Effects of Drying on Quality Attributes of Wheat (Triticum aestivum) Flour Meal Supplemented with Watermelon (Citrullus Lanatus) Rind Flour

Abstract

Every part of the watermelon fruit (The rind, peel and seed) have important nutritional values. The fruit wastes are rich in phytochemicals and had been exploited to investigate its nutritive properties. Thus, the present study was designed to determine the effects of drying on the quality attributes of wheat flour dough supplemented with watermelon rind flour. The rinds were dried using three different methods (freeze drying, sun drying and air drying) and were added to the wheat flour at different ratio. While 100% Wheat flour was used as control. The proximate, functional, phytochemical, pasting and mineral content of the flours were determined using standard methods. The sensory evaluation test consisted of 30 Semi Trained Panelists and results verified. The protein content of the flours ranged from 8.3% – 14.1 %. Crude fibre content ranged between 0.85 – 11.4%, crude fat 1.13 – 6.11%, total ash 1.74 – 4.9%, moisture content 6.3- 10.2% and carbohydrate 63.23 – 76.52%. The carbohydrate content of samples WFD1, WFD2, WFD3 and WFD4 increased with increasing level of watermelon rind flour substitution. There were significant differences (p<0.05) in phosphorus content of all the samples. The results of the bulk density of the flour showed there were significant differences (P<0.05) between the control and the other samples except for sample WSD3 at various level of watermelon rind flour substitution respectively. Whole Wheat flour (Control) had the lowest water absorption capacity (156%). Wheat-watermelon flour at 30% substitution with watermelon rind flour (air and freeze dried) could find application in confectionary and pastry industries. Although none of the dried samples in this study had tannins, the alkaloid, and saponin content from this study compared relatively well to those present in some similar findings. The sensory results from the study revealed that there were significant differences in the flavour, texture and overall acceptability of all the samples while the colour and taste had no significant differences between the freeze dried samples and the sundried samples.