关键词: 南极磷虾虾酱, 流变特性, 固相微萃取-气相色谱-质谱, 挥发性风味成分, 发酵温度

Abstract: Static and dynamic rheological properties, volatile compounds and sensory characteristics of Antarctic krill (Euphausia superba) pastes fermented at different temperatures (15, 25, and 35 ℃) were investigated. The results showed that krill paste was non-Newtonian pseudoplastic fluid with shear thinning behavior, and had weak gel characteristics. Higher fermentation temperature and longer fermentation time could more significantly break up the gel structure of krill paste, especially at 35 ℃. Fermentation at 25 ℃ improved the stability of krill paste gel. The apparent viscosity, storage modulus and loss modulus of the samples reached maximum levels on the 9th day. A total of 39, 41 and 37 volatile flavor compounds were identified in the three different krill pastes by solid phase microextraction-gas chromatography-mass spectrometry. (E,E)-2,4-Heptadienal, nonanal, decanal, benzaldehyde and benzothiazole were found to significantly contribute to the characteristic odor of krill paste; in krill paste fermented at 25 ℃, 3-ethyl-2,5-dimethyl-pyrazine and 2,3,5-trimethyl-6-ethyl-pyrazine, enhancing its flavor, were also identified, and trimethylamine in krill paste fermented at 35 ℃, responsible for stinky, fishy odor. Krill paste fermented at 25 ℃ for 9 to 12 days showed the best rheological and flavor characteristics.

Key words: Antarctic krill (Euphausia superba) paste, rheological properties, solid phase micro-extraction-gas chromatography-mass spectrometry, volatile flavor compounds, fermentation temperature