Commercial extra virgin olive oils: Global Quality Index computation and pattern recognition by chemometrics

Purpose The purpose of this paper is to guide the choice of consumers, putting on the label an additional claim, which can provide more information on the sensory profile and the nutritional and preservation features of the marketed extra virgin olive oil. Design/methodology/approach In order to define the concept of global quality, the following parameters were considered: fruity, bitter, pungency, 1-penten-3-one, phenolic substances, tocopherols, peroxide value, free acidity, palmitic acid, stearic acid oleic acid linoleic acid, and the campesterol/stigmasterol ratio. The study was carried out on 143 commercial extra virgin olive oils. Findings The Global Quality Index was calculated as the square root of the sum of the squares of the individual local indices, according to three different algorithms. The computation obtained was recognised by chemometric analysis. Social implications A legislative amendment on the labelling could be proposed through an additional claim that safeguards the consumers on the health profile, inducing them to a more targeted purchase. Originality/value Three different global quality levels “excellent”, “good”, and “sufficient” have been determined. This clustering has also been recognised with a statistical approach. Since in the market, consumers can find extra virgin olive oils of different overall quality levels, it is possible to guide the choice of customers through an additional claim on the label, able to give more information on the sensory profile and the nutritional and preservation features of the product.