Evaluation of blends of wheat (Triticum aestivum) flour and African walnut (Tetracarpidium conophorum) flour in biscuit production

Article history: Received: June 3, 2018 Accepted: August 16, 2019 The use of underutilized crops has been the focus of recent research in developing countries like Nigeria because of inadequacy of protein supply in diets. In attempt to improve the use of underutilized crops, biscuit samples were produced from flour blends containing different combinations of African walnut flour and wheat flour. The 100% wheat flour served as control. The African walnut and wheat flours were mixed in ratios 10:90, 20:80, 30:70, 40:60 and 50:50%. The proximate composition, functional and pasting properties of the blends as well as physical and sensory properties of the biscuits were determined The results showed the increase in the level of protein, ash, fat and moisture content of the blends with increasing levels of walnut flour. The bulk density, water absorption and swelling power of the blends reduced, while oil absorption capacity, emulsion capacity and least gelation concentration increased with increasing levels of walnut flour. Variations exist in the pasting properties of the blends. The diameter of the biscuits increased with increase in the level of walnut flour, hence the spread ratio increased from 3.52 to 6.56. There were significant differences between the biscuit samples in terms of aroma, taste and appearance. However, biscuit sample with inclusion level of 30% walnut flour compared favourably with the control in terms of sensorial quality.