Resumo

The increasing demand for fresh-tasting, healthy, nutritious and ready-to-eat foods has stimulated the expansion of minimally processed fruit and vegetable markets worldwide. However, the increased consumption of these products has been associated with foodborne illness. To further expand the minimally processed food market, alternative preservation strategies have been suggested. Among this, the use of bacteriocins from lactic acid bacteria has been widely considered. The aim of this study is to examine the effects of nisin-incorporated cellulose films on the physicochemical and microbiological quality of minimally processed mangoes. The antimicrobial films were produced by the casting method using cellulose acetate, and nisin was added at 25% (w/w) of the cellulose weight. The mango slices were packed with the antimicrobial films and at every 3 days samples were taken and evaluated about the physicochemical characteristics. The mango slices were inoculated with Staphylococcus aureus and Listeria monocytogenes (10⁷CFU/g) and at time intervals of 0, 2, 4, 6 and 12 days of incubation at refrigeration temperature the microbial analyses were performed. The antimicrobial films did not affect the physicochemical characteristics of mangoes. In samples packed with antimicrobial films, the viable number of L. monocytogenes cells was reduced below the detection level after 4 days. After 6 days, a reduction of six log units was observed for S. aureus. The viable cell numbers of control treatments remained at 10⁵ and 10⁶ CFU/g, respectively, after 12 days. In conclusion, nisin showed antimicrobial activity in mangoes without interfering with the organoleptic characteristics of the fruit. This result suggests that nisin could potentially be used in active packing to improve the safety of minimally processed mangoes. Apoio: FAPITEC; CNPq