Physical Properties, Antioxidant Content and Anti-Oxidative Activities of Malaysian Stingless Kelulut (Trigona spp.) Honey

Honey produced by stingless bee of Trigona spp. is popularly known as Kelulut honey (KH) in Malaysia. Even though KH has been increasingly accepted by Malaysians, information relating to its physical and antioxidant properties is still limited. This study aimed to determine the physical properties, antioxidant content and anti-oxidative properties of KH collected from different regions in Peninsular Malaysia. Physical properties of KH including total soluble solids, pH, moisture, ash content, and colour were determined. Antioxidant content namely total phenolics, flavonoids, carotenoids, ascorbic acid equivalent antioxidant content (AEAC) and quercetin equivalent antioxidant content (QEAC) were also quantified. Anti-oxidative potential of KH was assayed using DPPH radical scavenging and FRAP assays. KH has pH of 3.29-3.71, total soluble solids (66.23-73.70 °Brix), 21.40-31.59% moisture and 0.22-0.41% ash content. Colour measurement showed KH from the northern region was lightest (L = 39.32) while KH from east coast (b = -5.06) and central (a = 5.65) regions were more pronounce in blue and red colours. KH from east coast region showed highest values for phenolics (1169.36±51.11 mg GAE/kg), flavonoids (79.13±0.49 mg QE/kg), carotenoids (4.61±0.38 mg/kg), AEAC (146.20±5.56 mg/kg) and QEAC (177.08±5.54 mg/kg). In line with the antioxidant content, honey from the east coast region also had strongest anti-oxidative activities indicated in its lowest IC50 value of DPPH radicals (15.07±1.05 mg/mL) and highest FRAP value (7477.03±48.80 uMFe(II)/kg). The KH collected from different regions showed varied physical and antioxidant attributes which may due to variety source of floral origin.