Control of foodborne pathogenic and spoilage bacteria by garcinol and Garcinia indica extracts, and their antioxidant activity

Spent rinds of Garcinia indica were extracted with hexane and benzene using a Soxhlet extractor for 4 h. The major compound present in both extracts was found to be garcinol, as confirmed by fractionation and spectroscopic studies. The minimum inhibitory concentrations of hexane extract, benzene extract, and garcinol against a few Gram-positive and Gram-negative bacteria were in the range of 15 to 1000, 20 to 1250, and 1.5 to 500 ppm, respectively. The antioxidant activity of these fractions at 25 ppm was 63.2%, 61.7%, and 92.4%, respectively, as evaluated by the 1,1-diphenyl-2-picrylhydrazyl method. Hexane extract, benzene extract, and garcinol showed 1027, 985.5, and 1195.9 mumol/g of ascorbic acid equivalents, respectively, at 100 ppm concentration using the phosphomolybdenum method. These findings may be useful for possible application of the previously described fractions as biopreservatives.