Effect of freeze-concentrated glass transitions on the shattering behavior of frozen cabbage leaves

This study aimed to clarify the effect of freeze-concentrated glass transitions on the shattering behavior of frozen cabbage leaves. A single impact was applied to frozen leaf samples at various temperatures using a free-falling force gauge. Shattering was not observed at −10 ºC. The number and mean area of fragments increased and decreased logarithmically, respectively, with decreases in temperature over the range of −15 to −40 ºC. The number and mean area of fragments observed at −50 ºC were slightly lower and higher, respectively, than those expected based on the trend seen at higher temperatures. Calorimetric analysis demonstrated that the freeze-concentrated glass transition of cabbage extract occurred at −42 ºC. Rheological analysis demonstrated that the freeze-concentrated glass transition of hydrated pectin occurred at −11 ºC. Freeze-concentrated glass transitions will have affected the shattering characteristics of frozen cabbage leaves.