To understand the effect of 1-(2-chloropyridin-4-yl)-3-phenylurea (CPPU) on the optical parameters and internal quality of ‘Xuxiang’ kiwifruit during growth and the relationship between optical parameters and internal quality. Growing ‘Xuxiang’ kiwifruits treated with 0, 10 and 20 mg/L CPPU solutions were measured for absorption coefficient μa and reduced scattering coefficient μs’ using single integrating sphere system (950–1 650 nm). The internal quality indices, such as soluble solid content (SSC), moisture content and firmness, were also measured. Partial least squares regression (PLSR) was used to build an internal quality prediction model based on optical parameters. The results showed that CPPU reduced the firmness and increased the moisture content, but had no significant effect on the SSC of kiwifruits (P > 0.05). CPPU led to changes in the optical parameters of kiwifruits. μa and μs’ showed different correlations with the same internal quality attribute of kiwifruits, the correlation coefficients changed with wavelength, and there was a good correlation in a certain band. The PLSR model based on μa had the best prediction effect on the SSC and moisture content with correlation coefficient of prediction (Rp) of 0.709 and 0.790 and root mean square error of prediction (RMSEP) of 0.579% and 0.408%, respectively, while the model based on μa + μs’ had the best performance in predicting the hardness (Rp = 0.796, RMSEP = 7.890 N). This study provides a theoretical basis for predicting the internal quality of kiwifruits based on spectral technology.

The purpose of this study was to comprehensively explain the key components and mechanism of action of tea made from the leaves of Dracocephalum rupestre Hance (DRH) for intervening in hyperlipidemia by using network pharmacology and molecular docking. Eight active components of DRH tea and 160 targets for intervention in hyperlipidemia were selected by using the Traditional Chinese Medicine System Pharmacology Database and Analysis Platform (TCMSP), and a ‘DRH tea-active ingredients-intersection targets-hyperlipidemia’ network was constructed. Gene ontology (GO) pathway analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that the tumor necrosis factor (TNF) signaling pathway, insulin resistance and the peroxisome proliferators-activated receptor (PPAR) signaling pathway were mainly involved in the intervention of DRH tea in hyperlipidemia. Molecular docking and visual analysis showed that the core components of DRH tea could be stably combined with the key targets. Therefore, it is speculated that DRH tea intervenes in hyperlipidemia through the synergistic effect of multi-components, multi-targets, and multi-pathways, which can provide a theoretical basis for the development and utilization of plant resources for herbal tea.

Vibrio qinghaiensis sp. Q67 was used as an indicator strain to study the toxic effects of five common pesticides, pirimicarb (PIR), carbaryl (CAR), glyphosate (GLY), dimethoate (DIM), and acephate (ACE). The toxicities were evaluated by toxic unit and concentration addition model. The results showed that the toxicity of the pesticides decreased in the following order: PIR > GLY > CAR > DIM > ACE. Four of the 10 binary mixtures of these five pesticides showed antagonistic toxic effects, while the remaining six showed additive or synergistic toxic effects. Among the seven five-component mixtures designed by uniform design ray, four showed synergistic and then antagonistic effects, while the remaining three showed a consistent antagonistic effect. The toxicity of the five-component mixtures was strongly positively correlated with the concentration of CAR (r = 0.947). Based on this result, a linear model was established to predict the toxicity of pesticide mixtures. This method has the advantages of low cost, rapidity, simplicity and convenience, which can be used as a potential preliminary screening method for rapid detection of pesticide residues in agricultural products and foods.

In this study, the bactericidal effect and mechanism of plasma activated water (PAW) against Shewanella putrefaciens, a common microorganism found in aquatic products, were investigated by plate counting, fluorescence staining and scanning electron microscopy (SEM). The impact of PAW on cell morphology, cell membrane permeability, cell membrane potential and cell content leakage was examined. The results showed that the count of Shewanella putrefaciens was significantly decreased by PAW (P < 0.05). After 6.0 min of treatment with activated water from plasma discharge 120 s (PAW120), the colony count decreased by 7.44(lg (CFU/mL)), the cell morphology showed shrinkage and rupture, and the permeability of the inner and outer membranes increased by 989.31% and 474.51%, respectively. Moreover, intracellular macromolecules such as nucleic acids and proteins leaked out of the cells, and the electrical conductivity increased significantly (P < 0.05). The results of Fourier transform infrared (FTIR) spectroscopy showed that the structures of intracellular lipids and proteins were changed after PAW120 treatment. In conclusion, PAW could destroy the cell wall, and increase the permeability of the cell membrane, thereby leading to the leakage of intracellular nucleic acids and proteins and eventually cell death. This study provides a theoretical basis for the application of PAW in the preservation of aquatic products.

Objective: To study the mechanism of ultrasonic emulsification of soy protein isolate (SPI) and to investigate the emulsification efficiency of SPI under different ultrasonic powers. Methods: Different ultrasonic powers of 28, 47, 69, 88 and 109 W were used to treat SPI emulsions. The finite element analysis method was applied to simulate the phenomenon of acoustic streaming in the sound field and obtain the distribution of acoustic flow field under different ultrasonic powers. The distribution characteristics of the ultrasonic cavitation field were analyzed by sonochemiluminescence assay. The particle size, emulsification activity, and emulsion stability of SPI emulsions were measured. Results: The effect of ultrasonic cavitation, the cavitation enhancement of acoustic flow, the dispersion and mixing of acoustic flow were the main mechanisms for the homogeneous stabilization of ultrasonic emulsification. Ultrasonic disruption and homogenization as a result of acoustic cavitation could reduce the particle size of SPI emulsions. The acoustic flow effect caused by an increase in ultrasonic power could increase the action area of ultrasonic cavitation enhancing the cavitation effect. Meanwhile, the impact, gyration and vortex motion of acoustic flow could cause the emulsion to be fully stirred, dispersed and mixed, effectively improving the emulsification activity, emulsion stability and apparent stability. The emulsification efficiency of SPI was highest when the ultrasonic power was 88 W. Conclusion: Increased ultrasonic power can effectively improve the emulsification characteristics of SPI.

