The effect of filtration on the chemical profiles and quality attributes of Greek olive oils produced from drupes of irrigated cultivations in northern Greece

Abstract

Olive oil is a highly regarded product with unique qualities and health benefits. It has a long history dating back 6000 years, and its production is deeply rooted in Mediterranean culture. The production process involves various stages, from harvesting and cleaning to extraction and storage. Olive oil's chemical composition is rich in saponifiable and unsaponifiable fractions, including fatty acids, phenolic compounds, pigments, vitamins, sterols, alcohols, and phospholipids. Virgin olive oils are categorized based on their acidity levels, such as extra virgin, virgin, ordinary virgin, and lampante. There are also olive-pomace oils produced from the by-products of olive oil extraction. Olive oil is highly valued for its quality and is consumed as part of the Mediterranean diet, offering numerous health benefits. The maturity index of olive oil (OO) is a critical factor affecting its quality characteristics. The examined OO samples in this study were obtained from low maturity index olive drupes. Filtration had an impact on the acid value. Peroxide value increased after filtration. Filtration did not significantly affect the K values or water activity, but it reduced the total chlorophyll and carotenoid contents in most samples. The impact on color attributes was minimal, with slight changes observed in L*, a*, and b* values. Filtration reduced the oxidative stability of the oils and also led to a decrease in total phenol content. The volatile profiles showed alterations in peak areas of certain compounds. Overall, filtration had varying effects on the quality characteristics of the examined OO samples.