This study examined the changes in the physicochemical properties and safety of traditional Suanyu prepared by adding different amounts of salt (3%, 6%, and 9% relative to the mass of raw material) during fermentation. The results indicated that increased salt addition accelerated the loss of moisture, led to an increase in chloride content and promoted fat oxidation as evidenced by higher thiobarbituric acid reactive substances (TBARS) values. Conversely, reducing salt addition rapidly lowered the pH and increased the total acid content of Suanyu. However, this reduction led to excessive production of total volatile basic nitrogen (TVB-N), accelerating product spoilage. Higher salt addition resulted in increased hardness and chewiness of Suanyu. The elasticity of all groups varied dynamically between 0.42 and 0.57, showing no significant correlation with salt addition. As the level of salt addition increased, the lightness (L*) value tended to decrease, while the yellowness (b*) value increased. There were no notable differences in the redness (a*) values among the groups. Compared with its fresh unfermented counterpart, Suanyu exhibited an increased variety of organic acids as well as higher amounts of each organic acid detected. Lower levels of salt addition resulted in higher lactic acid and acetic acid contents. When the level of salt addition was 3%, the levels of putrescine, cadaverine, histamine, tyramine, and total biogenic amines were highest. In contrast, the addition of 6% salt demonstrated the most effective inhibition of biogenic amine production in Suanyu. In summary, the addition of salt significantly impacted the quality formation of Suanyu. The findings of this study provide theoretical support for optimizing the technology for processing Suanyu and enhancing the product quality.

Low-frequency electric field thawing (LFEFT) and room temperature thawing (RTT) lead to significant differences in the pH, color, volatile base nitrogen (TVB-N) content, textural properties and water-holding capacity of beef. In order to elucidate a possible mechanism for the effect of LFEFT on the quality of beef at the molecular level, the current study conducted a proteomic analysis of frozen beef thawed by LFEFT or RTT. The results showed that there were 551 differentially abundant proteins (DAPs) between the LFEFT and RTT groups. Among these, 14 were significantly correlated with quality traits (pH, color, TVB-N content, texture and water-holding capacity). Bioinformatics analysis showed that DAPs were mainly involved in biological functions such as protein binding, metabolic enzymes and protein turnover. In summary, LFEFT can improve production efficiency while ensuring beef quality.

The rate of flavor release in the mouth from traditional dry-cured pork was evaluated in this study. It was hypothesized that a slow steady release of flavor would occur on chewing and hydration. To test this, high salt dry-cured pork was chewed and held in oral cavity without swallowing for 4 different chewing stages (B, NC₃₀, C₃₀, EC). Saliva and food bolus from 16 healthy subjects were collected during oral processing, and analyzed for saliva flow rate, total saliva protein content, saliva pH, conductivity, saliva and sodium, and taste components. Results show that oral processing behavior and salivary release have important effects on flavor release of dry-cured pork. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that oral processing has a certain effect on the protein composition and concentration in saliva. This study suggests that the interaction between food and saliva that accompanies chewing can lead to significant changes in sensory perception during oral processing.