Determination of the effects of different filtration processes and packaging materials on the preservation of properties and quality of extra virgin olive oil obtained in different harvesting periods

Important processes are applied to olive oil, from cultivation to processing, until consumption, and the physicochemical and sensory properties of olive oil are affected. In addition, the quality must be maintained during the storage phase and the shelf life of the supply to the consumer. In this study, it is aimed to investigate the effects of different filtration processes and packaging materials on some quality parameters during the storage process of extra virgin olive oils obtained at different harvest periods. In the study, olives of the Ayvalik variety were used and the harvest time of olive fruits was determined according to the maturity index (early harvest/green ripe stage and late harvest/black ripe stage). Olive oils from olive fruits in different physiological maturity periods were produced in a 2-phase continuous centrifugation system. Half of the olive oils obtained were subjected to filtration process using a mini filtration machine. Market launch of early harvest filtered and unfiltered, late harvest filtered and unfiltered virgin olive oils in seven different packages (transparent pet bottle, colored pet bottle, glass bottle, colored glass bottle, tin, doypack and tetrapak) conditions (shelf system) and by applying light as much as the timer and market operating times, they were kept for 12 months. The arrangement of the olive oils on the shelves was changed periodically every week, and alignment changes were made between the lower and upper shelves and the right and left rows for equal heat and light distribution. Olive oil samples were first analyzed for purity such as fatty acid composition, sterol composition, total sterol and triterpenic alcohols, ECN42, stigmastadienes, waxy substances. During the shelf life, some chemical and sensory properties were followed and the relationship of continuous variables and their effects on each other were examined. Free fatty acidity, peroxide value, oxidation stability (ransimate), specific absorption in ultraviolet light, fatty acid ethyl esters, fatty acid methyl esters, total polyphenols, phenolic compounds, alpha tocopherol, volatile aroma components were monitored during 12 months and 3-month periods. The sensory properties of olive oils were evaluated at the beginning and during the storage period (6th and 12th months). Statistical analysis methods were applied to the obtained data. The quality criteria most affected by the harvest time were median of fruitiness, free fatty acidity, and fatty acid ethyl esters, respectively. Fatty acid methyl esters, specific extinction at 270 nm, specific extinction at 232 nm and median of fruitiness were affected during storage. Antioxidant components of olive oils were most affected by harvest time and storage time. The filtration effect was low. The effect of packaging type was only on alpha tocopherol. In terms of harvest time, oxidation stability decreased as fruit ripening progressed. The oxidation stability of unfiltered oils was found to be higher. Aroma components of olive oils showed significant differences according to harvest time, filtration status, type of packaging used in storage and storage period.