美国康塔仪器公司：奶粉的水吸附研究

Milk powder is a valuable commodity for industrialized and third world countries. It is widely used in industrialized countries as the basis for powdered infant foods and by the baking and confection industries as a raw ingredient. In developing countries, especially those hit by famines, milk powder is an important source of protein and calories. In both cases transportation charges for an equivalent nutritional value are significantly lower for milk powder than for bulk whole milk, and milk powder has greater shelf life not requiring refrigeration. Free moisture promotes mold growth in foods; the higher the relative humidity the greater the potential for molding, particularly over 65%RH. However, like most desiccated food stuffs, milk powder exhibits a tendency to absorb moisture from the atmosphere. In a closed container, therefore, it has self-desiccating qualities to some degree. Sugar and table salt are two examples of foods with strong desiccating qualities and are therefore used as preservatives for other foods which are less desiccating. So, the moisture sorption quality of a foodstuff is essential information when it comes to considering packaging and storage conditions. Moisture sorption can also affect texture, color and flowability of powders. The moisture sorption behavior of foods is quickly and conveniently measured by dynamic gravimetric water vapor sorption, often referred to simply as DVS.