Inhibition of growth and aflatoxin production in Aspergillus flavus by Garcinia indica extract and its antioxidant activity

Garcinia is a large genus of polygamous trees or shrubs, distributed in the tropical Asia, Africa and Polynesia and is a rich source of bioactive molecules including xanthones, flavonoids, benzophenones, lactones and phenolic acids. In the present study, an attempt was made to evaluate the antimicrobial and antioxidant properties of Garcinia sp. Concentrated and vacuum dried chloroform extract of rinds of Garcinia indica was tested for the inhibition of Aspergillus flavus and aflatoxin B 1 production using peanut powder as a model food system. Aflatoxin B 1 was estimated by Spectrofluorophotometric and thin layer chromatographic methods. At lower concentrations of G. indica extract (500–1000 ppm), the relative aflatoxin inhibition was much higher than the growth inhibition. At 3000 ppm the aflatoxin production was completely inhibited, which was taken as the minimum inhibitory concentration. The antioxidant activity (AA) of G. indica extract was evaluated using β-carotene-linoleate and 1,1-diphenyl-2-picryl hydrazyl (DPPH) model systems. G. indica extract showed 53% and 78% AA at 50 ppm concentration in β-carotene-linoleate and DPPH model systems, respectively. The major compound present in the extract was found to be garcinol as confirmed by fractionation using silica gel chromatography and spectroscopic studies. The G. indica extract has both antifungal and antioxidant properties and has a potential for use as a biopreservative in food applications and neutraceuticals.