Fatty Acids Profile of Wild and Cultivar Tunisian Peanut Oilseeds (A. hypogaea L.) at Different Developmental Stages

Abstract

Eleven fatty acids were identified during maturity in the wild (AraA) and varieties peanut kernels (AraC and AraT). These fatty acids included C_16:0 (palmitic acid), C_18:0 (stearic acid), C_18:1 (oleic acid), C_18:2 (linoleic acid), C_19:0 (nonadecanoic acid), C_20:1 (gadoleic acid), C_20:0 (arachidic acid), C_22:1 (erucic acid), C_22:0 (behenic acid), C_23:0 (tricosanoic acid) and C_24:0 (linoceric acid). Two fatty acids C_19:0 and C_23:0 were not previously detected from peanut kernels. Furthermore, eight major fatty acids (C_16:0, C_18:0, C_18:1, C_18:2, C_20:0, C_20:1, C_22:0 and C_24:0) were quantified during maturity. Wild AraA was distinguished by its highest level of oleic (38.72%) and stearic (2.63%) acids contents and the lowest one of linoleic acid (19.40%) compared to the varieties. As for the O/L ratio, wild AraA presents a significantly higher (p < 0.05) (O/L = 2) than that of the AraC and AraT varieties with (O/L = 1.7 and 1.04) respectively. Correlation coefficients (r) between the eight major fatty acids revealed an inverse association between oleic and linoleic acids (r = -0.99, p < 0.001), while linoleic acid was positively correlated to palmitic acid (r = 0.97). These results aim to provide a detailed basis for quality improvement in the cultivated peanut with wild resources.

Keywords: GC-MS; O/L; correlation coefficients; cultivar peanut; fatty acids; wild peanut.