In order to improve the added value of foxtail millet and the processing quality of foxtail millet noodles, the effect of different periods (0.5, 1, 2, 4, 6, and 8 h) of ball milling on the nutritional components, hydration properties, gelatinization properties, rheological properties and crystalline structure of foxtail millet flour and the quality of the resulting noodles was investigated. The correlation between some physicochemical properties and noodle quality was analyzed. The results showed that the crystalline structure of foxtail millet flour was damaged obviously, and the damaged starch content increased significantly with an increase in milling time. It was also found that the amylose content decreased continuously (except for 8 h), and the L* value rose from 77.27 to 81.37. The peak viscosity, trough viscosity, and final viscosity of foxtail millet flour increased from 1 478, 665 and 1 384 Pa·s to 3 271 (ball milling 1 h), 982 (ball milling 2 h) and 2 199 (ball milling 2 h) Pa·s (P < 0.05), respectively, and the hydration properties (water-holding capacity and swelling capacity) improved (P < 0.05). Ball milling for 4 h made the gel network structure of dough more compact and resulted in noodles with the best texture and cooking quality. Correlation analysis showed that noodle texture properties (elasticity, stickiness and chewiness) and sensory quality (color, appearance and stickiness) were significantly negatively correlated with amylose content (P < 0.01), but significantly positively correlated with damaged starch and amylopectin contents (P < 0.01). The cooking quality (breakage rate) of noodles was positively correlated with amylose content (P < 0.01), but significantly negatively correlated with damaged starch and amylopectin contents (P < 0.01) and gelatinization viscosity was also strongly correlated with noodle quality. Taken together, the modification of foxtail millet flour by ball milling can be used to produce high-quality foxtail millet noodles.

The effect of microwave pretreatment of sesame seeds on the flavor, sensory quality, nutrition, and safety of sesame oil was systematically studied to provide a theoretical foundation for the application of microwave for aroma enhancement in sesame oil. Sesame oil samples were hydraulically pressed from sesame seeds microwaved at different powers (0, 180, 360, 540, 720 and 900 W) for 6 min. A total of 91 aroma active compounds were identified in sesame oil by solvent-assisted flavor evaporation and headspace solid-phase microextraction combined with gas chromatography-olfactometry-mass spectrometry. The total concentration of heterocyclic compounds including pyrazines, pyrroles, pyridines, thiazoles, thiophenes, and furans in sesame oil were positively correlated with microwave power, while the total concentration of carbonyl compounds including aldehydes, ketones, and esters increased initially and decreased later with an increase in microwave power. The intensities of roasted sesame-like, nutty, burnt and smoky aromas, and the bitter taste of sesame oil gradually increased, while the intensities of earthy, woody, and green odors decreased. The oil yield of microwave-pretreated sesame seeds (30.02%–31.93%), which was higher than that of raw sesame seeds (24.89%), was positively correlated with microwave power. Microwave pretreatment increased the nitrogen solubility index (NSI, from 11.7% to 18.07%) of sesame meal and the concentration of tocopherol in sesame oil (from 392.18 to 462.92 mg/kg). The highest NSI and tocopherol content appeared after 540 and 700 W microwave pretreatment, respectively. The concentrations of sesamin (13.01–15.78 mg/100 g), heterocyclic amines (HCAs, 33.19–143.88 ng/g), and polycyclic aromatic hydrocarbons (PAHs, 0.40–9.03 ng/g) in sesame oil were positively correlated with microwave power. The concentrations of PAHs and HCAs in sesame oil did not exceed the Chinese national standard limit. In summary, appropriate microwave pretreatment can provide sesame oil with a rich flavor, improve its nutritional value and oxidation stability, and increase the utilization value of sesame meal protein. Therefore, microwave pretreatment is highly advantageous and promising for application in aroma enhancement in sesame oil l and high-value utilization of sesame meal protein.

Emulsions prepared using myofibrillar protein (MP) as an emulsifier have poor stability under low NaCl condition. The effect of high-intensity ultrasound (HIU) treatment (frequency of 20 kHz, and power of 450 W) for different periods of time (0, 3, 6, 9, and 12 min) on the emulsifying properties of chicken MP under low NaCl condition (0.15 mol/L NaCl) and the stability and rheological properties of MP emulsions were investigated. The results showed that compared with the control group, the emulsifying activity index (EAI) and emulsion stability index (ESI) of MP significantly increased with increasing ultrasonic treatment time (P < 0.05). The Turbiscan stability index (TSI) and particle size of MP emulsions decreased significantly with increasing ultrasonication time, and the absolute value of the zeta potential significantly increased (P < 0.05). The rheological analysis showed that ultrasound treatment significantly improved the viscoelasticity of MP emulsions. The oil-water interfacial tension analysis showed that ultrasound treatment effectively enhanced the mobility of MP, and rapidly decreased the interfacial tension. Meanwhile, ultrasound treatment significantly increased the amount of adsorbed protein in MP emulsions (P < 0.05), indicating that ultrasound treated MP contributed to emulsion stability. As observed by cold-field scanning electron microscopy, the emulsion prepared with MP treated by ultrasound for 12 min had the smallest droplet size. In conclusion, ultrasound treatment can significantly improve the emulsion stability of MP under low NaCl condition, which provides a theoretical reference for the application of ultrasound treatment to reduced-salt emulsified meat products.

As there are some problems with the traditional noodle processing technology, a vibrating plate-type ultrasonic device designed in our laboratory was applied to dough processing, and the effects of ultrasonic time and power as well as dough pressure and thickness on the quality of fresh noodles were investigated by texture analyzer, scanning electron microscopy (SEM) and comprehensive weighted score method. The improving effect of ultrasonic-assisted dough processing on the texture of fresh noodles was evaluated. The results indicated that ultrasonic treatment had a significant effect on improving the quality of fresh noodles. The highest comprehensive weighted score was observed at ultrasonic time of 30 s, ultrasonic power of 330 W, dough pressure of 94.0 Pa and dough thickness of 3 mm. Compared with the control group, the elasticity and hardness of fresh noodles were increased by 19.5% and decreased by 18.1%, respectively. SEM showed that the cross section of fresh wet noodles treated by ultrasound exhibited a more complete and denser network structure, with smaller pore size and porosity. In addition, the starch granules were more uniformly and tightly wrapped in the gluten network structure, suggesting that ultrasonic treatment can contribute to a more stable and denser gluten network. Overall, ultrasonic-assisted dough processing technology can significantly improve the quality of fresh noodles. This study may provide a new idea for the production of flour products.

