Study on the Fermentation and In Vitro Digestion and Antioxidant Properties of Antarctic Krill Shrimp Meal

PurposeTo develop a high-quality feed protein source from shrimp meal.

MethodsThe antarctic krill shrimp meal was fermented with Streptococcus thermophilus 18748, and the factors affecting fermentation were explored. The fermentation condition of the strain were optimized by response surface methodology to increase enzyme activity. After simulated gastric digestion in vitro, the antioxidant activity was analyzed by DPPH free radical scavenging rate, OH· free radical scavenging rate, total phenol content and total antioxidant capacity.

ResultsThe significant factors affecting fermentation were: the temperature of fermentation was 43 ℃, initial pH 6, inoculum amount 5%. At this condition, the protease activity of S. thermophilus 18748 reached the maximum of 6.82 U/mL. Antioxidant analysis result showed that: both OH· and DPPH free radical scavenging rate were significantly decline (P<0.05), and it still had a high clearance level. The total phenol content and total antioxidant capacity were significantly improved (P<0.05).

ConclusionDuring the simulated digestion process of antarctic krill shrimp meal fermentation broth, pepsin may promote the release of antioxidant active substances, and still has good antioxidant activity after digestion. This study provides a reference for the further industrial development of fermented shrimp meal research and the development of antioxidant products.