Changes in the Physicochemical Properties of Starch Syrups after Processing by Honeybees

In recent time, it has become a common practice to use different kinds of starch syrups available on the market as a winter food for bees. However, the physicochemical composition of these syrups and their suitability for winter feeding of honeybee colonies are still insufficiently investigated. Therefore, our study analyzed the composition of three commercially available starch syrups, inverted saccharose syrup and homemade saccharose syrups, and tested winter stores processed by bees from these syrups. The following physicochemical parameters were investigated: water, sugars composition, maltodextrins (DP4–DP7) and 5-hydroxymethylfurfural (HMF) content, pH and free acidity, as well as electrical conductivity. We found that the sugar composition of starch syrups ensures the suitable sugar composition of winter stores processed by the bees from these syrups. Winter stores compared to fresh syrups had a high content of total fructose and glucose (50 g/100 g), and some amounts of maltose (15 g/100 g), maltotriose (4 g/100 g), and maltodextrins (4 g/100 g). The small percentage of maltodextrins is responsible for maintaining the liquid consistency of the winter stores in honeybee combs during storage. Water content not exceeding 17.2% and adequate pH value (around 4.00) guarantee the stability of winter stores during storage in honeybee combs. A HMF content of up to 50 mg/kg was safe for bee colonies during wintering.