Novel Co-rendering Process for Enhancing Lard Quality-focusing on Oxidative Stability and Fatty Acid Composition of the Co-rendered Oils

This study developed co-rendered oils by extracting sesame seed oil (SSO) using lard as a green extraction solvent during the co-rendering of pork fat and ground sesame seeds at 170°C in an air fryer, with varying fat-to-seed ratios (80:20 to 40:60). Compared to lard, which is high in saturated fatty acids (SFA), and SSO, which is rich in polyunsaturated fatty acids (PUFA), the co-rendered oils demonstrated significantly improved fatty acid composition. As the proportion of sesame seeds increased, the oils showed a marked reduction in atherogenic index (AI) and thrombogenic index (TI), decreasing from 0.51 to 0.29 and from 1.27 to 0.84, respectively. The lowest values were observed at the 40:60 fat to seed ratio, with AI at 0.29 and TI at 0.84. Additionally, bioactive compounds from sesame seeds enhanced the oils' antioxidant activity, as indicated by increased DPPH values from 54.03 to 118.91 µg GEAC/100 g oil and ABTS values from 18.81 to 51.15 µg GEAC/100 g oil, in P80 and P40 samples, respectively. All co-rendered oils complied with Codex Alimentarius standards for acid value (AV), ranging from 0.99 to 2.02 mg KOH/g oil, and peroxide value (PV), ranging from 0.27 to 0.60 meqO₂/kg oil. Principal component analysis (PCA) revealed positive correlations between sesame seed content and antioxidant activity, oxidative stability, and PUFA levels, while higher pork fat content was associated with increased SFA levels and oil yield. The findings suggest that co-rendering pork fat with sesame seeds produces oils with enhanced nutritional value, oxidative stability, and bioactive compounds content, offering a healthier alternative to conventionally rendered lard for food industry applications.