Quality changes in thermally-treated Tetragonula testaceitarsis stingless bee honey during room temperature storage

This study examined quality changes in Tetragonula testaceitarsis (T. testaceitarsis) stingless bee honey subjected to thermal treatment and stored at room temperature. Honey was heated at 55, 75, and 90 °C for 10 or 20 min and then stored at 30 °C for 40 days. Physicochemical parameters including moisture content, total soluble solids (TSS), pH, acidity, viscosity, hydroxymethylfurfural (HMF), color (L*, a*, b*), antioxidant activity, and total phenolic content were analyzed. Thermal treatment significantly (p < 0.05) affected all parameters, except pH. Heating reduced moisture content, viscosity, lightness, and antioxidant activity, but increased TSS, acidity, HMF, color values (a*, b*), and total phenolic content. High-temperature heating mitigated the increase in moisture content and acidity, while slowing the decline in TSS and pH during storage. However, by day 40, all honey samples exceeded the national HMF limit (40 mg/kg), indicating that T. testaceitarsis honey is unsuitable for storage at room temperature.