ABSTRACT

Walnut (Juglans regia) seeds are edible rich source of several essential nutrients which can be processed into flour for several purposes. It can serve as a modifier to our food products as a result of its high protein content and essential fatty acid. In this present study, analysis on the physiochemical properties of the composite flour blends (wheat/walnut flour) in the ratio 100:0, 90:10, 80:20, 70:30, and 50:50 were carried out using standard technique, cakes were produced from the composite flour to determine consumers acceptability and their staling properties were determined during five days storage. Proximate composition data indicates an increasing level of protein and fat (12.17% - 25.70% and 2.40% - 37.57%) respectively while carbohydrate decreased (63% - 19.4%) with increasing level of substitution with walnut flour. Functional analysis data indicates a decreasing level of bulk density and water absorption capacity (0.78% — 0.52% and 5.17% - 4.03%) respectively while swelling capacity increased (2.00% - 7.53%) with increasing level of walnut flour substitution. The composite cake with 90% wheat flour and 10% walnut flour was overall best accepted by the panelists during sensory evaluation. High percentage of walnut flour addition (50% wheat flour and 50% walnut flour) affected the appearance of the cake giving it an unattractive dark appearance. Pasting properties data indicates a decreasing level of pasting viscosity (92.69 - 42.30) RI/U, trough (59.19 - 39.60) RVU, breakdown (33.55 — 2.92) RVU, final viscosity (252.09 — 95.51) RI/U, setback (192.85 — 55.93) RVU with increasing level of walnut flour substitution. Physical properties data indicate a decreasing level of height, weight and volume of the cakes (4.99cm — 3.93cm, 134.58g — 86.55g and 196.50cm3— 127.01cm3) respectively with increasing level of walnut substitution in the cakes. Moisture content, weight loss, amylose, soluble starch, and specific volume of the cakes were monitored and were found to be significantly affected when stored at ambient temperature for 5days thereby inducing staling. Moisture, amylose and soluble starch of the cakes decreased each day during the storage studies, the specific volume of the cakes increased while the weight of the cakes reduced each day during the storage studies.