Determination of the content of honey pads
June 21, 2018
Equipment and utensils: marching laboratories for determination of admixture of honey paddies, pad determinant, salt cellars with lids, glass sticks (sharpened at one end), chemical test tubes, 10 ml graduated, muffle furnace, desiccator, analytical balance.
Materials and reagents: distilled water, rectified spirit (96 њ), acetic acid lead (25% aqueous solution), calcareous water, samples of honeydew and flower honey.
Preparation of equipment and reagents. It is also easy to manufacture marching laboratories by yourself. The main parts of the laboratory are: a comparator, a set of test tubes, 2 pipettes, 2 glass sticks, a wooden rack for drying test tubes, dishes for reagents and for sampling honey.
The comparator is made of a wooden block with a height of 90 mm, a length of 60 mm and a width of 40 mm. In the front wall of the bar, 2 horizontal holes with a diameter of 10 mm are drilled, and in the
The set of test tubes consists of three small test tubes with a diameter of 10 … 12 mm and a height of 120 mm and two small, dimensional, 6 … 8 mm in diameter and a height of 40 mm, calibrated to 1.2 and 0.2 ml of water. In one of the large test tubes serving as a standard, pour the standard solution of floral honey in alcohol, then tightly close the cork and pour it with wax; two other test tubes serve for the solution of the investigated honey. The solution for the standard is prepared as follows: in 1 ml of flower honey add 1 ml of distilled water and
Methodical instructions. Honey bees are made from padi-sugary isolates of sucking insects. It differs from flower honey with a high content of dextrins, mineral elements, protein and other substances and is therefore harmful to bees, especially during the wintering period. In this connection, during the autumn audit or shortly after its end, the quality of the honey left for the bees for wintering is checked. If a significant admixture of honey is found, it is replaced with benign floral honey or sugar syrup.
Padewood honey often differs from flower honey by external, organoleptic signs. So, many samples of honeydew honey have a darker color, are less sweet in taste, less hygroscopic than flower honey, have greater viscosity and unpleasant odor. Individual samples of honey are not crystallized and are not sealed by bees. However, these signs are not always reliable, since varieties of flower honey with a dark color (buckwheat, heath) are known, and, conversely, light specimens of honeydew honey (fir). Sometimes pade honey crystallizes in honeycombs even before flower. It is especially difficult to determine the admixture of pade honey to flower honey.
If you add a small amount of a vinegar with an unpleasant odor and dark color to a known good flower honey sample, the result is a mixture of reactions to the fall, which is clearly not suitable for wintering bees. However, the color of this mixture will become only slightly darker, and the smell will be pleasant and even stronger than that of flower honey. Therefore, it is necessary to know the available and at the same time reliable methods for determining the admixture of honey in honey.
Work can be performed both in summer and winter. Regardless of the period of carrying out, it is necessary to have 2 … 3 samples of honey with a different admixture of padi and one – flower honey. At the same time, they are instructed to determine the content of the pad in the sample using one of the methods discussed below. At the end of the definition, the results are compared and each of the methods used is evaluated. Then they make a conclusion about the suitability of this honey sample for wintering bees.
When carrying out work in August during the autumn audit of the apiary, samples of honey are taken directly from the frame of the nest. If there are frames with honey in the nest, which differ markedly in color, they are first sorted and a separate sample is taken from each group of frames. Honey is selected with a glass rod or plastic spatula in a special jar with a lid from the places of the honeycomb, the most suspicious on the pad. In each sample there should be 15 … 20 g of honey. Honey in the sample is thoroughly mixed and labeled from the outside. On the label with a simple pencil indicate the family number and ordinal numbers of the honeycombs (from north to south) from which this sample is composed.
In a graduated tube with a glass rod with a pointed end, 1 ml of the test honey sample is dropped by drop. Then, using a pipette, 1 ml of distilled water and 10 ml of ethyl alcohol (96 њ) are added to the same tube. The contents of the tube vigorously shake. If there is a padi in honey, the solution becomes turbid, and after a while a flocculate sediment appears on the bottom of the tube.
Disadvantages of the method: the inability to quantify the padi and the turbidity of the solution in the presence of buckwheat or heather honey.
