MATRICOL®
Freeze-drying
What happens during lyophilization/freeze-drying?
Freeze-drying is a two-stage high-tech procedure for gentle drying of sensitive products. It uses the physical rule that ice in a vacuum is directly converted to water vapor without the ice becoming a liquid first. This process of direct conversion of solid ice to vapor is called sublimation.
In Phase I of the freeze-drying process the product to be dried, e.g. a homogeneous collagen or algae emulsion, is first flash-frozen at temperatures well below zero.
In Phase II, the product remains in a vacuum chamber for many hours or days. The ice becomes a vapor in the vacuum, and appears in the form of ice on the deep-frozen condensers.
The result is a dry, spongy matrix having a three-dimensional structure. The natural, biological and physical properties of the raw material are completely intact. The molecular structure that has been completely drained of water form a large, highly absorbent internal surface, and can be rapidly hydrated.
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In Phase II, the product remains in a vacuum chamber for many hours or days. The ice becomes a vapor in the vacuum, and appears in the form of ice on the deep-frozen condensers.
The result is a dry, spongy matrix having a three-dimensional structure. The natural, biological and physical properties of the raw material are completely intact. The molecular structure that has been completely drained of water form a large, highly absorbent internal surface, and can be rapidly hydrated.
What are the advantages of lyophilization/freeze-drying?
Freeze-drying maintains the natural biological and physical properties of the raw material. For this reason, the process was first used for the preservation of blood plasma in the Second World War. Not until 20 years later were its advantages discovered for the preservation of foods because freeze-drying fully preserves taste, aroma, color and shape of foods. This led to the development of freeze-dried instant coffee and the freeze-drying of meat for ready meals, fruit for muesli and chocolate.
In contrast to freeze-drying, thermal drying with high temperatures leads to changes of the starting materials: temperature-sensitive aromas disappear, proteins coagulate (example: boiling eggs), fruit, vegetables and herbs wither (air-drying). The physical structure is destroyed by dehydration and rehydration of the products is more difficult and can lead to products becoming tough. This is completely different in the case of freeze-drying. Such issues are non-existent when employing freeze-drying technology.
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Why are the products freeze-dried?
A basic prerequisite for the efficacy of biological substances is a native, physically intact structure. Proteins and enzymes can be changed to such an extent by external influences (temperature, chemicals and pressure) that their original three-dimensional form is changed. In the vast majority of cases, the substances denature and lose their biological function. As freeze-drying preserves the native, three-dimensional structure of the starting materials, the resulting products still have a high degree of biological activity. Furthermore, an important advantage of this procedure lies in the fact that substances are not exposed to high temperatures. Substances which are temperature-sensitive are protected and remain biologically active.
The removal of water produces dry products. This waterless environment does not permit microbial growth or proliferation. For this reason, freeze-dried substances do not require chemical preservation. This makes the products particularly compelling for the personal care industry, as preservatives can be irritating to the skin.
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The removal of water produces dry products. This waterless environment does not permit microbial growth or proliferation. For this reason, freeze-dried substances do not require chemical preservation. This makes the products particularly compelling for the personal care industry, as preservatives can be irritating to the skin.