Physical, nutritional, functional, and thermal properties of muskmelon (Cucumis melo L.) and watermelon (Citrullus lanatus L.) seeds and flours

Abstract: Food sustainability and waste reduction have gained considerable importance in recent years. Despite being rich in nutrients and functional characteristics, by-products like seeds from fruits remain underutilized. The decorticated seeds and seeds flour of muskmelon and watermelon were analyzed for their physical, nutritional, functional, and thermal properties to aid in designing systems for storage, processing, and incorporation as functional ingredients in food products. Standard methods estimated the seeds’ dimensional, frictional, gravimetric, nutritional, and functional properties. The seeds’ flour was defatted to assess thermal properties using the DSC (Differential Scanning Calorimetry). The seeds of muskmelon and watermelon were rich in proteins (29.21 %, 29.56 %) and fats (39.07 %, 44.31 %), respectively. Both the seeds’ flour exhibited a similar range of porosity (68.8 %). The static coefficient of friction (0.78) was the highest for thermocol among all tested surfaces for both seeds. The foaming capacity (39.39 %) and oil absorption capacity (1.26 g/g) of muskmelon seeds flour were higher than watermelon seeds flour (36.36 % and 1.00 g/g, respectively). The thermal denaturation temperature of defatted watermelon seeds flour (66.4 °C) was higher than defatted muskmelon seeds flour (63.8 °C). Reports on these seeds’ properties, especially the thermal properties of seed flour, are very scarce. This research work would aid in effectively utilizing seeds and their flours as functional ingredients in the food processing industry.