Spoilage Growth and Benzene Evaluation of Non-carbonated Soft Drinks

Abstract

Benzoic and ascorbic acids are common additives of many non-carbonated drinks but despite the presence of those preservatives, inappropriate production processes may allow the growth of spoilage. Furthermore, over time these acids tend to react, producing benzene, a known carcinogen. This study analysed the regular and low-calorie versions of three brands of commercial non-carbonated soft drinks, assessing their microbiological and chemical quality. Preservative resistant yeast analysis was performed in TGY medium supplemented with glacial acetic acid (TGYA) and incubating at 30 °C/72 h and lactic acid bacteria analysis was done in MRS medium incubating at 35 °C for 5 days. Isolated strains were identified by partial amplification of 16S rDNA. Benzoic acid and benzene quantification were carried out using, respectively, HPLC and HS-SPME-GC. Some soft drinks samples showed evidence of growth of spoilage bacteria, identified as members of the Acetobacteraceae family. Spoilage growth can change the sensorial standard of the products and make consumers discredit the product generating great damage to a brand’s reputation. In some samples, benzoic acid and benzene concentrations were above the thresholds established by regulatory agencies. Benzene’s risk arises from chronic exposure, which is usually the problem for soft drink consumers, and corrective measures must and can be taken. Keywords: soft drinks, acetic bacteria, benzene, benzoic acid, solid-phase microextraction (