Reducing the Bitterness of Tuna (Euthynnus pelamis) Dark Meat with Lactobacillus casei subsp. casei ATCC 393 Complex Biochemistry and Biotechnological Production of Betalains
Fabiano Cleber Bertoldi*, Ernani S. Sant’Anna and Luiz H. Beirão
Departamento de Ciência e Tecnologia de Alimentos, Universidade Federal de Santa Catarina, Rod. Admar Gonzaga 1346, CEP 88034-001, Itacorubi, Florianópolis, Santa Catarina, Brasil
Article history:
Received: November 16, 2003
Accepted: February 16, 2004
Key words:
fermented fish, lactic acid bacteria, Lactobacillus casei, tuna
Summary:
During the process of canning tuna fish, considerable amounts of dark tuna meat are left over because of its bitterness, which are then used in the production of animal food. Fermentation with Lactobacillus casei subsp. casei ATCC 393 was used as an alternative to reduce this bitter taste. Samples of meat were prepared, vacuum packed and then stored at –18 °C. The frozen dark meat was used immediately after defrosting and the experiment was carried out with 2 and 4 % of NaCl with the addition of 2 and 4 % of glucose, respectively. The dark tuna meat was inoculated with lactic acid bacteria (LAB) and fermented at 10 °C for 30 days. The fermentation process was monitored through bacteriological and chemical analyses, when an increase of acidity and the corresponding decrease of pH were observed due to the prevalence of LAB. Sensorial analysis, using a test of multiple comparison, was carried out with pastes of fermented dark tuna meat and presented a significant difference when compared to the paste control, indicating the reduction of bitter taste.
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