Effect of dynamic storage temperatures on the microstructure of frozen carrot imaged using X-ray micro-CT

Frozen vegetables are often exposed to dynamic temperature conditions during cold storage and distribution chain. The resulting ice recrystallization leads to microstructural changes, which is directly linked to the final vegetable quality. To this end, X-ray mu CT was applied to visualize and quantify 3D ice crystal changes in carrot over a period of two months of frozen storage with dynamically changing temperature. The studied conditions revealed a significant increase in ice crystal size during the storage period. The mean equivalent diameter of the ice crystals increased from 246 +/- 15.9 mu m, to 342 +/- 13.2 mu m, 394 +/- 18.5 mu m, 525 +/- 28.0 mu m and 578 mu 27.6 mu m at 0 d, 7 d, 14 d, 30 d and 60 d of storage, respectively, while the number of ice crystals decreased. The 3D data on the ice crystals and image analysis presented within this paper provide an insight making it possible to describe microstructure evolution, and for better control cold storage sector of frozen vegetables.