Whole-genome and comparative genome analysis of Mucor racemosus C isolated from Yongchuan Douchi

Removal of aflatoxin B1 from contaminated milk and water by nitrogen/carbon-enriched cobalt ferrite -chitosan nanosphere: RSM optimization, kinetic, and thermodynamic perspectives

In view of the feed/foods inevitably contaminated by toxic and carcinogenic aflatoxin B1 (AFB1), efficient mesoporous metformin-chitosan/silica‑cobalt ferrite nanospheres (Mt-CS/CFS NSs) was prepared to remove AFB1 from aqueous/non-aqueous media. The morphological, functional, and structural characteristics and adsorption properties of C/N-enriched CS/CFS were investigated systematically. The interactive operating variables (temperature (5.0-35 °C); time (10-100 min); AFB1 dose (50-100 μg/mL); and Mt-CS/CFS dosage (0.5-3.5 mg) were optimized via the Box-Behnken design (BBD), which demonstrated good agreement between the experimental data and proposed model. The adsorption efficiency in artificially contaminated cow's milk as well as aqueous environment reached over 91.0 % in a wide pH range (3.0-9.0), without significant change in the nutritional value of milk. Freundlich isotherm and second-order adsorption kinetics were regarded as the most suitable models to fit the adsorption results, and the adsorption rate is dominated by the intra-particle diffusion and boundary layer diffusion. Thermodynamic analyses proved that the process was spontaneous and exothermic. The adsorption mechanism could be explained as physisorption via hydrogen bonding, n-π interaction, and hydrophobic/hydrophilic interactions. The porous Mt-CS/CFS NS derived from chitosan nanoparticles is therefore outstanding adsorbent, offering great adsorptive performance and recycabilities, which impedes economic losses in the food industry.

Effects of aroma enhancement fermentation of Zygosaccharomyces rouxii ZR21 and Debaryomyces hansenii DH06 on the sensory properties and consumer liking of Yongchuan douchi

Yongchuan douchi is a well-loved condiment. However, the aroma of rapid Yongchuan douchi is inferior to that of traditional Yongchuan douchi. The objective of this study was to improve the aroma quality of rapid Yongchuan douchi and evaluate the effect of aroma enhancement from the perspective of consumers. The aroma characteristics of samples were analyzed by consumers through flash profile (FP) (n = 15) and rate-all-that-apply (RATA) (n = 75). The results showed improvement in the aroma quality of rapid Yongchuan douchi with the two yeast strains, and consumers could perceive the modification of the aroma characteristics. It shows that the douchi aroma and sour aroma of rapid Yongchuan douchi increased significantly after aroma-enhancing fermentation, while the soy sauce aroma, soybean aroma, and musty aroma decreased. Similar results were obtained from FP and RATA. RATA showed that rapid Yongchuan douchi with aroma-enhancing fermentation aroused higher levels of positive emotions, which may increase the acceptance of consumers to rapid Yongchuan douchi. In summary, the aroma quality and consumer preference of rapid Yongchuan douchi were enhanced. The work provides insights into the quality improvement of rapid Yongchuan douchi from the perspective of consumers.