Protocatechuic acid (PCA) is one of the main metabolites of anthocyanins in the body and has good anti-inflammatory activity. In this study, the protective effect of oral administration of PCA at a dose of 100 mg/(kg mb·d) on high-fat diet (HFD)-induced liver inflammation in C57BL/6J mice was investigated, and the underlying mechanism was investigated by in vitro experiments. In vivo studies showed that after 12 weeks of PCA intervention, the body mass and liver fat content of HFD-fed C57BL/6J mice were significantly reduced, and so were the levels of inflammatory factors such as interleukin (IL)-1β, IL-6, tumor necrosis factor α (TNF-α) and lipopolysaccharide (LPS) in serum and liver. In vitro transcriptome sequencing (RNA-Seq) and Western blot analysis of primary hepatocytes and livers demonstrated that PCA could significantly reduce the gene and protein expression of Toll like receptor 4 (TLR4), and then down-regulate the phosphorylation of nuclear transcription factor κB (NF-κB) inhibiting the expression of inflammatory factors such as IL-6. These results suggest that PCA can effectively improve HFD-induced liver inflammation, possibly by down-regulating the TLR4/NF-κB signaling pathway.

Objective: To explore the effect of genistein (GEN) on relieving fatigue in immunosuppressed rats and the underlying mechanism. Methods: A total of 96 male SD rats were randomly divided into six groups with 16 rats in each group, including blank control (CG), immunosuppression model (MG), low-dose GEN (LG), medium-dose GEN (MG), high-dose GEN (HG) and positive control (PG). All rats except those in the blank control group were injected intraperitoneally with cyclophosphamide at a dose of 40 mg/kg mb for three days to establish an immunosuppressed rat model. The rats in the LG, MG and HG groups were gavaged with GEN at doses of 10, 20, and 40 mg/kg mb, respectively. The positive control group was gavaged with 3.125 g/kg mb of Zhenqi Fuzheng granule, and the blank control group was gavaged with an equal amount of peanut oil. After the experiment, the exhaustive swimming time of rats was recorded. The activities of creatine kinase (CK) and lactate dehydrogenase (LDH) in rat serum were detected by colorimetry. The concentrations of immunoglobulin G (IgG) and tumor necrosis factor-α (TNF-α) in rat serum were detected by enzyme-linked immunosorbent assay (ELISA). Real-time fluorescence quantitative PCR was used to detect adenylate-activated protein kinase (AMPK), silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptorγ coactivator-1α (PGC-1α) and peroxisome proliferators-activated receptor-γ (PPARγ) mRNA expression levels. The protein expression levels of AMPK, SIRT1, PGC-1α and PPARγ in the skeletal muscle of rats were detected by Western blot. Results: Compared with the MG group, GEN supplementation significantly prolonged the exhaustive swimming time of rats (P < 0.01), and high-dose GEN significantly decreased CK and LDH activities and increased the concentrations of IgG and TNF-α in the serum (P < 0.01), and significantly increased the gene and protein expression levels of AMPK, SIRT1, PGC-1α and PPARγ in the skeletal muscle of rats (P < 0.05 and P < 0.01). Conclusion: GEN relieves fatigue in immunosuppressed rats, and the underlying mechanism may be related to activating the AMPK/SIRT1/PGC-1α signaling pathway in the skeletal muscle and improving the exercise endurance, energy production and immunomodulatory capacity of rats.

The hypoglycemic activity of lotus seedpod procyanidin was investigated in a Wistar rat model of diabetes mellitus induced by streptozotocin, and its mechanism of action was preliminarily explored. The rats were divided into six groups: blank control, diabetic model, and lotus seedpod procyanidin at low, medium and high doses. Body mass, food and water intake, fasting blood glucose, serum insulin, C-peptide concentration, oxidative stress, total cholesterol (TC) concentration, triglyceride (TG) concentration and organ indices were measured in each group of mice, and the pathological changes of liver and kidney tissues were also observed. The results showed that lotus seedpod procyanidin alleviated mass loss in diabetic rats. Compared with the model group, high-dose lotus seedpod procyanidin significantly or extremely significantly reduced food and water intake, and fasting blood glucose, serum TC and TG concentrations in rats (P < 0.05, P < 0.01). Medium- and high-dose lotus seedpod procyanidin extremely significantly reduced serum malondialdehyde (MDA) concentration (P < 0.01) and significantly or extremely significantly increased the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) (P < 0.05, P < 0.01), thus improving oxidative stress in diabetic rats. Microscopic observation of rat liver and kidney sections indicated that lotus seedpod procyanidin could protect liver and kidney tissues to a certain extent. In conclusion, lotus seedpod procyanidin has a significant hypoglycemic effect, possibly by affecting lipid metabolism and protecting rats from oxidative stress.

Instant rice with added coarse grain (IR/CG) is a new type of coarse grain product which is self-heating and convenient to eat and has the nutritional value of coarse grains. However, its health effects are not clear yet. Therefore, in this study, the effect of IR/CG on glucose and lipid metabolism was explored in mice with type 2 diabetes mellitus (T2DM) induced by high fat diet (HFD) combined with intraperitoneal injection of streptozotocin. The mice were fed on HFD alone (model), its mixture with IR/CG in different ratios: 25% (low-dose IR/CG, IR/CG-L), 50% (medium-dose IR/CG, IR/CG-M), and 75% (high-dose IR/CG, IR/CG-H), IR/CG alone, or a basal diet (control). During the dietary intervention, the body mass, fasting blood glucose, food intake and glucose tolerance of the mice were measured. After the IR/CG intervention for four weeks, the organ coefficients were calculated, and the pathological changes in liver and pancreas tissues were examined by hematoxylin and eosin (HE) staining. Fasting insulin levels, blood glucose and lipid levels, and proinflammatory cytokines levels were determined. The experimental results showed that dietary supplementation of IR/CG improved blood glucose and lipid levels in T2DM mice to different extents, and this effect was more prominent in the IR/CG-H and IR/CG groups. In addition, IR/CG-H and IR/CG significantly mitigated insulin resistance, decreased insulin secretion, glucagon and HbA1c levels, and reduced oxidative stress injury and inflammatory cytokine levels in T2DM mice. By analyzing the organ index and pathological sections of liver and pancreas tissues, it was found that IR/CG intervention could effectively alleviate liver steatosis and partially restore the structure of the pancreatic islets in mice. Therefore, the substitution of high-fat diet by IR/CG has a significant effect on regulating blood glucose and lipids in T2DM mice, which can provide a theoretical basis for the development of self-heating rice products and functional foods with coarse-grain.

