Comparison of 37 Fatty Acids and Squalene in Walnut Oil and Common Vegetable Oils

To explore the difference of nutritional value between walnut oil and soybean oil, sesame oil, corn germ oil and other common vegetable oils. The content of 37 fatty acids and squalene in four vegetable oils were determined by the gas-mass spectrometry and gas chromatography method, and the results were compared and analyzed. The results showed that walnut oil and vegetable oil commonly used nutritional value exists significant difference (P<0.05), walnut oil was rich in α-linolenic acid, eicosadienoic acid, linoleic acid 3 kinds of polyunsaturated fatty acids and oleic acid and other unsaturated fatty acids, also contained a small amount of palmitic acid, stearic acid and other saturated fatty acids, polyunsaturated fatty acid in the walnut oil composition and proportion was significantly higher than other vegetable oils (P<0.05). The composition and proportion of saturated fatty acids were significantly lower than those of other vegetable oils (P<0.05). Walnut oil contained slightly less squalene than sesame oil, making it a high-quality vegetable oil. The order of total fatty acid content was soybean oil> sesame oil>walnut oil>corn germ oil, and the contents were 78.11, 73.96, 69.20 and 48.83 g/100 g, respectively. The four vegetable oils all contained human essential fatty acids (EFA) such as α-linolenic acid, linoleic acid and eicosadienoic acid. The content of ETA from high to low was walnut oil>soybean oil>corn germ oil>sesame oil, accounting for 90.0%, 70.7%, 64.9% and 54.1% of the total fatty acids, respectively. The ratio analysis of oleic acid content to linoleic acid content showed that the order of the ratio R for four kinds of vegetable oils from high to low was sesame oil>corn germ oil> soybean oil>walnut oil, and the value was 0.62, 0.35, 0.27 and 0.10, respectively. The results showed that sesame oil had the highest antioxidant capacity and the longest shelf life among the four vegetable oils in this study. Squalene was detected in soybean oil, sesame oil and walnut oil, but not in corn germ oil. The content of squalene in soybean oil, sesame oil and walnut oil from high to low were173.3、72.9 and 31.4 mg/kg , respectively. The study indicated that the content of fatty acids and squalene in different vegetable oils were different, which would provide scientific data support for the analysis of nutritional value of edible vegetable oil and the research and development of related food and health care products.