超声波处理对酪蛋白酸钠-大豆油预乳化液乳化稳定性的影响

Effect of Ultrasound Treatment on the Emulsion Stability of Pre-emulsified Soybean Oil with Sodium Caseinate

为改善预乳化液的乳化稳定性,本研究应用超声波技术制备酪蛋白酸钠-大豆油预乳化液,研究不同时间(0、3、6、9、12 min)超声波处理(20 kHz,450 W)对预乳化液的p H值、电导率、乳液分层指数、液滴粒度分布和平均粒径大小以及黏度的影响。结果表明,不同超声波处理时间对酪蛋白酸钠-大豆油预乳化液p H值和电导率没有显著影响(P>0.05)。在0 h时,各超声波处理组和对照组的乳析率差异不显著(P>0.05),在贮藏12、24、36 h时,各超声波处理组的乳析率显著低于对照组(P<0.05)。超声波时间对预乳化液的粒径分布范围和粒径大小影响显著(P<0.05),随着超声波时间的延长,D_(4,3)、D_(3,2)和D_(50)显著变小(P<0.05)。在剪切速率0.1 s^(-1)时,超声波时间对酪蛋白酸钠-植物油预乳化液的黏度有显著影响,各组超声波预乳化液的黏度均显著高于对照组(P<0.05)。因此,应用超声波处理酪蛋白酸钠-大豆油预乳化液,可以延长贮藏期,减小乳化液粒径,提高黏度,有效改善乳化稳定性。

The objective of this study was to use ultrasound treatment to improve the emulsion stability of pre-emulsified soybean oil with sodium caseinate. The effect of ultrasound irradiation at 20 kHz and 450 W for different times (0, 3, 6, 9 and 12 min) on pH, conductivity, creaming index, mean droplet diameters and size distribution and viscosity of preemulsified soybean oil was investigated. Our results illustrated that there was no significant difference in pH or conductivity among all treatment groups (P > 0.05). All treatment groups showed no significant difference in terms of creaming index at 0 h of storage (P > 0.05); however, they were significantly lower than the control at 12, 24 and 36 h (P < 0.05). With prolonged ultrasound irradiation, D4,3, D3,2 and D50 of soybean oil emulsion droplets decreased, and viscosity at a shear rate of 0.1 s-1 increased significantly (P < 0.05). These findings showed that the application of ultrasound treatment to pre-emulsified soybean oil with sodium caseinate could extend the storage period, reduce the particle size, increase the viscosity, and thus improve the emulsion stability.