BACKGROUND Microalgae are a promising alternative source to meet the increasing global demand for protein. The insoluble microalgae protein fraction which makes up over half of the protein composition of the biomass has shown potential to serve as a functional emulsifier after acidic hydrolysis. However, creaming was observed due to the flocculation of emulsion droplets suggesting a preferred use in concentrated emulsions. RESULTS In this study, we thus examined the emulsifying behaviour of the untreated insoluble microalgae protein fraction and two of their hydrolysates [obtained in 0.5 M HCl for 4 h at 65 °C (Hydrolysates 65) or 85 °C (Hydrolysates 85)] at a concentration of 3% (w/w), and elevated levels of oil (50% - 70%). Results showed an increase in droplet size and apparent viscosity with increasing oil contents in the emulsions. The emulsions made with Hydrolysates 85 had the smallest droplet size and the highest apparent viscosity. The gravitational separation was hindered when oil content was increased. The Hydrolysates 85-stabilized emulsions had a gel-like structure and were stable against coalescence or creaming during a 7-day storage test. CONCLUSION Results suggest that the thermal acid-treated fraction Hydrolysates 85 may, in particular, be a good emulsifier to formulate concentrated emulsion-based foods at oil contents over 50%, such as mayonnaise, salad dressings or dips. This article is protected by copyright. All rights reserved.

中文翻译：

---

原壳小球藻酸水解不溶性微藻蛋白制备浓缩乳剂的行为

背景微藻是满足日益增长的全球蛋白质需求的有前途的替代来源。占生物质蛋白质组成一半以上的不溶性微藻蛋白质部分已显示出在酸性水解后用作功能性乳化剂的潜力。然而，由于乳液液滴的絮凝而观察到乳状液，这表明优选用于浓缩乳液。结果 在本研究中，我们因此检查了未处理的不溶性微藻蛋白级分及其两种水解产物的乳化行为 [在 0.5 M HCl 中在 65 °C（水解产物 65）或 85 °C（水解产物 85）中获得 4 小时] 3% (w/w) 的浓度，以及高水平的油 (50% - 70%)。结果表明，随着乳液中油含量的增加，液滴尺寸和表观粘度增加。用水解物 85 制成的乳液具有最小的液滴尺寸和最高的表观粘度。当含油量增加时，重力分离受到阻碍。Hydrolysates 85 稳定的乳液具有凝胶状结构，并且在 7 天的储存测试期间对聚结或乳脂化是稳定的。结论 结果表明，经过热酸处理的馏分水解物 85 尤其可以作为一种良好的乳化剂，用于配制油含量超过 50% 的浓缩乳液类食品，例如蛋黄酱、沙拉酱或蘸酱。本文受版权保护。版权所有。Hydrolysates 85 稳定的乳液具有凝胶状结构，并且在 7 天的储存测试期间对聚结或乳脂化是稳定的。结论 结果表明，经过热酸处理的馏分水解物 85 尤其可以作为一种良好的乳化剂，用于配制油含量超过 50% 的浓缩乳液类食品，例如蛋黄酱、沙拉酱或蘸酱。本文受版权保护。版权所有。Hydrolysates 85 稳定的乳液具有凝胶状结构，并且在 7 天的储存测试期间对聚结或乳脂化是稳定的。结论 结果表明，经过热酸处理的馏分水解物 85 尤其可以作为一种良好的乳化剂，用于配制油含量超过 50% 的浓缩乳液类食品，例如蛋黄酱、沙拉酱或蘸酱。本文受版权保护。版权所有。