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The dietary fiber (DF) composition, physicochemical and functional properties of triticale dietary fiber (TRDF) and hull-less barley dietary fiber (HUDF) were investigated and compared in this study. Results revealed that triticale soluble dietary fiber (TRSDF) had higher arabinose and xylose contents but lower glucose content than that of hull-less barley soluble dietary fiber (HUSDF). Compared with hull-less barley insoluble dietary fiber (HUIDF), triticale insoluble dietary fiber (TRIDF) had more arabinose and xylose. HUSDF exhibited a smaller particle size and lower viscosity than TRSDF. HUSDF had greater hydroxyl scavenging activity, whereas TRSDF showed higher DPPH radicals scavenging activity. Glucose adsorption capacity, glucose dialysis retardation index, and α-amylase and α-glucosidase inhibitory activities of TRSDF were all higher than those of HUSDF. TRIDF and its bound polyphenols demonstrated higher α-amylase and α-glucosidase inhibitory activities than those of HUIDF and its polyphenols. In conclusion, TRDF had better hypoglycemic activities than that of HUDF and the antioxidant activity of TRIDF was lower than that of HUIDF.

The lactic acid bacterial diversity of wheat sourdoughs collected in Ya'an city, Sichuan province was investigated by culture-dependent methods combined with 16S rRNA gene sequencing, and the exopolysaccharide (EPS) production characteristics of ropy lactic acid bacteria (LAB) strains from these sourdoughs were evaluated. Two hundred nineteen LAB strains were isolated, and genotypic characterization indicated that the isolated LAB strains included Lactobacillus plantarum (L. plantarum), L. pantheris, Leuconostoc citreum (Leu. citreum), Weissella viridescens, Leu. pseudomesenteroides, Lactococcus lactis (L. lactis), L. raffinolactis, and Leu. mesenteroides. All the isolates were found to harbor genes coding for EPS, and the yield of EPS produced by “ropy” LAB strains ranged between 2.3 and 229.5 mg/g wet cell weight. The present study enhances our knowledge about LAB diversity in Ya'an sourdoughs and provides information about the EPS-producing LAB strains in sourdough samples, which might be favorable for the application of specific LAB strains in sourdough technology.

Bacteriophages are considered a promising candidate for controlling food pathogens. In this study, we isolated and characterized S. aureus-infecting bacteriophages, and investigated their potential for antibiotic substitute and bacteriophage cocktail effect in Luria-Bertani (LB) broth and skim milk. Bacteriophages LSA2308 and LSA2366 possessing lytic activity against drug-resistant S. aureus were isolated. The latent period of LSA2308 and LSA2366 was approximately 20 and 10 min, with burst size of 407 and 258 PFU per infected cell, respectively. A combination of LSA2308 (or LSA2366) and 1/2 MIC ampicillin achieved better clearance of S. aureus CR003 in LB broth than treatment with either bacteriophage or ampicillin alone. Biocontrol with 105–107 PFU/mL LSA2308 or LSA2308/LSA2366 cocktail was effective in LB broth, whereas it was less active in skim milk. Compared with treatment using 105 or 106 PFU/mL bacteriophages, the bactericidal efficacy of 107 PFU/mL bacteriophages on single or mixed S. aureus strains in skim milk was the best at 4 and 25 °C, revealing a dose-dependent mode. Our study further expands the repertoire of bacteriophages infecting drug-resistant S. aureus, and provides insights into the control of S. aureus in milk production chain.

Soluble and insoluble dietary fiber (SDF and IDF) were extracted from quinoa and wheat. Results showed that all the dietary fiber (DF) samples exhibited typical infrared spectrum characteristics of polysaccharides. Compared with wheat soluble dietary fiber (WHSDF), quinoa soluble dietary fiber (QUSDF) displayed a compact structure, higher reducing power and digestive enzyme inhibitory activity. WHSDF showed stronger DPPH radical scavenging activity than QUSDF. Quinoa insoluble dietary fiber (QUIDF) and wheat insoluble dietary fiber (WHIDF) displayed similar network structure, but the α-glucosidase inhibitory activity of WHIDF was higher than QUIDF. Moreover, the bound polyphenols in QUIDF and WHIDF also showed better DPPH radical scavenging activity and α-amylase inhibitory activity. In summary, the DF of quinoa and wheat showed different structural, physicochemical and functional properties, and in both samples bound polyphenols had significant contributions to the antioxidant and hypoglycemic capacity of IDF.

The detection of H2O2 in milk was carried out using a CIC-biosensor based on collagen-immobilized catalase (CIC) and a dissolved oxygen probe. The CIC-biosensor response was fastest at pH 7.0 at 30 °C. Further, the biosensor exhibited responses over a H2O2 concentration range from 1.47 × 10−6 mol/L to 2.94 × 10−4 mol/L with response times of 20–120 s, and could be reused eight times. When the CIC biosensor was applied for the detection of H2O2 in milk, the recovery of H2O2 ranged from 83.4% to 95.8%. The biosensor can potentially be used for rapid detection of H2O2 in milk as a result of its sensitivity and rapid response time, easy preparation, and simple sample pretreatment.

