Figure 1. Per capita consumption of dried fruits in the United States, 1997.

4.6 mmHg, the vapor pressure of the ice and water at 0°C, is necessary) to around 2% moisture.

Intermediate-moisture fruits (IMF) are dried on the basis of water activity level rather than on the percentage of moisture. Restraint of the water molecules to a degree that prohibits spoilage by microorganisms occurs at different moisture contents depending on the amount and nature of the dissolved material present and to some degree on the insoluble components. Food may be classified as an IMF if it has water activity level greater than a common low-moisture fruit (0.2) and less than that of most fresh fruit (0.85). In practice, most IMF has a water activity in the range of 0.65 to 0.85 and contains 15 to 30% moisture.

Water activity (aw) is defined as the ratio of the water vapor pressure in equilibrium with a food to the vapor pressure of water at the same temperature. Bacteria will not grow if aw is below 0.9, and yeast and molds, are inhibited below ^ of 0.7.

Dehydrofreezing is a hybrid process that combines the best features of both drying and freezing. The process consists of drying fruit to about 50% of its original weight, then this intermediate material is quick-frozen by standard freezing techniques. The quality of dehydrofrozen fruit is equal to that of frozen products, as the drying process is discontinued at a stage where quality impairment usually does not occur. The advantages of the process are a 50% reduction in storage and freight charges and even greater savings in packaging costs in comparison with traditional frozen products.

The Mediterranean Diet Meltdown

The Mediterranean Diet Meltdown

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