Chemical changes in cacao beans associated with mold contamination
This investigation was undertaken to determine the change which occurs in the carbonyls of mold infested cacao beans. Quantitative data were obtained for total carbonyls and total monocarbonyls, methyl ketones, saturated aldehydes, 2-enals and 2,4-dienals. Thin layer and gas chromatography were employed to identify individual monocarbonyl compounds. Cacao fat and carbonyls were extracted from 30 grams of finely ground beans, and then passed throung a column of 2,4 dinitrophenylhydrazine, H3PO4 and Celite to form DNP-hydrazones. Total carbonyls were quantitated spectrophotometrically then the fat and dicarbonyls were separated from monocarbonyls using a column containing Celite 545 and Sea Sorb 43. A quantitative value for monocarbonyls was obtained after removal of ketoglycerides utilizing an alumina column. Concentrates of methyl ketones, saturated aldehydes, 2-enals and 2,4-dienals were measured after class separation on Celite 545 Sea Sorb 43 column. For the analyses carried out in this investigation, moldy cacao beans averages 59 percent higher in total carbonyls, and monocarbonyl concentration was double that of beans showing no visible evidence of mold. Quantitatively the most pronounced increase in the monocarbonyls occurred in the methyl ketone fraction. Both GLC and TLC indicated that moldy and non-moldy beans contained acetone, butan-2-one, hexan-2-one, heptan-2-one and several other ketones not positively identified. The principal differences were that moldy beans had much greater concentrations of these ketones and also contained C13, C15 and C17 methyl ketones from B-oxidation of cacao bean fatty acids. The saturated aldehyde concentrations decreased in most moldy samples whereas 2-enals and 2,4-dienals usually increased. Spots, corresponding to 2,4-pentadienal and 2,4-octadienal were observed on TLC plates of moldy and non-moldy beans along with other 2,4-dienals and 2-enals.
| Main Authors: | , |
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| Format: | biblioteca |
| Published: |
Pennsylvania (EUA)
1968
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| Subjects: | CACAO, ALMENDRA, PROPIEDADES FISICO-QUIMICAS, MOHO, ENFERMEDADES FUNGOSAS, CONTENIDO DE LIPIDOS, |
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| Summary: | This investigation was undertaken to determine the change which occurs in the carbonyls of mold infested cacao beans. Quantitative data were obtained for total carbonyls and total monocarbonyls, methyl ketones, saturated aldehydes, 2-enals and 2,4-dienals. Thin layer and gas chromatography were employed to identify individual monocarbonyl compounds. Cacao fat and carbonyls were extracted from 30 grams of finely ground beans, and then passed throung a column of 2,4 dinitrophenylhydrazine, H3PO4 and Celite to form DNP-hydrazones. Total carbonyls were quantitated spectrophotometrically then the fat and dicarbonyls were separated from monocarbonyls using a column containing Celite 545 and Sea Sorb 43. A quantitative value for monocarbonyls was obtained after removal of ketoglycerides utilizing an alumina column. Concentrates of methyl ketones, saturated aldehydes, 2-enals and 2,4-dienals were measured after class separation on Celite 545 Sea Sorb 43 column. For the analyses carried out in this investigation, moldy cacao beans averages 59 percent higher in total carbonyls, and monocarbonyl concentration was double that of beans showing no visible evidence of mold. Quantitatively the most pronounced increase in the monocarbonyls occurred in the methyl ketone fraction. Both GLC and TLC indicated that moldy and non-moldy beans contained acetone, butan-2-one, hexan-2-one, heptan-2-one and several other ketones not positively identified. The principal differences were that moldy beans had much greater concentrations of these ketones and also contained C13, C15 and C17 methyl ketones from B-oxidation of cacao bean fatty acids. The saturated aldehyde concentrations decreased in most moldy samples whereas 2-enals and 2,4-dienals usually increased. Spots, corresponding to 2,4-pentadienal and 2,4-octadienal were observed on TLC plates of moldy and non-moldy beans along with other 2,4-dienals and 2-enals. |
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