The present study investigates the antimicrobial and preservative potentials of turmeric extracts for food industry. Turmeric extracts prepared in n-hexane, water, chloroform and ethanol were applied to meals as preservatives and antibacterial agent. The samples were assessed microbiologically (total bacterial, total fungal and total coliform counts) and organoleptically (color, odor, taste) at day zero and after 15 days intervals. Meals autoclaved for shorter time (5 min) and treated with combination of 1 % or 2 % turmeric extract preserved for longer period. These results were comparable with samples autoclaved for longer period (15 min) with out turmeric extract. The antibacterial activities of different turmeric extracts were also tested against Escherichia coli, Staphylococcus aureus, Salmonella typhi and Candida albicans by disc diffusion method. Water extracted samples of turmeric stored at room temperature inhibited the growth of Escherichia coli and Salmonella typhi while aqueous extract autoclaved at 121 °C for 30 min reduced the growth of Escherichia coli and Staphylococcus aureus. Methanol extracted samples stored at room temperature or autoclaved at 121 °C was effective to control the growth of all microbes under study. Chloroform and n-hexane extracts (stored at room temperature) showed weak activity against all tested microbes.
Keywords: Antibacterial activity; Antifungal activity; Disc diffusion method; Food preservative; Turmeric extracts.