Evaluation of Various Technological Factors (Variety, Drying Method, Solvent Type, Time) on Chemical Composition and Antioxidant Activity of Date Palm Seed in Jiroft Region

Date palm seeds are obtained as waste in many date packing and processing workshops and have extensive therapeutic properties in traditional medicine.

In this study different cultivars of date seeds (Kaluteh, Mardasang, Khanizi and Mozafati) were dried by two methods (sun and oven dried), then their extracts were obtained using methanol (80%), ethanol (50%) and hot water on solvents at 6, 12 and 18 hours of extraction. The amount of phenolic compounds using Folin-Ciocalteu method, antioxidant activity by DPPH method and soluble fiber by AOAC standard analysis method were determined.

The results showed that the highest amount of phenolic compounds and antioxidant activity were obtained in Mordasang cultivar by sun drying method, methanol of 80% and 18 hours of extraction time respectively (10.08,93.38%) , in Kaluteh cultivar by sun drying method, hot water extraction and 12 hours of extraction time, respectively (8.03,87.94%) in Khanizi cultivar by oven drying method, ethanol of 50% and 18 hours of extraction time respectively(7.36, 71.91%)  and in Mazafati cultivar by sun drying method, methanol of 80% and 12 hours of extraction time, respectively (8.48, 88.95%). The highest and lowest amount of insoluble fiber were observed in Mordasang cultivar by sun drying method and Mozafati cultivar by sun drying method, respectively. The highest and lowest amount of soluble fiber were related to Kaluteh cultivar by sun drying method and Khanizi cultivar by oven drying method.

In general, this study showed that the seeds of different date cultivars in the Jiroft region, despite having anti-radical properties and rich in natural antioxidants, are affected by variety and drying method.