[关键词]
[摘要]
本文以1% m/V浓度的大豆分离蛋白和乳清浓缩蛋白为材料,对蛋白热处理形成颗粒后制备油分数为0.4的水包油型Pickering乳液,未加热处理的蛋白和酪蛋白酸钠稳定乳液作为对照。将不同蛋白稳定的乳液在-20 ℃冷冻24 h随后在30 ℃恒温箱解冻3 h,如此冷冻-解冻处理循环三次,探讨未加热处理的活性蛋白和热诱导形成的蛋白颗粒稳定乳液的冻融稳定性,包括新鲜制备和每次冻融之后乳液的乳滴粒径分布、聚结和絮凝程度、乳液分层和脂肪上浮情况、以及乳液的光学显微结构。结果表明冷冻乳液融化时不可避免的被部分破坏,而大豆分离蛋白热诱导聚集颗粒稳定的Pickering乳液具有优良的冻融稳定性,这可能为一些水包油乳液型冷冻食品、热敏性生物活性物质和低温储存药品的制备和研发提供一条有效的技术途径。
[Key word]
[Abstract]
Soy protein isolate (SPI) (1% m/V) and whey protein concentrate (WPC) (1% m/V) were used as the test materials in this study. Protein particles formed from heat treatment were used to prepare an oil-in-water Pickering emulsion with an oil volume fraction of 0.4, and native SPI, WPC, or sodium caseinate (SC)-stabilized emulsions were employed as controls. The emulsions stabilized by native proteins and protein particles were stored at -20 ℃ for 24 h and then thawed at 30 ℃ for 3 h in an incubator; this freeze-thaw cycle was repeated three times. The freeze-thaw stability of the emulsions stabilized by the native proteins and protein particles was investigated, including the droplet size distribution, degree of coalescence and flocculation, creaming index, situation of oil floating, microstructure of the fresh emulsion, and emulsions after each freeze-thaw cycle. The results showed that part of the emulsions was inevitably damaged during the thawing process, while the Pickering emulsion stabilized by the SPI particles that were produced from heat-induced aggregation had excellent freeze-thaw stability. This result may provide an effective technical approach for the study and development of some oil-in-water emulsions frozen foods, heat-sensitive bioactive substances, and medicines requiring storage at low temperature.
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[基金项目]
国家自然科学基金资助项目(31471695)