Tannin is the major active ingredient of the dried unripe fruits of Chinese raspberry (Rubus chingii Hu), Fupenzi in Chinese, and has the functions of lowering blood sugar, reducing blood lipid, resisting inflammation, delaying aging and preventing cardiovascular and cerebrovascular diseases. In this study, a tannin-enriched fraction was prepared from Fupenzi, and the changes in its tannin content, antioxidant activity and α-glucosidase inhibitory activity before and after in vitro simulated digestion were investigated. Its regulatory effect on the intestinal microflora was analyzed by in vitro anaerobic fermentation. Finally, ultra-high performance liquid chromatography-quadrupole time of flight-tandem mass spectrometry (UPLC-ESI-QTOF-MS/MS) was used to compare the changes in the contents of tannin and its metabolite after in vitro digestion and fermentation. The results showed that the content of hydrolyzed tannin increased first and then decreased during both gastric and intestinal digestion. Gastrointestinal digestion increased 1,1-dipheny1-2-picryl-hydrazyl (DPPH) radical scavenging capacity of the tannin-enriched fraction, with half-maximal inhibitory concentration (IC50) values ranging from 29.15 to 39.65 µg/mL, but had no significant effect on 2,2’-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging capacity (P > 0.05). In addition, after simulated intestinal digestion, the α-glucosidase inhibitory activity increased by 7.16–7.86 times. In vitro colonic fermentation experiments showed that tannin-enriched fraction significantly increased the relative abundance of beneficial bacteria such as Coprococcus, Anaerostipes, Ruminococcus and Faecalibaterium. Simulated gastrointestinal digestion reduced its effect in improving beneficial bacteria such as bifidobacteria. UPLC-ESI-QTOF-MS/MS analysis showed that the content of tannin metabolites decreased first and then increased during gastrointestinal digestion; the contents of urolithin A and urolithin B decreased significantly after colon fermentation, and neither urolithin C nor urolithin D was detected. Therefore, this study provides a theoretical basis for the establishment of stable tannin delivery system to improve its bioavailability.

In order to scientifically evaluate the health benefits of nut and dried fruit combinations, the antioxidant capacity of various combination of nuts with dried fruits was evaluated by chemical extraction method, an in vitro digestion model and a mouse model. The results of the chemical extraction method showed that the nut and dried fruit combinations were rich in nutrients such as polyphenols, fatty acids and proteins, and their capacity to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation and ferric reducing antioxidant power (FRAP) were significantly enhanced compared to those of the nuts. The in vitro digestion results showed that the phenolic content of the combinations was increased by 2.90%–60.38% and DPPH and ABTS radical cation scavenging capacity by 1.23%–18.60% compared to that of either alone. The best synergistic antioxidant effect was achieved with a 6:4 mixture of nuts and dried fruits. Meanwhile, the combinations of nuts and dried fruits increased the activity of catalase (CAT), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) in the serum and liver of mice after gastrointestinal digestion, effectively inhibited the production of malondialdehyde (MDA) and preserved the morphological integrity of mouse hepatocytes. In conclusion, the mixture of nuts and dried fruits has a synergistic antioxidant effect and good antioxidant capacity in vitro and in vivo.

Objective: To study the laxative effect of Lactiplantibacillus plantarum P9 on functional constipation in mice and its effect on the gut microbiota. Methods: One hundred Balb/c male mice were randomly divided into five groups of 20 mice each: blank, model, low-dose P9 (dried bacterial powder with a viable cell count of 2.0 × 1011 CFU/g, 0.42 mg/(kg mb·d)), medium-dose P9 (0.84 mg/(kg mb·d)), and high-dose P9 (2.5 mg/(kg mb·d)). The mice in the three dose groups were gavaged with L. plantarum P9 suspension in sterile deionized water at 10 mL/(kg mb·d) for 15 days, while those in the blank and model groups were gavaged with an equal volume of distilled water. On day 16 of the experiment, loperamide at 4 mg/(kg mb·d) was applied by gavage to induce functional constipation in mice. Ten mice with constipation were randomly selected for defecation test, where the time of the first black stool and the weight of black stool at 6 h were measured. The remaining 10 mice were measured for the rate of ink advancement, and the composition of the cecal flora was determined by 16S rRNA high-throughput sequencing. After the end of the defecation test, the remaining mice in the model and P9 intervention groups were continuously gavaged with loperamide at 4 mg/(kg mb·d) to establish a mouse model of functional constipation, while those in the blank group was given an equal volume of distilled water. The mice in the P9 intervention groups were administered with L. plantarum P9 at 1 h after modeling, whereas those in the blank and model groups were given an equal volume of distilled water by gavage for six days. The histopathological changes of the colon were observed by hematoxylin-eosin (HE) staining, and serum motilin (MTL), gastrin (GAS), acetylcholine (AchE), and nitric oxide (NO) levels were determined. Results: Compared with the model group, the medium dose of L. plantarum P9 significantly shortened the time the first black stool in mice with functional constipation (P < 0.05), and the medium and high doses of L. plantarum P9 significantly increased the volume of black stool excretion at 6 h (P < 0.01 and P < 0.001). The low, medium and high doses of L. plantarum P9 significantly increased the rate of ink advancement in mice (P < 0.01, P < 0.05, and P < 0.001), and augmented the serum levels of MTL, GAS and AchE. The low dose of L. plantarum P9 significantly increased the level of GAS (P < 0.001), the high dose of L. plantarum P9 significantly increased the level of MTL (P < 0.01), the low and medium doses of L. plantarum P9 significantly increased the level of AchE (P < 0.05), and the low and medium doses of L. plantarum P9 significantly decreased the level of NO (P < 0.05). The damaged intestinal barrier was repaired and the richness and diversity of the gut microbiota were significantly increased at all doses of L. plantarum P9. Conclusion: L. plantarum P9 has a good laxative effect, and its mechanism may be related to improving intestinal motility, regulating gastrointestinal serum neurotransmitters and increasing the richness and diversity of the gut microbiota.

