CHEMICAL AND PHYSICOCHEMICAL CHARACTERISTICS OF PECAN (CARYA ILLINOENSIS) OIL NATIVE OF THE CENTRAL REGION OF MEXICO

Abstract

The pecan (Carya illinoensis) kernels and oils from twenty-two different native trees of the central region of Mexico were evaluated through chemical and physicochemical parameters. The main constituent of the kernels was a high lipid content (70–79% wt/wt d. b.) with a large proportion of oleic acid (55–75% wt/wt). The concentration of α-, γ-, and δ-tocopherols in the oils extracted from Mexican native pecans, was substantially higher than those in the varieties commonly reported in the literature (i.e., Stuart, Desirable and Schley). However, the fatty acid and tocopherol composition of the pecan oil did not fully explain the high oxidative stability (OSI values from 8.5 to 10.8 h at 110C) observed in some oils, which might indicate the presence of some other natural antioxidants with activity at 110C. In general, the oxidative stability, the melting and crystallization properties, and the viscosity of pecan oils were similar or superior to those of extra-virgin olive oil and unrefined sesame oil. The results obtained indicated how oleic, linoleic, and linolenic acids are biosynthetically interrelated in vegetable tissues. The relationships among the concentrations of these fatty acids determined