Hydroxymethylfurfural Affects Caged Honey Bees (Apis mellifera carnica)

Aleš Gregorc,Snežana Jurišić,Blair Sampson

doi:10.3390/d12010018

Abstract

A high concentration of hydroxymethylfurfural (HMF) (e.g., 15 mg HMF per kg honey) indicates quality deterioration for a wide range of foods. In honey bee colonies, HMF in stored honey can negatively affect bee health and survival. Therefore, in the laboratory, we experimentally determined the effects of HMF on the longevity and midgut integrity of worker Apis mellifera carnica by feeding bees standard diets containing five concentrations of HMF (100, 500, 1000, and 1500 ppm). Simultaneously, we also examined HMF’s effect on Nosema ceranae spore counts within infected honey bees. We performed an immunohistochemical analysis of the honey bee midgut to determine possible changes at the cellular level. No correlation was established between HMF concentration and N. ceranae spore counts. Negative effects of HMF on bees were not observed in the first 15 days of exposure. However, after 15 to 30 days of exposure, HMF caused midgut cells to die and an increased mortality of honey bee workers across treatment groups.

Highlights

Honey is a highly concentrated mixture of mainly two dissolved sugars, fructose and glucose, plus at least 22 other composite sugars [1] and 70 other compounds including proteins, vitamins, minerals, organic acids, aromatic compounds, and various derivatives of chlorophyil [2]
Toxicological tests on the autochthonous Carniolan honey bee Apis mellifera carnica occurred in laboratory conditions
Carniolan honey bees exposed to HMF suffer increased death, especially after feeding on it for 15 to 30 days

Summary

Introduction

Honey is a highly concentrated mixture of mainly two dissolved sugars, fructose and glucose, plus at least 22 other composite sugars [1] and 70 other compounds including proteins, vitamins, minerals, organic acids, aromatic compounds, and various derivatives of chlorophyil [2]. HMF can be selectively produced from keto-hexose—notably from D-fructose [3] and other acidic media containing dissolved monosaccharides [4]. HMF is present in honey in trace amounts [5]. Excessive heating or inappropriate storage conditions can increase HMF levels, which are recognized as a marker of quality deterioration for a wide range of foods containing carbohydrates [8]. HMF can occur at concentrations as high as 15 mg HMF/kg, but it normally occurs at levels between 0.06–0.2 mg HMF/kg [5]. HMF is naturally present in honey, and at low concentrations (e.g., ~100–500 ppm) it does not reduce honey quality; it could be used as an identifier of a honey’s origin and quality.

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