Microbial dynamics during shelf-life of industrial Ricotta cheese and identification of a Bacillus strain as a cause of a pink discolouration.

Microbial dynamics during shelf-life of industrial Ricotta cheese and identification of a Bacillus strain as a cause of a pink discolouration. Food Microbiol. 2016 Aug;57:8-15 Authors: Sattin E, Andreani NA, Carraro L, Fasolato L, Balzan S, Novelli E, Squartini A, Telatin A, Simionati B, Cardazzo B Abstract Dairy products are perishable and have to be preserved from spoilage during the food chain to achieve the desired shelf-life. Ricotta is a typical Italian soft dairy food produced by heat coagulation of whey proteins and is considered to be a light and healthy product. The shelf-life of Ricotta could be extended, as required by the international food trade market; however, heat resistant microflora causes spoilage and poses issues regarding the safety of the product. Next-generation sequencing (NGS) applied to the Ricotta samples defined the composition of the microbial community in-depth during the shelf-life. The analysis demonstrated the predominance of spore-forming bacteria throughout the shelf-life, mostly belonging to Bacillus, Paenibacillus and Clostridium genera. A strain involved in spoilage and causing a pink discolouration of Ricotta was isolated and characterised as Bacillus mycoides/weihenstephanensis. This is the first report of a food discolouration caused by a toxigenic strain belonging to the Bacillus cereus group that resulted the predominant strain in the community of the defective ricotta. These results sugges...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research