In a test tube with a glass rod, 1 ml of the test honey sample is dropped by drop. Pipette 1 ml of distilled water is added here and shaken until the honey dissolves. If the honey dissolves slowly, the tube is slightly heated. Then 2 ml of calcareous water is poured into the honey solution and heated to boiling. The resulting flocculate sediment indicates the presence of the padi. In this case, according to the amount of sediment in several samples, one can judge whether a lot or a small amount of honey is contained in one or another sample of honey.
Lack of method: it is difficult to judge the amount of honey in the sample. However, the accuracy of the method can be improved by pre-precipitating the protein by heating the solution and compacting the precipitate by centrifugation. Analysis by method, goes as follows.
2.1 g of honey are weighed into a beaker (which corresponds to approximately 1.5 ml by volume) and 3 ml of distilled water are added. The resulting solution is heated to boiling and 15 ml of lime water is added. The liquid is again brought to a boil and after cooling it is shaken with a glass rod, poured into two graduated conical tubes, centrifuged for 3 minutes at 3000 rpm. Clarified in both test tubes, the liquid is carefully poured into the same cup to re-wash the precipitate. Then the pellet obtained in one of the tubes is stirred with a stick with the remaining liquid and poured into another tube so that the whole precipitate is collected in a single tube.
After a secondary 3-minute centrifugation, the volume of the precipitate is measured and referred to the total volume of honey taken, for which the volume of sludge expressed in milliliters is multiplied by 100 and divided by 1.5. Honey, which produces a precipitate of less than 2% with this method, is considered a flower, which is quite suitable for wintering bees. With a draft of more than 5.5%, the admixture of the padi is too high and honey is unsuitable for feeding bees that winter in the room.
Reaction with acetic acid lead.
It is carried out with the help of a marching laboratory. In a small graduated test tube, distilled water is pipeted to the first lower label (1.2 ml). Then, in the same tube, honey is transferred dropwise to the second label (0.2 ml) with a glass rod. In this case, the tube is held strictly vertically, making sure that the drops of honey do not touch the walls of the tube. Honey with water thoroughly mixed with a clean glass rod.
The resulting solution of honey from a small tube is poured into a large one, located in the comparator. A small test tube is again filled with distilled water to the top label (1.4 ml) and after dissolving the honey residues drain again into the same large test tube. After this, two drops of reagent (25% solution of acetic acid lead) are added here by a special pipette. After shaking the contents, a large test tube is placed in a wooden comparator. In the adjacent socket of the comparator put a control tube with flower honey of the same concentration, the contents of it before the scan also shake. The comparator is brought to the eyes and looked alternately through both holes (more precisely – through the solution in test tubes) to the horizon. If a sample is present in the test sample, the solution will be cloudy and the horizon can be seen poorly, while the horizon is clearly visible through the left-hand control tube. Then the solution of honey in a test tube is diluted with distilled water until it becomes equal to the solution of the control tube by its transparency. At the same time, they do not pay attention to the color of the solution.
Water in a solution of honey is added dropwise from a large pipette. The number of drops added to the solution characterizes the degree of saturation of honey with a drop. If the number of drops added to the analyzed solution does not exceed 10, then such honey is considered a flower, which is quite suitable for the wintering of bees. Honey, in which it was required to add more than 60 drops of water, is unfit for hibernation and is subject to replacement. In the remaining cases (10 … 60 drops), the admixture of the padi is less dangerous, but families with such honey are taken under special control and, if necessary, they are primarily assisted (watered, overfilled, etc.). If the number of added drops varies from 35 to 60, it is better to give bees 3 to 5 kg of sugar in advance in addition to the honey that is present in the hives. This bee will be laid near the club and will be fed by it for most of the winter.
Thus, unlike the previous methods, this method is not only qualitative, but also quantitative. It should only be taken into account that these indicators (the number of droplets added) are to some extent conditional. They depend both on the duration of wintering and on the quality of honeydew honey. For example, with a shorter wintering of bees in the southern regions and at will, the specified standards may be slightly increased.
Сбор пчелами нектара и пыльцы.
Determination of the content of honey pads