Coalho cheese with incorporated chitosan and as a coating: effect on the viability of Staphylococcus aureus and sensory acceptance

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.

Avaliação Da Qualidade Microbiológica De Queijos De Coalho Comercializados Em Lavras-Mg

“…Algumas de suas cepas podem causar doenças intestinais e extra intestinais, devido a seus fatores de virulência, que afetam diversos processos celulares. Os surtos de E. coli tem sido associados à ingestão de alimentos contaminados como carnes, maionese, cidra de maçã, vegetais e produtos lácteos (BHUNIA, 2008;KAPER;NATARO;MOBLEY, 2004;KASNOWSKI et al, 2007;ROSA;BARROS;SANTOS, 2016).…”

“…Dentre os diversos tipos de queijo, o queijo de coalho é um produto típico da região Nordeste do Brasil, muito popular e amplamente consumido pela população. Devido ao seu alto valor nutritivo e sabor agradável, sua produção e consumo se expandiram consideravelmente pelo país (BARROS et al, 2019;BEZERRA et al, 2017;MACHADO et al, 2021;SOUSA JÚNIOR et al, 2015).…”

“…Desse modo, a utilização de matéria prima de má qualidade associada à falta de padronização do processo de produção, torna o produto mais susceptível à contaminação e uma possível fonte de toxinfecção alimentar. Essa contaminação por microrganismos patogênicos pode ser proveniente de manipuladores, do ambiente de produção ou do armazenamento do produto (BARROS et al, 2019;SOUSA JÚNIOR et al, 2015).…”

Effect of the application of probiotic strains of Enterococcus faecium on the physicochemical and sensory characteristics of coalho cheese

“…Despite its relevance in the cultural and socioeconomic context, this dairy product still requires standardization, especially with respect to physicochemical and microbiological aspects. The variation in its obtainment process, coupled with the lack of good manufacturing practices (GMP) in some dairy products, generates low-quality and even microbiologically unsafe products (Barros et al, 2019;Medeiros et al, 2016). The reputation of this cheese is often reported negatively, especially when it is produced artisanally without pasteurization of milk (Castro et al, 2018).…”

“…In the search for alternatives to relieve the notoriety of this product, several studies have been conducted to increase its microbiological safety and shelf life. These studies highlight the use of plant extracts with antimicrobial activity (Costa et al, 2020), chitosan coating and incorporation (Barros et al, 2019), and the inclusion of probiotic microorganisms, such as Enterococcus faecium, with antagonistic activity against pathogens (Castro et al, 2018).…”