Enzymatic Acylation of Cranberry (Vaccinium macrocarpon Aiton) Anthocyanins with Fatty Acid: Improvement of Stability, Lipophilicity, and Antioxidant Capacity.

The crude anthocyanin extract isolated from cranberry (Vaccinium macrocarpon Aiton) was enzymatically acylated with fatty acids of varying chain lengths using Novozyme 435 (Candida antarctica lipase B immobilized on acrylic resin). After optimization, the highest acylation rates of 65.72% and 70.64% for cyanidin-3-O-galactoside and peonidin-3-O-galactoside, respectively, were obtained by acylating with octanoic acid under the conditions of lipase dosage of 10 mg/mL, molar ratio of 1:418, at 50 °C for 30 h in 2-methyl-2-butanol. Acylated anthocyanins with high purity (>97%) were obtained through liquid-liquid extraction and medium-pressure liquid chromatography and identified as cyanidin-3-O-(6″-octanoyl) galactoside and peonidin-3-O-(6″-octanoyl) galactoside by MS/MS and 2D NMR. The acylated cranberry anthocyanins exhibited enhanced lipophilicity, photostability, thermostability, and excellent antioxidant activity in both aqueous and lipid systems. These findings demonstrate enzymatic acylation in a crude anthocyanin matrix and provide insights into acylation-induced structure-property relationships, supporting the rational development of functionalized anthocyanins from natural extracts.