This study aimed to investigate the impacts of vegetables with different textures on food oral processing behavior, food intake and satiety. Broccoli cooked by microwave for different periods of time were tested in this study. The oral processing behavior of simultaneous and sequential consumption of cooked broccoli and rice, ad libitum food intake and postprandial satiety were measured in healthy subjects. Results showed that compared with co-ingestion of soft broccoli and seasoned rice (SSR), sequential ingestion of hard broccoli followed by seasoned rice (H + SR) increased the number of chews, the oral sensory exposure time and the number of chews per gram by 44%, 34% and 57%, respectively, and reduced the eating rate by 25% and the rice intake by 20%. Moreover, compared with SSR, H + SR effectively suppressed the perception of postprandial hunger. In conclusion, hard-cooked broccoli helped to reduce food intake and inhibit subjective hunger by enhancing oral processing, and this effect was more significant when the vegetable was first consumed cooked by cooked.

Early-season Satsuma mandarin fruit produced in Chongqing are usually harvested when the flesh reaches the acceptable internal maturity standards, while the peel is still green. In order to solve this problem, ethylene degreening treatment is widely used in the citrus industry. However, the light color and poor organoleptic quality of ethylene-degreened Satsuma mandarin fruit affect its acceptance by consumers. The effect of light on the coloration of ethylene-degreened Satsuma mandarin fruit was investigated in our previous study, and we found that treatment with 300 lx, 450 nm blue light-emitting diode (LED) irradiation was effective in improving the coloration of ethylene-degreened Satsuma mandarin fruit. The underlying mechanism was explored from the perspective of carotenoid metabolism. Since the color formation of mandarin fruit is determined by both chlorophyll and carotenoids, the effect of blue LED irradiation on chlorophyll metabolism in ethylene-degreened mandarin fruit was investigated in this study. The results showed that combined treatment with blue light and ethylene promoted the degradation of chlorophyll a, chlorophyll b, pheophytin a, pheophorbide a, and pheophorbide b and thus accelerated fruit color change by up-regulating the expression of the chlorophyll degradation-related genes CcRCCR and CcNYC1 and down-regulating the expression of the chlorophyll synthesis-related genes CcCAO, CcChIH and CcMPEC in Satsuma mandarin fruit. These results provide a theoretical reference for understanding the regulation mechanism of blue LED light irradiation on the coloration of ethylene-degreened Satsuma mandarin fruit.

To explore the effect of a chitosan-based preservative solution (10 mg/mL chitosan + 5 mg/mL tea polyphenol + 2 000 U/mL lysozyme) on the change in the muscle proteome of grass carp during cold storage, differential proteomic analysis of fresh fish and nine-day-stored fish with or without (control) preservative treatment was conducted by two-dimensional electrophoresis-mass spectrometry (2DE-MS). The results showed that the 2DE map of the preservative-treated group was not obviously different from that of the fresh group, except for a decrease in the abundance of fast troponin T and an increase in the abundance of slow troponin T and adenylate kinase isoenzyme. However, the 2DE profile of the control group differed greatly from that of the fresh group in both the number and signal intensity of protein spots. Further analysis showed that the abundance of fast troponin T, tropomodulin 4, synaptopodin 2 and pyruvate kinase type M were down-regulated, while the abundance of myosin heavy chain, myosin light chain 1, α-actin, α-tropomyosin and intermediate light meromyosin were up-regulated. Moreover, compared with the preservative-treated group, the abundance of three troponins T were decreased, while the abundance of myosin heavy chain, intermediate light meromyosin, α-actin, α-tropomyosin and creatine kinase M-type were increased in the control group, suggesting that creatine kinase could serve as an indicator for evaluating grass carp muscle spoilage. This study demonstrates that the chitosan-based composite preservative can maintain the stability of grass carp muscle protein during cold storage.

The aim of this study to develop a stable anthocyanin indicator film to monitor the freshness of chilled beef. Composite anthocyanin microcapsules (CAM) were prepared and used to prepare indicator films using carrageenan (Car) and sodium carboxymethyl cellulose (CMC) as film-forming matrix with different amounts (5%, 10%, 15% and 20%, V/V) of added CAM, and the structural and physical properties of the resulting films were characterized, and their application to monitor beef freshness was investigated. The results showed that the addition of CMC significantly improved the mechanical properties, barrier properties and thermal stability of Car films. The film with 15% CAM had the highest tensile strength (17.76 MPa) and lowest water vapor transmission rate (1.35 × 10－11 g/(m·s·Pa)), and showed a tightly and orderly arranged cross-section. The Fourier transform infrared spectra showed that the components of the indicator film were structurally similar and compatible. When the indicator film was exposed to ammonia, its color changed from pink to blue-green and eventually to yellow. The indicator film was applied to monitor the freshness of beef during storage at 4 ℃. The results showed that beef reached secondary freshness and spoilage on day 4 and 7, respectively, and that the color of the indicator film changed from pink to purple and green correspondingly. In conclusion, the film with 15% CAM is the most sensitive to changes in the freshness of beef and thus can be used to detect it.

The interaction between food-derived peptides and starch has an important impact on the structure and properties of starch-based foods. Food-derived peptides can adhere to the surface of starch granules through hydrogen bonds and electrostatic and hydrophobic interactions, forming a physical barrier, and they can also form a gel structure with starch molecules by hydrogen bonds and electrostatic interaction, which in turn can change the structure and characteristics of starch-based foods. This paper reviews the interaction between food-derived peptides and starch, the effects of food-derived peptides on the structure, physicochemical (rheological, thermodynamic and gelatinization properties) and digestive properties of starch, and the application of food-derived peptide-starch system. This review is expected to provide a theoretical basis for the application of food-derived peptides and starch in functional foods.

The two-peptide (class IIb) bacteriocins are generally thermostable small-molecule (< 10 kDa) two-component antimicrobial peptides produced by Gram-positive bacteria. This class of peptides mainly rely on peptide-peptide interactions mediated by typical motifs to form active dimeric transmembrane proteins. Numerous studies have shown that two-peptide bacteriocins have reliable safety and desirable bacteriostatic effect, holding great potential in the control of drug-resistant bacteria. Therefore, the structural features and action mechanisms of two-peptide bacteriocins have received considerable research attention. From the perspectives of the structure formation of two-peptide bacteriocins, peptide-peptide interaction, and peptide-membrane interaction, this article summarizes the mechanism of action of this class of antimicrobial peptides. Meanwhile, the structural regularity of two-peptide bacteriocins and the structural features affecting their activities are elaborated by synthesizing current research. This review will provide new ideas for future research on two-peptide bacteriocins.

