HMF in HONEY

Biagio Fallico, Elena Arena, Mario Zappalà, Antonella Verzera

University of Catania - University of Messina (Italy)

3rd AOAC Europe – EURACHEM Symposium3 March 2005

Brussels

HONEY REGULATIONS

• Codex Alimentarius Commission Joint FAO/WHO Food Standard Programme (24th session, Geneva, 2-7 July 2001)

Report of the seventh session of the Codex Committee on Sugars(ALINORM 01/25, London 9-11 Feb. 2000)

• EC Directive 2001/110 Relating to Honey

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Essential Composition and Quality Factors• Chemical composition (moisture, sugars, insoluble solids, conductivity)• Contaminants• Hygiene• Labelling• Methods of sampling and analysis

ALINORM 01/25

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Additional Composition and Quality Factors• Free acidity• Diastase activity• Hydroxymethylfurfural (HMF)

After processing and/or blending: 40 mg/Kg 80 mg/Kg for honey from Countries or Regions with tropical ambient temperatures

ALINORM 01/25

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

EC Directive 2001/110

Annex II – Composition criteria for honey1. sugars2. moisture3. water insoluble solids4. electrical conductivity5. free acids6. Diastase activity and HMF (determined after processing)

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

6.a Diastase (Schade scale) 8 (in general, except bakers honey)3 (honey with low natural enzyme content (e.g. citrus honey) and a HMF level not higher than 15 mg/kg.

6.b HMF 40 mg/Kg 80 mg/Kg in honeys of declared origin from Regions with tropical climate

Analyses: moisture, glucose, fructose, pH, free acids,lactones, total acidity, conductivity, ash, diastase and HMF

Heating at:50 °C up to 144 h (6 days); 70 °C up to 96 h (4 days)100°C up to 60 h (2.5 days)

HEATING TREATMENTS

Citrus (Citrus Aurantum L.)

Chestnut ( Castanea Sativa L.)

Eucalyptus (Eucalyptus Camaldulensis L.)

Sulla ( Hedysarium Coronarium L.)

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Chemical composition of the Unifloral honeys

Parameter Citrus

Chestnut

Eucalyptus

Sulla

pH 3.4 5.9 3.7 3.4Free acids (meq/kg) 22.5 9.7 23 15.5Total acidity (meq/kg) 25 11.4 32.5 18Electrical conductivity(S)

193 1128 413 126

Diastase (DU) 7.6 27.3 33.9 10.8HMF (mg/kg) 5.95 - - 1.23

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Chestnut Eucaliptus Citrus Sulla

HMF formation during heating at 100°C

hours of heating

0

4000

8000

12000

16000

0 4 8 12 24 36 48 60

mg/

kg

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

HMF formation during heating at 70°C

Chestnut Eucaliptus Citrus Sulla

0100200300400500600

0 4 8 12 24 48 60 72 84 96hours of heating

mg/

kg

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

HMF formation during heating at 50°C

Chestnut Eucaliptus Citrus Sulla

05

1015202530

0 48 60 72 84 96 108 120 144hours of heating

mg/

Kg

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Influencing factors on HMF levels at 50°C (Results applying ANOVA and Multiple linear regression model analyses)

Main factors: • pH of honey• temperature and time of heating

Specific factors:• Eucalyptus and Sulla were correlated to acidity• Citrus was correlated, at the same time, to: time, pH and free acidity.

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

HMF is clearly an heating index, but the statement that

the amount of HMF is independent of honey type

and composition could be wrong.

Among the studied honeys, Citrus, at the same time of heating, gives the highest amount of HMF

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Citrus honey is a low natural enzyme content9.3±2.7 (Range: 3.4-16.3) D.U.

(Persano Oddo et al., 1995, 1999)

The half life of Diastase in honey at 30°C is:6/7 months

This means 15 mg/kg as HMF limit

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Storage of Citrus Honey (244°C)

0

15

30

45

60

75

0 5 6 8 10 15 17 18Citrus 1 Citrus 2 Citrus 3

HM

F (m

g/K

g)

Months

This does not sound as “scientific based” because:

• a very low limit when there is a natural attitude to form HMF, independently from heating

• at the same time, honeys of different origin (chestnut) can be overheated without reaching the limit (40 mg/Kg).

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Practical consequences (2004):

High honeys sampling levels

10 not conform samples

in 6 months 35 samples (25 citrus)

EU Alert

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Practical consequences (2004):

Direct Effects10 criminal proceedings1000€ each as penaltiesLegal expensesProduct declassificationor destruction Side Effectscostumers complaints•No honey to sell•Toxic or contaminated samples

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005

Conclusions:

More attention to: Hygiene aspects and Contaminants

Eliminate the limit of 15 mg/kg for low enzyme honeys

Correlate HMF limits to chemical parameters of honeys and not to the diastase activity

3rd AOAC Europe, Eurachem Symposium, Brussels 3 March 2005