The effects of phosphorylation modification on the structure, interactions and rheological properties of rice glutelin during heat treatment.

Rice glutelin (RG) and phosphorylated rice glutelin (PPRG) were treated with heating for different time (15, 30, and 45 min), the effects of phosphorylation modification on the structure, interactions and rheological properties of rice glutelin during heat treatment were investigated. The results showed that the turbidity of PPRG samples were higher than those of RG samples after heating. Particle size distribution showed that the protein aggregates with particle size of 1000-1500 nm were formed after heating for 45 min. Changes in protein structure indicated that the protein unfolded after heating for a short time, and aggregated when heating time extended to 45 min. In addition, the microstructure of PPRG sample became tight when heated for 45 min. Rheological analysis showed that phosphorylation modification and heat treatment improved RG viscoelasticity. These results suggest that phosphorylation modification improves thermal aggregation of RG, which will facilitate the application of RG in food industry.