脂质自由基诱导氧化对花生蛋白功能特性的影响

Effect of lipid free radical-mediated oxidation on the functional properties of peanut proteins

为探究脂质自由基处理对花生蛋白在食品生产过程中功能特性的影响,该文建立铁/过氧化氢/抗环血酸(Fe/H2O2/Asc)和2,2’-盐酸脒基丙烷(2,2’-azobis (2-amidinopropane) dihydrochloride,AAPH)体系,代表脂质氧化中产生的羟自由基和过氧自由基对花生蛋白进行氧化修饰,研究氧化对花生蛋白羰基、溶解度、乳化性能和起泡性能等功能特性的影响。结果表明,随着两个体系中自由基浓度的增加,花生蛋白的羰基含量分别增加1. 42倍和1. 66倍,溶解度分别下降43. 06%和49. 62%,内源荧光最大吸收波长蓝移,荧光强度分别下降33. 01%和28. 02%,乳化性分别下降63. 91%和28. 91%,乳化稳定性分别下降46. 79%和33. 08%,起泡性及起泡稳定性呈先上升后下降的趋势,起泡稳定性分别在5 mmol/L和0. 5 mmol/L时最高。研究结果表明羟自由基和过氧自由基氧化对花生蛋白的功能特性有较大影响,可通过适度氧化对其性质进行调控。

To explore the effect of the treatment with the lipid free radical on the functional properties of peanut proteins during food production,the hydroxyl radicals generating system( Fe/H2O2/Ascorbate) and peroxy radicals generating system( 2,2’-azobis( 2-amidinopropane) dihydrochloride,AAPH) were established to oxidize the peanut proteins,respectively. The functional properties( carbonyl content,solubility,emulsifying and foaming properties) of oxidized peanut proteins were further studied. The results showed that increase of radical concentration in 2 systems raised the carbonyl derivatives of peanut protein 1. 42 times and 1. 66 times,and the solubility decreased by 43. 06% and 49. 62%,respectively. Fluorescence analysis revealed a blue shift of maximum absorption wavelength,and the fluorescence intensity decreased by 33. 01% and 28. 02%,respectively. In addition,the emulsifying ability decreased by 63. 91% and 28. 91%,respectively,while emulsifying stability decreased by 46. 79% and 33. 08%,respectively. With the increase of free radical concentration,foamability and foaming stability first increased and then decreased. The highest foaming stability was obtained at hydroxyl radical concentration of 5 mmol/L and peroxy radical concentration of 0. 5 mmol/L,respectively. In conclusion,these results imply that the functional properties of peanut proteins are greatly affected by the lipid free radicals,and could be regulated by appropriate oxidation.