| Summary: | 碩士 === 國立臺灣海洋大學 === 食品科學系 === 101 === Formaldehyde (FA) is the most widespread gas-phase carbonyl compound in the environment and the toxic aldehydes classified “as carcinogenic to humans” by the International Agency for Research on Cancer (IARC). It is illegal to add in foods and ingredients occasionally; Dimethylamine (dimethylamine, DMA) and nitrite are in foods that can digest and metabolism to produces the carcinogenic nitrosamines (nitrosoamines) compounds at the low pH environment of human gastrointestinal tract via. And rich in trimethylamine oxide (trimethylamine oxide, TMAO) of aquatic products after heated, the thermal pyrolysis of TMAO pyrolysis will significantly improve FA and DMA content. In this study, for regular barbecue eating squid, neritic squid and fish three kinds of aquatic products, investigated that the 160-200oC heated for 5-60 minutes, for the influence of products on TMAO pyrolysis generated, and comparison of the open (unsealed) and closed (sealed) heating system while the differences simultaneously. Results the squids only a small part of TMAO have been transformed into DMA and FA within 15 minutes heated, The thermal degradation rate of TMAO this heating process changes only 23-39%, more than 90% of TMAO pyrolysis after heated for 60 minutes and in sealed can significantly enhance the DMA and FA formation rate after heated for 200oC. It’s content were increased 85.26 ± 0.56~99.21 ± 1.28 and 5.46 ± 0.11~9.59 ± 0.08 mol/g dry weight basis, equivalent of the highest DMA and FA containing approximately 1490 ppm and 96.12 ppm wet weight basis. TMA also added 4-4.7 times of the original content more significant, moreover the bad orders accompanied. Therefore, proposed that roasted the aquatic products of open heating system at the same time is better. Migratory species of fish in the pyrolysis of TMAO that changes slow over comparatively of cephalopods, among them, Swordfish of TMAO pyrolysis rate were 65-67% for the highest after heating 60 minutes. DMA and FA levels also increased significantly 1.5-1.8 and 1.4 times from the original content. Changes in the content of dry weight basis was 30.56 ± 0.12~37.38 ± 0.50 and 1.93 ± 0.02~2.11 ± 0.03 mol/g, equivalent of the highest DMA and FA containing approximately 561.70 ppm and 22.32 ppm wet weight basis. All aquatic products, the thermal pyrolysis of TMAO in Argentine shortfin squid mantle meats were the highest after broiled at 200oC for 60 minutes. Sealed and unsealed heating system of decomposition rate was 94 and 95%. The production of FA and DMA content in jumbo squid mantle meats was 9.59 ± 0.08 and 99.21 ± 1.28 mol/g dry weight basis in sealed that were heated at 200oC for 60 minutes and up to the maximum, and FA growth rate in neritic squid was the most significant from the original to 2-2.4 times after heated for 60 minutes, up to 5.30 ± 0.10~7.01 ± 0.25 mol/g dry weight basis content.
By the studies that, all kinds of aquatic products with the heated temperature and time extended, the pyrolysis of TMAO will gradually increased, and the cephalopods of the thermal pyrolysis rate significantly greater than migratory species of fish. Where the DMA and FA formation rate of changed in the species-rich TMAO that be more obvious, which produced large amounts of DMA and FA after heated for 60 minutes. Along with the decrease in TMAO content, TMA, DMA and FA will increase the amount of change. And the relationship between the change of the three parties Into a certain proportion.
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