羧甲基纤维素钠对绿豆分离蛋白乳液稳定性的影响

Effects of sodium carboxymethyl cellulose on the stability of mung bean protein isolate emulsions

采用添加羧甲基纤维素钠(sodium carboxymethyl cellulose,CMC)的方法来提高绿豆分离蛋白(mung bean protein isolates,MBPI)乳液的稳定性。该文研究了在中性(pH 7.0)和酸性(pH 4.5)条件下,CMC对MBPI乳液的稳定作用及加热对稳定性的影响。结果表明,在pH 7.0条件下,体系出现不同程度的微观相分离,但随着CMC浓度的增加,体系黏度增加,MBPI乳液稳定性增强。在pH 4.5条件下,随着CMC添加量由0增加至0.5%(质量分数),乳液ζ-电位值由5.84 mV降低到-26.87 mV,当CMC用量增加至0.4%时,CMC可有效抑制MBPI乳液在酸性条件下的失稳,液滴平均粒径由33.5μm减小到1.08μm。此外,0.4%CMC稳定的MBPI乳液的稳定性随着加热温度(60~100℃)的增加而降低,但在观测期间,不同温度下处理后的乳液未产生微观相分离和明显的分层现象。结果表明添加CMC改善了MBPI乳液的稳定性。

Sodium carboxymethyl cellulose(CMC)was added to improve the stability of mung bean protein isolate(MBPI)emulsions.The effects of CMC and heating on the stability of MBPI emulsions were studied under neutral(pH 7.0)and acidic(pH 4.5)conditions.The results showed that at pH 7.0,different degrees of microscopic phase separation occurred in the system.However,the viscosity increased and the stability of MBPI emulsions was enhanced with the increase of CMC concentration.At pH 4.5,as the CMC content increased from 0 to 0.5%,the zeta potential of emulsions declined from 5.84 mV to-26.87 mV.When the amount of CMC increased to 0.4%,CMC could effectively inhibit the instability of MBPI emulsions in acidic conditions,and the average particle size of the emulsions decreased from 33.5μm to 1.08μm.Additionally,the stability of MBPI emulsions stabilized by 0.4%CMC decreased with the increase of heating temperatures(60-100℃).However,during the observation period,no microscopic phase separation or obvious emulsion stratification occurred to the emulsions after treatment at different temperatures.The results indicated that adding CMC improved the stability of MBPI emulsions.