morphology and freezing** **
**Of the many components in food starch and water are very common. The starch within the food is usually gelatinized. Thus, the study of the freezing behavior of a simple mixture of gelatinized starch and water is applicable to many products. **
**A directional solidification apparatus (DSA) is used to observe the solid liquid interface during freezing. Therefore, one can see what is happening to the mixture during freezing. It works by moving the sample cell from a hot stage to a cold stage at a preset velocity. **
The interaction between the starch granule at the interface can produce a non-homogeneous distribution of granules with in the frozen product. This unequal distribution remains even after the product is thawed, altering it’s properties. The rate of freezing influences this distribution of starch granules in the frozen sample.
**There are two effects: **
**1. Segregation Behavior-areas of high and low starch concentration. **
2. Band Formation- caused by changes in velocity of the formation of the solid liquid interface. ** 
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**This pictorial shows why a bad formation and segregation behavior occurs upon freezing when carbohydrate reacts with freezing water it is pushed to the side (lighter area), while the dark area represents frozen sections of water, where freezing first occurs. **
Which solution (a 2% corn starch or a 2% potato starch solution will freeze more uniformly at a given temperature? Corn Maltodextrin Starch’s smaller granules permit more even distribution during freezing, while potato starch clumps together unevenly.