Impact of UV-C assisted drying treatment on the quality of Malaysian stingless bee honey

• Main Authors: Afendi, Nurul Alissa, Abdul Karim Shah, Nor Nadiah
• Format: Article
• Published: HH Publisher 2022
• Online Access: http://psasir.upm.edu.my/id/eprint/101805/; https://journals.hh-publisher.com/index.php/AAFRJ/article/view/596

Stingless bee honey (SBH) has been the focus of various drying studies aimed atlowering the moisture content to an acceptable limit of less than 20%. The low moisture level of SBH has been found to slow yeast development and hinder the fermentation process, thereby prolonging its shelf-life. Conventionally, SBH is usually treated using thermal treatment to lower its moisture content. Due to issues with the quality degradation of thermal-treated SBH, other alternatives are being explored. Non-thermal treatment, namely ultraviolet (UV-C) assisted drying, has been proposed in this study with the expectation of replacing the conventional heat treatment. The UV-C closed system, when properly employed, mayprovide enough radiationenergy (below 40°C) to evaporate the moisture bound in the honey.Hence, this study was aimed at determining and correlating the effects of the UV-C assisted drying process on the quality of UV-C treated SBH. The experiment was carried out on SBH (Heterotrigona itama) under UV-C treatment with the stated parameters; wavelength: 254 nm, power: 7 W, UV-C dose: 8 mJ/cm2, thickness of SBH: 3 mm for 0, 30, 50, 75, and 120 min in a controlled environment (35 ±5% relative humidity and 25 ±5 °C temperature). The results of this study showedthat the moisture level of SBHwas below the critical moisture content of 20%, with the lowest moisture content recorded at 17.42% after 120min of UV-C treatment time (moisture loss: 3.5%) and the highest moisture content of 18.40% after 30 min of treatment time (moisture loss: 2.21%). However, the value of 5-hydroxymethylfurfural (5-HMF)obtained in this study was significantly high (above 80 mg/kg), which mightbe due to the high content of fructoseto glucose ratioin SBH. Nevertheless, while it has been demonstrated that UV-C assisted drying wasable to lower the moisture content of SBH, further study is necessary to evaluate its effectiveness without compromising on the quality of SBH.