Brazilian artisanal "Coalho" cheeses from six Northeast towns were investigated as a functional food based on their peptide profiles and antioxidant, zinc-binding and antimicrobial activities. The peptides (WSP) from "Coalho" cheese showed high antioxidant activity, the best value of TEAC being 2223±10.10μM, which means 91.1±0.43% oxidative inhibition and peptide concentration for IC(50) of 7mg/mL (21μg of peptides) for sample from the town of Correntes. The smallest TEAC value (1896±17μM), which means 75.9±0.7% oxidative inhibition and IC(50) of 10.5mg/mL (31.5μg of peptide), was obtained for samples from the town of São Bento do Una. The zinc-binding activities were: Arcoverde (72.21±0.24%) Cachoeirinha (75.02±0.02%), Capoeiras (61.78±0.65%), Correntes (75.47±0.5%), São Bento do Una (75.41±0.15%), and Venturosa (74.36±0.04%). The WSP extracts showed antimicrobial activity against Enterococcus faecalis, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. All the results obtained suggest that "Coalho" cheese has potential as a functional food.

RESUMOO objetivo desta pesquisa foi avaliar a qualidade microbiológica e o perfil ácido-láctico do queijo de coalho artesanal. Todas as amostras de queijo apresentaram coliformes totais, termotolerantes e presença de Escherichia coli, porém com os valores dentro dos padrões estabelecidos pela legislação vigente no país. O perfil ácido-láctico estudado mostrou uma microbiota heterogênea, constituída por lactobacilos, lactococos, estreptococos e enterococos, confirmadas as espécies Enterococcus faecalis, Enterococcus faecium, Streptococcus thermophilus e Lactococcus lactis.Palavras-chave: queijo de coalho artesanal, reação em cadeia da polimerase, bactérias ácido-lácticas ABSTRACTThe aim of this study was to evaluate the microbiological quality and lactic-acid profile of artisanal coalho cheese. All cheese samples analyzed showed total coliforms, were thermotolerant, and had Escherichia coli, but all the values were within the standards established by current legislation in the country, and could be considered a food fit for human consumption. The cheese showed a heterogeneous microbiota, being constituted of all tested genus, such as lactobacilli, lactococcus, streptococcus and enterococcus, and confirmed the species: Enterococcus faecalis, Enterococcus faecium, Streptococcus thermophilus and Lactococcus lactis. Keywords: artisanal coalho cheese, polymerase chain reaction, lactic-acid bacteria INTRODUÇÃO A produção de queijo de coalho representa uma atividade bastante significativa para a economia regional, visto que em determinadas localidades é a principal fonte de renda e sobrevivência da população (Almeida et al., 2010). No Nordeste do Brasil a maior parte da produção de queijo de coalho é realizada em pequenas e médias queijarias, as quais movimentam, mensalmente, algo em torno de 10 milhões de reais, o que torna essa atividade importante tanto no âmbito social quanto no econômico (Perry, 2004).Recebido em 1 de julho de 2011 Aceito em 7 de agosto de 2012 *Autor para correspondência (corresponding author) E-mail: mtcvsoares@yahoo.com.br De acordo com Almeida et al. (2010), o queijo de coalho é uma representação genuína da tradição e cultura do estado de Pernambuco, onde está sendo desenvolvido um trabalho de certificação desse queijo visando a uma identidade própria que irá diferenciá-lo dos demais produzidos na região Nordeste.As propriedades organolépticas típicas e o aroma particular dos queijos obtidos com leite cru, tais como o queijo de coalho artesanal, estão associados com atributos do próprio leite, relacionados à raça e ao tipo de nutrição das vacas, ao processo de fabricação básico do queijo tradicional e à microbiota natural autóctone,

Invertase was covalently immobilized on polyurethane (PU), inox plate covered with plast-film layer and ferromagnetic azide-Dacron. The immobilization processes, physico-chemical parameters and a model for coupling reactions were studied. The preliminary studies for selection of the support showed that the best activity was obtained for PU treated with HCl, polyethylenimine and glutaraldehyde (156.7+/-4.9 U/g support). All plast-film-invertase derivatives did not show activity and the Dacron-invertase derivative showed an activity of 105.39 U/g support. The invertase immobilized in presence of substrate (10% w/v sucrose) was the most efficient (832.74+/-1.48 U/g support). The optimal pH was shifted from 4.5 (free enzyme) to 5.0 (immobilized derivative) and optimal temperature was not affected. Activation energy values of free enzyme, Dacron-invertase and PU-invertase were 32.4+/-0.34 kJ/mol, 33.4+/-0.36 kJ/mol and 44.0+/-0.67 kJ/mol, respectively. The PU-invertase could be used over 2 months without considerable activity loss (68.5% activity retention) and retained 12.6% (287.97+/-27.9U/g support) of the activity after five cycles.