Efeito da aplicação de coberturas biodegradáveis à base de amido nas características microbiológicas, físico-químicas e sensoriais de queijo duro

Abstract

During the ripening process, cheese can become contaminated with undesirable microorganisms, often leading to processing losses. One alternative is to vacuum-pack cheeses with petroleum-based packaging, which has a negative impact on the environment. The application of coverings to cheese could therefore be an interesting alternative to plastic materials. The aim of this work was to study the preparation and application of a coating based on cassava starch and oregano essential oil (Origanum Vulgare) on hard cheese, as well as its effect on the physicochemical, microbiological and sensory characteristics of the product obtained. The parameters analyzed in the cheese were moisture content, texture profile, color, pH, protein, ash, fat and index of extent and depth of proteolysis. For the microbiological assessment, mold and yeast cultures and total counts were identified. The sensory analyses used were Check-all-that-apply (CATA) and acceptability. To characterize the essential oil, antioxidant activity (DPPH and ABTS), total phenolic compounds and minimum inhibitory concentration (MIC) were evaluated. The results show a decrease in the internal and external brightness of the cheeses (16.38% CT - control, 16.00 AM - starch and 15.17 OE - essential oil) during ripening. The external color showed that the Hue angle at the end of the evaluation was between 78.23 and 75.63, indicating a yellow color. The hardness results on day 0 were 613.15 CT, and at the end of ripening the cheese with AM had the lowest hardness among the treatments of 3055.09g (p ≤ 0.05), chewiness was also lower on day 30 for AM with a value of 936g. The initial moisture content of the cheese was 49.68% and there was a decrease for all the cheeses, 39.55% for CT, 39.62% for AM and 37.23% for OE. Note the decrease in aW during the test period, with a reduction of 4.08% for CT, 3.02% for AM and 3.70% for OE. The cheese coated with essential oil was associated with pizza flavor and oregano flavor in the CATA and was well accepted, as was the AM cheese. With regard to the ripening index of the coated cheeses, it can be seen that there was a delay in the depth of proteolysis and in the extension index, and one of the reasons may be the influence on the activity of the protease enzyme. Research has shown advantages in the application of biodegradable cassava starch coatings, since this coating gives the product barrier properties. The incorporation of Origanum Vulgare essential oil into the starch polymer matrix resulted in the delay of microbial deterioration and added flavor characteristics to the product. Therefore, its use is viable as a natural alternative for preserving hard cheese.