Effects of Sesame Seed Enrichment on Physico-Chemical and Nutritional Characteristics of Flour from Two Cultivars of White Yam (Dioscorea rotundata Poir)

Abstract

The effects of enriching two cultivars of yam (Dioscorea rotundata Poir) flour with sesame seed (Sesamum indicum L) flour on their physicochemical and nutritional characteristics were studied. Yam flours were produced from Abuja and Efuru yams by parboiling at 60°C for 10 minutes and left overnight, followed by sun drying for four days. Enriched yam flour samples were prepared by thoroughly mixing the yam and sesame seed flour in ratios 95:5, 90:10, 85:15 and 80:20 respectively. Proximate, mineral and anti-nutrient content, as well as functional properties of enriched flours, were determined using standard methods of AOAC. The two yam-flour samples were low in moisture, crude protein, fat and ash content, high in carbohydrate and macro minerals, while Sesame seed was very low in moisture and carbohydrate, but very high in crude protein, fat, ash and macro minerals. The moisture, crude protein, fat, ash and carbohydrate content of the yams and enriched samples ranged between 11.9-13.8 g, 3.3-7.5 g, 0.5-13.8 g, 2.0-2.6_g and 63.3-81.8_g/100 g respectively. Addition of sesame seed flour resulted in the reduction of moisture and carbohydrate content and significant increase (p=0.05) in protein, fat and ash values of enriched samples. The protein, fat and mineral content of the enriched samples increased with increased level of sesame seed flour inclusion (p=0.05). Both yam and sesame flours were low in the antinutritional factors studied. Sesame flour was high in trypsin inhibitors and polyphenols. Enrichment with sesame flour resulted in further reduction in the antinutritional factors content with increase in trypsin inhibitors and polyphenols content of the products. Efuru variety flour with its enriched products had higher water and oil absorption capacity, loose and packed bulk density and swelling capacity than Abuja variety flour. Enriching yam flour with sesame flour can improve the nutrients and functional properties of their products which can improve the nutritional status, health and well-being of consumers.