The following explains how we were able to achieve the desired results. The emulsion type used in the recipe is W/O (water in oil) as used in other margarine and spread products. In theory it is difficult to reduce the fat content to lower than 25.4% if the water droplets have exactly the same size in a W/O emulsion, as shown in figure 1a. In practice, however, by utilizing the combined benefits of emulsifiers Palsgaard® DMG 0298 and Palsgaard® PGPR 4175 it is possible to create water droplets with different sizes. By so doing the emulsion can be much more closely packed as shown in figure 1b. This is the reason why it is possible to produce 20% - 15 % or even 10% low fat spreads. Instability problems in low fat spreads When creating a low fat spread it is important that the fat composition contains more liquid oil than similar high fat products, due to the fact that the oil phase needs to cover a higher amount of water droplets. If the fat phase contains too much solid fat the smoothness of the product will disappear. Equally, if the emulsion contains too much palm stearin it will tend to become more unstable in 10% low fat spreads compared to palm oil. The reason is probably more brittleness during and after production. Figure 1a: Water droplet size in a traditional 25.4% spread Figure 1b: Water droplet size in a 10% spread made with Palsgaard® DMG 0298 and Palsgaard® PGPR 4175. Figure 2a: Primary crystal bond structure. Figures 2a and 2b demonstrate the buildup of primary crystal bond structure and how the fat, if it is brittle more or less, squeezes out the water with mechanical treatment. The emulsifiers that are located at the surface between water- and oil phase cannot avoid this phenomena. Only a combination of the right process parameters and fat composition can solve this problem. It is therefore not always an emulsifier problem when free water is found. Figures 2a and 2c show the effect of crystallization and the development of crystals and the formation of crystal network. Mechanical treatment will break down the primary crystal bond structure and give a more smooth structure with plasticity mainly based on van der Waals forces (Secondary crystal bond structure). Figure 2b: Free water after squeezing Figure 2c: Secondary crystal bond structure. Palsgaard® DMG 0298 comes in paste form whereas Palsgaard® PGPR 4175 is in liquid form. Palsgaard Technical Paper - September 2013 How to successfully manufacture a low fat margarine spread with only 10% fat 3
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