臭氧处理对蛋清粉脱腥效果及改善机制

Deodorization of Egg White Powder by Ozone Treatment and Underlying Mechanism

本研究探究不同臭氧处理时间(0、10、20、30、40、50 min)对蛋清粉脱腥效果及其机制的影响。结果表明,与未处理组(0 min)相比,臭氧处理导致蛋清粉中的特征腥味物质(香叶基丙酮、1-辛烯-3-醇、辛醛和壬醛)含量下降40.94%以上,感官腥味在20 min时达到最低值(降低75%);此时,蛋清蛋白处于轻度氧化,蛋白结构展开趋于无序,羰基含量增加,内源荧光强度降低,粒径增大。此外,荧光猝灭和分子对接分析结果表明,蛋清蛋白与腥味物质结合的主要作用力为疏水相互作用,主要结合在由Leu66、Lys69、Glu87E、Ala87F、Cys87H、Glu129、Tyr130、Cys133、Gly320等氨基酸组成的疏水空腔中。臭氧处理20 min时,蛋清蛋白-腥味物质作用力与未处理组相比降低45.98%,释放腥味物质,感官腥味降低,从而达到脱腥的目的。综上,臭氧处理可以显著降低蛋清粉的腥味,处理20 min脱腥效果最好。

This study investigated the effects of different ozone treatment times(0,10,20,30,40,and 50 min)on off-flavor removal from egg white powder(EWP)and the underlying mechanism.Results showed that compared with the untreated group(0 min),ozone treatment reduced the contents of the characteristic off-flavor substances(geranyl acetone,1-octen-3-ol,octanal,and nonanal)in EWP by more than 40.94%.The sensory off-flavor score reached its lowest point(which decreased by 75%compared with the untreated group)after 20 min of ozone treatment,when egg white protein was slightly oxidized,leading to protein unfolding and structural disordering,increased carbonyl content and particle size,and decreased endogenous fluorescence intensity.In addition,fluorescence quenching and molecular docking showed that the major binding force between egg white protein and off-flavor substances was hydrophobic interaction,and their main binding sites were in a hydrophobic cavity composed of amino acids such as Leu66,Lys69,Glu87E,Ala87F,Cys87H,Glu129,Tyr130,Cys133,and Gly320.Ozone treatment for 20 min reduced the hydrophobic interaction between egg white protein and off-flavor substances by 45.98%compared with the untreated group,releasing off-flavor substances and reducing sensory off-flavor score, thereby ultimately deodorizing EWP. In conclusion, ozone treatment can reduce the off-flavor of EWP, themost pronounced effect being observed after 20 min treatment.