45C-15 |
Headspace volatile components in fermenting red rice inoculated with a Monascus sp. |
H. Y. CHUNG, Biology Dept., Chinese Univ. of Hong Kong, Food & Nutritional Sciences Programme, Shatin, New Territories, Hong Kong SAR, China, W. C. J. Ma, Biology Dept., The Chinese University of Hong Kong, and J. S. Kim, Pulmuone R&D Center, Pulmuone Co., Ltd., Seodaemun PO Box 146, Seodeamun-Ku, Seoul, 120-600, South Korea. Sufu is a popular condiment used in the preparation of southern Chinese dishes. They are roughly divided into plain and red types in Hong Kong. Their basic production steps are similar. However, for the red type, fermented red rice (FRR) is introduced during the aging period of sufu to produce the reddish product. Although the primary purpose of the fermented red rice is to act as a natural colorant, its alternate purpose may be used as a flavoring agent to add a subtle flavor to the characteristic product. In this investigation, the headspace volatile components of the FRR and its control were compared to determine its contribution to the red sufu. Glutinous rice was steamed, cooled and equal amount was transferred to 250-mL conical flasks. A Monascus species in both liquid and solid culture media were aseptically prepared and inoculated to the rice-containing flasks. The remaining rice-containing flasks (control) were no inoculated. All flasks were incubated at 37ºC for 14 days. Headspace components were collected by a 10-mL gas-tight syringe and injected directly into a cooled-injection system coupled with a gas chromatography/mass spectrometry (-120ºC). Volatile components produced by the FRR were very different from that of the control. In the control, ten compounds were found with 2-pentylfuran as the most abundant compound. In the fermented red rice, 15 compounds were found and composed of mainly alcohols (6) and esters (4). Ethanol was the most abundant. Thirteen of them were previously identified in commercial red sufus. Overall, volatile compounds from the FRR contributed to the volatile composition of red sufus and provided valuable information to understand the origin of the volatile components in red sufus.
Session 45C, Food Chemistry: Flavor and aroma chemistry
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