QUALITY AND SENSORY EVALUATION OF CAKES FROM WHEAT, WATERMELON RIND AND SOURSOP SEEDS FLOUR

ABSTRACT Watermelon rind and soursop flours are nutrient-rich non-conventional ingredients with potential to enhance the nutritional, functional, and sensory qualities of bakery products. This study evaluated the effects of substituting wheat flour with watermelon rind and soursop flours on the proximate composition, mineral content, functional properties, and sensory quality of composite flours and cakes. Design Expert Version 13 was used to optimize blend ratios, with substitution levels ranging from 10–30%. Standard analytical methods were used for all analyses. Proximate composition of the flour blends showed moisture 5.67–12.13%, ash 1.13–2.88%, protein 3.08–9.33%, fat 0.78–5.32%, crude fibre 0.88–4.61%, and carbohydrate 61.80–84.42%, indicating improved nutrient content with higher substitution. Functional properties, including water and oil absorption, bulk density, and swelling capacity, increased with higher levels of watermelon rind and soursop flour. Mineral composition also improvement, with calcium 28.42–58.17 mg/100 g, magnesium 12.13–42.55 mg/100 g, iron 2.14–9.27 mg/100 g, zinc 1.34–6.18 mg/100 g, and copper 0.22–1.17 mg/100 g increasing progressively. Proximate analysis of cakes revealed moisture 15.12–20.38%, ash 1.28–3.02%, protein 4.07–9.18%, fat 12.03–16.08%, crude fibre 1.88–4.56%, and carbohydrate 52.24–66.00%, showing that nutritional improvements in the flour were retained after baking. Sensory evaluation showed that cakes containing up to 23% soursop flour and 30% watermelon rind flour were most preferred in terms of appearance, flavour, taste, texture, and overall acceptability. The study concluded that the incorporation of watermelon rind and soursop flours significantly enhanced the nutritional, functional, and sensory qualities of both composite flour and cake, highlighting their potential as sustainable, nutrient-enriched ingredients in bakery product development while promoting the utilization of fruit by-products.