The influence of rice protein content and mixed stabilizers on textural and rheological properties of jasmine rice pudding

Abstract

Jasmine rice flour containing unique fragrance is a preferred choice to improve the rice pudding flavor and texture. A substitution of rice grain and egg with the jasmine rice flour (high and low protein content: 7.70% HPJF and 3.54% LPJF, respectively) and with mixed stabilizers, respectively in the pudding was evaluated. Mixed stabilizers (KHPS and KOSA) composed of κ-carrageenan (K) at 0.25, 0.50 and 1.00% with hydroxypropyl starch (HPS) or octenyl succinic anhydride starch (OSA) were used for egg substitution by controlling the total solid content at the same level as in the egg. The puddings were randomly checked for textural and rheological properties at day 0 to day 6. The hardness and stability of all puddings egg-substituted by mixed stabilizers increased significantly when compared with the egg formula. As a function of time, the hardness, gumminess, and chewiness of LPJF-puddings were higher than those of HPJF-puddings, attributed to the protein content and gelation of starch granules in the flour. OSA gave higher values than HPS via a possible electrostatic interaction with K. All puddings behaved like a weak gel with G′ > G″ in all studied frequencies. G′' and G″ of LPJF-puddings increased as the storage time increased while those of HPJF-puddings were constant. The mixed stabilizers and their concentration could enhance the harder texture and more stable structure, especially in the LPJF puddings. The microstructures of LPJF gel were finer and showed a tighter cluster but less void spaces than those of HPJF gel, resulting in the harder texture and more stable structure. Thus, the integrated effect of protein content and the concentration of mixed stabilizers resulted in a different textural and rheological properties of the puddings that could be adopted in the pudding production to achieve the specific attributes.