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標題: Improvement of freezing resistance and freeze-drying suitability of traditional tofu
作者: 劉家芳
Liu, chia-Fang
關鍵字: 傳統豆腐;curdlan;冷凍乾燥;反應曲面法;質地輪廓分析;冷凍;traditional tofu;curdlan;freeze-drying;response surface methodology;texture profile analysis;freeze
出版社: 食品科學系
ABSTRACT Traditional tofu is liable to deterioration and
possesses no freezing resistance. Its texture becomes sponge-
like after freezing. This makes itinconvenient in
transportation, storage, and consumption. Curdlan is a bacterial
polysaccharide which is composed mainly of β-1,3- glucosidic
linkage. A rigid and elastic thermal irreversible gel could be
formed from its suspension by heating above 80℃. Excellent gel
strength couldbe maintained by the gel after freezing and
thawing. The gel would result in syneresis when it is stored,
and the syneresis of curdlan gel could bedecreased by the
addition of waxy corn starch. On the other hand, concentration
of coagulant required was also affected owing to thebinding
capacity of curdlan. Therefore, traditional tofu with freezing
resistance and higher water holding capacity was developed in
this study.Effects of curdlan(0 ~1.5%), waxy corn starch(0
~1.5%), and coagulantconcentrations(0.5 ~1.5%) on traditional
tofu were studies by using response surface methodology (RSM)
and a three-variable and three-leveldesign. The objectives were
to obtain a traditional tofu with freezingresistance by the
study of their interactions and by the determination of some
optimum conditions. On the other hand, freezing temperature(-5℃
~-45℃) was combined with those three above-mentioned
conditionsin the freeze-drying study in order to develop a
dehydrated product with good qualities and to expand the
applicability of traditional tofu in modern foods. Items tested
included gel strength, water holding capacity,rehydration ratio,
Instron texture profile analysis (TPA), as well assensory
evaluation and scanning electron microscopic examination.
Besides, the studies of pure curdlan was also be performed by
using RSM. Differences among those processes was going to be
compared and studied,and actions of curdlan in application was
going to be further investigatedand elucidated. Results showed
that the optimum processing conditions of frozen traditional
tofu were curdlan 0 ~ 0.2%, waxy corn starch 0.94 ~ 1.5%,and
coagulant 1%. The optimum processing conditions of freeze-dried
traditional tofu were found to be curdlan 0 ~ 0.18%, waxy corn
starch 1.31~1.5%, coagulant 0.5%, and freezing temperature

中 文 摘 要 傳統豆腐十分容易腐敗,而且不具抗凍性,冷凍貯藏之
力,利用反應曲面法(RSM)對傳統豆腐製程中所用curdlan濃度(0 ~
1.5%)、糯玉米澱粉濃度(0 ~ 1.5%)及凝結劑濃度(0.5~1.5%)進行三因子
冷凍傳統豆腐。此外,將前述三因子再配合上預備凍結溫度(-5℃ ~
用情形。結果發現冷凍傳統豆腐的最適加工條件為:curdlan濃度0 ~
0.2%,糯玉米澱粉濃度0.94 ~ 1.5%,凝結劑濃度 1%。冷凍乾燥傳統豆腐
的最適加工條件為:curdlan濃度0 ~ 0.18%,糯玉米澱粉濃度1.31 ~
Appears in Collections:食品暨應用生物科技學系

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