Honey moisture is important parameter and quality criterion that will help us to determine the capability of honey to remain stable and to resist spoilage by yeast fermentation. If the moisture is too high, the probability that honey will ferment upon storage will be higher too. You can simply measure the moisture in honey with refractometer through refractive index. It is very simple and reproducible method.
Moisture content criteria for honey according
to European Union honey legislation
to European Union honey legislation
- in general – not more than 20 %
- heather (Calluna) and baker’s honey in general – not more than 23 %
- baker’s honey from heather (Calluna) – not more than 25 %
The refractive index is measured by a refractometer that works on the principle of refraction of light when light passes through a solution. The measurement is usually performed at 20 ° C, and the obtained results differ depending on the measurement temperature. With the help of refractive index data, we can calculate the proportion of water in honey. To determine the mass fraction of water in the honey, prepare a sample according to the IHC protocol and measure the refractive index using a refractometer at 20 ° C.
PRINCIPLE OF METHOD
The method is based on the principle that refractive index increases with solids content.
RELATIONSHIP OF WATER CONTENT OF HONEY TO REFRACTIVE INDEX
| Water Content g/100g | Refractive Index 20°C | Water Content g/100g | Refractive Index 20°C |
|---|---|---|---|
|
13.0
|
1.5044 |
19.0 |
1.4890 |
|
13.2 |
1.5038 |
19.2 |
1.4885 |
|
13.4 |
1.5033 |
19.4 |
1.4880 |
|
13.6 |
1.5028 |
19.6 |
1.4875 |
|
13.8 |
1.5023 |
19.8 |
1.4870 |
|
14.0 |
1.5018 |
20.0 |
1.4865 |
|
14.2 |
1.5012 |
20.2 |
1.4860 |
|
14.4 |
1.5007 |
20.4 |
1.4855 |
|
14.6 |
1.5002 |
20.6 |
1.4850 |
|
14.8 |
1.4997 |
20.8 |
1.4845 |
|
15.0 |
1.4992 |
21.0 |
1.4840 |
|
15.2 |
1.4987 |
21.2 |
1.4835 |
|
15.4 |
1.4982 |
21.4 |
1.4830 |
|
15.6 |
1.4976 |
21.6 |
1.4825 |
|
15.8 |
1.4971 |
21.8 |
1.4820 |
|
16.0 |
1.4966 |
22.0 |
1.4815 |
|
16.2 |
1.4961 |
22.2 |
1.4810 |
|
16.4 |
1.4956 |
22.4 |
1.4805 |
|
16.6 |
1.4951 |
22.6 |
1.4800 |
|
16.8 |
1.4946 |
22.8 |
1.4795 |
|
17.0 |
1.4940 |
23.0 |
1.4790 |
|
17.2 |
1.4935 |
23.2 |
1.4785 |
|
17.4 |
1.4930 |
23.4 |
1.4780 |
|
17.6 |
1.4925 |
23.6 |
1.4775 |
|
17.8 |
1.4920 |
23.8 |
1.4770 |
|
18.0 |
1.4915 |
24.0 |
1.4765 |
|
18.2 |
1.4910 |
24.2 |
1.4760 |
|
18.4 |
1.4905 |
24.4 |
1.4755 |
|
18.6 |
1.4900 |
24.6 |
1.4750 |
|
18.8 |
1.4895 |
24.8 |
1.4745 |
|
|
|
25.0 |
1.4740 |
For measuring refractive index Hanna Instruments has simple solution:
HI96800
Digital Refractometer
for Refractive Index and Brix
for Refractive Index and Brix
Hanna’s new HI96800 Digital Refractometer measures Refractive Index and displays results in both temperature compensated (nD20) and non-temperature compensated (nD) formats on the dual-level LCD screen. The HI96800’s intuitive layout and pinpoint accuracy ensures effortless operation and reliable readings every time.
Refractive Index is measured to determine a liquid’s composition and assess its concentration and density. It is used by many industries including pharmaceutical, food and environmental, as an important indicator of quality and consistency. The HI96800 also converts Refractive Index to % Brix with the push of a single button.
Author:
Tajana Mokrović, mag.nutr.
Tajana Mokrović, mag.nutr.
