Compositional and sensory characteristics of three native sun-dried date (Phoenix dactylifera L.) varieties grown in Oman

Abstract

Three native sun-dried date varieties grown in Oman, namely, Fard, Khasab, and Khalas, were examined for their proximate composition, sugars, dietary fiber, minerals, and organic acids as well as sensory characteristics. The study was conducted on sun-dried dates due to their higher consumption compared with fresh dates. All results are expressed as mean value +/- standard deveiation (n = 3) on a fresh weight basis except for sensory analysis. Date varieties were found to be low in fat and protein, but rich in sugars, dietary fiber, and minerals. They were found to be a good source of energy (278-301 kcal/100 g), due to the high sugar content. Total sugar content ranged from 56.1 to 62.2 g/100 g, being lowest in Khasab and highest in Khalas. Total dietary fiber content of dates varied from 6.26 to 8.44 g/100 g, of which 84-94% was insoluble fiber. Twelve minerals were studied in dates, among which the major minerals were potassium, calcium, magnesium, and phosphorus. Date varieties were also found to be an excellent source of selenium (ranging from 0.36 to 0.53 mg/100 g). Six organic acids were positively identified, among which malic acid predominated in all varieties. Differences (p < 0.05) in the contents of dietary fiber, organic acids, and certain minerals were observed among the three date varieties examined. Descriptive sensory analysis showed that among the nine sensory attributes studied, only the attributes color and desirability were rated as being of significantly (p < 0.01) higher intensity in Fard than in Khasab, whereas flesh firmness was lower (p < 0.01). Thus, these results suggest that although all three dates serve as a good source of vital nutrients, the Khalas variety, which is considered as premium quality, had significantly higher contents of sugar and selenium and a significantly higher energy value than the other varieties studied.