ABSTRACT
Bacteria and molds may spoil and/or contaminate apple juice either by direct microbial action or indirectly by the uptake of metabolites as off-flavours and toxins. Some of these microorganisms and/or metabolites may remain in the food even after extensive procedures. This study aim to identify the presence of molds (including heat resistant species) and Alicyclobacillus spp., during concentrated apple juice processing. Molds were isolated at different steps and then identified by their macroscopic and microscopic characteristics after cultivation on standard media at 5, 25 and 37ºC, during 7 days. Among the 19 isolated found, 63% were identified as Penicillium with 50% belonging to the P. expansum specie. With regards to heat resistant molds, the species Neosartorya fischeri, Byssochlamys fulva and also the genus Eupenicillium sp., Talaromyces sp. and Eurotium sp. were isolated. The thermoacidophilic spore-forming bacteria were identified as A. acidoterrestris by a further investigation based on 16S rRNA sequence similarity. The large contamination found indicates the need for methods to eliminate or prevent the presence of these microorganisms in the processing plants in order to avoid both spoilage of apple juice and toxin production.
Subject(s)
Alicyclobacillus/isolation & purification , Beverages/microbiology , Food Handling , Fungi/classification , Fungi/isolation & purification , Bacterial Load , Colony Count, Microbial , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Malus , Microscopy , /genetics , Sequence Analysis, DNAABSTRACT
Foi avaliada a atividade antimicrobiana do eugenol contra Alicyclobacillus hesperidum, Alicyclobacillus cycloheptanicus, Alicyclobacillus acidiphilus, Alicyclobacillus acidoterrestris e de Alicyclobacillus spp., isolados em indústrias de sucos de laranja de várias regiões do Estado de São Paulo. O teste de suscetibilidade para o eugenol foi realizado determinando-se a concentração inibitória mínima (CIM)pela técnica de microdiluição em placas de 96 cavidades. A CIM do eugenol variou de 66,65 a >1066,4μg/mL, evidenciando-se a atividade inibitória forte e moderada frente a todas as amostras testadas e a atividade bactericida. Este estudo demonstrou ser significativa a fonte de isolamento das linhagens de Alicyclobacillus spp. nas indústrias. Conclui-se que o eugenol possui eficaz atividade antimicrobiana contra Alicyclobacillus spp. e sugere-se o uso deste composto para prevenir a deterioração de bebidas acidificadas e para diminuir o custo do controle microbiológico mais especificamente em suco de laranja.