Detection method of gutter oil

Abstract

The invention relates to a detection method of gutter oil, which comprises: sampling after mixing uniformly a sample, and detecting and recording an iodine value; then centrifuging the sample for 10min at 2700r / min at a normal temperature condition, if layering occurs, respectively sampling an upper layer and a lower layer and detecting and recording an iodine value, and judging whether the sample is gutter oil according to the change of the iodine value. A detection method of the iodine value comprises: weighing a sample (correct to 0.0002g), injecting into a clean and dry iodine value bottle, adding 20ml of a mixed solvent of cyclohexane and glacial acetic acid to dissolve the sample, accurately adding 25ml of Webster's liquid with a transfer pipette, instantly plugging and shaking uniformly, and placing in a shady place for 1 hour; then instantly adding 20ml of 10 percent of potassium iodide solution and 150ml of water, titrating with 0.1mol / l of sodium thiosulfate solution till yellow of the iodine is close to disappearing, then adding 1ml of starch indicator, continuously titrating while shaking an iodine flask with force till the blue just disappears. The detection method is fast, precise, low in cost and easy to realize.

Description

technical field [0001] The invention belongs to the technical field of food detection and relates to a detection method of waste oil. Background technique [0002] Unscrupulous merchants often sell waste oil as cooking oil. Waste oil is actually a general term. Usually, waste oil can be roughly divided into three classes: the one, waste oil in a narrow sense, about the greasy floating thing in the sewer or with leftovers, leftovers (common name swill) of hotel, restaurant through simple processing, the oil that extracts; It is the oil produced after processing and refining low-quality pork, pig viscera, and pig skin; the third is the oil that is reused after the oil used for fried food exceeds the specified requirements. The first type is more common in daily life, usually also called "swill oil". The main production process of this type of waste oil is: collect the swill discharged from the above-mentioned catering industry, first pour it into the sedimentation tank, add ...

AI Technical Summary

Problems solved by technology

[0012] The detection methods disclosed in the above prior art can only be roughly checked and are not accurate enough, or require expensive large-scale equipment, and the high detection cost is not conducive to popularization and application.

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