Efeito inibitório de óleos essenciais de citros sobre o crescimento de microrganismos

Abstract

The current trend adopted by the lawmaking agencies of food production and consumers has demanded a progressive removal of chemical additives in food production. The essential oils found in medicinal, aromatic and seasoning plants have interested to the food industries as an alternative to synthetic additives. Essential oils present an antimicrobial activity against a great number of decaying and/or pathogenic bacteria, including species resistant to antibiotics and antifungal. Lemon production, in addition to destined to "in natura" consumption and juice industry, meant also for the extraction of the essential oil. With the purpose of evaluating the inhibitory effect of essential oils of the rind and leaf of e Citrus limonia Osbeck (Cravo-lemon), Citrus aurantifolia (Chrst.) Swingle (Galego-lemon) and Citrus latifolia Tanaka (Tahiti-lemon), experiments were accomplished in laboratory by utilizing the agar dish hole diffusion method with bacteria Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa and with yeast Candida utilis For the fungus Penicillium expansum, important food -decaying pathogens. In the results of the in vitro tests, essential oils tested promoted the inhibition of all the tested microorganisms; but, they presented the best formation of inhibition haloes on yeast Candida utilis. For the bacteria, the oils promoted better inhibition on Staphylococcus aureus than on Escherichia coli and Pseudomonas aeruginosa. The inhibitory effect of the citros oils was effective on fungus Penicillium expansum; but the essential oil of the Cravo-lemon rind stimulated the mycelial growth of the fungus. It was possible to verify that the oils in study possess inhibitory effect on the studied microorganisms, which enables to corroborate that essential oils are an alternative in the biologic control of microorganisms, its being an alternative to obtaining natural foods.