Heat treatment can induce muscle protein denaturation and aggregation and eventually the sol-gel tradition of proteins. The aggregation rate, degree, morphology and pattern can affect the quality of protein gels. Traditional Chinese soy sauce and pot-roast meat products are processed at temperatures above 100 ℃, and secondary heating treatment is commonly used to extend the shelf life of canned foods, both of which can lead to excessive protein aggregation, in turn reducing the fluidity of water as well as protein digestibility, destroying the quality of meat products and reducing the nutritional value. In this paper, the mechanisms of protein aggregation are analyzed by using the Lumry-Eyring nucleated polymerization (LENP) model. Three protein aggregation modes are described including fibril aggregation, hydrogel aggregation and amorphous aggregation. Four strategies for inhibiting excessive thermal aggregation are reviewed from the perspective of the spatial conformation of proteins. pH, amino acids and polyphenol compounds along with hydrophobic and reducing small molecules can effectively inhibit excessive aggregation of myofibrillar proteins and improve the gel properties of heat-induced proteins. As a molecular chaperone, casein can obviously enhance the thermal stability and reduce the degree of aggregation of proteins. Therefore, these strategies for inhibiting excessive aggregation can enhance the gel and texture quality of meat products.

Bioactive peptides are small protein molecules with specific physiological activity. The efficient separation and purification of bioactive peptides contributes to the full exertion of bioactive peptides and research on their structure-activity relationship. However, the separation process is difficult and tedious. In view of this, researchers have developed mixed-mode chromatography (MMC) to separate and purify bioactive peptides by virtue of the differences in their properties such as hydrophilic, hydrophobic and charge characteristics, which exerts multiple retention mechanisms through the multifunctional stationary phases and the adjustable mobile phases. MMC has the advantages of controllable stationary phase, specific recognition and high efficiency. The development of MMC stationary phases and their application in the separation of bioactive peptides are summarized in this paper in order to provide a reference for the efficient utilization of bioactive peptides.

Fermented meat products are vulnerable to microbial contamination because of their long production cycle and rich nutrients, which can affect product quality and result in adverse effects on human health. As consumers pay increasing attention to the flavor and safety of fermented meat products, it is very important to explore the safety and flavor characteristics of meat products. Lactic acid bacteria were the first microorganisms isolated from fermented meat products, which are important dominant microorganisms in traditional fermented meat products and are closely related to product quality. In fermented meat products, lactic acid bacteria can not only produce antibacterial substances that inhibit the growth of harmful microorganisms and therefore improve the safety of meat products, but also improve the flavor of fermented meat products by affecting carbohydrate metabolism as well as protein and lipid decomposition and oxidation. This paper reviews the effect of lactic acid bacteria on improving the product quality by inhibiting the growth of harmful microorganisms in fermented meat products and the effect of lactic acid bacteria the flavor of fermented meat products in order to provide new ideas for future research of fermented meat products.

Salt is a seasoning widely used in the food industry and our daily diet. Excessive intake of salt, whose major component is sodium chloride, will increase the risks of multiple diseases such as hypertension, gastric cancer, and stroke. How to reduce the salt content of foods without affecting the flavor is a hot topic of current research. Structural and compositional optimization of solid sodium chloride, which constitutes an important part of daily dietary salt intake, is an effective way to develop low-salt foods. This article provides a detailed discussion on the mechanisms of salty taste perception and sodium absorption and metabolism in the body, and summarizes the salt reduction strategies developed based on structural regulation and compositional design of sodium chloride in recent years. The novel technologies for reducing the salt content without affecting the salty taste, such as regulating the physical structure (morphology and particle size) of sodium chloride, encapsulating sodium chloride, and adding sodium chloride substitutes (salty mineral salts, flavor enhancers and natural taste substances) are discussed. In the end, the salt reduction mechanisms, shortcomings and applicable scenarios of salt with different structures and components are analyzed. We hope that this review will provide theoretical evidence and technical support to design new salt products, develop low-salt foods, reduce the dietary salt intake of residents and improve human health in the future.

Heterocyclic amines (HAs) are a class of toxic compounds with strong teratogenic and carcinogenic activities which are produced during thermal processing of meat products. Three types of HAs, including 2-amino-3-methyl-imidazo[4,5-f]-quinoline (IQ) and 2-amino-3,4-dimethyl-imidazo[4,5-f]-quinoline (MeIQ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP), and 1-methyl-9H-pyrido[3,4-b]indole (harmane) and 9H-pyrido[3,4-b]indole (norharman), are common and widely distributed in heat-processed meat products. This article briefly analyzes the formation pathways and mechanisms of these HAs, elucidates the inhibitory mechanism of exogenous plant polyphenols on their formation, and clarifies the structure-activity relationship of polyphenol compounds for the inhibition of their formation. This review will provide theoretical guidance for the effective application of plant polyphenols to control the formation of HAs in heat-processed meat products.

During the conversion of muscle to meat, a series of biochemical changes are required for meat aging. Protein phosphorylation, a dynamic regulation mechanism of proteins, regulates almost every major biological process, and is one of the extensive post-translational modifications in the biological world. Therefore, studying the relationship between protein phosphorylation and postmortem muscle is helpful to the development of the meat industry. This article begins with an introduction to protein phosphorylation, discusses the technical progress in phosphorylated protein detection, summarizes the proteins that are phosphorylated in muscle after slaughter and the influential factors of protein phosphorylation, and reviews the effect of protein phosphorylation on meat quality attributes such as tenderness, color and water-holding capacity. The application of salts and amino acids in improving postmortem meat quality is reviewed and future research directions are also proposed.

