Avaliação do uso de surfactantes na remoção de Salmonella Enteritidis Aderida em superfície foliar da alface (Lactuca sativa L.)

• Ano de defesa: 2009
• Autor(a) principal: Zerdas, Evelyn Rosse Mary Arnez
• Orientador(a): Andrade, Nélio José de
• Banca de defesa: Peña, Wilmer Edgard Luera , Silva, Washington Azevedo da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Ciência e Tecnologia de Alimentos
• Departamento: Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
• País: BR
• Palavras-chave em Português: Vegetais; Surfactantes; Controle microbiológico; Hidrofobicidade; Salmonella Enteritidis
• Palavras-chave em Inglês: Vegetables; Surfactants; Microbiological control; Hydrophobicity; Salmonella Enteritidis
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/2871

Surfactants have been evaluated in their antimicrobial activity as an alternative to chlorine compounds to sanitize vegetable. However, the interactions between surfaces microorganisms- surfactants should be better understand, improving the sanitizing procedures. The efficiency of solutions of benzalkonium chloride (300 to 2000 mg·L-1 of BAC) and sodium dodecil sulphate (600 - 3500 mg&#903;L-1 de SDS) and the contact time in the inactivation of sessile of Salmonella Enteritidis in the lettuce leaves surfaces was evaluated. The effect of time and temperature in adherence process, and the hydrophobicity of the microorganism and the leaves surfaces with different roughness and position in the rosette of the lettuce also were evaluated. The results showed that the hydrophobic-hydrophilic characteristics of surface affect (p < 0.05) the adherence of the Salmonella Enteritidis. The &#916;Gadhesion was favorable for internal and external leaves and for intermediary leaves in the rosette, in different magnitudes. The number of Salmonella Enteritidis cells adhered to lettuce leaves (7.0 log cfu·cm-2) was lower than the microbial numbers found in the external (7.51 log UFC / cm2 ), and internal leaves (7.75 log UFC / cm2). Solutions of 1200 mg·L-1 de BAC and 600 mg·l-1 of SDS, a 25 oC e 10 min contact reached 1.20 and 0.83 decimal reduction (DR) in the S. Enteritidis population, and these values were lower (p < 0.05) than the obtained by 200 mg·L-1 of free available chlorine prepared from sodium dychloroisocianurate (1.8 DR). Increases in the contact time (5 to 60 minutes) for solutions more efficient of SDS did not present differences (p<0.05) in the DR numbers. The adherence of S. Enteritidis to lettuce leaves was affected in an additive form by time 5 to 90 min, and temperature 5 a 25oC, without interaction between the factors, although temperature showed higher effect in the adherence process. The BAC and SDS solutions showed a limited efficiency, because they did not reach 3 DR, as recommended sessile cells. The SDS solutions could be an alternative to be used as a detergent in the cleaning am sanitizing process for lettuces. However, the toxicological and sensorial aspect of this application should be taken in consideration.