61B-27 |
Volatile flavor compounds in Alaska pollack Sikhae during fermentation |
Y. J. CHA1, H. Kim1, E. J. Jeong1, Y. M. Lee1, and J. S. KIM2. (1) Dept. of Food and Nutrition, Changwon National University, Sarim-dong 9, Changwon, 641-773, South Korea, (2) Division of Marine Bioscience/Institute of Marine Industry, Gyeongsang National University, Inpyeong-dong 445, Tongyeong, 650-160, South Korea Alaska pollack Sikhae is a traditional fermented fish product that has been favored by Koreans for centuries. Eviscerated and salted Alaska pollack is the main ingredient with various other minor components added such as cooked rice and millet, red pepper, malt powder, chopped radish, garlic and ginger and allowed to ferment at 5 or 20oC until a suitable taste (slightly acid) has formed. The proper combination of minor ingredients has been said to be key for palatable Sikhae aged under moderate fermentation temperatures. However, the role of these ingredient in formation of flavor compounds of Sikhae during fermentation has not been entirely investigated. The objective of this study was to identify and compare volatile flavor compounds during 30 days aging at 5, 20oC and alternating temperature (storage at 5oC after 10 days aging at 20oC), respectively. Volatile flavor compounds in Alaska pollack Sikhae at various intervals were extracted by liquid liquid continuous extraction (LLCE). Aroma-active compounds were identified and compared gas chromatography/mass spectrometry/olfactometry (GC/MS/O). A total of 84 volatile compounds was detected in Alaska pollack Sikhae during fermentation, consisting mainly of S-containing compounds (11), alcohols (22), acids (16), aldehydes (4), ketones (4), esters (5), aromatic compounds (5), terpenes (7), and miscellaneous compounds (10). Among S-containing compounds, various allyl and/or alkyl sulfides having garlic-, garlic salt-, green onion-like odor were in higher abundance. Their levels increased up to 16 days at 20oC (optimal sensory quality) and then decreased. The levels of esters, alcohols and aromatic compounds increased in samples during fermentation, while those of terpenes decreased regardless of aging temperatures. Acetic acid was found in the highest abundance during fermentation at 20oC and also kept the levels still at alternating temperature. These results suggested that S-containing compounds may play important roles in formation of Alaska pollack Sikhae flavor with their low thresholds.
Session 61B, Food Chemistry: Flavor and aroma chemistry
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