Bioactive Compounds of Fermented Soybean Natto as Antioxidant and Antimicrobial Agents.

Abstract

Soybean and its products became one of the most important functional foods due to its bioactive compounds (isoflavones and bioactive peptides), which have a greet health benefits to human being. In this study, it was prepared a fermented soybean natto with different treatments: drying natto with oven, solar, undervacuum, and extracting them with different solvents to check its antioxidant and antimicrobial activities. Results showed that, acetonitrile extract had the highest amount of peptides followed by methanol extract then water came in the last order. On the other hand, acetonitrile extract had the strongest antioxidant and antimicrobial activities, meanwhile water and methanol extracts had a close effect in general, but still methanol extract had the higher activities than water extract. Methanol extracted all of total isoflavones and some of bioactive peptides, acetonitrile extracted bioactive compounds and some of isoflavones. Upon correlation of these results, it was found that the highest antioxidant and antimicrobial activities excess in acetonitril extract. Therefore, it was assumed that the antioxidant and antimicrobial activities of natto came from both, isoflavones and bioactive peptides, but bioactive peptides had stronger activities.

Antioxidant and Ace Inhibitor Potential of Stripe Trevally Fish (Selaroides leptolepis) Hydrolysate

“…The results obtained are in line with those reported by Nielsen et al (2001) that the levels of soluble proteins and peptides increase as the degree of hydrolysis increases. In this study, peptide content was analysed based on free amino acid present in the mixture using O-pthalaldehyde (OPA) method (Mahmod et al, 2011), while the protein content was analysed based on Lowry method which measure peptide bond of protein. That is the reason why the peptide content resulted from protein hydrolysis was much higher than the protein content itself.…”

“…Large size of protein has a low bioactivity while the protein that has been hydrolyzed or with a smaller size will has better bioactivity (Mahmod et al, 2011). According to Clemente (2000); Kristinsson and Rasco (2000) in general, short-chain peptides of smaller molecular weights have higher bioactivity than proteins in their intact form.…”