冷榨山核桃油的理化性质及氧化稳定性研究

以山核桃仁为原料,通过冷榨机机械压榨,得到冷榨山核桃油,通过化学方法分析其理化指标,用气相色谱法分析其脂肪酸组成,用Rancimat法分析其氧化稳定性和抗氧化剂对其抗氧化效果。结果表明:冷榨山核桃油主要理化指标:酸价1.96 mg KOH/g,过氧化值2.24 mmol/kg,碘值102.84 g I2/100 g,皂化值189.73 mg KOH/g;冷榨山核桃油主要有不饱和脂肪酸组成,不饱和脂肪酸含量占91.83%,其中油酸60.95%,亚油酸26.69%,α-亚麻酸3.11%;建立了lg(诱导期)与Ranciamt氧化诱导温度之间的线性关系;在抗氧化剂添加量相等的情况下,TBHQ的抗氧化效果最好,其次是迷迭香提取物和和茶多酚;使用100 mg/kg TB-HQ+200 mg/kg迷迭香提取物作为冷榨山核桃油的抗氧化剂,可使冷榨山核桃油在120℃的诱导期延长2.88倍。

Physicochemical properties and Oxidative Stability of Cold-Pressed Carya cathayensis Sarg Oil

Cold-pressed Carya cathayensis Sarg oil was extracted by mechanical press.The physicochemical indexes of the oil were analyzed,the fatty acid composition of the oil was determined with GC method,Rancimat test was used to evaluate the oxidative stability of the oil and antioxidative effect of antioxidants by comparing the induction periods of the oil samples.The results indicated that the main physicochemical indexes of cold-pressed Carya cathayensis Sarg oil were acid value 1.96 mg KOH/g,peroxide value 2.24 mmol/kg,iodine value 102.84 I2 g/100 g,saponification value 189.73 mg KOH/g;Cold-pressed Carya cathayensis Sarg oil were mainly composed of unsaturated fatty acids which accounted for 91.83%,in which,oleic acid was 60.95%,linoleic acid 26.69% and α-linolenic acid 3.11%.A linear relationship was established between lg(induction period)and the temperature of Rancimat.In the case of added equal amount of antioxidant,the best antioxidant was TBHQ,followed by the rosemary extract and tea polyphenol;when 100 mg/kg TBHQ+200 mg/kg rosemary extract was added,the induction period of cold-pressed Carya cathayensis Sarg oil at 120 ℃ can extend 2.88 times than it of cold-expressed Carya cathayensis Sarg oil without antioxidant at the same temperature.