Fatty acid profile of table olives and its multivariate characterization using unsupervised (PCA) and supervised (DA) chemometrics

The fatty acid composition of 67 commercial presentations of table olives was determined. The most abundant fatty acids, in decreasing order of presence, were C18:1, C16:0, C18:2 n-6, and C18:0. The ranges, expressed as grams of fatty acids per 100 g of edible portion, for the different nutritional fractions were as follows: saturated fatty acids, 2.07-5.99; monounsaturated fatty acids, 5.67-19.42; polyunsaturated fatty acids, 0.52-3.87; and trans-fatty acids, 0.08-0.44. Principal component analysis of the matrix of the fatty acid composition led to the deduction of new factors. The first accounted for 55.10% of the total variance and was mainly related to C16:10, C18:0, C20:0, C22:0, C24:0, C18:1, C18:1t, and C20:1. The second factor accounted for 10.33% of variance and was related to C16:1 and C18:2 n-6. They did not permit differentiation among elaboration types or cultivars. However, discriminant analysis was successfully applied for this objective. The fatty acids that most contributed to discriminate among elaboration styles were C17:1, C18:1, C16:0, C17:0, and C18:0 (function 1) and C17:0, C17:1, C20:0, C16:0, C18:1, and C24:0 (function 2). In the case of cultivars, they were C20:0, C18:1, C17:1, C18:2 n-6, C18:1t, and C18:2t (function 1); C18:2 n-6, C18:1, C16:0, C20:0, C18:0, and C18:2t (function 2); and C17:0, C18:3 n-3, and C17:1 (function 3). Results from this study have shown differences among the fatty acid composition and fat content of the diverse commercial presentations of table olives, which can be applied in predictive and classification discriminant analysis.