| Summary: | 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.
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