Factor affecting the concentration of pyrazines in cocoa beans
Gle of the pyrazine fraction from roasted cocoa beans yielded nine well resolved peaks which could be quantitated. When beans from several producing countries were roasted under identical conditions, pyrazines generated varied between 142 microgram/100 g of beans and 698 microgram/100 g. The potential for generating pyrazines was greatest in samples from countries where beans are traditionally fermented. Tetramethylpyrazine, trimethylpyrazine, and pyrazines under a peak representing a mixture of 2-ethylpyrazine, 2,5-dimethylpyrazine, and 2,6-dimethylpyrazine were present in the highest concentrations. In fermented cocoa beans, pyrazine concentration increased rapidly during roasting to a near maximum value which did not change during extended roasting. Results indicate that fermentation influences the rate of formation and final concentration of pyrazines in roasted beans primarily through its effect on the free sugars. Ketoses dominated the sugars fraction (62 percent of total) in well fermented beans compared to 21 percent in nonfermented varieties. Tetramethylpyrazine was the only pyrazine detected in unroasted beans and then only in fermented samples
| Main Authors: | , , |
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| Format: | biblioteca |
| Published: |
1972
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| Subjects: | TOSTADO, CACAO, PIRAZINAS, COMPUESTOS ORGANICOS, VARIEDADES, COMPOSICION QUIMICA, ANALISIS QUIMICO, |
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| Summary: | Gle of the pyrazine fraction from roasted cocoa beans yielded nine well resolved peaks which could be quantitated. When beans from several producing countries were roasted under identical conditions, pyrazines generated varied between 142 microgram/100 g of beans and 698 microgram/100 g. The potential for generating pyrazines was greatest in samples from countries where beans are traditionally fermented. Tetramethylpyrazine, trimethylpyrazine, and pyrazines under a peak representing a mixture of 2-ethylpyrazine, 2,5-dimethylpyrazine, and 2,6-dimethylpyrazine were present in the highest concentrations. In fermented cocoa beans, pyrazine concentration increased rapidly during roasting to a near maximum value which did not change during extended roasting. Results indicate that fermentation influences the rate of formation and final concentration of pyrazines in roasted beans primarily through its effect on the free sugars. Ketoses dominated the sugars fraction (62 percent of total) in well fermented beans compared to 21 percent in nonfermented varieties. Tetramethylpyrazine was the only pyrazine detected in unroasted beans and then only in fermented samples |
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