Counts of aerobic mesophilic micro-organisms and aerobic mesophilic spore-forming bacteria were determined in 91 ultra-high-temperature (UHT) commercial Brazilian samples. Forty-six sporeforming bacteria were identified and characterised in terms of their spoilage potential. Among the 20 brands evaluated, 45% had counts of aerobic mesophilic micro-organisms higher than 1.0 9 102 cfu/mL. The sporulated bacteria were identified as Bacillus subtilis/amyloliquefaciens, Bacillus licheniformis, Bacillus pumilus and Bacillus megaterium, and 31% and 33% showed proteolytic and lipolytic activity, respectively. Our findings indicate that there is a potential risk of UHT milk samples becoming spoiled during their commercial shelf life.

RESUMO -O sistema UHT permite a conservação e o prolongamento da vida útil do leite à temperatura ambiente. Objetivou-se determinar a qualidade microbiológica, características físico-químicas e a presença de conservantes e/ou reconstituintes de leite UHT integral. Avaliou-se amostras de 20 marcas quanto a contagem de bactérias aeróbias mesofílicas, pH, índice crioscópico, densidade, estabilidade ao álcool 68°GL, pesquisa de peróxido, neutralizantes, amido, cloreto e sacarose. Constatou-se alto percentual de marcas em desacordo com o padrão microbiológico além da presença de fraudes por adição ao leite de substâncias neutralizantes e substâncias reconstituintes em algumas das marcas. O alto percentual de marcas de leite UHT integral em desacordo com o padrão microbiológico vigente indica a necessidade de implementação das boas práticas higiênicas de produção, estocagem, transporte e processamento do leite para fins de prevenção de contaminações e consequentes perdas de qualidade e perdas econômicas. A presença de substâncias conservantes, neutralizantes e reconstituintes constatada em algumas marcas de leite UHT são fraudes que denotam a falta de controle do processo e falta de conscientização por parte dos integrantes da cadeia produtiva do leite.Palavras chave: Contaminações, fraude, legislação, produto lácteo. ASSESSMENT OF MICROBIOLOGICAL AND PHYSICOCHEMICAL QUALITY OF UHT WHOLE MILK FROM DAIRY INDUSTRIES IN MINAS GERAIS STATE, BRAZIL

Consumers worldwide are increasingly demanding food with fewer ingredients, preferably without chemical additives. The trend called “Clean Label” has stimulated the development and commercialization of new types of bioprotective bacterial cultures. These bacteria are not considered new, and several cultures have been available on the market. Additionally, new bioprotective bacteria are being identified to service the clean label trend, extend the shelf life, and, mainly, improve the food safety of food. In this context, the lactic acid bacteria (LAB) have been extensively prospected as a bioprotective culture, as they have a long history in food production and their antimicrobial activity against spoilage and pathogenic microorganisms is well established. However, to make LAB cultures available in the market is not that easy, the strains should be characterized phenotypically and genotypically, and studies of safety and technological application are necessary to validate their bioprotection performance. Thus, this review presents information on the bioprotection mechanisms developed by LAB in foods and describes the main strategies used to identify and characterize bioprotective LAB with potential application in the food industry.

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