Physicochemical and Functional Properties of Pumpkin (Cucurbita Pepo) Pulp Flour and Acceptability of its Inclusion in Cake

Abstract

A study of the Physico-chemical and functional properties of pumpkin / wheat flour blends and sensory attributes of cakes made from the flour blends where evaluated in the food science laboratory of Rivers State University. The physico-chemical analysis were carried out using standard AOAC methods with 100% wheat flour serving as control. Result of chemical analysis of wheat/pumpkin composite flour blends ranged from 6 .51 – 11.78%, 0.58 – 6.74%, 5.81 – 11.97%, 0.90 – 1.56%, 0.51 – 6.93% and 72.22 – 73.68% for moisture, ash, protein, fat, crude fiber and carbohydrate, respectively.  There was a decrease in moisture, fat, protein and carbohydrate and an increase in ash, and crude fiber as the level of pumpkin flour substitution increased.  Starch, amylose and amylopectin ranged from 37.68 – 83.82%, 8.76 – 24.64 % and 28.92 – 59.18%, respectively. The lowest starch (37.68%) content was recorded in pumpkin flour made entirely of pumpkin. Depending on the mixing ratios between flour and pumpkin flour, a wide range of functional properties were recorded, including 1.04 – 5.30 ml/g water absorption capacity, 0.58 – 0.61 g/ml bulk density, 8.50 – 16.50% least gelation concentration, 1.07 – 54.26% foaming capacity, 0.00 – 27.84% foaming stability, 53.71 – 93.33% swelling capacity, 45.46 – 48.49% emulsion capacity and 35.50 – 56.02% emulsion stability. Sensory evaluation of the cakes showed no significant difference (p>0.05) in general acceptability between the control and up to 70% substitution with pumpkin flour. The scores ranged from 2.61 – 8.22, 4.13 – 7.13, 5.04 – 7.70, 3.87 – 7.70 and 2.74 – 7.83 for taste, appearance, colour, mouthfeel and general acceptability respectively.  Incorporation of pumpkin flour to wheat flour increased the ash and crude fiber content of the composite flour.