Abstract
Groundnut cake (GNC) and soybean cake (SBC) by-product of agriculture industry had protein and protein digestibility in the range of 42.7–50.5 and 71.3–76.8%, respectively. Polyphenols present in GNC and SBC were cholorogenic acid, syringic acid and p-coumaric acid. The number of bands separated in soybean meal was greater than the bands observed in GNC flour as seen in SDS–PAGE pattern, respectively. SEM of groundnut flour showed distension of protein bodies due to roasting of the oil cakes. The water absorption of wheat flour GNC blends decreased from 59.2 to 57.3% and increased in wheat flour SBC blends from 59.2 to 68.3% with an increase in oil cake from 0 to 20%. With increase in either GNC or SBC, the biscuits became harder. Addition of glycerol monostearate and sodium stearoyl lactylate in combination with 20% blend of GNC/SBC decreased the breaking strength values and increased the sensory parameters of the biscuits. Nutritionally rich biscuits were thus prepared by incorporating GNC/SBC.
Acknowledgements
The authors are greatful to Mr Lokesh, Central Instruments Facility Services, CFTRI, Mysore, for his help in carrying out colour parameters. The authors are also greatly thankful to Mr Anbalagan, Central Instruments Facility Services, CFTRI, Mysore, for his help in carrying out scanning electron microscopy.