Phenolic Biotransformations during Conversion of Ferulic Acid to Vanillin by Lactic Acid Bacteria

Baljinder Kaur,Balvir Kumar,Debkumar Chakraborty

doi:10.1155/2013/590359

Abstract

Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB), and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel of LAB isolates for their ability to release phenolics from agrowaste materials like rice bran and their biotransformation to industrially important compounds such as ferulic acid, 4-ethyl phenol, vanillic acid, vanillin, and vanillyl alcohol. Bacterial isolates were evaluated using ferulic acid esterase, ferulic acid decarboxylase, and vanillin dehydrogenase assays. This work highlights the importance of lactic acid bacteria in phenolic biotransformations for the development of food grade flavours and additives.

Highlights

Vanillin is the most widely used flavor compound in the food industry
ferulic acid (FA) is present as ester-linked dehydrodimers in wheat bran, which can be released by ferulic acid esterase (FAE) enzyme activity by Streptomyces sp. [16]
Out of nine lactic acid bacteria (LAB) isolates, three bacterial strains were selected on the basis of specific FAE activity (Table 1)

Summary

Introduction

Vanillin is the most widely used flavor compound in the food industry. Because of the scarcity and higher cost of natural vanilla extract, there has long been interest in the biotechnological preparation of vanillin. Degradation of FA to other metabolic products like 4-vinyl guaiacol (4-VG) and 4-ethyl phenol (4-EP) reported previously in many strains of lactic acid bacteria (LAB) by decarboxylase enzyme is a major obstacle in their industrial implementation [4]. Vanillin which is a phenolic aldehyde shows toxic effect on the microbes and gets reduced spontaneously to less toxic intermediates like alcohol (vanillyl alcohol) or acid (vanillic acid). This metabolic degradation could interfere with vanillin production by reducing its amount in the biotransforming media, which has been previously reported by many scientists [5]

Methods

Results

Conclusion