The casein cold-set gel was prepared from yak qula and the gel characterizations and embedding features were investigated by means of rheological property analysises, texture profile analysises, laser confocal microscopic observation, and in vitro simulated digestion experiment. The results showed that the hardness and elasticity of the gel were increased with the concentration of glucono-δ-lactone (GDL) and NaCl. Better water holding capacity (WHC) was observed in the gel with a lower concentration of GDL (1%) and NaCl (0.2M) than that with high concentration of GDL (2%) and NaCl (0.2M, 0.4M). GDL significantly affected the energy storage modulus (G’) and loss modulus (G”) values. Confocal laser scanning microscopy (CLSM) observations and fractal analysis further demonstrated that electrostatic interaction was the major force in the gel formation, which was characterized by reactive limited polymerization. The in vitro experiment on casein cold-set gel encapsulation of bioactive ingredient (Que) showed favorable encapsulation and controlled-release performance. In conclusion, Yak casein (YCN) cold-set gel would be an useful matrix for the application of encapsulation, protection, delivery and controlled-release of some bioactive components.

The objective of this work was to evaluate the effects of different cooking methods (steaming, boiling, frying and microwaving) on nutrients and their bioaccessibility by an in vitro simulated digestion model. The result demonstrated that the degree of protein hydrolysis (42.84%) after digestion under microwaving was the highest. The fatty acid composition can influence the lipid digestion fate, and the stearic acid content of all samples was significantly increased, except for the methods of frying (only from 4.72 to 8.37 g/100 g). The highest bioaccessibility was discovered in Cu (83.35%, frying), and the lowest was in Fe (3.96%, frying), but Pb was not digested. Frying method caused severe losses of protein bioaccessibility but it has the highest amount of reducing sugar release and antioxidant activity. The scientific and in-depth nature of the above study provides a reference for the daily consumption of C. cornucopioides.

To further improve the utilization rate of starch in the fermentation of Baoning vinegar, the effects of Aspergillus niger biofortification on the quality and microbial community of vinegar Pei (a mixture of fermentation materials) and Baoning vinegar were evaluated. The results suggested that the total acid content, a crucial parameter for vinegar production, in vinegar Pei increased by approximately 1.70 g/100 g at the end of fermentation. The utilization rate of starch and content of organic acid increased significantly after biofortification, and the content of lactic acid was the highest in Baoning vinegar, followed by acetic acid. Similarly, the total amount of free amino acids increased after biofortification, especially the content of histidine and tyrosine. The esters and acid compounds were the most abundant in the vinegar Pei, while the contents of acid and carbonyl compounds were the highest in liquid vinegar. As revealed by high-throughput sequencing, the microbial community in vinegar Pei changed little after biofortification. Lactic acid bacteria and yeast are the most abundant microbes throughout the fermentation process. The present study provides insights into the improvement of the solid-state brewing process of vinegar.

As the natural antibacterial agents, bacteriophages have great potential for controlling food pathogens. Compared to broad-spectrum bacteriophages, narrow-spectrum bacteriophages can reduce the risk of developing community-wide resistance and have little impact on microbial flora. The present study aimed to isolate and characterize a narrow-spectrum bacteriophage that effectively controlled Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) in food. A narrow-spectrum bacteriophage LSE7621, which can effectively lyse Salmonella Enteritidis, was obtained from sewage by the double-layer agar plate method. LSE7621, which belonged to the order Caudovirales and family Myoviridae, showed good pH tolerance (pH 4.0–11.0) and thermal stability (30–50 °C). LSE7621 was able to significantly and effectively control Salmonella on lettuce and tofu (p

Salmonella strains pose a great challenge to food safety. The exploration of bacteriophage endolysins can be a valuable measure for the prevention of Salmonella propagation in food, feed and agricultural products. The current study aims to obtain endolysins that efficiently lyse Salmonella Typhimurium (S. Typhimurium). Two possible endolysins LysWL59 and LysWL60 from bacteriophage LPST10 were identified, prepared, and characterized. Afterward, LysWL59 was utilized for the reduction of S. Typhimurium in Tris-HCl buffer or on lettuce. The results revealed that both LysWL59 and LysWL60 displayed broad lytic activity against chloroform treated Gram-negative bacteria. LysWL59 was more stable and remained active at pH ranging from 6.0 to 10.0, and at temperatures ranging from 4 to 90 °C. LysWL59, in combination with outer membrane permeabilizing agents, had the ability to reduce viable S. Typhimurium in Tris-HCl buffer or on lettuce, and 2.50 μmoL/L LysWL59 with 0.50 mmoL/L EDTA decreased S. Typhimurium by 93.03% within 1 h on lettuce. To the best of our knowledge, the activity of LysWL59 was superior to that of previously reported endolysins against Gram-negative strains, especially Salmonella. Therefore, LysWL59 represents a promising agent against Salmonella contamination. This study provides insights into the control of food pathogens by using endolysins.