Soybean protein hydrolysates were prepared using two proteolytic enzymes (Alcalase and Protamex) and the degree of hydrolysis (DH) and their functional and antioxidant properties were evaluated. The highest DH value was 20%, with a yield of 19.77% and protein content of 51.64%. The total amino acid content was more than 41% for all protein hydrolysates. The protein hydrolysates from Protamex at pH 2.0 had excellent solubility, emulsifying activity, and foaming capacity, at 83.83%, 95.03 m²/g, and 93.84%, respectively. The water-holding capacity was 4.52 g/g for Alcalase, and the oil-holding capacity was 4.91 g/g for Protamex. The antioxidant activity (62.07%), as measured by the samples’ reaction with DPPH (2,2-diphenyl-1-picrylhydrazyl) and the reducing power (0.27) were the strongest for Protamex. An ABTS activity rate of 70.21% was recorded for Alcalase. These findings indicated a strong potential for the utilization of soybean protein hydrolysates to improve the functional properties and antioxidant activity of soybeans as well as their nutritional values.

This experiment was conducted to evaluate the efficacy of application of acetic acid and ascorbic acid spray on the surface decontamination and shelf-life of silver carp fish at refrigerated temperature (40C) during 9 days of storage period. Silver carp is one of the most abundant freshwater fish speciesin the world. However, the rapid quality degradation soon after post-mortem makes them highly putrefactive while reducing the nutritional attributes. In this regard, our study aimed at applying organic acids to extend shelf-life of silver carp fish while investigating the quality attributes such as sensory, peroxide values, pH and microbial loads of the fish fillets during 9 days of refrigerated temperature storage (40C). Acetic acid and ascorbic acid are found to have strong antibacterial activities against different microorganisms. Fish fillets samples were treated with alone or in combination with acetic acid and ascorbic acid spray while keeping one group of fish fillets untreated. Total Viable Count (TVC) was found greater in the samples kept untreated and treated alone with acetic acid and ascorbic acid. However, fish fillets treated with acetic acid and ascorbic acid in combination were reported with lesser number of microbial counts. Moreover, Peroxide Value (PV) and pH were significantly lower in the sample treated with in combination of acetic acid and ascorbic acid. Sensory analysis revealed that fish fillets treated with combined treatment had better quality retention at the end of 9 days storage period. The findings suggest that the application of acetic acid and ascorbic acid alone or in different combination have the potential to decrease microbial loads while facilitating the shelf-life of fish fillets during 9 days of refrigerated temperature (40C) storage period.

Nutritional composition, functional and antioxidant properties of different parts from grass turtle were investigated. Muscle contained high protein, essential amino acids, and vitamin B6, which were 74.97%, 28363.84, and 14.47 mg/100 g, respectively. Unsaturated fatty acids, vitamin K were significantly higher in the liver which reached 7489.45 and 1591.67 mg/100 g, respectively. Hardshell high content of minerals and vitamin B3 (48998.06 and 17.52 mg/100 g), correspondingly. The molecular weight was obtained in the range of 0.27–87.38% (Mw˂1000 Da). Solubility, emulsifying activity, and emulsion stability index at different pH ranged from 3.89 to 45.89%, 47.53 to 90.22 m²/g, and 65.45 to 89.93%, respectively. Water and oil holding capacities were high in muscle (7.97 and 2.19 mL/g). The highest antioxidant activity was observed in the muscle (88.58% ABTS) and liver (66.71% DPPH and 0.49 FRAP). Muscle, liver, and hard shell properties will provide producers and consumers with useful new information about the nutritional value and health benefits.