The effect of harvest time and variety on quality and purity criteria and sensory characteristics of Hatay olive oils

In this study, three varieties of olive oil samples (Saurani, Karamani, Halhalı) which were collected from the province of Hatay, Turkey researched by their on quality and purity criteria and sensory characteristics. The olives were examined according to the water content, oil yield, ripening index of olives at three maturation stage. Subsequently free fatty acids, peroxide value, UV specific absorbance, fatty acid composition, total phenolic substance, color, sterol composition and sensory characteristics of the attained olive oil were determined. The oil content of olives ranges between 23.77-34.77% and the highest oil yield was determined in the olive variety, Karamani (3rd edition). In olive oils, free fatty acids were found in the range of 0.33-1.02% (oleic acid), and peroxide numbers between 2.47-8.40 meq / O2 kg. The total phenolic substance values of olive oils ranged from 156.78-584.25 mg GAE / kg and the highest total phenolic substance content was demonstrated by Halhalı variety's first year. Decrement of the total phenolic substances' amount have determined with the maturity of varieties. In terms of fatty acids, the lowest oleic acid values were found in the third maturity period of the Karamani variety (59.78%), and the highest oleic acid values in the first maturity period (69.97%) of the Halhalı variety. In line with the maturity, olive oil's free fatty acids, peroxide value, stearic and linolenic acid contents were increased. Total sterol amounts of olive oils varied between 946-1782 ppm and showed a significant increase with maturity (p<0.01). The highest β-sitosterol amount was detected in the 1st maturity period of Saurani variety (91.66%) and the lowest β-sitosterol amount in the 2nd maturity period of the Halhalı variety (86.16%). The highest ∆5-avenasterol amounts were detected in the 3rd maturity period of Saurani variety (6.54%), the lowest ∆5-avenasterol amounts were detected in the 1st maturity period of the Halhalı variety (2.36%). Total β-sitosterol, stigmasterol and erythrodiol+uvaol contents of olive oils are fluctuating with maturity. The fruity property was determined as greater than 0 by all panelists in the sensory analysis of olive oil samples. The fruity median varied in the range of 3.62-5.88 and the fruity median decreased in all variety depending on ripeness. The median bitterness varied between 2.62-5.23 and decreased depending on maturity. The pungency median varied in the range of 3.12-5.34, and pungency was reduced with maturity. Halhalı olive oil was determined the best quality with its highest median of fruity, bitterness and pungency.