One of the functional proteins in rapeseed—the amphiphilic protein oleosin—could be used to stabilize emulsions. The objectives of this study were to extract oleosins from cold-pressed rapeseed press-cake, optimize the extraction process, and investigate their emulsifying and anti-oxidative capacity. The proteins were recovered from industrially cold-pressed rapeseed press-cake at different alkali pHs. Emulsifying properties and oxidation rates were assessed. Oleosin extracted at pH 9 stabilized smaller emulsion droplets than oleosin extracted at pH 12, although the protein yield was higher at pH 12. Emulsions were formulated from flaxseed oil and corn oil and were stabilized by oleosin, bovine serum albumin, de-oiled lecithin and Tween 20,h and the emulsions were stored in accelerated conditions (30 °C) for 12 days. Oleosin stabilized emulsions to the same extent as commercial food-grade emulsifiers. Flaxseed oil emulsions stabilized by oleosin had a significantly lower concentration of malondialdehyde (MDA) which indicates a lower oxidation rate compared to BSA, de-oiled lecithin and Tween 20. For corn oil emulsions, oleosin and BSA had a similar capacity to delay oxidation and were significantly more efficient compared to de-oiled lecithin and Tween 20. Rapeseed oleosin recovered from cold-pressed rapeseed press-cake could be a suitable natural emulsifier with anti-oxidation properties.

中文翻译：

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从工业冷榨油菜籽压榨蛋糕中提取的蛋白质的乳化和抗氧化性能。

油菜籽中的一种功能性蛋白质-两亲性蛋白质油质蛋白-可用于稳定乳剂。这项研究的目的是从冷榨油菜籽饼中提取油质蛋白，优化提取工艺，并研究其乳化和抗氧化能力。从工业冷压的菜籽压榨饼中在不同的碱性pH值下回收蛋白质。评估了乳化性能和氧化速率。pH 9萃取的油质蛋白比pH 12萃取的油质蛋白稳定的乳液液滴更小，尽管在pH 12时蛋白产量更高。乳液由亚麻籽油和玉米油配制而成，并由油质蛋白，牛血清白蛋白，脱油卵磷脂和将吐温20，h和乳液在加速条件下（30°C）保存12天。油脂蛋白稳定的乳液的程度与食品级乳化剂相同。用油质蛋白稳定的亚麻籽油乳液的丙二醛（MDA）浓度要低得多，这表明与BSA，脱油卵磷脂和Tween 20相比，氧化速率较低。对于玉米油乳液，油质蛋白和BSA具有相似的延迟氧化能力和与脱油的卵磷脂和Tween 20相比，它们的效率要高得多。从冷压的菜籽压榨饼中回收的菜籽油质蛋白可能是具有抗氧化性能的合适天然乳化剂。