Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

IN VITRO EVALUATION OF FUNCTIONAL PROPERTIES OF PROTEIN FROM PIGEON PEA (CAJANUS CAJAN) AND ITS APPLICATIONS IN FOOD

ANMAR NAZAR HASAN, B. VAJIHA AAFRIN AND USHA ANTONY

Abstract

The pigeon pea (Cajanus cajan) contains various proteins, carbohydrates such as starch, fibre, vitamins and minerals. The various functional properties of legume flours are provided by the composition of proteins, starch and complex carbohydrates present in them. Pigeon pea with seed coat (CO6 variety from Tamil Nadu Agricultural University, TNAU) and without seed coat were evaluated for their protein, moisture, ash and fat contents. Protein content of the legume without seed coat was 4.97 and 5.41 mg/mL in water and saline extracts respectively. The protein content of the legume with seed coat (CO6) was higher both in water and saline extracts (5.16 and 5.72 mg/mL in respectively). Pigeon pea with seed coat exhibited higher amount of protein, fat, moisture and ash. Foaming capacity and foam stability of the proteins extracted varied depending upon pH, temperature and fat content. Highest foaming capacity (with seed coat) was observed as 67.8% in water extract when maintained at 25 oC and foam stability (with and without seed coat) was observed as 100% in saline extracts when maintained at -20 oC. While foaming capacity of 55.4% was obtained in the water extract in the full fatted flour, highest foam stability of 100% was obtained in the saline extract of with seed coat when it was de-fatted. Foaming capacity and stability of flour suspensions at pH 2 to 11 varied significantly. Emulsifying activity with corn oil of the water extract was 33.3%, while the saline extracts shown slightly higher value (36.6%). The emulsion stability of water extract of sample with seed coat decreased by 10% and the emulsion stability of saline extract of sample without seed coat increased by 36% respectively after heat treatment. The results of this study demonstrated the potential of Pigeon pea as a good foaming and emulsifying agent. The leguminous protein may act as an alternative for the commercial foam inducers and emulsifiers using in food products.