Autochthonous and international olive cultivars in Malta : morphometric characteristics and physicochemical analysis

Abstract

The olive has been cultivated since antiquity for its use as a table olive or for the production of olive oil. This study aims at obtaining chemical characterization of olive leaves and from locally grown Maltese and International varieties. Thirteen olive varieties of both oil and dual purpose were selected, two of which were of Maltese origin, known as Tal-Bidni and Tal-Malti. The maturity index at harvest and olive oil yield were recorded. Chemical analysis was carried out on all samples for polyphenols, chlorophyll content, anthocyanins, tint, colour intensity, and tonality using spectrophotometry. The findings from the olive leaf and fruit analysis indicated that the polyphenolic content had a similar trend in both fruit and leaf, and anthocyanin and chlorophyll content had different trends. PCA conducted on the olive leaf and fruit samples revealed that tint and tonality showed an inverse correlation with anthocyanin and polyphenolic content, and that chlorophyll content of leaves showed an inverse relationship with that of the fruit. Agglomerative hierarchical clustering (AHC) analysis revealed that the local variety Tal-Bidni is closely related to Bosana, Pendolino and Leccino, whilst the other local variety TalMalti is closely related to Frantoio and Ottobratica.