Abstract Natural emulsifiers have become of increasing interest within the food and beverage industry. Oat bran is a natural side-stream product produced during oat refinement that may be used to obtain amphiphilic extracts. Our hypothesis was that the oat bran extract is rich in surface-active and amphiphilic oat saponins and proteins that can form and stabilize emulsions. For this, we examined the surface activity of oat bran extract at oil-water and air-water interfaces, its ability to form oil-in-water emulsions and their stability against various stress tests. The highly surface-active oat bran extract acted as an ionic emulsifier, forming highly negatively charged submicron-sized emulsion droplets. These emulsions were stable over a wide range of pH (4–9), heat treatment (≤50 °C), and during storage at ≤25 °C up to 42 days. However, the emulsions showed instability at pH 2–3, at high ionic strengths, and during freeze-thawing. The formation and stability of the emulsions is related to interfaces containing oat saponins or oat saponin-protein complexes rather than a protein layer. These findings show that oat bran extract is a highly promising natural emulsifier, providing the food and beverage industry with a viable substitute to traditional emulsifiers.

中文翻译：

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来自食品副产品流的燕麦麸提取物 (Avena sativa L.) 作为新的天然乳化剂

摘要 天然乳化剂在食品和饮料行业越来越受到关注。燕麦麸是在燕麦精炼过程中产生的一种天然副产品，可用于获得两亲提取物。我们的假设是燕麦麸提取物富含表面活性和两亲性燕麦皂苷和蛋白质，可以形成和稳定乳液。为此，我们检查了燕麦麸提取物在油-水和空气-水界面的表面活性、其形成水包油乳液的能力及其对各种压力测试的稳定性。高度表面活性的燕麦麸提取物充当离子乳化剂，形成带高度负电荷的亚微米大小的乳液液滴。这些乳液在很宽的 pH 值 (4-9) 范围内、热处理 (≤50 °C) 以及在≤25 °C 下储存长达 42 天期间都是稳定的。然而，乳液在 pH 2-3、高离子强度和冻融过程中表现出不稳定性。乳液的形成和稳定性与含有燕麦皂苷或燕麦皂苷-蛋白质复合物的界面有关，而不是与蛋白质层有关。这些发现表明，燕麦麸提取物是一种很有前途的天然乳化剂，为食品和饮料行业提供了传统乳化剂的可行替代品。