スケトウダラ卵中の亜硝酸根定量のための試料液調製法の最適化 [in Japanese] The Optimization of Pollack Roe Sample Solution Preparation for Determination of Nitrite [in Japanese]
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Within the standard method for determination of nitrite in processed foods, sample solutions containing nitrite extracted from the foods are treated with sodium hydroxide and zinc acetate, as deproteinizing agents, before colorimetry is conducted by diazotization-coupling. However, in the case of pollack roe, analysis is very difficult or often impossible to carry out due to the turbidity, decrease in filtration rate, and foaming of the sample solution. It is suspected that these conditions are caused by the high concentration of soluble proteins originating from pollack roe. With this in mind, improvement of the procedure for preparing sample solution from pollack roe and its products was investigated. Results showed that decreases in filtration rate were resolved by the use of half the volume of deproteinizing agents in addition to twice the concentration as that of the standard method. The addition of silicone-type antifoaming agent SI suppressed the sample solution foaming and increased the filtration rate. Adding sodium chloride was not effective in avoiding turbidity or decreasing filtration rate and foaming. Using our modified method for preparing sample solutions, concentration of nitrite in pollack roe was determined to be 0.08±0.02 ppm and the recovery ratio of 5 ppm of nitrite added to pollack roe was 89.8±2.5%, respectively.
- NIPPON SHOKUHIN KOGYO GAKKAISHI
NIPPON SHOKUHIN KOGYO GAKKAISHI 54(3), 128-132, 2007-03-15
Japanese Society for Food Science and Technology