61B-16 |
Headspace analysis of common volatile compounds in plain sufu |
C. W. YEUNG, Biology Dept., The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China and H. Y. Chung, Biology Dept., Food and Nutritional Sciences Programme, and Food Sci. Lab., The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China. Sufu is a traditional soy-based fermented food serving as a side dish or seasoning in oriental countries. Its characteristic flavor is well accepted by consumers. Molds responsible for sufu fermentation include Mucor sp., Actinomucor sp. and others. Different molds are utilized in sufu fermentation, but it is likely that the aromas produced would be similar as the raw materials and fermentation process are the same. The objective of the current study was to determine by headspace technique the common volatile compounds in several brands of plain sufu. Three brands of plain sufu were obtained. Two were manufactured in China and one in Hong Kong. Fifteen grams of sufu sample were transferred to a closed glass container containing 1 mL of 2,4,6-trimethylpyridine (1 mg/mL) as internal standard. The container was maintained at 50¢XC for 30 min. Headspace sample (1 mL) was collected with a gas-tight syringe and injected into a gas chromatography/mass spectrometry for analysis. Volatile compounds detected in the headspace were similar amongst the brands. A total of seventy-three common compounds were identified including acids (3), alcohol (12), aldehydes (33), alkanes (3), alkene (1), benzene (1), ester (1), furans (6), ketones (12) and miscellaneous (1). Compounds with high abundance included acetic acid ester (aroma: pineapple, ethereal), ethanol, ethanal (aroma: pungent, ethereal), heptanal (aroma: fatty, penetrating, sweet, fruity on dilution), hexanal (aroma: fatty, penetrating), nonanal (aroma: floral, citrus, fatty), octanal (aroma: fatty, citrus) and pentanal (aroma: vanilla, fruity). Ethanol has the highest abundance because it was part of the aging solution. Three brands of plain sufu shared similar headspace profiles (73 compounds). Although headspace technique identified twenty-two compounds in common with results using steam distillation technique, headspace technique is a much milder technique and the results are closer representation of the aroma in sufu.
Session 61B, Food Chemistry: Flavor and aroma chemistry
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