Production of gallic and glutamic acid-rich extract from Albertisia Papuana Becc leaves using Tannase in various pH and temperature hydrolysis

The Dayak’s Tribes in West Kalimantan of Indonesia uses the leaves of san-sangk ( Albertisia papuana Becc.) as one of the seasoning ingredients. The leaves are known to contain gallic and glutamic acid, which are important chemical compounds for human health. Various extraction methods using solvents have been used to produce gallic and glutamic acid. Commercially, fermentation methods are preferred to use tannase from microbial for hydrolysis of tannins to produce gallic acid with glutamic acid as a by-product. Enzyme activity is strongly influenced by the condition of its enzymatic process conditions, especially pH and temperature. Therefore, the conditions of the research are carried out at certain pH and temperature conditions. The purpose of this research is to find conditions of hydrolysis to produce a crude extract which is rich in gallic acid and glutamic acid using commercial tannase. The research was applied factorial design, combination between the temperature (30; 35; 40°C) and pH (5; 5.5; 6). The observed variables: yield, total phenolic (as mg GAE/g) and total free amino acids (as glutamic acid). The results showed that the combination of temperature and pH affected the yield, total free amino acids and total phenolic. The highest yield and total phenolic, produced from incubation at 35°C and pH 5 and the highest total free amino acids which produced at 35°C and pH 6.0. This is important to explain that A. papuana Becc. leaves is very potential to be developed using enzyme hydrolysis to produce of gallic acid and glutamic acid.