Phosphorylated protein concentrate pumpkin seed (Cucurbita moschata): optimization by response surface methodology and nutritional characterization

Concentrado proteico fosforilado de semente de abóbora (Cucurbita moschata): otimização pela metodologia de superfície resposta e caracterização nutricional

ABSTRACT:

Response surface methodology was used to determine optimum conditions for extraction of protein from pumpkin seed meal. A central composite rotational design (CCRD) including independent variables such, pH and sodium trimetaphosphate (STMP) content was used. Maximum yield was obtained at a central point of CCRD, with STMP content and pH of 4% and 4.5, respectively. These conditions resulted in protein yield of 50.04 g of soluble protein from extract/100 g pumpkin seed. The optimization of pH and STMP content allowed obtaining a product with a high protein concentration (62.56 g 100 g^-1), digestibility (62.03 g 100 g^-1) and concentration of essential amino acids (27.26 g 100 g^-1). Regarding the polyphenols concentration, phosphorylated protein concentrate from pumpkin seed and the pumpkin seed meal presented 13.11 g 100 g^-1 and 23.19 g 100 g^-1, respectively. The adequacy of the model was confirmed by extracting the protein under optimum values. These results help in designing the process of optimal protein extraction from pumpkin seeds.

Key words:
amino acids; central composite rotational design; in vitro digestibility; new ingredient