Effect of oxidative modification by malondialdehyde on functional properties of rice protein

Fresh indica rice which oxidatively modified by different concentration of malondialdehyde were used as material to investigate effects of oxidative modification by malondialdehyde on functional properties of indica rice protein. The results indicated that as concentration of malondialdehyde increased,content of rice protein carbonyl and disulfide increased,and content of free sulphydryl decreased,which indicated that incubation of malondialdehyde with rice protein resulted in oxidation of rice protein. As concentration of malondialdehyde increased from 0 to 100 mmol/L,solubility of rice protein decreased from 28.88% to 12.20%,water holding capacity of rice protein decreased from 353.67% to 132.33%,oil-absorbing capacity of rice protein decreased from 89.40% to 189.40%,foaming capacity and foam stability of rice protein decreased from 74.27% and54.06% to 57.56% and 38.01%,respectively,emulsification and emulsion stability of rice protein decreased from55.32 m2/g and 97.59 min to 45.13 m2/g and 75.29 min,respectively. The results indicated that oxidative modification by malondialdehyde had a negative effect on function properties of rice protein. The results provided effective basis for further improve the functional properties of rice protein.