Development Of Water-in-Oil Macro-emulsions To Form Mould Release Agent

The objective of this study was to develop a W/O emulsion to be used as a mouldrelease agent in bakery products. Stabilisation of water-in-oil (W/O) emulsion as a mouldrelease agent with combination of non-ionic emulsifiers has been investigated. Water-in-oilemulsions (W/O) of water, soybean oil, emulsifiers were studied to prepare a useful mouldrelease with low viscosity which can be sprayed, high physical stability, provides good releaseproperties, decreases the burning color of the cake surface which is in contact with the mouldsand has low smoke point in the range of baking temperature.The combinations of PGPR/sucrose ester and PGPR/span40showed an ability offorming W/O emulsions up to ratio of55/40water/oil respectively. Combination ofPGPR/Tween80formed W/O emulsions up to ratio of45/50water/oil respectively. Moreover,combination of polyglycerol/sucrose ester was not able to form W/O emulsions it formedO/W emulsions in all water: oil ratios.Combination of polyglycerol/sucrose ester which formed O/W system showed higherphysical stability followed by combination of PGPR/span40, PGPR/Tween80and then PGPR/sucrose ester was the lowest physical stability. O/W emulsions formed with combination ofPolyglycerol/sucrose ester showed low viscosity and low smoke point than W/O emulsions.Combination of PGPR/span40was chosen for further analysis because of its ability to formW/O emulsions with high water ratio in the system and high physical stability compare toother combinations of W/O system.Two hydrophilic and lipophilic non-ionic emulsifier were used in combination tostabilise the water droplets, PGPR (Polyglycerol polyricinolate)(HLB=3), span40(HLB=6.7).These were investigated in combination with or without alcohol and sodium stearate. Increasethe HLB number (3to4.48) had significantly increased the stability of W/O emulsion.Meanwhile, further increase in the HLB (4.85-5.59) had significantly decreased the stabilityof W/O emulsion. Emulsion stability was enhanced when ethanol concentration increased up to10wt%but, more than10wt%had decrease the stability of emulsion by forming smallerdroplet size and droplet size distribution than those prepared without ethanol. Low ratios ofethanol (5-15wt%) had no significant effect on the smoke point of emulsion. Moreover, highratios of ethanol had slightly increased the smoke point of W/O emulsion. In general ethanolhad decrease the viscosity of W/O emulsion. Addition of sodium stearate (0.05-0.2wt%) hadincreased the stability, viscosity and decreased the smoke point of W/O emulsion. As thewater content increased the emulsions become high viscosity, high smoke point and lowstability.A comparison of the physical and viscoelastic properties of the mould release oil wasmade with the market release agent and soybean oil. There was no much different in thephysical and viscoleastic properties between the mould release agent and soybean oil.Application of the mould release agent to the surfaces of the mould before addition of thedough it helped the cake to be easy to release more than using soybean oil. There was noburning color on the surface of the cake with using mould release agent compare to soybeanoil.