Cong Wang

Abstract To study the nutritional composition of Indian Moringa oleifera seed and the antioxidant activity of M. oleifera seed polypeptide, Indian M. oleifera seed was used as raw material for composition analysis and content determination. After extraction of the seed protein, enzymatic hydrolysis with flavourzyme, dispase, papain, pepsin, and alcalase was conducted for different time, and the optimal enzymatic hydrolysis conditions was determined with DPPH scavenging capacity as an indicator. The seed polypeptides obtained by enzymatic hydrolysis were ultrafiltered, and the active peptide fragments were tracked with DPPH, HO (•OH), ABTS and superoxide anion (O 2 • − ) free radical scavenging ability and lipid oxidation inhibition rate as indicators. The results showed that the protein content in Indian M. oleifera seed was high to 40.34%, containing seven essential amino acids. The content of macroelements such as potassium, sodium, and magnesium is high, with the potassium content as high as 2,357.71 mg/kg, among the microelements, the iron content as high as 36.2 mg/kg. The optimum enzymatic hydrolysis conditions were as follows: enzymatic hydrolysis with flavourzyme (50°C, pH 6.7) for 300 min, and DPPH scavenging capacity was 84.76%. Activity tracing found that the polypeptide fragment with molecular weight <3.5 kDa had the strongest antioxidant capacity, and the EC 50 values of DPPH, •OH, ABTS, and O 2 • − free radical scavenging rates were 4.0, 4.2, 5.3, and 4.3 mg/ml, respectively. The above results show that Indian M. oleifera seed not only has high nutritional value, but its protease enzymatic hydrolyzate also has significant antioxidant activity, which can be further developed into nutrition products, healthcare products, functional foods, beauty and skin care products, liver protection drugs, etc.

Abstract BACKGROUND Surimi is produced from deboned fish muscle through washing to remove blood, lipids, sarcoplasmic proteins and other impurities. There is an increasing interest in the fortification of surimi with ω‐3 polyunsaturated fatty acids because of their health benefits. However, lipid oxidation should be considered as an important factor during storage. Hence, in this study, the quality properties and oxidative stability of surimi fortified with 30 g kg −1 perilla oil ( PO ), or 5 g kg −1 6‐gingerol ( GI ) or their combination ( PO + GI ) was investigated. RESULTS Perilla oil significantly improved whiteness of surimi gel, but negatively influenced its gel strength, water holding capacity ( WHC ) and texture. However, there was no significant difference in texture properties among GI , PO + GI and control groups. During the whole storage period, GI and PO + GI groups had higher gel strength and WHC than control and PO groups. Moreover, lower thiobarbituric acid reactive substances ( TBARS ), total volatile basic nitrogen ( TVB‐N ), carbonyl content and total plate count ( TPC ) were observed in GI group compared with other groups. CONCLUSION Perilla oil and 6‐gingerol could be applied together to effectively fortify surimi qualities. Additionally, 6‐gingerol could prevent lipid and protein oxidation and microbial growth of surimi during refrigerated storage. © 2017 Society of Chemical Industry