Nutritional Composition of Some Unconventional Plant Protein Sources

Abstract

This study was conducted to determine the nutritional composition of some unconventional prótein sources namely, pigeon pea, bambara groundnut, locust bean, sunflower and jack bean. The range of values obtained from the proximate composition of the seeds were; dry matter (94.56-96.64%), crude protein (18.70-28.90% ), crude fat (2.72-23.98% ), crude fibre (5.48- 17.88%), ash (3.36-4.69%) and nitrogen free extract (31.56-59.51%). Among all seeds studied, jack bean had the highest crude protein value of 28.90% while sunflower seed recorded the lowest crude protein value of 18.70%. Results showed that sunflower seed had the highest crude fat content of 23.98% and jack bean recorded the lowest value of 2.72%. Locust bean was the most fibrous with the crude fibre content of 17.88% while the least fibrous among the seeds was bambara groundnut with 5.48% crude fibre value. Locust bean also recorded the highest concentration of ash (4.69%) whereas sunflower seed had the lowest value of 3.36%. Methionine and cystine were the most limiting amino acid for all the seeds analysed. Results revealed that pigeon pea seeds are rich sources of lysine and phenylalanine. Interestingly, locust bean had the highest concentration of leucine as well as isoleucine. In order to ensure food security, people who cannot afford the expensive staple protein food sources can opt for other non-conventional locally available and affordable substitute, in order to avoid protein malnutrition.