) radical scavenging capacity, and ferric reducing antioxidant power (FRAP). The content-effect relationships between the contents of various phenolic compounds and antioxidant activity were analyzed by grey relational analysis to explore the substance basis of the antioxidant activity of Chaenomeles fructus. The results indicated that the chlorogenic acid content was the highest in all 18 types of samples of Chaenomeles fructus grown in different regions, ranging from 1 479.68 to 4 902.39 μg/g. A total phenolic content (TPC) of up to 37.13 mg GAE/g was detected in the plant extracts. The DPPH radical scavenging capacities, ABTS+ radical scavenging capacities, and FRAPs of the samples were in the ranges of 10.13%~74.66%, 26.37%~79.44%, and 43.56~132.53 mg TE/g, respectively. The correlation coefficient between TPC and antioxidant activity was>0.91. An analysis of the contenteffect relationships revealed that eight phenolic compounds, including chlorogenic acid, protocatechuic acid, catechin, and neochlorogenic acid, contributed most to antioxidant activity. The TQ LC-MS/MS method developed in this study enabled accurate determination of the contents of 14 phenolic compounds in Chaenomeles fructus grown in different regions. Through correlation analysis, the primary active components contributing to antioxidant activity were determined, and the substance basis of the antioxidant activity of Chaenomeles fructus was elucidated. The results of this study can serve as a scientific reference for quality control and resource development of Chaenomeles fructus.

Abstract:In this study, a novel detection method for rapid and accurate detection of the tetraniliprole residues in cereal crop samples was developed using improved m-PFC purification combined with HPLC-MS/MS. The samples were extracted with acetonitrile, dehydrated by 4 g of anhydrous sodium sulfate and 4 g of anhydrous magnesium sulfate, purified by m-PFC HF-A column, separated on Agilent Venusil MP C18 (100 mm×2.1 mm, 3 μm), eluted in a gradient with methanol and water as the mobile phase, iscanned with electrospray ionization and in negative ion mode, and detected by the multiple reaction monitoring (SRM) mode, and quantified by the matrix-matched external standard method. The results showed that the coefficient of determination (r2) values of tetraniliprole within the linear range (0.1~20 μg/L) and in different grain and cereal food matrices were all higher than 0.999. The limit of quantification (S/N≥10) was 0.80 μg/kg. Taking rice, wheat, barley, millet, soybeans, green beans, corn, and sorghum as the substrates, the recovery rates of tetraniliprole spiked at three levels of 0.80, 1.6 and 8.0 μg/kg ranged from 84.67% to 98.14%. The evaluation of assay stability revealed that the relative standard deviation of six measurements within the same batch (RSD, n=6) had a minimum of 0.77% and a maximum of 3.36%, whilst the relative standard deviation of six replicates between different batches (RSD, n=6) was within the range of 0.95% to 2.53%. This method is convenient, efficient and highly precise, and meets the requirements for detecting tetraniliprole residues in grain and cereal foods.

Abstract:The contents of 31 elements in 10 kinds of fresh edible fungi and 16 kinds of dried edible fungi sold in Meizhou were determined. The Nemerow comprehensive pollution index evaluation method was used to assess the quality grade of the edible fungi sold in the market. The dietary exposure risk of five heavy metals in the commercially available edible fungi was evaluated based on the estimated daily intake (EDI), target hazard quotient/total target hazard quotient (THQ/TTHQ) method, and carcinogenic risk/total carcinogenic risk coefficient method (CR/TCR). The results showed that the contents of 31 elements in edible fungi varied greatly, and palladium was not detected. Only 10.08% of chromium in fresh edible fungi exceeded the standard. The over-standard rates of cadmium, chromium, arsenic and mercury in dried edible fungi were 11.06%, 11.98%, 14.75% and 17.51%, respectively. The Nemerow comprehensive pollution index of heavy metals indicated moderate pollution level of dried Tricholoma matsutake and dried Dictyophora indusiata, light pollution level of fresh Pleurotus ferulae and dried bolete and dried Russula vinosa , the risk alert level of dried shiitake mushrooms, and the safety of the rest of the commercial edible fungi. The assessment of dietary exposure risk of heavy metals showed that EDI values of Pb, Cd, Hg, As and Cr in commercial fresh and dried edible fungi were all smaller than PTDI value, THQ was less than 1.0, and TTHQ was less than 1.0, indicating that the non-carcinogenic health risk of fresh and dried edible fungi sold in the market was low. The TCR values of Pb, Cr, As and Cd in fresh edible fungi were less than 10-4, indicating low carcinogenic risk. The TCR of dried edible fungi was higher than 10-4, indicating potential carcinogenic risk. The research showed that the 10 kinds of fresh edible fungi sold in Meizhou were overall safe. There was a certain risk of dietary exposure to heavy metals in dried edible fungi. Therefore, the quality control of dried edible fungi should be strengthened.

Abstract:The Cd and Cr contents of 49 sorghum samples from five regions of Liaoning Province were determined by inductively coupled plasma mass spectrometry (ICP-MS). Based on Monte Carlo simulation, the non-carcinogenic risk index (HQ), total non-carcinogenic risk index (HI), carcinogenic risk index (CR), and total carcinogenic risk index (TCR) of the sorghum samples were evaluated, and guidelines for consumption were provided considering the existing health risks. The Cd and Cr content of the sorghum samples from five regions in Liaoning were in the range of 0.002~0.056 and 0.116~0.782 mg/kg, respectively. For adults, the HQ and HI of sorghum from the five regions were less than 1, whereas the CR and TCR were less than 1×10-4. For children, the HQ and HI of sorghum from the five regions were less than 1, whereas the CR was less than 1×10-4, with the TCR of sorghum from the Shuangta and Tieling regions being less than 1×10-4. However, the TCR for sorghum from the Shenhe, Jianping, and Fumeng regions was 1.04×10-4, 1.16×10-4, and 1.06×10-4, respectively, where the values are slightly larger than 1×10-4. The overall degree of pollution of sorghum samples from the five regions in Liaoning Province was low, with the Cd and Cr levels meeting national standards. The HQ, HI, CR, and TCR of sorghum for adults were at safe levels for all five regions. The HQ, HI, and CR of sorghum from all five regions were at safe levels for children, with only the Shenhe, Jianping, and Fumeng regions having a lower total carcinogenic risk for children. However, the total carcinogenic risk could be minimized when the frequency of exposure in Shenhe, Jianping, and Fumeng was controlled to less than 58, 52, and 57 d/a, respectively.

