18-22°C 18-22°C Low Fat Spread 60-65°C Cooling 22-25°C Figure 3: Process flow chart of a low fat spread emulsion Creating an emulsifier system for 10% low fat spreads In order to face the challenge of oil separation and secure the right mouth-feel of the spread we used two different types of emulsifiers: Palsgaard® DMG 0298, which is a mono-diglyceride (E471) but atypical in comparison to many other mono-diglycerids since the fatty acid combination is mainly based on oleic acids. The unsaturated fatty acids offer better emulsification and emulsion stability for reduced and low fat spreads compared to standard mono-diglycerides. Palsgaard® PGPR 4175 is made from polyglycerol polyricineolate (E476) but is more polymerised than normal PGPR types. PGPR is a co-emulsifier, meaning that you will only obtain the desired effect if it is used in combination with another type of emulsifier. In low fat spreads PGPR is exceptionally good at coating water droplets, fat crystals and increasFigure 4 Viscosity in low fat spread emulsions 30000 25000 20000 15000 10000 5000 0 300 350 400 ing viscosity in low fat emulsions. Without PGPR it is not possible to make the very low fat spreads. Palsgaard® PGPR 4175 is therefore necessary for stabilizing the 10% low fat spread as it helps avoid fluctuations during the production process and reduces the amount of rejected product. Palsgaard® PGPR 4175 is neutral in both taste and smell and is thus a unique non-flavour component. Stabilising the fat phase The oil absorber Palsgaard® 6118 is based on non-hydrogenated vegetable fats and is especially suited for applications where we don’t want to use hydrogenated products. The oil absorbing effect of Palsgaard® 6118 is effective in products which contain a high amount of liquid oil, such as the oil phase in low fat spreads. The oil absorbing behaviour reduces the risk of oiling out. The effect of sodium alginate in 10% low fat spreads In the water phase we ad sodium alginate (E401), which reacts as a thickener of the water phase. It stabilizes the water phase in the 10% low fat spread and reduces the risk of squeezing out the water. Sodium alginate also improves the mouth-feel of very low fat spreads. The optimal effect is achieved when using 0.55% sodium alginate. At 0.75% sodium alginate the water droplets become too viscous and the spread starts to become less stable with a higher risk of free water. How to set up the right processing conditions The process of manufacturing these low fat spreads is the opposite of what is traditionally used when making a 40% spread. Therefore, the practical experience from producing 40% low fat spreads cannot be used in the production of very low fat spread emulsions. Figure 3 shows the process flow needed to successfully manufacture a 10% low fat spread. The water phase needs to be added slowly, but the emulsion itself will have a tendency to build up a lot of viscosity in very low fat spreads if the mechanical treatment is too intensive. The stirrers that are functioning fine when making 30 - 40% low fat spread emulsions, need to be designed for more viscous emulsions otherwise “dead” areas will arise in the emulsion tank. Anker stirrers function very well in emulsion tanks for the relative high viscous emulsions. Slow agitation is important to avoid the build-up of too viscous emulsions. Figure 4 shows that double up of agitation in a pre-emulsifying unit can increase the viscosity up to 5 times. cp 450 500 550 600 r/min Palsgaard Technical Paper - September 2013 How to successfully manufacture a low fat margarine spread with only 10% fat 4
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