Study on the manufacture of tzau-egg

• Main Authors: Lu, Yung-Wei, 陸永偉
• Other Authors: Su Hou-Pin
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/92391575132322073764

碩士 === 國立臺灣大學 === 畜產學系 === 85 === This study used chiu-yao as starter to prepare chiu-niang that was used to manufacture tzau-egg. In addition to reveal the physico-chemical changes in tzau-egg during ripening period, the changes of components and enzymatic activities in chiu-niang were also explored, for the purpose of being the basis of improving the processing procedures of tzau-egg. After ripening at 30℃ for 16 weeks, the results showed, the egg shells thinned gradually and egg whites coagulated by acids and alcohol. Egg yolks coagulated by the dehydration effect of salt , respectively, then softened gradually with forming the hydrolyzed layer on the surface. Alcohol and salt contents of tzau-egg whites and yolks increased with ripening time. pH value decreased significantly within 2 weeks. Free fatty acids, soluble nitrogen and ripening ratio of tzau-egg yolks were decreased after 2 eks ripening, then were trended to increase. The general compositions of tzau-egg whites were moisture 70.12%, crude fat 0.12%, crude protein 16.68%, ash 5.71%, salt 5.19% and alcohol 3.80%. These of tzau-egg yolks were moisture 42.02%, crude fat 36.42%, crude protein 23.00%, ash 3.87%, salt 3.09% and alcohol 2.31%, respectively. As for the properties of chiu-niang: On this study, salt was added in chiu-niang ( salt:glutenious rice=1:8 ) to simulate the ripening environment of tzau-egg. As the results showed, pH value decreased immediately within 3 days and then was stable about 4.00. Titratable acidity increased gradually and then trended to be stable. Alcohol content increased within 7 days and then decreased gradually. Alcohol content was about 3.96% after 120 days incubation. The results of analysing the enzyme properties of chiniang showed, the maximum activities of α- Amylase, β-Amylase and lipase appeared after 3 days incubation, and 5 days the acid protease, respectively. After salt was added, activities of these enzymes decreased significantly. This phenomenon was attributed to the decline of dielectric constant of the enzyme system. Alcohol could also made the similar inhibition effect.