Risk in some honey-based instant bee product mixtures

Lemon juice concentrate is one of the components included in the product recipe in addition to fractions such as propolis, royal jelly, pollen, bee bread, ginger, cinnamon, cloves, black pepper, ginkgo, and ginseng in the commercial sale of honey-based beekeeping products in Turkey. The present work aimed to examine the changes in some physicochemical properties of honey by adding lemon juice concentrate at different ratios (0, 1, 2, and 3%) to pine, flower, and chestnut honey during six-month storage period. Changes in the total phenolic content, antioxidant activity, and HMF levels of the samples stored at 25, 35, and 45°C were monitored. The degree of reaction, reaction rate constants, and Arrhenius coefficients were also determined by examining the HMF formation kinetics. HMF levels at the end of 24 months, the general shelf life of commercial mixtures, were calculated from the modelled kinetic data. Brix (78.8 - 82.0°), pH (3.00 - 4.46), free acidity (8.5 - 72.3 meq kg-1), reducing sugar (87.5 - 105.1%), total sugar (93.7 - 111.1%), sucrose (4.0 - 7.7 g/100 g), total phenolic content (4.1 - 218.7 mg GAE/100 g), antioxidant activity (1.0 - 16.1 mg GAE/100 g), and HMF (12.4 - 7646.5 mg kg-1) levels of the samples were measured. Adding lemon juice concentrate dramatically increased HMF levels. The estimated HMF levels of the samples at the end of 24 months were between 49.7 - 30038.7 mg kg-1. The threshold energies of the HMF formation reactions were 126.2 - 219.2 kJ mol-1.