Ultrasound-assisted extraction and antioxidation stability of silkworm pupa oil | 蚕蛹油超声波辅助萃取及其抗氧化稳定性

Chinese. 【目的】研究蚕蛹油（silkworm pupa oil）超声波辅助萃取的最佳工艺、蚕蛹油的理化性质、影响蚕蛹油氧化的因子和不同抗氧化剂及几种天然多酚类提取物对蚕蛹油的抗氧化效果。【方法】利用响应曲面法（response surface methodology）建立超声波辅助萃取蚕蛹油的数学模型,获得最佳萃取工艺;利用气相色谱法测定蚕蛹油中脂肪酸组成及含量;采用Schaal烘箱法,研究不同因子和添加不同抗氧化剂及几种天然多酚提取物对蚕蛹油抗氧化稳定性影响。【结果】通过二次回归模型响应曲面分析得出超声波辅助萃取蚕蛹油的最佳工艺条件为：超声功率102 W,超声时间20 min;超声温度40℃,在此条件下,蚕蛹油实际得率的平均值为28.9%,提取率为96.3%;超声波辅助萃取的蚕蛹油中不饱和脂肪酸相对含量为74.2 %,其中油酸相对含量为38.3%,α-亚麻酸相对含量为30.2%,亚油酸相对含量为4.3%,棕榈油酸相对含量为1.0%,花生酸相对含量为0.4%;光照、金属离子、温度均可显著加速蚕蛹油氧化,几种天然多酚提取物中五倍子单宁对蚕蛹油抗氧化性最强。【结论】蚕蛹油超声波辅助萃取的提取率高、萃取时间短,油脂品质好;在蚕蛹油储存、加工中应降低温度、避光、避免接触金属离子,添加五倍子单宁可作为蚕蛹油良好的天然抗氧化剂。

English. 【Objective】 The optimum conditions of Ultrasound-assisted extraction of silkworm pupa oil (SPO), physicochemical property of SPO, factors influencing SPO oxidation, and antioxidant effects of different antioxidants and several polyphenols extracts for SPO were all investigated in this paper. 【Method】 Response surface method (RSM) was used to establish the mathematical model of ultrasound-assisted extraction of SPO to obtain the optimum conditions. Fatty acid compositions and contents of SPO were tested by gas chromatography (GC). Factors influencing SPO oxidation and antioxidation stability of different antioxidants and several polyphenol extracts for SPO were investigated by Schaal oven method. 【Result】 The optimum conditions obtained through RSM analysis were as follows: ultrasonic power was 102 W, ultrasonic time was 20 min and ultrasonic temperature was 40℃. The average yield of SPO was 28.9% and the extraction rate was 96.3%. The relative content of unsaturated fatty acid in SPO was 74.2%, where oleic acid was 38.3%, α-linolenic acid was 30.2%, linoleic acid was 4.3%, palmitoleic acid was 1.0% and arachidonic acid was 0.4%. Light, metallic ions and temperature can significantly speed up SPO oxidation. Among several polyphenol extracts, gallnut tannin had the strongest antioxidant capacity. 【Conclusion】 These results suggest that Ultrasound- assisted extraction of SPO had a higher extraction rate, a less extraction time and a good product quality. SPO should be stored and processed in a lower temperature condition and avoid light and metallic ions. Gallnut tannin could be used as a good natural antioxidant in SPO.