Physicochemical Properties, Bioactive Components and Volatile Compounds of Dietary Fatty Acid Balanced Blend Oil

Walnut oil is growing in consumer demand due to its rich nutritional profile; however, its fatty acid composition exhibits an imbalanced SFA:MUFA:PUFA ratio (0.13:0.18:1). To improve the fatty acid balance using locally available vegetable oils in Xinjiang, we investigated the effects of blending walnut oil with linseed oil, safflower seed oil, sunflower seed oil, rapeseed oil, peanut oil, and soybean oil on physicochemical indexes, fatty acid composition, and bioactive components. Aroma characteristics were assessed by E-nose and HS-GC-IMS. The results showed that the acid value and peroxide value of the blended oil decreased, while the content of vitamin E and squalene increased inversely. The ratio of ω-6/ω-3 maintain steadily at 4–6:1, and the ratios of SFA, MUFA, and PUFA were close to 0.27:1:1. Significant differences were observed between the aroma characteristics of walnut oil and the blended oil. HS-GC-IMS identified 85 volatile organic compounds (VOCs), among which walnut oil had a higher content of alcohols, aldehydes, and ketones, with 4-hydroxy-5-ethyl-2-methyl-3(2H)-furanone as its characteristic aroma compound. The acetophenone serves as the key aroma component after blending, and the unique flavor components of each base oil (e.g., 4-nonanone in linseed oil, 3-methyl-2-pentanone in rapeseed oil, etc.) exert a synergistic effect after rationing to present a composite aroma characteristic of blended oils, which mainly consists of 3-methylbutyl butyrate and 4-ethylphenol.