Suchergebnisse

Abstract: Coalho cheese is a dairy product typical of the Northeast region of Brazil and widely consumed by the population; however, the poor quality of the raw material used in association with the absence of standardization in the manufacturing process makes it susceptible to microbial contamination, mainly by Staphylococcus aureus. The objective of this study was to evaluate the influence of chitosan as a coating and incorporated in coalho cheese on S. aureus viability and the sensorial acceptance of the cheese. For this, coalho cheeses were made with chitosan in the coating or added to the curds at 5 mg mL-1, 10 mg mL-1 and 15 mg mL-1 and 1 mg g-1, 2 mg g-1 and 4 mg g-1, respectively. Products without chitosan (C) and 1% acetic acid (CA) were used as controls. The bacterial inhibition of chitosan in the artificially contaminated samples was assessed by comparing the viable cell count of S. aureus (ATCC 6538) in each treatment over five time intervals (0, 4, 8, 12 and 16 d storage). Product C was evaluated for moisture and fat content. The sensorial and shelf stability analyses were performed with the control and chitosan treated samples at the most efficient antibacterial concentrations. The sensorial analyses were performed with 100 consumers. Chitosan antimicrobial activity was observed in all treatments; however, the highest concentrations of chitosan added as a coating and to the cheese, 15 mg mL-1 and 4 mg g-1, respectively, inhibited S. aureus. The moisture and fat contents met the standards established by the Brazilian legislation. Regarding stability, the samples complied with the regulatory microbiological limits and presented acceptable pH, acidity and water activity values. As far as sensorial acceptance was concerned, the scores corresponded to hedonic concepts between "I liked it slightly" and "I liked it a lot", with an improvement in the texture of the products when chitosan was incorporated. Acceptability values were higher than 70%, except for the taste the products with chitosan covering them, which was 68.3%. It can be inferred from the results that the use of chitosan as a coating and incorporated in coalho cheese is a favourable alternative for the preservation of this product and has potential commercial applicability.

Abstract: Coalho cheese is a dairy product typical of the Northeast region of Brazil and widely consumed by the population; however, the poor quality of the raw material used in association with the absence of standardization in the manufacturing process makes it susceptible to microbial contamination, mainly by Staphylococcus aureus. The objective of this study was to evaluate the influence of chitosan as a coating and incorporated in coalho cheese on S. aureus viability and the sensorial acceptance of the cheese. For this, coalho cheeses were made with chitosan in the coating or added to the curds at 5 mg mL-1, 10 mg mL-1 and 15 mg mL-1 and 1 mg g-1, 2 mg g-1 and 4 mg g-1, respectively. Products without chitosan (C) and 1% acetic acid (CA) were used as controls. The bacterial inhibition of chitosan in the artificially contaminated samples was assessed by comparing the viable cell count of S. aureus (ATCC 6538) in each treatment over five time intervals (0, 4, 8, 12 and 16 d storage). Product C was evaluated for moisture and fat content. The sensorial and shelf stability analyses were performed with the control and chitosan treated samples at the most efficient antibacterial concentrations. The sensorial analyses were performed with 100 consumers. Chitosan antimicrobial activity was observed in all treatments; however, the highest concentrations of chitosan added as a coating and to the cheese, 15 mg mL-1 and 4 mg g-1, respectively, inhibited S. aureus. The moisture and fat contents met the standards established by the Brazilian legislation. Regarding stability, the samples complied with the regulatory microbiological limits and presented acceptable pH, acidity and water activity values. As far as sensorial acceptance was concerned, the scores corresponded to hedonic concepts between "I liked it slightly" and "I liked it a lot", with an improvement in the texture of the products when chitosan was incorporated. Acceptability values were higher than 70%, except for the taste the products with chitosan covering them, which was 68.3%. It can be inferred from the results that the use of chitosan as a coating and incorporated in coalho cheese is a favourable alternative for the preservation of this product and has potential commercial applicability. ; O queijo de coalho é um produto lácteo típico da região Nordeste do Brasil e amplamente consumido pela população, contudo, a qualidade precária da matéria-prima utilizada associada à ausência de padronização no processo de fabricação torna-o susceptível à contaminação microbiana principalmente por Staphylococcus aureus. Em vista disso, objetivou-se avaliar a influência da quitosana como revestimento e incorporada em queijo de coalho sob a viabilidade de S. aureus e a aceitação sensorial do queijo. Para isso, foram produzidos queijos de coalho com quitosana como revestimento e adicionada à massa nas concentrações 5 mg/mL, 10 mg/mL e 15 mg/mL e 1 mg/g, 2 mg/g e 4 mg/g, respectivamente. Produtos sem quitosana (C) e com ácido acético 1% (CA) foram usados como controles. A capacidade de inibição bacteriana da quitosana nas amostras artificialmente contaminadas foi avaliada por meio da comparação da contagem de células viáveis de S. aureus (ATCC 6538) em cada tratamento, no decorrer de cinco intervalos de tempo (0, 4, 8, 12 e 16 dias de armazenamento). O produto C foi avaliado quanto ao teor de umidade e gordura. As análises sensoriais e de estabilidade de prateleira foram realizadas com as amostras controles e tratadas com quitosana nas concentrações antibacterianas mais eficientes. As análises sensoriais foram realizadas com 100 consumidores. Verificou-se atividade antimicrobiana de quitosana em todos os tratamentos, porém, as concentrações mais elevadas de quitosana como revestimento e adicionada à massa, 15 mg/mL e 4 mg/g, respectivamente potencializaram a inibição do S. aureus. O teor de umidade e gordura atendeu aos padrões estabelecidos pela legislação brasileira em vigor. Quanto à estabilidade, as amostras cumpriram com os limites microbiológicos regulamentares e apresentaram valores de pH, acidez e atividade de água aceitáveis. No que se refere à aceitação sensorial, as pontuações equivaleram a conceitos hedônicos entre "gostei ligeiramente" e "gostei muitíssimo", verificando-se melhoria na textura dos produtos com quitosana incorporada. Valores de aceitabilidade foram maiores que 70 %, exceto no quesito sabor dos produtos com quitosana em cobertura, com 68,3 %. Pode-se inferir que a utilização de quitosana como cobertura e incorporada em queijo de coalho é uma alternativa favorável na conservação deste produto evidenciando potencial aplicabilidade comercial.