14B-12

W. C. J. MA¹, K. S. I. Yung¹, and H. Y. Chung². (1) Bio. Dept., The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China, Hong Kong, (2) Bio. Dept., Food and Nutritional Sciences Programme, and Food Sci. Lab., The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China, Hong Kong

Scallop is a popular, high-valued seafood used in different oriental cuisines. Upon heating, it will generate characteristic flavor. Different cooking methods such as steaming and boiling may alter the overall delicate aromas. Scallops are sold in raw, frozen or dried forms. Previous researches concentrated in the identification of volatile components in raw and dried scallops whereas limited investigation was done in freshly frozen ones. The objectives of this experiment were to determine and to compare the volatile components in freshly frozen scallops prepared by boiling or steaming methods. Freshly frozen scallops (Patinopecten yessoensis) obtained from a seafood store in Hong Kong were extracted with a simultaneous steam distillation-solvent extraction (SDE) apparatus, and by either boiling or steaming methods. Extracts were concentrated and analyzed by gas chromatography/mass spectrometry (GC/MS), and by gas chromatography/olfactometry (GC/O). A combined total of 135 volatile compounds were found. Common components (131) in both methods included 23 ketones, 17 alcohols, 16 aldehydes, 12 benzenes, 10 S-containing compounds, 7 naphthalenes, 7 pyrazines, 6 phenols, 5 terpenes, 5 alkanes, 4 esters, 4 furans, 4 pyridines, 2 pyrroles, 1 acid and 8 miscellaneous compounds. The concentrations of 31 compounds in the boiled samples were higher than that in the steamed ones (p<0.05). GC/O results showed that both boiled and steamed samples gave similar odor profiles. This included corn-like and acidic notes at retention time (RI) less than RI=1100; meaty, fishy, dried seafood-like and metallic flavor between RI=1100 and RI=1700. Results showed that both boiled and steamed scallops had similar volatile components. And the average quantities of common ones in the former were generally higher than that in the latter. This may account for the subtle differences in aromas caused by different preparation methods.