A Comprehensive Evaluation System for Quality Characteristics of Olive (Olea Europaea L.) in Longnan, China

Abstract

Olive (Olea europaea L.), originated from the Mediterranean region, has been cultivated in Longnan City, China for several decades and demonstrated a remarkable adaptation to the local environment. The cultivation plays a vital role at both social and economic levels. However, there have been limited reports on the comprehensive evaluation of olive quality. In this study, we revealed the differences and characteristics of twenty quality related indices across twenty olive varieties cultivated in China. Furthermore, Pearson correlation analysis, principal component analysis, and hierarchical clustering analysis were employed to comprehensively evaluate the quality characteristics of olives. As a result, all the tested indices exhibited significant variations among the twenty olive varieties, among which five principal component factors were extracted to establish a comprehensive quality evaluation model that represented by Y=0.398Y1+0.286Y2+0.140Y3+0.105Y4+0.071Y5. Based on their comprehensive scores, the twenty olive varieties were categorized into four distinct groups. The cultivars classified within the excellent-quality group included Cornicabra, Picholine Languedoc, Koroneiki, Picual, Yuntai14, and Coratina. The core quality parameters for olives in Longnan City encompassed moisture content, peroxide value, oil content, MUFA/PUFA, C18:1/C18:2, total polyphenol content as well as oxidative stability. This study not only holds substantial significance for the scientific evaluation of olive quality and the advancement of standardized quality classification, but also promotes high-value development and utilization within the olive industry, particularly for the development of functional foods and innovation in lipid-based products.

Keywords: Olive cultivars, Virgin olive oil, Quality characteristics, Comprehensive evaluation system, Principal component analysis