This standard is applicable to the determination of melting point of commercial vegetable oils and fats. GB/T 5536-1985 Melting point determination method for testing vegetable oils and fats GB/T5536-1985 Standard download decompression password: www.bzxz.net
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National Standard of the People's Republic of China Inspection of vegetable oilsbzxz.net Methods for determination of melting point This standard applies to the determination of melting point of commercial vegetable oils. GB/T5536-85 The melting point of oils is the temperature at which the oils melt from solid to liquid, that is, the temperature at which the vapor pressures of the solid and liquid are equal. 1 Instruments and appliances 1.1 Capillary glass tube: inner diameter 1mm, outer diameter up to 2mm, length 80mm; 1.2 Mercury thermometer: 100℃, 1/10℃ scale: 1.3 Refrigerator, constant temperature oven, electric furnace, constant temperature water bath 1.4 Beaker: 500ml; 1.5 Alcohol burner, conical flask, funnel, filter paper, etc. 2 Operation method 2.1 Sample treatment: filter and dry the sample. Take three clean and dry capillary glass tubes, absorb the sample to a height of 10mm respectively, use a blowtorch flame to seal the end of the tube that absorbs the sample, then put it in a beaker, put it in a refrigerator at 4-10℃ overnight, then take it out and tie the three tubes tightly to the thermometer with a rubber band so that the sample is level with the mercury ball. 2.2 Heating: In a 500ml beaker, first fill half a cup of water, hang a thermometer, and then hang the sample tube and thermometer in the water in the cup, so that the mercury ball is immersed in the water at 30mm. Put it in a water bath and start heating. The starting temperature should be 8-10℃ lower than the melting point of the sample. At the same time, stir the water in the cup so that the water temperature rises at a rate of about 0.5℃ per minute. 3 Determination results The sample often softens before melting. Continue heating until the sample in the glass tube completely becomes a transparent liquid. Immediately read the temperature at that time, which is the melting point of the oil. The allowable difference between the two test results shall not exceed 0.5℃, and the average value shall be taken as the test result. The test result shall be rounded to the first decimal place. Additional Notes: This standard was proposed by the Ministry of Commerce of the People's Republic of China. This standard was drafted by the Grain Storage and Transportation Bureau of the Ministry of Commerce. The main drafters of this standard are Gao Xiuwu, Yang Haoran, Wu Yanxia, and Lv Guifen. Issued by the National Bureau of Standards on November 2, 1985 Implementation on July 1, 1986 Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.