Antioxidative Activity of Philippine Salt-Fermented Shrimp and Variation of Its Constituents during Fermentation

抄録

Shrimp (Acetes sp.) was mixed with salt in a ratio of 3:1 and allowed to ferment at room temperature (28-30°C). From the shrimp paste samples collected at the initial (1 day) and end (10 days) of fermentation, 85% ethanol extracts were prepared for their antioxidative assays. Both extracts exhibited high free radical scavenging property against 1,1 diphenyl 2-picrylhydrazyl and suppressed peroxidation of methyl linoleate initiated by 2,2′azobis 2-amidinopropane dihydrochloride. These antioxidative activities, however, did not change significantly during fermentation for 10 days, thus suggesting that the observed antioxidative activities could have mainly due to original antioxidants present in shrimp but not to its fermentative products. The salt-fermented shrimp samples contained large amount of polyunsaturated fatty acids including EPA and DHA, although the polar lipids like phospholipids were hydrolyzed during fermentation to produce the corresponding amount of free fatty acids. In addition, free amino acids of the shrimp sample significantly increased during the fermentation and could be responsible for the unique flavor of salt-fermented shrimp paste. Since the salt-fermented shrimp paste was found to obtain potent antioxidative substances and large amount of EPA, DHA, and amino acids, it is expected to act as an effective antioxidant in our body and to be a good source of these nutrients.