Dried silken tofu
Provided is a dried soft bean curd and a drying method of soft bean curd capable of recovering a taste and texture of soft bean curd before drying as it is by vacuum freeze-drying the soft bean curd without a pre-freezing process. In addition, provided are soft bean curd having excellent physical properties of the bean curd, and a manufacturing method of soft bean curd including a step of adding starch to soy milk and a step of heating the starch for gelatinizing starch. Further, provided is a stirring method capable of uniformly dispersing the starch in soy milk by preparing and using starch in a starch dispersion solution state. Furthermore, provided are a manufacturing method of soft bean curd for drying by adding starch and gelatinizing the added starch, and a manufacturing method of dried soft bean curd by vacuum freeze-drying this soft bean curd for drying.
1. A vacuum freeze-drying method of soft bean curd, comprising:
a) vacuum-freezing soft bean curd to produce frozen soft bean curd; and
b) freeze-drying the frozen soft bean curd produced from step a) to produce dried soft bean curd,
wherein the method does not include a step of freezing soft bean curd before the step of vacuum freezing, and
wherein the dried soft bean curd produced from step b) has a hardness of 50 to 90 g measured after recovery by pouring water onto the dried soft bean curd under the following conditions;
a cylindrical probe having a diameter of 20 mm is used as a probe for measuring the hardness;
a speed at which the probe descends to a sample (pre-test speed) is set to 1.00 mm/sec;
a speed at which the probe contacts a surface of the sample and then infiltrates into the sample (test speed) is set to 5.00 mm/sec,
a speed at which the probe infiltrated into the sample and returns to an original position (post-test speed) is set to 5.00 mm/sec;
a distance at which the probe recognizes the surface of the sample and infiltrated through the sample is set to 5.000 mm;
a condition for allowing the probe to recognize the sample (trigger type) is set to force; and
a minimum force for allowing the probe to recognize the sample (trigger force) is set to 5.0 g.
2. The method of claim 1 , wherein in the step of vacuum-freezing, the soft bean curd is rapidly frozen while passing through a section in which a degree of vacuum is 4.5 to 2.0 torr within 30 minutes.
3. The method of claim 1 , wherein in the step of vacuum-freezing, the soft bean curd is rapidly frozen while passing through a section in which a central portion temperature of the soft bean curd is 0 to −5° C. within 30 minutes.
4. The method of claim 1 , wherein in the step of freeze-drying, the soft bean curd is dried so that a central portion temperature of the soft bean curd becomes 40° C. or less.
5. The method of claim 4 , wherein in step of the freeze-drying, in a range of the degree of vacuum of 2 to 0.5 torr, the soft bean curd is dried while controlling a temperature of a heating plate in an apparatus used for freezing and freeze-drying at 10 to 80° C.