Physiological properties of Scomber japonicus meat hydrolysate prepared by subcritical water hydrolysis.

The health-beneficial biological activities, including antioxidant and tyrosinase inhibitory activities, of Scomber japonicus muscle protein hydrolysates prepared by subcritical water hydrolysis were investigated. After 5 min of subcritical hydrolysis at 140 degrees C, 59.76% of S. japonicus muscle protein was hydrolyzed, the highest degree of hydrolysis in all the groups were tested. According to the response surface methodology results, as the reaction temperature and reaction time became lower and shorter, the yield became higher. The highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity (90.63%) occurred in hydrolysates treated at 140 degrees C for 5 min, and the highest tyrosinase inhibitory activity (65.54%) was identified in hydrolysates treated at 200 degreesC for 15 min. Changes in the molecular weight distribution of S. japonicus muscle proteins after subcritical water hydrolysis were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Subcritical water hydrolysis is a suitable technique for obtaining S.japonicus muscle protein hydrolysates with useful biological activities, within a short time (5-15 min).

Characteristics of esterified rice bran oil converted by enzymatic esterification.

In the present study, esterified rice bran oil (ERBO) was characterized using enzymatic esterification to improve stability, prevent acidification, enhance health-promoting biological activity and generate ω-3 PUFA-rich rice bran oil (RBO). Esterification reactions using RBO and ethanol were performed at 50°C under 200 bar with 3% lipozyme TL-IM (Thermomuces lanuginosa immobilized on silica gel) or RM-IM (Rhizomucor miehei immobilized on ion exchange resin) for 3 hr under supercritical CO2. The molar ratios of ethanol to RBO were 3, 6, 9 and 12, respectively. Total lipid contents and acid values decreased (maximum 83.75%),but γ-oryzanol content increased (maximum 41.33%) in esterified RBO (ERBO) prepared using TL-IM or RM-IM. In addition, DPPH radical scavenging activity of ERBO prepared by RM-IM atan ethanol to RBO molar ratio of 3 was 0.02 µg µl(-1), which was 63-fold higher than that of α-tocopherol (IC50 =1.25 µg µl(-1)). The anti-inflammatory effect of RM-IM 1:3 hydrolysate of RBO was verified showing its suppressive effect towards iNOS and Cox-2mRNA expression in a dose-dependent manner. Therefore, ERBO is a promising source of functional food, cosmetics and pharmaceuticals.