Study on the generation of pyrazines and change in amounts of volatile compounds in smoke during preparation of dried bonito [Japanese]

摘要

The generation mechanisms of pyrazines and phenols, which have already been confirmed to be the key flavor components of dried bonito, were examined by GC-MS analysis of various volatile compounds in model dried bonito prepared with and without smoking. Pyrazines were generated during heat treatment of boiled bonito meat without smoking, but their amounts and varieties were less than those in ordinary dried bonito. These results suggested that some of unknown substances in smoke could be related to the generation of pyrazines. By the addition of acetol and 2,3-pentanedione, both of which are known to occur in smoke, the amounts and varieties of pyrazines increased markedly in heated model powder prepared from crushed dried bonito. These findings suggested that acetol and 2,3-pentanedione react with amino acids or proteins in boiled meat and generate pyrazines. Phenols were not detected in the dried bonito prepared by heating without smoking. Most probably, phenols in dried bonito were mainly derived from smoke. The incubation of the mixture prepared from crushed dried bonito together with smoked cellulose powder, resulted in a decrease in the amounts of furfural, 2-cyclopenten-1-one and 5-methylfurfural. Possibly, these compounds were converted to the non-volatile compounds in the production process of dried bonito.