Protein-polysaccharide conjugates are potential carriers to deliver polyphenols such as curcumin in beverages. In this study, the objective was to study properties of casein-alginate conjugates prepared using a transacylation reaction as carriers of curcumin. For encapsulation, 2 mg/mL conjugate was mixed with 0.5, 1.0, or 1.5 mg/mL curcumin at pH 13.0 for 1 h, followed by adjusting pH to 7.0, 4.6, and 3.0 and centrifugation. The treatments had an encapsulation efficiency of about 80%, and the loading capacity of 18–36% was higher than studies using other protein-polysaccharide conjugates. The encapsulation resulted from hydrophobic interactions between curcumin and casein and the capsule dispersions were stable during 30-day storage at 4 °C and with additional 0–500 mM NaCl. Nanoencapsulation did not change the antioxidant activity of curcumin and resulted in 57% bioaccessibility, much higher than <10% of pristine curcumin. This work may be significant to deliver hydrophobic bioactive compounds in functional beverages.

中文翻译：

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通过转酰基反应制备酪蛋白-海藻酸盐缀合物作为姜黄素的新型纳米载体，以增强负载能力、pH 稳定性和生物可及性

蛋白质-多糖缀合物是在饮料中传递姜黄素等多酚的潜在载体。在本研究中，目的是研究使用转酰基反应作为姜黄素载体制备的酪蛋白-海藻酸盐缀合物的特性。为了封装，将 2 mg/mL 缀合物与 0.5、1.0 或 1.5 mg/mL 姜黄素在 pH 13.0 下混合 1 小时，然后将 pH 调节至 7.0、4.6 和 3.0 并离心。该处理的包封率约为 80%，负载能力为 18-36%，高于使用其他蛋白质-多糖缀合物的研究。封装是由姜黄素和酪蛋白之间的疏水相互作用产生的，并且胶囊分散体在 4°C 和额外的 0-500 mM NaCl 下储存 30 天期间保持稳定。纳米封装不会改变姜黄素的抗氧化活性，并且具有 57% 的生物可利用性，远高于原始姜黄素的 <10%。这项工作对于在功能性饮料中传递疏水性生物活性化合物可能具有重要意义。