Kanyanat Wongsa1, Thitipan Meemongkolkiat2, Orawan Duangphakdee3, Sehanat Prasongsuk4, and Atsalek Rattanawannee1*
1Department of Entomology, Faculty of Agriculture, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok, Thailand
2Department of Biology, Faculty of Science, Chulalongkorn University, 254 Phayathai Rd.. Bangkok, Thailand .
3Native Honeybee and Pollinator Research Center, Ratchaburi Campus, King Momgkut’s University of Technology Thonburi, Rang Bua, Chom Bueng, Ratchaburi, Thailand
4Plant Biomass Utilization Research Unit, Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
Corresponding Author E-mail: fagralr@ku.ac.th
This research aimed to investigate the impact of heat treatment on stingless bee honey obtained by Heterotrigona itama, a commercial stingless bee found in the southern region of Thailand. Ten honey samples originating from three different forest types (mangrove forest, swamp forest, and mixed forest) were heated to 37 °C and 45 °C for 24 and 48 h and then analyzed for their physicochemical properties, total phenolic content, the flavonoid content, and antioxidant activity by radical scavenging activity on 2,2-Diphenyl-1-picrylhydrazyl (DPPH). The results showed the raw honey from mixed forest had the highest radical scavenging activity with IC50 of 43.996±0.377 mg/ml. In addition, this honey sample also exhibited the highest phenolic and flavonoid contents with 89.916±0.358 mg GAE /100 g of honey and 58.093±0.294 mg QE/ 100 g of honey, respectively. After heat treatment, the honey samples showed little change in physicochemical properties when compared to raw honey samples. After incubation at 45 °C for 48 hours, the moisture content decreased 27.93±0.17 to 20.14±0.34 g/100 g. Interestingly, heat treatment at 37 °C and 45 °C did not affect the total phenolic, flavonoid contents, and antioxidant activities (p > 0.05) in the honey samples. While heat treatment aids in keeping the physicochemical and bioactive properties of dehydrated honey, it can be concluded that the proposed method can be employed as an alternate method for preserving honey from stingless bees.
Antioxidants; Flavonoids; Heat treatment; Honey; Phenolics; Stingless bee