赤子爱胜蚓油脂的提取及脂肪酸组成分析Extraction and fatty acid composition analysis of Eisenia foetida oil

为促进蚯蚓蛋白粉加工副产物的开发与利用，以赤子爱胜蚓渣料为原料，采用超声辅助水酶法结合酸水解法提取蚯蚓油，研究酶种类、酶解时间和加酶量对蚯蚓油得率的影响，通过正交实验确定最佳酶解条件。同时，对提取的蚯蚓油理化指标及脂肪酸组成进行分析。结果表明：超声辅助水酶法结合酸水解法提取蚯蚓油的最佳酶解条件为使用胃蛋白酶（适宜温度50 ℃、pH 2.0）、酶解时间2.0 h、加酶量4%，在此条件下蚯蚓油得率为11.45%；蚯蚓原油为浅棕色，稍有浑浊，稍有蚯蚓特有的土腥味，略带有油脂酸败味；蚯蚓油由24种脂肪酸构成，其中饱和脂肪酸含量较高，占总脂肪酸的82.381%，主要为硬脂酸、月桂酸，单不饱和脂肪酸占总脂肪酸的8.565%，主要为油酸、棕榈油酸，多不饱和脂肪酸占总脂肪酸的8.995%，主要为亚油酸，另外蚯蚓油奇数碳脂肪酸含量为13.867%。综上，超声辅助水酶法结合酸水解法对于提取蚯蚓渣料中的油脂有一定效果，具备实际应用的潜力，且得到的蚯蚓油含有丰富的奇数碳脂肪酸，营养价值较高。In order to promote the development and utilization of by-products from earthworm protein powder processing, Eisenia fetida residue was used as the research object to extract earthworm oil using ultrasonic-assisted aqueous enzymatic-acid hydrolysis method. The effects of hydrolase type, enzymatic hydrolysis time and enzyme dosage on the yield of earthworm oil were studied, and the optimal enzymatic hydrolysis conditions were determined by orthogonal experiments. The physicochemical indexes and fatty acid composition of the earthworm oil were analyzed. The results showed that the optimal enzymatic hydrolysis conditions of earthworm oil were obtained as follows: with pepsin as the enzyme (optimal temperature 50 ℃, pH 2.0), enzymatic hydrolysis time 2.0 h and enzyme dosage 4%. Under these conditions, the yield of earthworm oil was 11.45%. The extracted crude earthworm oil was light brown, slightly cloudy, slightly earthy smell of earthworms, slightly fatty rancid taste. The earthworm oil consisted of 24 fatty acids, with high saturated fatty acid content, accounting for 82.381% of total fatty acid, mainly stearic acid and lauric acid; monounsaturated fatty acid accounted for 8.565% of total fatty acid, mainly oleic acid and palmitoleic acid; polyunsaturated fatty acid accounted for 8.995% of total fatty acid, mainly linoleic acid. In addition, the odd-chain fatty acids content in earthworm oil was 13.867%. The ultrasonic-assisted aqueous enzymatic-acid hydrolysis method has a certain effect on the extraction of oil from earthworm residue, and has practical application potential, and the obtained earthworm oil is rich in odd-chain fatty acids and has high nutritional value.