Nutritional potential, bioaccessibility of minerals and functionality of watermelon (Citrullus vulgaris) seeds

Watermelon (Citrullus vulgaris) seeds are high in protein and fat, on enriching protein, it can find application as a protein source in various food formulations. Most of the processed foods are generally fortified with micronutrients. The effect of the matrix on the mineral bioavailability is highly important and hence investigated. Defatted flour and protein isolate were prepared from watermelon seed meal and chemical composition and functionality was analyzed by standard techniques. Multiple regression analysis was done to study the compositional influence on the mineral bioaccessibility. Invitro digestibility of the protein was good. The seeds were a moderate source of iron and zinc. The percent bioaccessibility of all the minerals were found to correlate (R = 0.97-0.99) with the concentration of phytate, tannin and oxalate contents. The seed components exhibited good functionality with good macro and micronutrient density and can find application in many food products.

► Watermelon seed (WMS) isolate with 88 g protein per 100 g was prepared. ► Invitro digestibility of WMS protein was 88%. ► WMS proteins are rich in tryptophan, leucine, phenylalanine and arginine WMS isolate had 12.3 mg iron and 9.3 mg zinc per 100 g with moderate bioaccessibility. ► Functional properties of WMS proteins are good and find application in food products.