Effect of incorporation of decorticated pigeon pea (Cajanus cajan) protein isolate on functional, baking and sensory characteristics of Wheat (Triticum aesitivum) biscuit

Abstract

This study was undertaken with the objectives of using the decorticated pigeon pea protein isolate in the development of protein rich-biscuit, suitable for general and specific nutritional purposes and to study the effect of incorporation of pigeon pea protein isolate on the sensory evaluation and quality of biscuit produced. Decorticated Pigeon Pea protein Isolate (DPPI) was incorporated in wheat (Triticum aesitivum) flour (WF, extraction rate 72%), for making fortified biscuit. Ratios of DPPI in wheat flour were adjusted to protein levels of 15, 20 and 25%, respectively. Rheological and functional properties as well as proximate composition, nutritive value and sensory characteristics for the biscuit produced were assessed. The gluten quantity (dry and wet) and falling number of wheat flour were significantly (p≤0.05) decreased with the incorporation of DPPI from 10.25 to 7.6%; from 31.2 to 22.5% and from 657 to 443 sec., for 0,15, 20 and 25% protein levels, respectively.Water Retention Capacity (WRC), Bulk Density (BD) and Fat Absorption Capacity (FAC) were obtained. Addition of DPPI resulted in an increase in water absorption which was found to be ranged from 66.7 to 71.0%; dough development time from 4.5 to 7.3 min and dough stability 1.7 to 5.8 min. Biscuit supplemented with DPPI showed significant increase (p≤0.05) in ash, protein with high level of incorporation and significant decrease (p≤0.05) in carbohydrates and caloric values when biscuit wheat was supplemented with high level of DPPI. Incorporation of DPPI showed no significant differences (p≤0.05) on biscuit spread ratios compared to wheat biscuit (control). Biscuit with 15% protein level was found to be superior in all its sensory characteristics compared to the other blends. © Maxwell Scientific Organization, 2012.