橄榄油与椰子油混油基对类蛋黄酱乳液流变及冻融稳定性的影响

Rheology and freeze-thaw stability of mayonnaise-like emulsion based on olive oil/coconut oil blends

以类蛋黄酱体系为研究对象,运用Turbiscan、流变仪、粒度仪、显微镜研究在pH 3条件下橄榄油与椰子油不同比例复配(10∶0、9∶1、8∶2、7∶3)的混油基对于乳清分离蛋白-蛋黄卵磷脂稳定的乳液体系流变性质及冻融稳定性的影响。结果表明:随着椰子油比例增加,乳液黏度增加,弹性模量增加,橄榄油与椰子油质量比7∶3复配混油基制得的乳液具有最大的黏度和最高的弹性模量;所有乳液在4~40℃弹性模量下降,说明乳液在贮存、冷藏运输过程中内部结构完整,乳液具有良好的稳定性;蛋黄卵磷脂能够提高含椰子油(饱和脂肪酸含量高)乳液的冻融稳定性,并且椰子油比例越大(饱和程度越高),冻融稳定性提高效果越好;乳液冻融稳定性从高到低依次为橄榄油与椰子油质量比为7∶3>8∶2>9∶1>10∶0。

With the mayonnaise-like system as the object, the effects of different ratio of olive oil to coconut oil(10∶0,9∶1,8∶2,7∶3) on rheology properties and freeze-thaw stability of whey protein isolate-egg yolk lecithin stabilized emulsion system at pH 3 were studied by Turbiscan, rheometer, particle size analyzer and microscope. The results showed that the viscosity and the elastic modulus(G′) of the emulsion increased as the increase of coconut oil proportion. The emulsions made from olive oil and coconut oil in a mass ratio of 7∶3 had the largest viscosity and the highest elastic modulus. All emulsion samples had a declined elastic modulus(G′) at 4-40℃, which indicated that the emulsion with a complete internal structure had a good stability during refrigerated transportation and storage. Egg yolk lecithin could improve the freeze-thaw stability of emulsions containing coconut oil(high content of saturated fatty acids), with the proportion of coconut oil(high saturation degree) increased, the freeze-thaw stability of the emulsion improved. As a result, the freeze-thaw stability of emulsion made from olive oil and coconut oil from high to low was mass ratio of 7∶3,8∶2,9∶1,10∶0.