Selenium (Se) is an indispensable micronutrient in the human body, which participates in various physiological and metabolic processes. Around the world, about 500 million to 1 billion people are at risk from selenium deficiency related diseases. In the agriculture-food system, selenium enters the food chain mainly from soil, and is accumulated in crops and then assimilated by the human body through diets. Using suitable agronomic measures to enhance the ability of crops to absorb and transform soil selenium can enable organic selenium to effectively accumulate in the edible parts of crops. However, the enrichment of selenium in crops does not mean that selenium can be completely retained in crop foods. The influence of food processing is extremely critical as well. Various processing conditions and parameters will affect the selenium content and speciation of the final products, thus affecting its bioavailability in the human body. This paper reviews the flow of selenium in the “soil-crop-food-human” chain, and summarizes the key factors that affect the content and speciation of selenium in foods and the bioavailability of selenium in the human body. It is suggested that all factors should be considered comprehensively to realize efficient conversion of selenium from farm to table.

Osteoporosis afflicts 200 million patients worldwide. With the aging of the global population, the incidence of osteoporosis will continue to increase, and the prevention of osteoporosis has become an urgent problem in the field of public health. This paper analyzes the mechanisms by which milk and dairy products as well as their components such as minerals, vitamins, protein, fat and lactose modulate the intestinal flora and in turn affect calcium absorption and bone health. The interventional effects of dairy products fortified with vitamin D, prebiotics and/or probiotics in different populations and their effect in reducing the risk of osteoporosis are reviewed. The interventional effects of dairy products and plant-based milk are compared. This review hopes to provide a scientific reference for precision intervention with dairy products to improve bone health.

Food flavor is an important factor which affects consumer purchase intention, and the formation of flavor perception is affected by multiple senses such as olfactory and gustatory sense. The application of the interaction between odor and taste in food flavor improvement has become one of the most concerned new directions of food flavor regulation. On this basis, this paper analyzes the main formation pathway and mechanism of the cross-modal perceptual interaction between odor and taste from the neurobiological perspective, and summarizes the main methods used to research the cross-modal perceptual interaction from the aspects of static sensory analysis and dynamic sensory analysis. Finally, the effects of odor substances on taste perception (sweet, salty, bitter, umami and sour) and the effects of taste substances on olfactory perception are reviewed based on relevant literature and cases, in order to provide new ideas for the regulation of flavor quality during food processing.

As the consumption demand for rice gradually changes from the pursuit of yield to the pursuit of quality, more attention has been paid to the nutritional and eating quality of rice. Therefore, clarifying the relationship between rice components and eating quality and understanding the formation mechanism of rice texture, aroma and taste are of great significance to guide improve the eating quality of rice. Protein is the second most abundant component of rice after starch, and is directly or indirectly involved in the formation of rice flavor quality. In this paper, the relationship between rice protein and texture, aroma or taste characteristics is summarized and future research priorities are discussed. This review may provide a reference for the improvement of rice eating quality.

Aquatic products are popular among consumers due to their rich nutrients and delicious taste. Their muscle quality always attracts attention, which can be judged from the microstructure of muscle tissues. Microstructure is often used as a key indicator for evaluating the muscle quality of aquatic products. The evolution of the microstructure of aquatic products during storage, processing and circulation is reviewed in this article. The technical characteristics and applicability scope of various methods for detecting the microstructure of muscle tissues of aquatic products are summarized, and the relationship between the microstructure of muscle tissues and the physicochemical indexes related to muscle quality is described. The purpose of this review is to provide a theoretical reference for further improving the quality evaluation and regulation system of aquatic products in the future.

China is a big producer and consumer of grains and oils. The development of high-yield grains is closely related to chemicals such as pesticides. With the improvement of people’s living standards, residents’ requirements for foods have changed from ‘security of output’ to ‘equal emphasis on quality and output’. In order to strengthen the management of grain quality and safety, it is urgent to comprehensively understand the status of pesticide pollution in grains and develop more efficient, convenient and rapid detection technologies. This paper briefly summarizes the characteristics of pesticides and pesticide residues, analyzes the current status of the use and residues of pesticides in raw materials for grains and oils in China, reviews the existing rapid detection methods and technologies for pesticide residues in grains, and compares the advantages and disadvantages of various rapid detection methods and products. This review is expected to provide a reference for quality inspection during grain purchase.

With the improvement of people’s living standards, food safety has attracted more and more social attention. Organisms, especially microorganisms, are the most important factor that affects food safety. There are many methods currently available to detect biological (microbial) factors in the field of food safety, including isothermal amplification technology especially the new techniques of recombinase polymerase amplification (RPA), recombinase-aided amplification (RAA) and enzymatic recombinase amplification (ERA), which is widely used for food safety detection because it can detect biological ingredients rapidly and accurately without relying on complicated instruments. The three isothermal amplification techniques require milder reaction conditions and simpler design of primers than others, despite having similar principles. In this article, we review the principles and concepts of these techniques and their recent application in the rapid detection of food pathogens, summarize their advantages and problems in food inspection, and present future prospects.

Protein is an important nutrient for the human body. Long-term lack of proteins will directly or indirectly lead to increased incidence of low immunity, muscle attenuation, osteoporosis and other diseases. This phenomenon is more prominent in the elderly, which reduces their exercise and metabolic capacity, directly affects their quality of life. This in turn increases the burden on the public health and medical system in China, which hinders the steady advancement of the ‘Healthy China’ strategy. At present, the major ways to improve inadequate protein intake and deficiency in the elderly include improving food properties (changing protein structure) and physical function (adding ingredients that can promote the secretion of protein-digesting enzymes), and changing the diet structure (increasing oligopeptide intake) and habits (increasing protein intake and types). The effects of aging on protein digestion and absorption capacity are discussed, the existing methods to promote protein digestion and absorption are summarized, and future directions for improving the protein digestion and absorption capacity of the elderly are discussed in order to provide a reference for future research to promote nutrition especially protein absorption in the elderly.

The primary criterion for selecting probiotics having application potential is their adhesion capability to the host intestinal mucosa. The adhesion mechanism of probiotics is affected by many factors such as adhesins. Probiotics with high adhesion capability has a long intestinal residence time, contributing to their intestinal colonization in animals and stimulating intestinal barrier and metabolic functions, in turn maintaining the health of organisms. In addition, they can exert antagonistic effects against pathogens to protect intestinal health via many mechanisms such as producing antimicrobials and decreasing the adhesion capacity of pathogens and competitive binding sites. In this article, the adhesion mechanism of probiotics is reviewed, and a comprehensive overview of the state of the art in research on the adhesion characteristics and antagonistic activity against pathogens of probiotics is given.

