Evaluation of qualitative traits and bioactive compounds of some cultivars and promising genotypes in Tarom region in Zanjan province

Abstract

In this study, qualitative traits and bioactive compounds of edible oil that extracted from three olive promising genotypes (T2, T7, and T18) and two cultivars (Zard and Koroneiki) from Tarom olive collection in Zanjan province were evaluated during two crop seasons (2017)(2018). Edible oil quality traits including free fatty acids (FFA), peroxide value (PV) and extinction coefficients (K232 and K270), total chlorophyll, total carotenoids, total phenols, total flavonoids and antioxidant capacity were measured. The results of analysis of variance of year  cultivar / genotype on oil qualitative traits showed that their interactions on all traits except K270 were significant at 1% probability level. The results showed that edible oil of T7 genotype (0.79% as oleic acid) and Zard cultivar (0.43% as oleic acid) in 1997 had the lowest and highest FFA contents, respectively. Edible oil of T7 in 2018 (17.22 m Eq / kg of oil) and T2 in 2017 (96.67 m Eq / kg) showed the highest and lowest PV levels, respectively. The K232 extinction coefficient of T18 oil was the lowest in both years (0.8 and 1.03 for 2017 and 2018, respectively). Edible oil of Zard cultivar had the highest amount of total phenol in 2017 (243.94 mg gallic acid per kg of oil). T7 genotype had the highest amounts of total flavonoids in 2018 (21.45 mg of quercetin per kg of oil). Koroneiki cultivar with 90.55% had the highest antioxidant capacity in 2017 and T7 genotype with 41.65% had the lowest value of this index. T2 genotype in both years in terms of antioxidant capacity was in a statistical group with commercial cultivars.