Respostas fisiológicas e bioquímicas de diferentes cultivares de batatas ao processamento mínimo / Physiological and biochemical responses of different potato cultivars to minimal processing

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The purpose of the present work was to evaluate physiological and biochemical aspects of minimally processed Agata, Asterix and Monalisa potato cultivars. First physiological and microbiological variables of fresh-cut potatoes stored at 5, 15 and 25ºC were evaluated. Potatoes Asterixshowed the highest respiratory rates when compared to potatoes cv. Agata and Monalisa, regardless of the storage temperature. Psychrotrophic bacteria and total coliforms counts were within acceptable limits for all cultivars stored at 5oC during 9 days of storage. Storage at 5oC was effective to control the metabolic activity and to keep food safety of minimally processed potatoes. In a second experiment, the effect of different cultivars and storage temperatures (5 and 15ºC) on the enzymatic activity of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) was studied. Enzymatic activity increased in all cultivars at 15ºC. Agataand Asterixpotatoes were more suitable for minimal processing than Monalisa. This last cultivar is more susceptible to enzimatic browning. The third experiment was aimed at evaluating non-structural carbohydrates levels in mimally processed potatoes stored at 5 and 15ºC. The highest starch degradation rate was observed in potatoes Asterixstored at 5ºC, which was related to the increase in the soluble sugar amount verified in this experiment. There was an increase in starch content in Agatapotatoes stored at 5ºC. Sucrose contents decreased in all cultivars stored at 5ºC and remained constant in cultivars stored at 15ºC. In a fourth experiment, different combinations of antioxidants in the three potato cultivars stored at 5ºC were studied. Potatoes Monalisashowed the highest total phenol amounts and the highest activities of PAL, PPO and POD, regardless of treatment. Agatapotatoes treated with ascorbic acid 2% + cysteine 0.5% and cysteine 0.5% + 4-hexylresorcinol 0.01% showed the lowest valves activities of PAL, POD and PPO. For the Asterix and Monalisa cultivars, the best results were obtained when combinations of 4-hexylresorcinol and cysteine were used, respectively.

ASSUNTO(S)

enzimas microbiologia de alimentos microbiology antioxidants. carbohydrates enzymes antioxidantes batata browning physiology solanum tuberosum l. fisiologia pós-colheita carboidratos minimally processed processamento de alimentos.

ACESSO AO ARTIGO

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