Effect of Nisin on the Physical and Chemical Characteristics of Apple Juice and the Control of Alicyclobacillus acidoterrestris

Apples are sold as fresh fruits on the national and international markets, and sub-standard apples are often used for juice production. The juice can be contaminated by Alicyclobacillus acidoterrestris, a spore-producing thermoacidophilic bacterium that is resistant to the pasteurization process. Alicyclobacillus acidoterrestris causes deterioration of the juice and alters its taste, and the use of nisin is one of the options available to combat contamination by the bacterium. In this work, nisin was tested at concentrations of 5, 10, 25, 50, and 100 UI/mL for inhibition of germination of the bacterial spores, and at a concentration of 10 UI/mL for evaluation of changes in the physicochemical characteristics of apple juice (pH, colour, vitamin C content, and concentration of phenols). The results showed that nisin was able to significantly decrease spore germination, without changing the characteristics of the apple juice