بررسی خصوصیات فیزیکوشیمیایی و ترکیبات آنتی‌اکسیدانی میوه و هسته‌ی ارقام خرمای شاهانی و خاصویی منطقه زرین‌دشت فارس

خرما به‌عنوان یک محصول عمده کشاورزی ایران دارای ارزش غذایی بالایی می‌باشد. در این پژوهش، برخی خصوصیات فیزیکوشیمیایی میوه و هسته‌ی دو رقم خرمای شاهانی و خاصویی پرورش یافته در منطقه زرین‌دشت استان فارس مورد بررسی قرار گرفت. بر اساس نتایج حاصل از این پژوهش، در بین تمام صفات کیفی به جز ph اختلاف معنی‌داری وجود داشت (0.01< p). در مقایسه‌ی ویژگی‌های گوشته‌های دو رقم، مشاهده شد که بیشترین میزان فیبر (1/78%)، اسید قابل تیتر (0/59 %)، خاکستر (1/64 %) و چربی (0/85 %) مربوط به گوشته‌ی رقم شاهانی و بیشترین میزان فنول کل (mg/gfw 8/1)، خاصیت بازدارندگی dpph  (13%)، رطوبت (18/7 %)، قند (63/8 %) پروتئین (0/29 %) و ph (5/74) به گوشته‌‌ی رقم خاصویی تعلق داشت. همچنین در مقایسه‌ی ویژگی‌های هسته‌ی دو رقم، مشاهده شد که بیشترین میزان خاکستر (3/17 %)، فنول کل (mg/gfw 10/8)، خاصیت آنتی‌اکسیدانی (72 % بازدارندگی dpph)، پروتئین (2/55 %)، ph (6/11) و چربی (9/20 %) مربوط به هسته‌ی رقم شاهانی و بیشترین میزان فیبر (26/2 %)، رطوبت (5/26%)، قند (15/8%) و اسید قابل تیتر (0/38%) به هسته رقم خاصویی تعلق داشت. بنابراین در مجموع، هسته‌ی رقم شاهانی قدرت بازدارندگی dpph بیشتری در بین همه‌ی نمونه‌ها داشت.

investigation of physicochemical and antioxidant properties of shahani and khassui date’s palm and kernel from zarrin dasht region in fars province

introductionthe date palm (phoenix dactylifera l.) plays an important social, environmental, and economical role for many people living in arid and semiarid regions of the world. date fruit is one of the major agricultural crops in the east asia region, where about 90% of the world’s dates are cultivated. dates are rich in certain nutrients and provide a good source of rapid energy, due to their high carbohydrate content (70–80%). moreover, date fruits contain fat (0.20–0.50%), protein (2.30–5.60%), dietary fibre (6.40–11.50%), minerals (0.10–916 mg/100 g dry weight), and vitamins (c, b1, b2, b3, and a) with very little or no starch. in addition to the direct consumption of the fruit, various industrial products are also extracted derived from this product, including date juice, date honey, liquid sugar, vinegar, alcohol, caramel, date paste and date chocolate. the annual production of one million and 400 thousand tons of dates in iran has made iran the second pole of date production in the world after egypt. zarin dasht region is located in fars province, and the annual production of dates in this region reaches more than 1000 tons. the aim of the present work was to investigate the chemical composition, carbohydrate, and antioxidant capacity of two cultivars of zarin dasht dates. materials and methodsafter collection, all date fruits were washed with tap water, and the seeds were then removed, and the flesh were shade dried at room temperature. the dimensions and area of the imaged surfaces were measured by the physical properties measurement device in 100 repetitions. the working principle of this device is based on image processing technique. by placing the product in three different positions and perpendicular to each other, pictures of the date samples were taken individually. date mass was obtained using a sensitive digital scale with an accuracy of 0.01 g. the displaced water method was used to determine the volume and density of each date seed. bulk density, date porosity, geometric mean diameter, sphericity coefficient and surface area of the samples were determined. the amount of moisture was determined by weight method, ash by burning in an electric furnace, titratable acidity based on malic acid and ph of the samples were measured by a digital ph meter. to measure the amount of total phenol in the fruit, folin–ciocalteu reagent was used and the absorbance of the reaction mixture was read at 750 nm by a spectrophotometer. the amount of total phenol was reported in terms of gallic acid. the antioxidant capacity was determined through the neutralization of free radical 2 and 2 diphenyl 1-picrylhydrazyl (dpph). to measure the sugar of all samples, first a standard curve was drawn from the glucose solution in different concentrations, then the sugar content of the samples was measured in milligrams per gram of fresh weight at 490 nm using the sulfuric phenol method. the amount of crude fibre was calculated according to the standard method of aoac-991/43. the amount of fat was obtained with the universal extractor e-800 device for 3 hours at a suitable temperature and in 250 cc of n-hexane solvent. finally, the statistical analysis of the data was done factorially and in the form of a completely random design in 3 replications using sas 4, 9 software and the comparison of the means was done using the lsd test at a probability level of 1%. results and discussionaccording to the results of this research, there was a significant difference in all qualitative traits except ph (p<0.01). in comparing the characteristics of the palms of two cultivars, it was observed that the highest amount of fibre (1.78 %), titratable acid (0.59 %), ash (1.64 %) and fat (0.85 %) is related to shahani cultivar,and the highest amount of total phenol (8.1 mg/gfw), dpph inhibitory property (13 %), moisture (18.7%), sugar (63.8 %), protein (0.29 %) and ph (5.74) belonged to khassui cultivar. also, comparing the kernel characteristics of two cultivars, it was observed that the highest amount of ash (3.17 %), total phenol (10.8 mg/gfw), antioxidant property (72 % dpph inhibition), protein (2.55 %), ph (6.11) and fat (9.20 %) related to the kernel of shahani variety and the highest amount of fibre (26.2 %), moisture (5.26 %), sugar (15.8 %) and titratable acid (0.38 %) belonged to the kernel of khassui cultivar. overall, the kernel of shahani variety had more dpph inhibitory power among all the samples.