3. Determination of 5-hydroxymethylfurfural (HMF) content
3.1 Mix 1 ml of sample and 1 ml of 12% trichloroacetic acid and 1 ml of 0.025 M
thiobabituric. (Prepare in the screw cap tube)
3.2 Prepare blank for setting zero in spectrophotometer by replacing 1 ml of sample
with 1 ml of distilled water.
3.3 Incubate the mixture in a water bath at 40oC for 20 min
3.4 Cool the tube with water.
3.5 Measure the absorbance at 443 nm.