Effect of Infrared Pretreatment on Quality and Storage Stability of Cold-Pressed Pecan Oil

Abstract

After infrared (IR) pretreatment for 22, 41, 68, 104 and 148 s, the internal temperature of pecan kernels reached 70, 90, 110, 130 and 150 ℃, respectively. To investigate the effect of IR pretreatment on the quality and storage stability of cold-pressed pecan oil, oil yield, fatty acid composition, lipid concomitants, physicochemical indicators, microstructure, and antioxidant capacity and storage stability were analyzed. The results showed that IR pretreatment increased the oil yield of pecan kernels by 11.10%–58.42% compared with the control group, but had no significant effect on the fatty acid composition of cold-pressed pecan oil. Moreover, IR pretreatment significantly the activities of lipase and polyphenol oxidase in pecan oil (P 0.05), and a 23.52% and 13.16% increase in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and ferric reducing antioxidant power (FRAP), respectively, thereby significantly enhancing the storage stability. To summarize, IR pretreatment for 148 s is the best pretreatment method to obtain cold-pressed pecan oil. The results of this study provide a theoretical basis for the application of IR pretreatment in the preparation of cold-pressed pecan oil.

Keywords

• cold-pressed pecan oil; infrared pretreatment; oil yield; quality; storage stability