Physical properties of kelulut honey emulsions with different oil types and emulsifier concentrations
Kelulut honey (KH) is a honey produced by stingless bee species, known for its high nutritional content and health benefits. Even though it is very healthy, some people cannot consume it directly. Therefore, incorporating this type of honey into an emulsion system is a good strategy to increase its consumption. Emulsion technology is one of the alternative technologies nowadays which combines two or more immiscible liquids to form a solution. In this study, KHemulsions were emulsified with glyceryl monostearate (GMS) and stabilised by xanthan gum. There were two stages involvedto determine the effects of variations in oil types and emulsifier concentrations on the physical properties of KH emulsions. In the first stage, three types of oil were used as the dispersed phase, which were palm oil, canola oil, and sunflower oil. Then in the second stage, different concentrations of GMS (0.25, 0.5, 0.75 and 1%) were applied. From the droplet size analysis, the emulsion with sunflower oil and the highest concentration of GMS gave the smallest diameter of 0.78 ± 0.01µm and the lowest polydispersity index (pdI) of 16.2±2.03 %. Meanwhile, the texture analysis shows that emulsion with palm oil has the highest firmness (45.16±2.83 g) and consistency (305.44±14.91 g.sec) values. The foaming index on the other hand depicts that emulsion with palm oil and that with the lowest concentration of GMS gave the highest foam stability. From this study, a physically stable oil-in-water KH emulsion was produced, which should undergo further chemical, sensory and storage studies for commercial production in the future.