Utilization of Pigeon Pea Milling Waste By-product as a Protein Source

The work addresses the environmental concerns attributed to the large
amount of biodegradable agricultural by-products through measures
for its utilization. India is one of the largest producers of pigeon pea in
the world and the seeds are widely consumed as dehulled splits. The
waste by-product obtained during pigeon pea seed processing includes
seed powder, broken seed and seed coat. This underutilized by-product
(20% protein content) has a great potential as a valuable protein
source. The protein extractability studies at different pH conditions
exhibited maximum extractability at both acidic and alkaline
conditions. The protein concentrate (PC) prepared by alkali extraction
had a protein content of 68% whereas the PC prepared under acidic
conditions exhibited 85% protein content, which was used for further
studies. In vitro digestibility studies of pigeon pea protein concentrate
was investigated for its usefulness for human consumption. The
Degree of Hydrolysis (DH) of PC increased during the in-vitro pepsinpancreatin
digestion. The DH reached 21% by 1hr pepsin digestion and
subsequent 2hr pancreatic digestion increased the DH to 50%.
Pepsinolysis of PC was performed to investigate the applicability of
the hydrolysate. SDS-PAGE pattern reveals the partial digestibility of
protein concentrate by pepsin. Pepsin hydrolysed PC exhibited
antioxidant activity which on heating resulted in the formation of a gel.
The gelling ability of pigeon pea PC could be exploited as a proteinbased
carrier system. This suggests the applicability of pepsin
hydrolysate as a functional food material. The food-based materials
can be used as drug/nutraceutical carriers which would be safe for
human consumption compared to synthetic materials. The utilization of
this agricultural by-product as a protein source would indirectly solved the environmental problems caused by the dispersion of agricultural
by-products.