|Budget Amount *help
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1992: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1991: ¥1,000,000 (Direct Cost: ¥1,000,000)
Commercially available seasoning extracts (83 samples) were collected directly from manufacturers and analyzed by ECD equipped GLC. MCP, one of mutagenic active monochlorohydrins, was detected at the concentration of 5 - 219 mg (Ave. 45.0 mg, SD 46.4 mg) from 21 samples. MCP was extracted from the sample using Merck Extrelut column with diethylether at least four times as much volume than instructed. This mutagenic compound was distributed only in HAP or HVP (hydrolyzed animal or vegetable protein), not in hot water extract, autolytic extract,or enzymatically hydrolyzed extract. Since acid hydrolyzed extract prepared from pure protein such as gelatin did not give rise any MCP, triacylglycerin which is one of the major neutral fat was thought to be the precursor of the compound.
Model experiment system consisted of pure protein, neutral fat, water, and emulsifier on the basis of general chemical composition for whale meat was hydrolyzed with HCl and analyzed for its concentration of MCP. The compound was not found in the system excluding any neutral fat, however, the amount of MCP increased along with that of fat added. This result led us conclusion that triacylglycerin was the precursor of the mutagenic compound during acid hydrolysis at high temperature. The relationship between the concentration of acid and that of MCP formed showed that hydrochloric acid lower than 3 M could not produce any MCP at all. The recovery of extractive nitrogen was over 89 % of total nitrogen of raw material when hydrolyzed with 3 M HCl and 56 % with 1 M HCL, respectively.
Hydrolysis of raw protein materials with 3 M HCl was safe and effective for HAP preparation.