Honeybee Production and Marketing Systems, Constraints - IPMS ...

The absorbance of the sample solution against the reference solution at 284 and 336 nm in 10mm quartz cells within one hour was determined. When the absorbance at 284 nm exceeds avalue of about 0.6, the sample solution diluted with water and the reference solution with sodiumbisulphite solution in order to obtain a sample absorbance low enough for accuracy. Whendilution is necessary,The dilution, D = final volume of sample solution10Calculation and expression of resultHMF in mg/kg = (A284 - A336) x 149.7 x 5 x D/WWhere:-A284 = absorbance at 284 nmA336 = absorbance at 336 nm3.2.4.5 Diastase ActivityThe unit of Diastase Activity, the Gothe unit, is defined as that amount of enzyme which willconvert 0.01 gram of starch to the prescribed end-point in one hour at 40 0 C under the conditionsof test. Results are expressed in Gothe units (or Schade units) per gram of honey. Filter orspectrophotometer with small band interference filter set at 660 nm is used. 10.0 g of honeyprepared for sampling into a beaker and dissolved completely in approximately 15 ml of waterand 5 ml of acetate buffer without heating. The solution was transferred quantitatively to a 50 mlvolumetric flask containing 3 ml of sodium chloride solution and adjusts the volume to the markwith water (sample solution). The time from the addition of the diluted starch solution to thedetermination of the absorbance was as constant as much as possible in the calibration as well asin determining the diastase activity because the color intensity is time dependent.10 ml of honey solution was pipette into a 50 ml flask and place it in the 40°C water bath with asecond flask containing about 10 ml of starch solution. After 15 minutes, 5 ml starch solution(Appendix 7.4) was pipette into the honey solution, mixed and started the timer. At periodicintervals, for the first time after 5 minutes, 0.5 ml aliquots removed and added rapidly to 5 ml of31