单硬脂酸甘油酯对酪蛋白再制稀奶油乳化稳定性的影响

Effect of Glycerin Monostearate on Emulsion Stability of Recombined Dairy Cream Formed with Caseins

分析单硬脂酸甘油酯(glycerin monostearate,GMS)对胶束酪蛋白(micellar casein,MCN)再制稀奶油(recombined dairy creams,RDCs)、酪蛋白酸钙(calcium caseinate,CaC)-RDCs及酪蛋白酸钠(sodium caseinate,NaC)-RDCs乳化稳定性的影响。结果表明:GMS可通过与酪蛋白共同吸附在油水界面上使RDCs的脂肪球分散程度改变,因而乳化稳定性也相应改变。对于MCN-RDCs,GMS可显著增加RDCs的相分离时间,其中2.5%MCN-RDCs的乳化稳定性最大,相分离时间从474 s显著增加至4622 s。CaC-RDCs中,蛋白添加量为0.5%~2.0%时,GMS的添加使CaC-RDCs的相分离时间由167~483 s增加至177~517 s;而2.5%CaC-RDCs的相分离时间有所下降。NaC-RDCs中,GMS的添加使0.5%NaC-RDCs的相分离时间由1245 s增加至1460 s;NaC-RDCs添加量大于1.0%时,相分离时间有不同程度下降。可见,GMS可增加MCN-RDCs的乳化稳定性;而其对CaC-RDCs和NaC-RDCs乳化稳定性的影响与蛋白含量有关,当CaC和NaC添加量分别为0.5%~2.0%、0.5%时,GMS才可增加RDCs体系的乳化稳定性。

This study aimed to analyze the effect of glycerin monostearate(GMS)on the emulsion stability of recombined dairy cream(RDC)formed with micellar casein(MCN),calcium caseinate(CaC)or sodium caseinate(NaC).The results showed that GMS could change the particle size distribution of lipids droplets by co-adsorbing onto the oil-water interface together with caseins and consequently the emulsifying stability of RDC.For MCN-RDC,a significant increase was observed in the phase separation time after GMS addition,and 2.5%MCN-RDC exhibited the best emulsion stability and an increase in the phase separation time from 474 to 4622 s.The phase separation time of 0.5%-2.0%CaC-RDC was in the range of 167-483 s,and increased to 177-517 s after GMS addition,whereas that of 2.5%CaC-RDC decreased slightly.The phase separation time of 0.5%NaC-RDC increased from 1245 s to 1460 s after GMS addition,while that of NaC-RDC with NaC concentration higher than 1.0%decreased.In conclusion,GMS can increase the emulsion stability of MCN-RDC,and its effect on the emulsion stability of CaC-RDC and NaC-RDC differs depending on the concentration of caseins.GMS can increase the emulsion stability of RDC only when the concentrations of CaC and NaC were 0.5%-2.0%and 0.5%,respectively.