ANTIBACTERIAL ACTIVITY OF SPRAY-DRIED ALECRIM PIMENTA ESSENTIAL OIL AND EXTRACT AGAINST LISTERIA MONOCYTOGENES

NU01

Reis, FB

Fernandes, LP

Oliveira, WP

De Martinis, ECP

Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - FCFRP, Universidade de São Paulo - USP, Av. do Café, s/nº - Campus Universitário da USP – Ribeirão Preto – SP – 14040903 – Brasil

Listeria monocytogenes is a foodborne pathogen that causes listeriosis, an infection that targets mainly immunocompromised individuals and pregnant women. Novel methods to inhibit L. monocytogenes in foods are of great interest, since this bacterium is ubiquitous and may persist in food processing environments for years. Essential oils of plants and their derivatives have wide application as flavouring ingredients in a variety of foods and beverages, and are also used for the control of pathogens carried by food, thereby improving safety of foods. In this work, spray-dried preparations of essential oils (FO1 and FO2) and hydroalcoholic extract (FE1 and FE2) from the plant Lippia sidoides, popularly called alecrim pimenta, were tested at different concentrations against L. monocytogenes ATCC 19115. The spray-dried preparations of essential oil and extract were introduced in Brain Heart Infusion broth (BHI) at concentrations of 3.125, 6.25, 12.5, 25, 50 and 100 mg/ml to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) by standard macrodilution technique. The tests and controls were done in triplicate and incubated to 37°C for 24 hours. The results showed a MIC of spray-dried preparations of FO1, FO2, FE1 and FE2 against L. monocytogenes of 12.5 mg/ml. The MBC of spray-dried preparations of FO1 and FO2 of 25mg/ml, FE1 and FE2 of 12.5 mg/ml. The results showed that different formulations of spray-dried (FO1 and FO2; FE1 and FE2) had antilisterial activity similar, and that the value of MBC differed between essential oil and extract. This study indicates the potential of the spray-dried preparations of essential oil and extract of L. sidoides to be used as a barrier to listerial growth.