Cambios en la calidad de un queso pategrás envuelto con películas de casinato de sodio incorporadas con aceites esenciales de orégano y laurel para mejorar si vida útil.

B. S. ALVAREZ; N. DAMIANI; J. F. MARTUCCI; L.B. GENDE

Congreso; X Congreso de Microbiologia general.; 2014

Active packaging is an innovative concept that can be defined as a type of packaging that changes the condition of the packaging to extend shelf-life or improve safety or sensory properties while maintaining the quality of the food. Current research, in this topic, has been focused on the strategy of elaboration of an antimicrobial film based on biopolymer matrix incorporated with herbs and spices extract (essential oils) with antimicrobial activity against food borne pathogens, for enhancing the quality and safety of a wide range of food during extended storage. In this work, essential oils of oregano (Origanum vulgare, OEO) and laurel (Laurus nobilis, LEO) were obtained by hydrodistillation. Their antimicrobial activities were analyzed by tube dilution method against two food borne pathogens: Escherichia coli and Staphylococcus aureus. Oregano and laurel proved to have antibacterial effects against both microorganisms. Minimal inhibitory concentration for OEO and LEO were 1600-1800 and >2000 μg/ml against E. coli; and 800-900 and >2000 μg/ml against S. aureus, respectively. From these results, sodium caseinate films (3%p/v) with essential oils (1000-10000 μg/ml) were developed by casting. The antimicrobial activities of the films against E. coli and S. aureus were determined by the inhibition zone technique. For both microorganisms, oregano films showed greater inhibition zone. One selected formulation (10000 μg/ml) was applied on packaging of semi-hard Pategrás cheese. Cheese portions were wrapped with the films by heat sealed and storage (temperature 8-12 °C y relative humidity 70-80 %). Antimicrobial effect of the packaging over the product was evaluated by the petri-dish viable cell count after different time periods (14, 28, 42 and 56 days). The effect against total microorganisms, fungi and yeasts, E. coli and S. aureus were determined. The results indicated that the obtained films have potential for packaging semi-hard cheeses, increasing the shelf life of the product over time.