To Detect adulteration of honey, fiehe’s test and analine chloride are the initial tests that are carried out in the laboratory.
Furthermore, you can also check the complete information on how to check if honey is pure or adulterated and the various regular and advanced tests available to detect honey adulteration.
Table of contents
- What is fiehe’s test?
- What does fiehe’s analyze in honey?
- What is Hydroxymethyle furfural (HMF)?
- How can fiehe’s test identify the purity of honey?
- Can Positive “Fiehe’s test result” confirms honey adulteration?
- Can negative “Fiehe’s test results” confirm the purity of honey?
- The procedure of Fiehe’s Test:
- Fssai Parameter for fiehe’s test:
- Aniline Chloride test:
- The procedure of the Aniline Chloride Test:
- Iodine test: (For the presence of starch)
What is fiehe’s test?
Fiehe’s test scans the presence of any commercial invert sugar in honey for adulteration.
This honey test help Identify:
What does fiehe’s analyze in honey?
This test helps identify the amount of HMF (Hydroxymethyl furfural) in honey.
What is Hydroxymethyle furfural (HMF)?
HMF is a decay (acid catalysed) product of natural fructose present in honey. Fresh natural honey has around 10-14 mg/kg of HMF whereas Old honey has a higher value.
How can fiehe’s test identify the purity of honey?
Invert sugar and jaggery has a very high level of HMF content. A positive result indicates the presence of a high level of HMF.
Can Positive “Fiehe’s test result” confirms honey adulteration?
No, because even pure honey could have a higher level of HMF in the following situations.
- If honey is stored for a longer period of time
- When honey is stored in a hot atmosphere
- If honey is heated during processing
Can negative “Fiehe’s test results” confirm the purity of honey?
No, because recent honey adulterants(fake honey) like HFCS and rice syrup has “Nil” HMF.
The procedure of Fiehe’s Test:
Time needed: 15 minutes
Fiehe’s test can detect adulteration of honey with inverted sugar (Acid hydrolyzed sugar). Above all, it actually detects the presence of HMF (Hydroxymethyl furfural) content in honey. Invert sugar has high HMF content whereas, honey has lesser HMF content (around 10 mg/kg).
Moreover, sometimes even genuine honey has higher HMF when Honey is heated or stored for a long time.
- Step 1
- Step 2
Take a Petri dish and add the supernatant solution from the mortar. Allow it to dry in the open air.
- Step 3
Take 5ml HCL (Hydrochloric acid) in a test tube. add 1 g of resorcinol crystals. shake it well to dissolve.
- Step 4
Add a few drops of resorcinol HCl solution to the petri dish (This should be done once the ether dries out completely)
- Step 5
Observe the colour in the petri dish.
Positive result: Pink or cherry red colour indicates the presence of high HMF. This means honey has either inverted sugar adulteration.
Negative result: There is no change in colour to a yellowish pink colour. Therefore, a Negative Result indicates No adulteration of common or Inverted sugar.
Fssai Parameter for fiehe’s test:
Fiehe’s test should be negative.
If Fiehe’s test is positive, and hydroxymethylfurfural (HMF) content is more than 80
milligram/kilogram, then fructose: glucose ratio should be 1.0 or more.
Aniline Chloride test:
The procedure of the Aniline Chloride Test:
Dissolve 3g aniline crystals in 10ml concentrated HCl. Consequently, this reaction produces Aniline chloride.
After that, take a few drops of honey in a Petri dish, add 2-3 drops of aniline chloride solution.
Result: If the solution turns to orange colour, It indicates the presence of inverted sugar.
No colour change result indicates pure honey.
Iodine test: (For the presence of starch)
The procedure of the Iodine test: Take 5ml of honey and 5ml of water, make it homogenise by mixing it well.
Prepare an Iodine solution by Adding 3g of potassium and 1g of Iodine in 50ml of water.
Add Iodine solution to the honey-water mixture.
Result: If the solution turns to purple or red colour it indicates the presence of starch in honey.
No colour change indicates pure honey.
Reliability: This test is only for the presence of starch. Not for other adulterants.
These tests can identify the adulteration of honey with Invert sugar, for other adulterants like HFCS & Rice syrup there are higher tests. Get the complete list at our blog post of types of honey adulterations.