Pectin methylesterase (PME) is a pectin-degrading enzyme widely present in plants, fungi and bacteria, which often leads to quality defects such as precipitation, water separation and agglomeration and texture softening in fruit and vegetable juice and fresh-cut fruits and vegetables during storage. Therefore, effective inhibition of PME activity is important for fruit and vegetable processing. Thermal processing is currently mainly used for the control of PME activity, which can cause irreversible adverse effects on the quality of thermosensitive fruit and vegetable products. With the improvement of people’s living standards and health awareness, in order to meet people’s pursuit of higher quality products, some thermal processing and non-thermal processing technologies have been gradually explored and applied to the inactivation of PME. In addition, many PME inhibitors have been gradually developed. In this article, the inhibitory effect and mechanism of the current major processing methods and PME inhibitors on PME are summarized, and the application of different processing methods together or combined with PME inhibitors to inhibit PME activity is reviewed. We hope that this review will provide a theoretical basis for the production of higher quality fruit and vegetable products in the future.

Storage and preservation techniques can play an important role in extending the shelf life of perishable foods. With consumers’ increasing awareness of environmental protection and safety, edible antibacterial packaging is highly favored because of its natural source and non-toxic nature. This paper introduces in detail the substrate materials, antibacterial agents and methods used to prepare edible antibacterial films, summarizes the application of edible antibacterial films in the food packaging field, and discusses future trends in the development of antibacterial food packaging. We hope that this review will provide a reference for reduction in white pollution and the recovery and utilization of agricultural and industrial wastes, and provide a scientific and theoretical basis for food storage and preservation.

Protein gels are three-dimensional protein networks with high moisture content, which have been widely applied in several fields such as food, medicinal, and industrial sectors. Gel texture can be improved by adding dietary fiber due to its good physical, chemical and physiological properties, which has become the focus of attention of researchers. In order to better understand recent progress in research on dietary fiber-protein composite gels, this paper focuses on the classification, structure and functional characteristics of dietary fiber, and summarizes the current state of knowledge on the effect and mechanism of dietary fiber on the characteristics of protein gels. Moreover, it gives an overview of the application of fiber-protein gels in the fields of food and medicine and predicts future development directions. This paper will provide a basis for the preparation and application of fiber-protein gels.

Melatonin, a trace efficient natural plant signaling molecule, has been widely reported in plant growth and development, abiotic stress, and postharvest preservation and other aspects. In recent years, melatonin has been found to play a positive role in inducing disease resistance in fruits. This paper describes the effect of melatonin on pathogens in vitro and in infected fruits, with a focus on the mechanism by which melatonin induces fruit resistance to invasive diseases. Furthermore, this paper reveals that melatonin and plant signal transduction pathways constitute a regulation network to mediate disease resistance responses in fruits. We conclude this paper with an outlook on future research directions in order to provide a theoretical reference for further research on the mechanism by which melatonin induces disease resistance.

Oxidation and microbial spoilage are the major factors affecting the quality and shelf life of meat and meat products. Phenolic compounds extracted from plants have antioxidant capacity and antibacterial properties. But their antibacterial mechanisms have not been clearly elaborated and a systematic review in this field is still lacking. Based on the classification of and the variability of the antibacterial activity of natural phenolic compounds, the possible antibacterial mechanism of phenolic compounds is summarized from the perspectives of the cell wall and membrane, biofilm formation and protein synthesis, and their application in the meat industry is reviewed. This paper is expected to provide a theoretical foundation for further research on the antibacterial mechanism of natural phenolic compounds and their application in meat production to extend the shelf life of meat and meat products.

Capsaicin is the source of spicy taste in pepper fruits. Capsaicin stimulates nerve endings and reacts with some molecules to produce bioelectric pulses, which trigger the transient receptor potential vanilloid 1 (TRPV1) channal in human nerves, and then transmit the signal to the brain to produce a spicy feeling. It is found that capsaicin synergizes with or inhibits taste, and the interaction between them varies depending on the concentration of capsaicin. Therefore, this paper summarizes the types, chemical properties and applications of capsaicinoids, describes the biological mechanism by which capsaicin causes a spicy sensation, namely activating the capsaicin receptor TRPV1 channel, and discusses the interaction of spiciness with sour, sweet and bitter taste. Next, this review points out the shortcomings of the current research on the interaction between spiciness and taste and the potential underlying mechanism, and provides an outlook on future research directions. It is expected that this review will provide theoretical support for the further development of the spicy foods industry.

Microbial communities interact in a complicated way, which can have a detrimental effect on the host’s health either individually or collaboratively. By employing causal inference methods to analyze the characteristics of the relationship between the microbiota and host observation data, the mechanism of action of microorganisms on host health can be inferred, which will help to reduce the possibility of causing unfavorable health consequences. This article reviews recent progress in the application of causal inference in the field of microbiological research, introduces the conception and development of causality, describes the paths of causal inference, modeling and interpretation, and summarizes the causal inference methods and their applications in various fields especially in the microbiological field. However, the mechanism of the causality between microbial communities and their external environments is not yet understood fully. Applying causal inference methods in research on microbial communities will be a hot topic in the future. Thus, the theory and methods of causal inference need be further refined to elucidate the interaction mechanism of microbial communities and their causality with human health.

The overweight or obese population in sub-health status and the aging population in China are increasing year by year. The intracellular level of nicotinamide adenine dinucleotide (NAD+) decreases dramatically with age and obesity. NAD+ is the key target of cellular energy metabolism and cell function regulation, which affects senescence. Therefore, improving physiological functions and delay aging by supplementing NAD+ precursors has become a hot topic of current research. β-Nicotinamide mononucleotide (NMN) is an intermediate metabolite of NAD+ in animals, and it is also the most direct and efficient NAD+ supplement precursor at present. However, NMN has complex effects on the physiological functions of various organs, the results of animal tests are not consistent with those of human clinical tests, and the optimal dosage has not been determined. This paper summarizes the results of recent animal and human clinical tests of NMN aiming to explore the effects, mechanisms, doses and adverse reactions of NMN supplementation on animal and human physiological functions. Through this paper, we hope to provide ideas for future research and application of NMN.