南极磷虾粉的营养成分分析及评价

目的开发以虾粉为原料的优质饲料蛋白源。方法利用嗜热链球菌18748 (Streptococcus thermophilus 18748)发酵南极磷虾粉，分析影响发酵的因素，并通过响应面法优化菌株的发酵条件以提高酶活力。经过体外模拟胃消化后利用DPPH自由基清除率、OH·自由基清除率、总酚含量和总抗氧化能力对抗氧化活性进行分析。结果影响发酵的显著因素为：发酵温度43 ℃，初始pH 6，接种量5%，此时嗜热链球菌18748产蛋白酶活力达到最大(6.82 U/mL)。抗氧化分析结果显示： OH·自由基和DPPH自由基清除能力显著降低(P<0.05)，但仍然具有较高的清除水平，总酚和总抗氧化能力显著提高(P<0.05)。结论南极磷虾粉发酵液在模拟消化过程中，胃蛋白酶可能促进抗氧化活性物质的释放，且消化后仍然具有良好的抗氧化活性。本研究可为进一步工业化开发发酵虾粉及抗氧化产品提供借鉴。

A re-appraisal of the total biomass and annual production of Antarctic krill

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.