Physicochemical and barrier properties of edible films based on protein isolated from grass pea (Lathyrus sativus) using response surface methodology

Legumes are rich sources of protein and consider a good alternative to make a protein films. In this study, central composite design to investigate the simultaneously effect of the grasspea protein isolates (2 - 10 percent), glycerol (0.5 - 7%) and oleic acid (0 - 2%) on properties of edible films made from grasspea protein isolates, such as thickness, density, percentage of solubility in water, acid and alkaline, and permeability to water vapor and oxygen were used. The result shows that increasing protein and glycerol concentrations were significantly increased water vapor permeability and increasing in concentrations of oleic acid decreased it signifcantly. Solubility in water and acid by increasing the protein content decreased and with increasing glycerol and oleic acid increased (P<0.05). Optimization results of edible films made from green pea protein isolates showed that for an optimal film that have minimum thickness with 0.087 mm, minimum equal density 697.486 (kg.m-3), Least equal to the water vapor permeability 1.42× 10-9 (g. m-1.pa-1.s-1), least permeability to oxygen (peroxide value), equivalent to 24.72, maximum solubility in water and acid, respectively, 53.52% and 46.64 percent, Parameters the green pea protein isolate concentration 2.46 percent, glycerol concentration 0.5 percent and oleic acid concentration had to 0.087 percent.