Production of γ- Aminobutyric Acid (GABA) by Monascus Purpureus isolated from Angkak, a mold isolated from Angkak in Semarang, Indonesia

Abstract

Angkak is a rice fermented product that has red colour because of the presence of Monascus sp. This product has long been used as a food colouring and traditional medicine, especially in Asian countries including Indonesia. Angkak is also commercialized in Semarang and used as a medicine for dengue fever. Monascus purpureus is a common mold obtained from Angkak marketed in Semarang. In addition to producing pigments for food, Monascus sp. can synthesize lovastatin or monacolin-K which could reduce blood cholesterol levels also produce γ-aminobutyric acid (GABA) which has physiological functions, such as neurotransmitters. This study aimed to determine the production of GABA produced by Monascus purpureus isolated from commercial Angkak in Semarang. M. purpureus was grown in broth medium (Potato Dextrose Broth) for 14 days in 28°C, and regularly measured the pigment concentration and GABA content every 6 days. The mould was also cultivated in rice solid medium (IR42) for 30 days to measure GABA concentration. The result showed that extracellular pigments were yellow and red with concentration for about 37,358 U/g and 2.6545 U/g, respectively. While intracellular pigment stored in mycelia, the yellow pigment had the highest concentration (30.176 U/g) followed by yellow pigment (7.1475 U/g). GABA content obtained from a broth culture of M. purpureus, Angkak from M. purpureus and commercial Angkak were 0.0796 mg/mL, 0.0332 mg/mL and 0.0203 mg/mL, respectively.