Respiratory activity and microbiological aspects of minimally processed potatoes cultivars stored at different temperatures/Atividade respiratoria e aspectos microbiologicos de cultivares de batatas minimamente processadas e armazenadas em diferentes temperaturas

The purpose of the present research was to evaluate physiological and microbiological aspects of different minimally processed potatoes cultivars. Potatoes cultivar 'Agata', 'Asterix' and 'Monalisa' were selected, classified, washed and abrasion peeled before being diced, sanitized and centrifuged. They were then placed in hermetically closed flasks and stored at 5, 15 and 25°C. The respiratory activity and ethylene production were determined immediately after the processing and during 10 hours. Microbiological analyses were carried out on the processing day and after one, five and nine days of storage at 25, 15 and 5°C, respectively. Potatoes cv. 'Asterix' showed the highest respiratory rates when compared to potatoes cultivar Agata' and 'Monalisa', regardless of the storage temperature. Potatoes cv. 'Agata' and 'Monalisa' behaved similarly to each other at 15 and 25°C. Psychrotrophic bacteria and total coliforms counts for all cultivars were within acceptable limits at 5°]C for nine days of storage. The presence of coliforms at 45°]C and Salmonella was not detected. Storage at 5°]C was effective to control the metabolic activity and to keep food safety of minimally processed potatoes. Key words: Solanum tuberosum, respiratory rate, microbiology, minimal processing. O presente trabalho teve como objetivo avaliar aspectos fisiologicos e microbiologicos de diferentes cultivares de batatas minimamente processadas. Batatas das cultivares 'Agata', 'Asterix' e 'Monalisa' foram selecionadas, classificadas, lavadas e descascadas por abrasao, sendo em seguida cortadas em cubos, sanitizadas e centrifugadas. Depois foram colocadas em frascos hermeticos e armazenadas a 5, 15 e 25°C. Foram determinadas a atividade respiratoria e a producao de etileno logo apos o processamento e durante 10 horas. As analises microbiologicas foram realizadas no dia do processamento e apos nove, cinco e um dia de conservacao, a 5, 15 e 25°]C, respectivamente. Observou-se que as batatas 'Asterix' apresentaram maiores taxas respiratorias em relacao as cultivares 'Agata' e 'Monalisa', independentemente da temperatura de armazenamento. Nas temperaturas de 15 e 25°]C, as batatas 'Agata' e 'Monalisa' apresentaram comportamentos semelhantes entre si. As contagens de bacterias psicrotroficas e coliformes totais, para todas as cultivares armazenadas 5°]C, mantiveram-se dentro dos limites aceitaveis durante nove dias de armazenamento. Nao foram detectados coliformes a 450C e Salmonella. Ficou evid