Gu Zi, Lee Kwang Yeon, Lee Hyeon Gyu
Department of Food and Nutrition, Hanyang University, Seoul, 04763 Korea.
Food Sci Biotechnol. 2016 Jun 30;25(3):757-761. doi: 10.1007/s10068-016-0129-0. eCollection 2016.
The aim of this study was to investigate the influence of length of freezing time (-18°C for 5 or 24 h) on the quality characteristics of tofu. The yield and moisture content of tofu obtained from frozen soybean were lower than control tofu. Tofu made from frozen soybeans showed higher hardness, gumminess and chewiness than the control. Freezing treatment also made the microstructure of the tofu more uniform than the control. However, after 24-h freezing, hardness decreased and the microstructure of tofu appeared to form pores. Sensory evaluation showed that mouth-feel decreased with an increase of freezing time. Among all of tofu frozen at -18°C, 5-h freezing treatment showed the highest overall acceptability. These results indicate that the length of time that soybeans are frozen before making tofu affects the quality of tofu.
本研究的目的是调查冷冻时间（-18°C下5小时或24小时）对豆腐品质特性的影响。冷冻大豆制成的豆腐的产量和水分含量低于对照豆腐。冷冻大豆制成的豆腐比对照豆腐表现出更高的硬度、黏性和咀嚼性。冷冻处理还使豆腐的微观结构比对照更均匀。然而，冷冻24小时后，硬度下降，豆腐的微观结构出现孔隙。感官评价表明，口感随冷冻时间的增加而下降。在-18°C冷冻的所有豆腐中，5小时冷冻处理的总体可接受性最高。这些结果表明，大豆在制成豆腐前的冷冻时间长短会影响豆腐的品质。
