Hydroxymethylfurfural (HMF) in honey - Why do we test for it?

Introduction

Honey has been cherished for its sweetness, health advantages, and diverse uses in both culinary and medicinal fields for centuries. However, its quality may degrade over time or due to improper processing. One important marker of honey's quality is the level of hydroxymethylfurfural (HMF), a compound that naturally forms in honey.

What is HMF

Hydroxymethylfurfural (HMF) forms in honey as sugars break down over time. While HMF is not inherently harmful, it is a key marker for assessing honey's age, the conditions in which it has been stored, and the degree of heat it has been subjected to during processing. Tracking HMF levels offers important information about the quality and freshness of honey products

Factors Influencing HMF Levels

HMF content in honey can increase for several reasons, which can signal different quality concerns

Heat Exposure: Honey that has been overheated during processing can have elevated HMF levels, indicating potential loss of nutrients and degradation of its natural properties.

Inadequate Storage: When honey is stored at high temperatures over long periods, HMF levels rise, reducing its freshness and quality.

Natural Aging: Even under ideal storage conditions, HMF levels naturally increase as honey ages, making it a reliable indicator of the honey's age.

Potential Effects of HMF on Health and Quality

While HMF itself is safe in moderate quantities, excessive levels can negatively impact the honey’s characteristics and, in rare cases, cause mild health concerns

Nutrient Loss: High levels of HMF can diminish honey's antioxidant properties, reducing its health benefits.
Flavor and Aroma Changes: Increased HMF content can alter the honey’s taste and aroma, making it less appealing.
Digestive Sensitivity: In some individuals, consuming honey with very high HMF levels might lead to digestive discomfort

Significance of HMF Testing in Honey

Importance of HMF Testing in Honey	Description
Freshness Indicator	Low HMF levels indicate fresh honey, reflecting careful handling and optimal storage conditions, enhancing consumer experience.
Quality Assurance	Monitoring HMF levels helps ensure honey meets high-quality standards, indicating whether it has undergone excessive heating or prolonged storage.
Authenticity Verification	Abnormal HMF levels can indicate adulteration, making HMF testing crucial for verifying the purity and authenticity of honey.
Storage Compliance	HMF testing provides feedback on storage practices, helping producers maintain optimal conditions to prevent unwanted HMF formation.
Regulatory Compliance	Ensures that honey products comply with established maximum HMF limits, safeguarding consumer health and meeting legal standards.
Shelf Life Determination	Elevated HMF levels signify aging honey, aiding in determining shelf life and guiding producers and consumers on optimal quality maintenance.
Consumer Confidence	Transparent HMF testing fosters trust in honey products, demonstrating producers' commitment to quality and authenticity.

Standards and regulations

To ensure consistency and protect consumers, international organizations, such as the Codex Alimentarius Commission, have set standards for hydroxymethylfurfural (HMF) levels in honey. These standards differ based on the type of honey and its geographical origin. For example, fresh honey typically has an HMF limit of 40 mg/kg, while honey sourced from tropical regions may have a higher limit due to natural factors affecting its composition

European Union: EU Directive (2001/110/EC)

The Council Directive 2001/110/EC, adopted on December 20, 2001, sets specific criteria for honey intended for human consumption within the European Union. This directive aims to ensure the quality, authenticity, and safety of honey by establishing comprehensive composition criteria.

Composition Criteria for Honey

Sugar Content

Fructose and Glucose (sum of both):
Blossom honey: Minimum of 60 g/100 g.
Honeydew honey or blends: Minimum of 45 g/100 g.

Sucrose Content

General honey varieties: Maximum of 5 g/100 g.
Specific varieties (e.g., false acacia, alfalfa): Maximum of 10 g/100 g.
Lavender and borage: Maximum of 15 g/100 g.

Moisture Content

General honey: Maximum of 20%.
Heather and baker's honey: Maximum of 23%.
Baker's honey from heather: Maximum of 25%.

Water-Insoluble Content

General honey: Maximum of 0.1 g/100 g.
Pressed honey: Maximum of 0.5 g/100 g.

Electrical Conductivity

Unlisted honeys and blends: Maximum of 0.8 mS/cm.
Honeydew and chestnut honeys: Minimum of 0.8 mS/cm (with exceptions for certain varieties).

Free Acid

General honey: Maximum of 50 milliequivalents of acid per 1,000 grams.
Baker's honey: Maximum of 80 milliequivalents of acid per 1,000 grams.

Diastase Activity and Hydroxymethylfurfural (HMF) Content

Diastase Activity (Schade scale)

General honey (except baker's honey): Minimum of 8.
Honeys with low enzyme content and HMF ≤ 15 mg/kg: Minimum of 3.

HMF Content

General honey (except baker's honey): Maximum of 40 mg/kg.
Honeys from tropical climates: Maximum of 80 mg/kg.

India: The Food Safety and Standards Authority of India (FSSAI) has set a higher maximum HMF limit of 80mg/kg, taking into account the warmer climate in the country.

Mandatory and optional analyses

Analysis Type	Description
Mandatory Analyses
Determination of HMF Content	Measures HMF concentration using methods like HPLC, colorimetry, or reflectometry.
Determination of Moisture Content	Assesses moisture levels affecting quality and shelf life.
Determination of Ash Content	Indicates inorganic mineral content; high levels may suggest adulteration.
Determination of Pesticide Residues	Screens for harmful pesticide residues to ensure safety for consumption.
Determination of Heavy Metal Contaminants	Tests for heavy metals (e.g., lead, cadmium) to ensure safety for consumers.
Optional Analyses
Determination of Other Flavonoids	Evaluates additional flavonoids for antioxidant properties.
Determination of Caffeine Content	Measures caffeine levels, relevant for sensitive consumers.
Determination of Sensory Properties	Assesses color, aroma, and taste to evaluate overall quality and market appeal.

Eurofins role in testing HMF in honey

Eurofins plays a significant role in testing hydroxymethylfurfural (HMF) levels in honey, which is crucial for assessing honey quality and authenticity.

HMF Testing Services

Comprehensive Testing: Eurofins offers a range of analytical services for honey, including the measurement of HMF levels. This testing helps determine the freshness and quality of honey, as HMF can indicate excessive heat treatment or prolonged storage. Fresh honey typically contains low levels of HMF, while higher concentrations suggest potential quality issues.

Accredited Methods: The laboratory utilizes advanced techniques such as HPLC to accurately quantify HMF levels. This method allows for detection limits as low as 1 mg/kg, ensuring precise assessments of honey quality against established regulatory standards, such as the EU directive which limits HMF to 40 mg/kg for most honey types.

Expertise and Support: Eurofins employs highly qualified technical staff who provide interpretation and technical support for HMF testing results. This expertise aids honey producers in understanding their product's quality and compliance with safety standards.

Global Standards Compliance: The testing services offered by Eurofins align with international standards, ensuring that honey products meet necessary regulatory requirements. This is particularly important for maintaining consumer trust and verifying product authenticity in a market prone to food fraud.