Efeito da embalagem à vácuo e aplicação de revestimentos comestíveis em queijo coalho

Abstract

Coalho cheese is a food that appeals to the palate of people of all ages, being a food rich in nutrients such as calcium and proteins, which contribute to a healthy diet. However, due to its high nutritional value and freshness, and due to possible processing failures (especially the absence of Good Manufacturing Practices - GMPs), it is a food highly susceptible to microbiological contamination, posing a risk to consumer health. To address this problem, food preservation techniques can be applied, and especially for cheeses, edible coatings, combined with various packaging methods, such as vacuum packaging, have been extensively studied. Thus, this research aimed to evaluate the efficiency of edible coatings (based on water and whey) combined with normal and vacuum packaging on the microbiological and physical-chemical quality of coalho cheese. Two types of coatings were developed, with treatment T1 having an edible coating based on water, T2 having an edible coating based on whey, and T3 having no coating. Each treatment was subjected to two packaging systems, one in regular nylon/polyethylene bags (QN) and the other in vacuum packaging (QV), totaling 6 treatments. The cheeses were evaluated for physical-chemical and physical parameters of moisture, titratable acidity, pH, soluble solids, and color, as well as microbiological parameters for the presence of Salmonella spp. and quantification of E. coli and coagulase-positive staphylococci during storage for 21 days under refrigeration. A positive effect of the water-based edible coating on the maintenance of moisture and the colorimetric coordinates L and a* (related to yellow, a characteristic color of cheeses) of the cheese in normal packaging was observed, as for treatment T1(QN) none of the parameters varied statistically during storage (moisture, L and a* parameters), while for treatment T3(QN) all the mentioned parameters showed a significant statistical difference. As for the microbiological parameters, both edible coatings (but especially the one prepared with whey) improved the preservation of the cheese, mainly with the association of vacuum packaging, which ensured better protection against the presence of the studied microorganisms, especially E. coli, which is an indicator of fecal contamination in food. This study then demonstrated the effectiveness of vacuum packaging and the application of whey-based edible coatings on the microbiological and physical-chemical quality of coalho cheese, valuing these packaging methodologies that are simple, quick to apply, and low-cost.