Rheological properties and gel strength of Phaseolus lunatus protein/carboxymethylated flamboyant gum systems

摘要

The rheological behaviour and gel strength of hydrocolloid mixture systems (HMSs) of carboxymethylat-ed flamboyant gum (CFG) with protein hydrolysates (PHs) of Phaseolus lunatus were examined to evaluate the influence of the protein/polysaccharide ratio (2:1 and 3:1), pH (3 and 9) and concentration of solids, according to a 2~3 factorial design. The protein concentrate of P. lunatus was hydrolysed with pep-sin-pancreatin enzymes. The flow curve results were fitted to the Ostwald-de Waele model. The flow behaviour index (0.66-0.78) for all conditions studied was indicative of the shear-thinning behaviour. For the HMS, the consistency index (k) values ranged from 0.4 Pa s~n to 1.2 Pa s~n. The analyses of variance showed that the ratio of PH/CFG and pH were the main variables that had significant effect on k values (P ＜ 0.05). Only PH system presented a weak gel-like viscoelastic behaviour. Both functional properties were affected by the protein degree of hydrolysis (DH).