Investigation effects of storage condition (periods and temperature) and olive cultivars Zard and Roghani, on olive oil quality

The potential of Olive mils usually are limit at the harvest time, harvested olives stored in open condition in field or enclosure of factory with present of decaying factors. This research was conducted for investigation of effects of decaying factors on quality of olive oil. Olive fruit sampling was done from cultivars Zard and Roghani in Tarom region in the end of November. Treatments was conducted in experimental factorial with 3 replication ant 3 main factors: Factor A: cultivar(a1 Zard, a2 Roghani), factor B :storage time( b1- 0day, b2 - 15day , b3 - 30day and b4- 45 day) and Factor C storage temperature ( open condition c1, c2- 4C°, c3- 14 C°, c3- 24C°). Results indicated that the acidity olive oil of both cultivars was in extra virgin category in treatment of 0 day storage time. Olive oil was in virgin category for cv. Zard in all of storage time treatments with 4C°storage temperature. In cultivar Roghani with increasing storage time more than 30 days the acidity of oil will be exceed from 3%. The highest acidity with 75.74% was recorded in treatment of cv. Roghani in open condition storage with 45 days storage time. Any of treatments hadn't acidity more than 22% in cultivar Zard. Saponification index changes had high correlation with alteration of acidity. The changes of amounts polyphenoles in olive oil indicated that was decreased with increasing storage time. Decreasing of polyphenoles was very fast in all treatments in the 15 days after storage. The effects of cultivars were significant in amounts of oleic acids (Zard 71% and Roghani 66%). The results indicated that Oleic acid and Palmetic acid content increased and Linoleic acid and linolenic acid contents decreased with increasing of storage temperature. The content of Stearic acid decreased with increasing temperature and storage time. The fungi's of Aspergillus, Fusarrium and Penicillium was detected in al treatments. The amount of olive fruits pollution to saprophyte fungi's was 60% at 4 C° after 45 day storage. The cultivar Zard had low decay related to cultivar Roghani.