Physicochemical Properties, Fatty Acid Composition, and Nutritional Quality of Thai Perilla Seed Oil, Sesame Seed Oil, and Their Blended Oil

Abstract: Perilla seed oil (PSO) and sesame seed oil (SSO) are recognized for their distinct fatty acid compositions and associated health benefits, yet each exhibit certain nutritional limitations when consumed individually. Oil blending provides a potential approach to optimize fatty acid balance and improve overall oil quality. This study investigated the oil yield, physicochemical properties, fatty acid composition, and nutritional indices of PSO, SSO, and a 50:50 blend. Seeds were sourced from Tak and Mae Hong Son Provinces, Thailand, cold-pressed, and analyzed in accordance with the Ministry of Public Health standards (Notification No. 421 B.E. 2564). SSO yielded a higher oil content (36.89 %) than PSO (33.4 %). Both oils largely met the specified quality requirements, however, mineral oil contamination was detected in PSO, although the level remained within the permissible limit. Fatty acid analysis revealed that PSO was rich in polyunsaturated fatty acid (PUFA), predominantly alpha-linolenic acid (omega-3), while SSO contained higher levels of monounsaturated fatty acid (MUFA) and linoleic acid (omega-6). The blended oil exhibited intermediate characteristics, with an improved omega-6:3 ratios (1.02:1) relative to SSO (158.64:1) and PSO (0.29:1). Nutritional indices demonstrated that PSO and the blended oil had lower atherogenic and thrombogenic indices and higher Hypocholesterolemic:hypercholesterolemic ratios than SSO. Collectively, the findings indicate that blending PSO and SSO can enhance the nutritional profile and fatty acid balance of edible oils. This study is among the first to report quantitative MOSH/MOAH contamination levels and nutritional indices for Thai PSO and SSO. Further research is warranted to evaluate oxidative stability, sensory attributes, and long-term health implications to support potential applications in functional food development.