Influence of the production way, the conditions of processing and keeping on its properties.

Properties, nutritious value and biological properties depend on the way of gathering and the processing technology. Pollen is produced from the healthiest families. Otherwise it can be the source of bee diseases, especially when it was used as additional fertilizing of bee families. Pollen assay from diseased families showed that in 76,7% contained mold fungi (Aspergillus and Penicillium mucor) and in assay of pollen taken from healthy families their number was fewer. Scientists found conventionally pathogenous micro-organisms to bee families (Bac. alvei, Bac. gracilosporus, and Bac. laterosporus), in some cases Bac. larvae, and Ascosphera apis, Aspergillus. The main components of environmental pollution (pesticides, industrial waste products) are found in considerable quantities in pollen.

It is known that contents of phosphor in pollen is more in the regions with the developed industry (from 1500 to 6300mcgr/gr) and in areas where measures aimed at protecting nature by organic phosphoric insecticides (18 160 mcg/gr). More over in industrial areas there are more copper (789mcg/gr) and zinc (631-722mcg/gr). In less industrially developed areas the quantity of these substances and hard metals is hundred times lower. These data shows that the quality and the purity of the pollen is straightway connected with the environmental pollution.

Determination of the presence hard metals and phosphor in pollen is used as the method of stating insecticides and chemical poisonous substances in the environment.

In fresh pollen there are 20-30% of water. While gathering it bees add there some nectar, honey, secretion of salivary glands. The contents of water also depends of the air humidity in the time of gathering pollen. In pollen there is a considerable number of microorganisms and ferments, that become active in humid medium. If the contents of water is high pollen turns sour and gets moldy and pollen grains are destroyed, change their shape and stick together. If the outward pollen catches are cleaned every day, pollen doesnít dampen at night. In all cases dampness should be diminished by drying up to 10-12%. With such humidity and room temperature pollen can be stored for a long time.

A simple method of drying, used at the apiaries consists in the following:

Pollen is thinly poured (1-2mm thick) over a sheet of white paper, covered with a gauze and stirred now and then. When pollen is gathered in large quantities it is dried in a drying apparatus: with the help of colorifer pollen is blown on at a temperature of 35-40 C. The duration of drying depends on its dampness. If humidity is about 30% it is necessary to dry about 78 hours, and if it 25% - 16-18 hours. It is possible to dry it under infrared waves. In any case the temperature mustnít exceed 45C, otherwise in the result of the destruction of thermolabile, biologically active substances pollen biological properties deteriorate. Sunlight canít be used in pollen drying.

Vacuum drying at a temperature of 48-50C takes about 6,5 hours and has some advantages as compared to drying by infrared waves and sublimation drying and drying in an ordinary thermostat. Vitamins and amino acids retain their properties in vacuum drying and the process is much faster. Drying in vacuum at a temperature of 120C is better as humidity lowers to 5% in 79-90 minutes and pollen is simultaneously sterilized.

Material admixtures (defilement) are effectively removed after drying. Seed purifying machine can be used for this purpose. Moreover sieves with different sizes of holes are used. A small amount of pollen can be purified by hand.

Many researchers have studied the change of pollen properties taking in account various ways of storage. Thus the changes in proteins, amino acids and proteins in sulfitic-hydrate of pollen kept less than a year at a constant temperature of 4C have been analyzed. It was found out that in CO2 medium or in vacuum the contents of proteins reduces in average to 2,8-3,23% within 12 months. Storing pollen in the open air reduces the contents of amino acids (33-50%)

Amino acids preserve better if pollen is kept in vacuum or in CO2 medium. It is also discovered that declining in the quality of sulfitic-hydrate group depends on the conditions and the length of storage. It has been stated that storing pollen in tanks made of dark glass at a constant temperature during 10-11 months the quantity of vitamin C decreases 30-52%, and the quantity of unsaturated compounds and acidity of water extracts slightly changes.

Scientists have proved that if pollen is kept during 6-9 months at a temperature of 2-3C carotenoids and chlorogenic acids, leucoantocyanide and flavonols are the most changeable. Vitamin C contents 10-62% decreases during 9 months depending on the plant origin of pollen. Stability of biologically active substances depends not only on storage conditions but also on the type of pollen and its plant origin. Carotenetes are the most susceptible to changes irrespective of storage conditions. Adding antioxidants (spirit extract for example) heightens its stability. Thatís why some researches advise to store pollen in low temperature (0-5C), and when lacking refrigeration engineering Ė in C2 medium with propolis extract treatment preceding.

So dried pollen is much more stable than damp. With a view to preserve all its qualities it should be stored at low temperatures (about 0C). More over it is necessary to disinfect it in CO2 medium and store it in vacuum if it is possible. For disinfecting it can also be kept for 24-48 hours at low temperature, as a result all the insect larvae and eggs are destroyed.

Dry as well as damp pollen is conserved with honey or powdered sugar. 2 parts of honey are mixed with a part of pollen or a part of pollen Ėwith a part of powdered sugar. Conserved pollen can be stored quite a long time.


English translation © Irina Yelsukova