Effect of different freezing and storage condition on the physical properties of protein coagulum (Firm Tofu)

Abstract

This article attempted to apply supercooling freezing under atmospheric pressure to minimize the freezing damage on firm (momen) tofu, which is a representative of agglomeration type protein coagulum. Especially, we focused on the influence of different freezing rate after the releasing from supercooling state. Storage test up to one month with different storage temperature was also carried out. The quality parameters such as drip loss, texture, and microstructure were analyzed and compared with conventional methods (slow freezing and rapid freezing) after the storage under −80 °C and -20 °C up to one month. As the results, significant advantages were confirmed on the sample prepared by supercooling freezing even after the one-month storage. Further, higher freezing rate after the releasing from supercooling states successfully reduced the drip loss and kept good texture, with less microstructural damage. The possible mechanism on which supercooling freezing affects ice crystals formation and quality degradation are thoroughly discussed.