Influence of walnut on the nutritional and physicochemical properties of biscuits made from whole wheat
In this study, the influence of walnut flour in biscuit production was studied. Biscuits were made from blends of whole wheat with walnut flours and were assessed for quality attributes and storability. Walnut was blended with whole-wheat thus: B (2%:98%); C (4%:96%); D (6%:94%); E (8%:92%) and F (10%:90%), while plain whole wheat flour served as control (Sample A). The biscuits were baked in the oven operated at 1800C for 20-30 minutes, cooled, packaged, stored for eight weeks, and analysed for physicochemical, microbial and sensory properties using standard methods. The results revealed that the proximate composition of the samples during storage were as follows: protein, moisture, ash, crude-fat, crude-fibre and carbohydrate values ranged thus: (9.30-14.26%), (10.28-12.06%), (2.20-2.92%), (13.24-16.66%), (0.69-1.17%) and (53.60-61.47%) respectively, with better nutrient stability in the treated samples when compared to the control. The colour varied with increasing substitution, while the essential amino acids were higher in the walnut-supplemented samples. The microbial load of the control was higher than those of the treated samples, due to high antioxidant activity of walnut. Sensory evaluation revealed that biscuit sample having 2% walnut flour was most preferred.
Keywords: Whole wheat flour; walnut; proximate composition; antioxidant properties; shelf life.