Abstract:In recent years, the demand for quality control in the fruit and vegetable processing industry has been increasing. Gas chromatography-ion mobility spectrometry, as a fast, practical, and visual analytical tool with stable on-line determination and accurate performance has gradually gained prominence for the detection of volatile organic compounds in the field of fruit and vegetable analysis. In recent years, the application of gas chromatography-ion mobility spectrometry has been widely utilized and studied. On this basis, this paper first briefly summarizes the technical principle, operation process, and analytical method of gas chromatography-ion mobility spectrometry. Thereafter, its specific application in the on-line, dynamic flavor analysis of different fruit and vegetable products is introduced, with emphasis on breakthroughs and the applicability of this technique. This technique is also widely used in identifying the adulteration of fruit and vegetable products, origin traceability, and assessing quality changes during storage. Finally, the challenges, future directions, and opportunities for gas-phase ion mobility spectrometry are discussed.

Abstract:Hyperuricemia (HUA), a metabolic disorder, is not only associated with gout but also represents an independent risk factor for numerous systemic diseases, such as kidney, endocrine, metabolic, and cardiovascular disorders. Recently, numerous epidemiological studies and clinical observations have indicated that the considerable increase in fructose consumption, particularly through the widespread consumption of soft drinks, is closely linked to the occurrence and progression of HUA. At the metabolic level, fructose can generate urate precursors in the liver during metabolism, and it interferes with the uric acid excretion process in the kidneys, leading to an increase in serum uric acid levels. Furthermore, fructose may indirectly affect urate metabolism through its impact on insulin sensitivity and the risk of obesity. Although existing research has already revealed the association between fructose and HUA, the specific mechanisms remain unclear. This review investigates the impact of fructose on HUA and its underlying mechanisms, aiming to deepen our understanding of the relationship between fructose and HUA and provide theoretical support for dietary intervention strategies for HUA.

Abstract:Long-term high-sodium diets are directly related to a variety of health problems, including increase of blood pressure and incidence of cardiovascular diseases. As people's health awareness increases, salt reduction actions are imminent, savory-enhancing peptides have become an ideal low-sodium substitute due to their own unique advantages, which is of great significance for the development of salt reduction products and has a wide range of application prospects. The development of animal-derived savory-enhancing peptides can not only make efficient use of animal products (such as chicken bones, cattle bones, shrimps and crabs), but also serve as efficient salt substitutes, showing great development potentialand high application value. Therefore, the research and development of animal-derived savory-enhancing peptides have become a current research hotspot in the field of food science. In this paper, the sources, preparation technologies, separation and purification technologies, identification techniques, and application status and prospects of animal-derived savory-enhancing peptides are reviewed, in order to provide a reference basis and theoretical support for the in-depth study of animal-derived savory-enhancing peptides, and the research and development of related salt-reducing products in the future.

Abstract:γ-Decalactone is a substance with a peach aroma, mainly found in cream, coconut and peach. Because of its pleasant aroma, good water solubility and high safety, it has been widely used in foods and cosmetics. The paper reviews the biological transformation and metabolic pathway of γ-decalactone from three perspectives, namely, substrate entry into cells, β-oxidation and cyclization reactions, respectively, and analyzes the factors affecting current production of γ-decalactone, including the type of substrate and its hydrophobicity, batch-based substrate replenishment , hydroxylation processand regulation of acyl-coenzyme A oxidase, in situ isolation technique, and culture conditions. Finally, in this paper, future research directions and possible problems of γ-decalactone bioregulation are also put forward, providing a theoretical reference for the preparation of aromatic compounds by microbial methods.

Abstract:Didecyldimethylammonium chloride (DDAC) is widely used as a bactericidal disinfectant in various fields, including the food industry, animal husbandry, and medical treatment. DDAC is chemically stable and difficult to degrade under natural conditions. With the large amount of DDAC being used, its residue on the surface of objects and in the environment is increasing, which can cause adverse effects to organisms. This study focuses on the hazards of DDAC to organisms, analyses the application of chromatography-tandem mass spectrometry, visual inspection, and biosensors in the detection of DDAC, summarizes the methods of DDAC degradation and the mechanisms, highlights challenges in current research, and provides projections for future research, with a view to providing a reference for reducing the hazards posed by DDAC residues.

Abstract:Probiotics are live microorganisms that confer health benefits on the host upon administration in adequate amounts. Probiotics have various functions, including immunoregulation effects, promotion of nutrient absorption, and inhibition of the growth and proliferation of pathogenic bacteria. The recognition of these functions has led to increased consumer demand, thereby positioning the screening and investigation of probiotics as a key focus within the health and functional food industry. Caenorhabditis elegans has been extensively utilized as an animal model owing to its distinct advantages, including short lifespan, transparent body, and completely sequenced genome. This review outlines the application of C. elegans in screening probiotics that promote longevity, and antioxidant, antimicrobial and antiobesity effects, thereby providing a valuable reference for the development and utilization of probiotics.