Chemical interaction between white onion, as natural antioxidant, on shrimp stored under freezing

Abstract The impact of white onion as a natural antioxidant on the lipid profile of “Vila Franca” shrimp (Litopenaeus schmitti Burkenroad, 1938), during storage under freezing, was evaluated by changes in the composition of fatty acids, carotenoids, centesimal composition and phenols. The lipid content in the shrimp samples in natura and with white onion was dimmed after 45 days of storage under freezing. At zero time and during storage, lower levels of fatty acids were detected in the shrimp with addition of white onion. There was a reduction in the total carotenoid content of fresh and white onion shrimp samples after 45 days of storage, corresponding to 30% and 43%, respectively. After 90 days of storage, was detected a loss of 28%, in the samples with addition of white onion, in relation to 45 days. In spite of the linear increase in phenol content during storage, no positive correlation was observed between the concentrations of phenols and the antioxidant activity exerted by white onion, in relation to the profile of fatty acids and carotenoids of the food.

摘要：本研究评估了白洋葱作为天然抗氧化剂，在冷冻储存条件下对“维拉弗朗卡”虾（Litopenaeus schmitti Burkenroad, 1938）脂质谱的影响，通过分析脂肪酸、类胡萝卜素、百分营养组成及酚类物质的组成变化开展相关研究。冷冻储存45天后，天然虾样与添加白洋葱的虾样中的脂质含量均有所下降。在储存初始时刻及整个储存周期内，添加白洋葱的虾样中检测到的脂肪酸水平均更低。冷冻储存45天后，新鲜虾样与添加白洋葱的虾样的总类胡萝卜素含量均出现衰减，降幅分别为30%与43%。储存至90天时，添加白洋葱的虾样相较于45天储存组的类胡萝卜素损失率达28%。尽管储存过程中酚类物质含量呈线性上升趋势，但相较于该食品的脂肪酸与类胡萝卜素谱，酚类物质浓度与白洋葱所发挥的抗氧化活性之间并未呈现出显著正相关关系。