5-hydroxymethyl-2-furaldehyde (5-HMF) is an important substance that affect quality of honey and shows toxicity for humans and honey bees. The pathway of 5-HMF formation in honey is still unknown. In this study, we tested the effect of thermal treatment (at 90°C for 4 h) on the formulation of 5-HMF formulation in rapeseed with varied honey composition. 5-HMF content of honey increased at higher water content, Ca 2? and Mg 2? content and lower pH. However, the formation of 5-HMF was not significantly influenced by glucose, fructose, Na ? , or K ? contents. Furthermore, different content of proline, the most abundant amino acid in honey (a substance in Maillard reaction), had no effect on 5-HMF formation. Free acids in honey can catalyze fructose and glucose to form 5-HMF. These results suggest that dehydration of glucose or fructose, instead of the Maillard reaction, is the main pathway of 5-HMF formation in honey. This study gives new insights for the mechanisms of 5-HMF formation and provides method for reducing 5-HMF formation during honey processing.

In the Western honey bee, Apis mellifera, queens and workers have different longevity although they share the same genome. Queens consume royal jelly (RJ) as the main food throughout their life, including as adults, but workers only eat worker jelly when they are larvae less than 3 days old. In order to explore the effect of RJ and the components affecting longevity of worker honey bees, we first determined the optimal dose for prolonging longevity of workers as 4% RJ in 50% sucrose solution, and developed a method of obtaining long lived workers. We then compared the effects of longevity extension by RJ 4% with bee-collected pollen from rapeseed (Brassica napus). Lastly, we determined that a water soluble RJ protein obtained by precipitation with 60% ammonium sulfate (RJP60) contained the main component for longevity extension after comparing the effects of RJ crude protein extract (RJCP), RJP30 (obtained by precipitation with 30% ammonium sulfate), and RJ ethanol extract (RJEE). Understanding what regulates worker longevity has potential to help increase colony productivity and improve crop pollination efficiency.

Orange juice is one of the most popular and the most consumed fruit juices all over the world, especially in Europe and the chemical food preservatives, such as sodium benzoate, potassium sorbate and their mixtures, have long been used in orange juice sold on the market. Excessive consumption of these preservatives may be hazardous to human health. Propolis, composed of resins collected from plant buds and exudates and mixed with salivary gland secretions and beeswax by honey bee workers, has been used as a human medicine and natural food preservative. We hypothesis that propolis, without alcohol, can serve as an alternative and non-synthetic preservative of orange juice. In this study, the preservative effect of propolis emulsion on orange juice was determined up to 35 days. Propolis emulsion (0.02 g/mL propolis, 12 mL), emulsion control (12 mL containing Tween-80, hydrophilic phospholipid and polyethylene glycol 400), sodium benzoate (0.4 g) and potassium sorbate (0.4 g) was each added to 388, 388, 400 and 400 mL orange juice respectively. Propolis emulsion showed significant inhibition of bacteria growth and l-ascorbic acid degradation. Orange juice pH value, titratable acidity, total phenolic content, color and antioxidant capacity were effectively maintained by propolis emulsion. A control solution with all the same emulsifying agents without propolis did not show these properties. It was concluded that propolis can be used as a natural additive agent in orange juice or other fruit juices as an alternative to chemical preservatives.