Effect of fruits storage conditions on the yield and the quality of Pistacia lentiscus oil

Abstract

This study aims to determine the effect of fruit storage conditions on the yield and quality of Pistacia lentiscus oil. Fruits were harvested in North Tunisia, and oil was extracted using the pressing method. Three storage conditions were tested; fruit is frozen at -20°C, fruit storage in a cold room at 4°C, and air-dried fruits at 25°C.  Oil yield, free fatty acids, peroxide value, and total polyphenolic content were determined after 30, 60, and 90 days of storage. During the first 30 days, the highest yield was reached by fruits stored in a cold room (15%). Oil acidity from freshly harvested lentisk fruits was around 6% and then increased during storage. With increasing storage time, the oil peroxide value and the total polyphenolic content decreased in the fruits from all treatments. The peroxide value reached the respective values of 8, 5, and 23 meq O2/kg oil for Frozen, Cold Room, and Air Drying treatments. The total polyphenolic content varied from 0.5 EGA/g oil for air drying and frozen treatments to 0.8 EGA/g oil for the cold room. This study allowed the determination of the optimal conditions of storage of Pistacia lentiscus oil. These results are important to preserve the oil's quality and chemical and medicinal properties.