CASE STUDIES OF SPOILAGE IN SOFT-DRINKS

Soft drinks are food matrices propitious to the growth of acidophilic bacteria, yeasts and filamentous fungi due to their pH, water activity and process. Legislation worldwide does not call for spoilage analysis in soft drinks. Off-flavor and packaging stuffing are the only parameters that producers have to detect spoilage when, sometimes, it’s already too late for the brand’s reputation. In this work, we gathered data from microbiological analyses of non-alcoholic beverages produced by five different industries, three from Rio de Janeiro (Brazil), one from São Paulo (Brazil) and one from Santa Cruz (Bolivia), which were analyzed in search of spoilers. In two of these industries, the producers needed to detect which microorganism, and at which point the contamination occurred, since the beverages were showing visible deterioration before the expiration date, by either gas formation or microbial growth. The work with the other three industries focused on looking for deteriorating microorganisms in beverages without visible deterioration. After following specific methodologies for spoilage isolation for all the five industries, a diagnosis was obtained. In the analysis of products from industries with no signs of deterioration, Komagataeibacter spp. were identified by characterizations tests followed by partial sequencing of 16S rDNA, in 50 % of the batches analyzed in one industry. From one of the industries, with packaging stuffing problems, Zygosaccharomyces bisporus were isolated from stuffing package products with different flavors, and Gluconacetobacter liquefaciens and Brevibacillus agri from packages without visible signs of deterioration, those microorganisms were identified by MALDI-TOF. For the industry with filamentous fungi growth, Aspergillus flavus, Penicillium citrinum, Paecilomyces niveus, and Paecilomyces variotti were identified by microscopic identification keys. All these spoilage microorganisms isolated from different industries can serve as a warning to the lack of control of spoilage worldwide, and give a focus on this neglected sector of the industry