A Study of the Quality Characteristics of Khraig Olive Oil the Factors Affecting them and their Conformation to the Syrian and International Standards

This research defines Khraig, whose production is restricted to Syrian coastal area. Khraig is the oil extracted from olive fruits after blanching, covered fermentation and drying. All qualitative characteristics of this oil are studied: weight, refractive index, saponification number, iodine value, ultraviolet absorption, fatty acids percentages, peroxide value and free acidity percentage determined as oleic acid. The last two parameters are found to be the main causes for the non-conformation of Khraig oil to the Syrian and International standards of virgin olive oil. Hence, it is necessary to study the effects of the abovementioned treatments of olive fruits on the produced oil. The results indicate that increasing either blanching time from five to ten minutes, or time of covered fermentation from two to three days considerably increases peroxide value of the produced Khraig oil exceeding thus the maximum limit set by the Syrian and International standards. In addition, both treatments lower oil quality by increasing its acidity. The results also show that drying olive fruits for two days instead of one day has a negative effect on oil quality by decreasing organoleptic score and increasing both acidity and peroxide value. Sun drying raises organoleptic score and decreases acidity compared to drying in the shade, but it increases peroxide value, and hence decreases the period of oil storability. There is a need for further studies of Khraig oil, especially the effects of the abovementioned processing steps on important oil constituents related to quality, nutritive value and storability such as tocopherols, sterols, and polyphenols. Likewise, the study of the desirable flavor compounds of this oil is also necessary.