Evaluation of Smoky Taste in Cocoa Powder.
The aim of this study was to determine the levels of nine phenols (phenol, guaiacol derivatives, xylenols, and cresols) by using a GC/MS technique in smoked samples under control, commercial samples taken from contaminated batches, and uncontaminated samples. The smoky taste of cocoa powder may have two origins: drying and storage. The sample was steam distilled, extracted with ethyl ether, concentrated, and chromatographed on a 50-m OV-351 fused silica column. The physicochemical data obtained were related to sensory evaluation and submitted to multivariate distribution (Mahalanobis distance) and Pearson Chi-squared test. The discriminatory phenols identified were phenol, 3-methylphenol (m-cresol), 2,3-dimethylphenol (2,3-xylenol), 3-ethylphenol, 4-ethylphenol, and total phenols. The results obtained imply that uncontaminated smoked cocoa samples should have the following maximum concentrations: phenol, 2 mg/kg; 3-methylphenol, 0.9 mg/kg; 2,3-dimethylphenol, 0.55 mg/kg; 3-ethylphenol, 0.90 mg/kg; 4-ethylphenol, 0.70 mg/kg; and total phenols, 9.6 mg/kg.
Serra Bonvehí J
Agricultural and Food Laboratory (Generalitat of Catalonia), 08348 Cabrils, Barcelona, Spain, and Nabisco Iberia, P.O. Box 2022, 08080 Barcelona, Spain.
Ventura Coll F