Sodium caseinate films with oregano and laurel essential oils for active packaging

Abstract

Argentine Pategrás cheese is one of the most popular types of cheese in Argentina. The main spoilage causes in these products are microbiological contamination and lipid rancidity. Semi-hard cheeses are usually covered with a paraffin wax that favors its preservation. When pieces are stored, cutting faces must be protected to prevent desiccation and contamination. Active biodegradable films are an alternative to the traditional materials. In the present work, active films of sodium caseinate with oregano (Origanum vulgare) and laurel (Laurus nobilis) essential oils were produced. Aseptical portions of Pategrás cheese were packaged by heat sealing, the samples were stored under shelf conditions (12 °C and 75% Relative Humidity) for 56 days. Portions were periodically removed and microbiological count of mesophilic microorganisms, food pathogens like S. aureus, as well as fungi and yeasts determination were made on samples surfaces. The results showed that the incorporation of 10000 μg / ml of essential oil confers antimicrobial properties to sodium caseinate films and oregano essential oil was the most effective. Sensory analysis of packaged cheeses was made; those involved with active films with essential oils, were the freshest at the end of shelf life and showed the highest acceptability by the sensory panel members throughout the study period.