精制对蚕蛹油抗氧化活性的影响

分别采用超临界CO2萃取和溶剂浸提2种途径从蚕蛹中提取毛油,再通过脱胶、脱酸、脱色、脱臭等工艺精制蚕蛹油,收集不同精制阶段的蛹油样品,测定色差变化,利用不同的抗氧化评价方法(包括总抗氧化能力FRAP、DPPH清除率、总酚含量、总类胡萝卜素含量)评估其抗氧化活性,并对评估结果进行相关性分析和主成分分析。结果表明,超临界萃取的蚕蛹毛油抗氧化活性明显优于正己烷浸提;随着精制过程的进行,蛹油亮度增加,黄色减少,自身抗氧化成分逐步损失,蛹油氧化稳定性下降,精制过程造成2种途径获得的蛹油总酚损失24.73%~65.14%,类胡萝卜素损失12.0%~69.27%,其中脱色阶段损失最为显著。相关性分析发现,蚕蛹油的抗氧化能力与总酚和类胡萝卜素的含量密切相关,而总抗氧化能力FRAP与DPPH清除率之间的相关性不显著;主成分分析发现,溶剂提取和超临界萃取2种途径制备的蚕蛹毛油抗氧化活性差异较大,但经精制处理后,二者的抗氧化能力又大幅下降至同一水平。

The Effect of Refining Processes on Antioxidant Activity of Silkworm Pupa Oil

Supercritical CO2 fluid extraction (SFE) and solvent extraction were used to extract crude oil in silkworm pupa. During refining processes of degumming, deacidification, decoloration and deodorization, oil samples in each stage were collected to determine their color changes and antioxidant capacity, including FRAP, DPPH clearance, TPC and TCC. In addition, correlation and principal component analysis of different levels of antioxidant capacity were run. Experimental results showed that antioxidant activity of silkworm pupa oil from SFE was superior to N-hexane clearly. During the refining process, brightness of silkworm pupa oil increased, but yellow decreased, antioxidant ingredients lost and oxidation stability also decreased gradually. The refining process of silkworm pupa oi from two ways caused 24.73%-65.14% losses of TAC, 12.0%-69.27% losses of TCC, especially decoloring step the highest losses. Correlation analysis found that antioxidant capacity of silkworm chrysalis oil was closely related to the contents of total phenol and carotenoids, but no significant correlation between FRAP and DPPH clearance was found. Principal component analysis suggested that, antioxidant activity of crude oil from SFE and solvent extraction had big differences, but after refining treatment, both total antioxidant capacity decreased to the same level significantly.