Efeito de óleos essenciais e compostos majoritários sobre endósporos de Clostridium botulinum inoculados em mortadela

Abstract

Essential oils are compounds formed by the secondary metabolism of plants and among their properties stand out the antioxidant and antimicrobial activities . The major compounds in the vast majority , are responsible for the antimicrobial activity and researches have been done to verify this action under the contaminating microorganisms in food . Clostridium botulinum is a sporulated microorganisms , their neurotoxin causes botulism , a disease that can lead to death or leave several sequels . This study aimed to evaluate the antimicrobial effect of essential oils of oregano and clove and the major compound carvacrol on endospores of C. botulinum , and mortadella inoculated in assessing the effect of these compounds on lipid oxidation , residual nitrite , pH, texture and color development in the product. To determine the minimum inhibitory concentration (MEC ) the essential oils and the major compounds broth dilution method was used. The bologna were prepared with combinations of essential oils and major compounds , more effective , in vitro tests, with 0 and 150 ppm nitrite . The samples for microbiological analyzes were stored at 25 ⁰ C/30 days, inoculated with 104 CFU / g endospores C. botulinum. Samples for physical and chemical analysis were stored at 4 ° C/30 days . There was a significant interaction p ( < 0.05 ) effect on the oil , nitrite and time on mircrorganismo with a decrease in cell counts and pH, in which there was an increase in this end of storage . There was also a significant interaction in all treatments p ( < 0.05 ) and nitrite , as the emulsion stability , this decrease occurring . As for lipid oxidation , significant effects p ( < 0.05 ) of nitrite , lower values being observed in samples with added nitrite. To the residual nitrite p significant effect (p <0.05 ) interaction between the nitrite and time, there is a reduction in nitrite levels according to time. The addition of the mortadella combinations did not affect the final color of the product , and the effect of nitrite was significant ( p < 0.05) in the color change. With respect to texture a significant effect ( p <0.05) isolated by the addition of nitrite to all the texture parameters , with higher values in the samples with added nitrite and significantly ( p <0.05) adding the mixture isolated from oils for flexibility and chewiness parameters , increasing the values of these parameters . Therefore, a reduction in the population occurred C. botulinum, when added to bologna , combinations of oils and major compound in the absence of combinations and the antimicrobial effect of nitrite was in charge . For the physicochemical analyzes nitrite demonstrated greater effectiveness.