Synthesis of propyl gallate by transesterification of tannic acid in aqueous media catalysed by immobilised derivatives of tannase from Lactobacillus plantarum

• Published in: Food chemistry 2011-09, Vol.128 (1), p.214-217
• Main Authors: Fernandez-Lorente, Gloria, Bolivar, Juan Manuel, Rocha-Martin, Javier, Curiel, Jose A., Muñoz, Rosario, de las Rivas, Blanca, Carrascosa, Alfonso V., Guisan, Jose M.
• Format: Article
• Language: English
• Subjects: 1-Propanol; Biological and medical sciences; Food industries; Food microbiology; Food plants; Fundamental and applied biological sciences. Psychology; Lactobacillus plantarum; Natural antioxidants; Transesterifications in aqueous media
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2011.02.057

► Enzymatic conversion of tannic acid into propyl gallate. ► An enzymatic transesterification in 70% of water is reported. ► Synthesis of pure propyl gallate with pure gallic acid as by-product. ► Utilisation of immobilised–stabilised tannase as catalyst. Immobilised derivatives of tannase from Lactobacillus plantarum were able to catalyse the transesterification of tannic acid by using moderate concentrations of 1-propanol in aqueous media. Transesterification of tannic acid was very similar to transesterification of methyl gallate. The synthetic yield depended on the pH and concentration of 1-propanol, although it did not vary much when using 30% or 50% 1-propanol. Synthetic yields of 45% were obtained with 30% of 1-propanol at pH 5.0. The product was chromatographically pure, and the reaction by-product was 55% pure gallic acid. On the other hand, immobilised tannase was fairly stable under optimal reaction conditions.