Abstract: Proteins are essential component of diet performing multifarious role in human body. Present project was an attempt to extract and characterize legumes protein isolates for their utilization in value added food products. Four different legumes i.e. cowpea, pigeon pea, peas and mungbean were evaluated for protein content, functional properties and their ability to improve nutritional quality of foods. Cowpea exhibited maximum protein content followed by mungbean, peas and pigeon pea. As for as functional properties are concerned, legumes protein isolates exhibited desirable characteristics. Moreover, cowpea and peas protein isolates showed significant results regarding biological studies. Overall, cowpea and peas have appealing nitrogen balance and growth potential and can be used up to 10% for the supplementation of cereal based products like bread and cookies..
Problem Statement: To introduce protein sources to cope with protein energy malnutrition in the vulnerable segments.
- To prepare and characterize protein isolates from locally available legumes
- To check the functional properties of the protein isolates, electrophoretic identification and biological assay of the prepared protein isolates
- To determine the acceptability of the baked products supplemented with protein isolates.
Methodology: Firstly, the legumes namely cowpea, mungbean, peas and pigeon pea were analyzed for proximate composition followed by protein extraction. Afterwards, prepared protein isolates were analyzed for functional properties and electrophoretic identification through SDS-PAGE. In order to determine the biological value, trials were conducted on Sprague Dawley rats. In the product development phase cookies and bread were prepared by using different levels of selected protein isolates after studying rheological properties.
Results and Discussions: Proximate composition of legumes explicated that cowpea exhibited maximum protein content 27.88±1.95% followed by mungbean, peas and pigeon pea. As for as functional properties are concerned, cowpea protein isolates showed highest bulk density 0.71±0.05 g/cm3 and maximum protein solubility 82±4.97 was observed in pea protein isolates. Maximum water and oil absorption capacity 163±10.05, 168±11.72% was observed in mungbean and pigeon pea protein isolates, respectively. Likewise, different legumes protein isolates showed significant results for emulsifying, foaming and gelling properties. Electrophoratic identification of tested legumes protein isolates followed almost similar distribution pattern and main components were found in the series of 14.4 to 68kDa. Biological studies showed that cowpea and peas have appealing nitrogen balance and growth potential and can be used for the supplementation of cereal based products like bread and cookies. Different treatments of legumes protein supplemented flours were tested for rheological characteristics. Flour supplemented with 5 and 10% protein isolates showed better performance for the preparation of bread and cookies, respectively.
Conclusion: In the nutshell, legumes tested in the present study are found to be a good source of protein. The extraction of isolates from different legumes by isoelectric point precipitation resulted higher protein yield proving legumes as an excellent source to cope with protein deficiency in vulnerable segments. Cowpea and peas protein isolates showed better bioavailability than rest of the legumes. Conclusively, indigenous resources, feasible extraction procedure, functional properties and biological trials proved legumes as an alternative source to enrich array of foods.
- Legumes especially cowpea and peas should be incorporated in cereal based value added products.
- Protein enriched cookies and bread should be introduced in the vulnerable segments to cope with the protein energy malnutrition.
- Government should focus on the low income population of the country for the provision of quality protein supplemented foods as per recommendations of FAO/WHO