Abstract

EFFECTIVE BIO PRESERVATION OF FOOD USING BACTERIOCINS WITH HURDLE TECHNOLOGY.

Neelima Devi and Sharayu Babar*

Abstract

Bio preservation is method of food preservation using natural antimicrobials like bacteriocins produced by lactic acid bacteria (LAB) considered as GRAS chemicals. LAB is predominant food fermenting bacteria producing several bacteriocins like lactocins, pediocins, nisin etc. Bacteriocins are used as bio preservatives in food due to their biosafety, efficiency, bioactivity, low dose, high stability and long term action. Bio preservation is enhanced using hurdle technology with modified atmosphere of food with respect to pH, redox potential, water activity and other natural inhibitory compounds. The LAB are isolated from dairy products, fermented foods using selective media and characterized biochemically till genus level. Purification of LAB bacteriocins can be done using methods like ammonium salt precipitation, gel and high performance liquid chromatography (HPLC). Bacteriocins activity assays are done by well diffusion assay, flipstreak method and spot-on-lawn method. Bacteriocins in combination with other stress factors show synergism and are valuable to control the growth of pathogenic and spoilage bacteria in foods. Since the efficacy of above mentioned antimicrobials can vary with chemical composition and physical conditions of the food. Therefore it is necessary food to validate for the antimicrobial activity and establish the effective concentration and best combination of additives or preservation treatments to be applied with the antimicrobials. The physiological responses of microorganisms during food preservation are basis for the application of advanced hurdle technology. Bio preservatives with hurdle technology in food preservation are compared with controls for analyzing the cumulative effect. The effect of bio preservation is checked on foods like fruits, vegetables initially can be extended to other foods.

Keywords: Bio preservation, Bacteriocins, Lactic acid bacteria (LAB), hurdle technology.