The quality of noncarbonated nonalcoholic beverages during their shelf life

Abstract

The manufacture of safe products that have important quality parameters and the preservation of these requirements during the specified shelf life are the main tasks of any manufacturer. To meet these requirements, it is necessary to implement appropriate manufacturing practices and adhere to the prescribed regulations. The aim of this study was to investigate the microbiological safety and sensory properties of seven types of non-carbonated non-alcoholic beverages (I - VII), produced by the Knjaz Miloš AD Company, Arandjelovac, Serbia, containing different ingredients (I: peach flavouring, citric acid, a mixture of vitamin B, sugar, potassium sorbate and sodium benzoate; II: herbal extracts of guarana and lemon grass, apple, grape and lemon juices, citric acid, caffeine, vitamins and lemon flavouring; III: inulin and extract of Aloe vera, apple, orange, pineapple, mango, passion fruit, kiwi and papaya juices, citric acid, L-ascorbic acid, melon flavouring and preservatives; IV: concentrated apple, grape and lemon juices, citric and L-ascorbic acids, juniper, gentian and lavender flower extracts, cherry flavouring and preservatives; V: Cambogia Garcinia extract, fructose, L-carnitine, Mg-citrate, vitamins, lemon, lime juice, green tea, and caffeine flavourings; VI: sugar, Mg and Ca-lactate, citric acid, preservatives and flavouring agents; VII: concentrated apple juice, Mg and Ca-lactate, sugar, citric acid, preservatives and flavourings). Samples were kept in the original packaging, at different storage temperatures (20, 25, 30 and 42 0C). Microbiological tests were carried out according to the national legislation on safety and non-alcoholic beverages, which is in accordance with both ISO methodology (Enterobacteriaceae, yeasts, fungi, aerobic mesophilic bacteria) and internal control requirements set down by the company (coagulase positive staphylococci, sulphate- reducing clostridia, E. coli, acid-tolerant microorganisms). All analyses were carried out at succesive ten-day intervals, during three months. At the end of the production, all samples were microbiologically safe. The presence of lactic acid bacteria wasnot recorded in the tested samples during the three months of storage. The number of aerobic mesophilic microorganisms significantly increased in beverage I (20 days at 25 0C), IV (20 and 50 days at 20 0C and 90 days at 25 0C), and V (50 and 80 days at 20 0C). The total numbers of mould and yeast, and acid-tolerant microorganisms significantly increased only in the samples of beverage I (90 days at 25 0C) and III (10 days at 25 0C). Other microbiological results were within the prescribed limits. Throughout the study, sensory test results for all samples showed normal quality.