Efeito da nisina na multiplicação de Staphylococcus aureus e nas características físico-químicas, reológicas e microbiológicas do queijo Minas artesanal da Serra da Canastra MG

• Autor(a) principal: Teodoro, Vanessa Aglaê Martins
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/455
• topic: Queijo Minas; Nisina; Staphylococcus aureus; Minas cheese; Nisin; Staphylococcus aureus; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS

The use of nisin in foods has been extensively investigated in recent years, including dairy products. The traditionals Minas cheeses are important cultural, economic, social and historical, however, despite advances in legislation and production, there are products not standardized, low quality and no safety for the population. This work aimed to evaluate the antagonistic effect of adding 0, 100 and 500 IU.mL-1 nisin added to Traditional Minas Canastra cheese production against S. aureus during 60 days of ripening. We also evaluated the lactic acid bacteria, aerobic mesophilic, Enterobacteriaceae, total coliforms and E. coli counts, determination of the staphylococcal enterotoxins in cheese and sea, seb, sec, sed and see enterotoxins genes in S. aureus isolates; as well its influence on fracturability, elasticity, gumminess, chewiness, adhesiveness and cohesiveness and physicochemical properties (moisture, fat content, protein, salt, ash, pH, aw, ripening indices). The nisin was effective in the reducing S. aureus population between inoculation up to the obtaining of the curd in treatment with 500 IU.mL-1 and until the seventh day of ripening in cheese treated with 500 IU.mL-1. The cheeses treated with nisin showed lower levels of S. aureus. It was not observed difference (P &#8805; 0,05) between nisin treatments and the control samples in lactic acid bacteria counts, ripening index and texture profile, except for cohesiveness that was higher (P < 0,05) in cheeses treated with 500 IU.mL-1. It was not observed difference (P &#8805; 0,05) in moisture, fat, protein, salt, ash and aw between nisin treatments and the control samples. The cheese treated with 500 IU.mL-1 of nisin showed higher pH levels (P < 0,05) in comparison with those treated with 100 IU.mL-1 of nisin and the control samples. It was not observed difference (P &#8805; 0,05) in mesophilic aerobic count, however Enterobacteriaceae, total coliforms and E. coli counts showed higher levels in cheeses treated with nisin (P < 0,05). All S. aureus isolates from Traditional Minas Canastra cheese were positive for sea, seb, sec and see enterotoxin genes and negative for sed gene. Staphylococcal enterotoxins were not found in Traditional Minas cheese Canastra samples.