local food standards and legislation. In terms of fat, cocoa butter is the main component in chocolate. Milk- and white chocolate also contain milk fat which makes the chocolate softer, more plastic in consistency and shows less contraction during crystallization. Even in dark chocolate for ice-cream applications it is highly recommended to add 4-5% anhydrous milk fat making the chocolate more plastic. This will reduce the cracking problems, especially in extruded ice-cream types where the centre is hard and there is no room for this contraction, and hence the chocolate will crack. Today also many countries allow addition of up to 5% non cocoa based vegetable fat to be added, and still maintain the status as a real chocolate. These so called cocoa butter equivalents (CBEs) might also be applied to plasticize the chocolate. Typically the total fat content of an ice-cream chocolate will reach approx 40 - 45%. Ice cream coating – compound coating Ice-cream coatings – typically thin layers are manufactured from rather inexpensive fats like coconut oil or hydrogenated palm kernel fat. Contrary to an ice-cream stick covered with a thick layer of real chocolate, the ice-cream coating should only form a thin layer round the icecream stick. The total fat content is therefore often above 60% in order to achieve a sufficient thin layer and a short crystallization time. Both coconut oil and palm kernel fat are forming quite hard and brittle coatings upon cooling, so as for the ice cream chocolate it is recommendable to “soften” the fat phase. Here addition of approx 8% liquid oil e.g. maize, peanut, sunflower or rape seed oil will provide the necessary plasticity to the coating. Addition of approx 5% skimmed milk powder to a dark coating will improve the flavour of the coating balancing the bitterness of the alkalized cocoa powder. Emulsifiers Emulsifiers work in the chocolate by improving the flow properties of the liquid chocolate mass. Especially some emulsifiers lower the plastic viscosity whereas other emulsifiers influence the so-called yield value. The yield value can be defined as the energy input needed to initiate flow of the chocolate. As an added benefit for the ice cream manufactures, the emulsifiers also have the ability to absorb a limited amount of water which is destined to be transferred from the ice-cream to the chocolate during dipping or enrobing of the ice cream sticks or bars. Soya lecithin (E 322) is the most abundantly used emulsifier in chocolate. The emulsifier has the ability to lower the plastic viscosity in the chocolate, but when added at dosages above 0.5%, the yield value of the chocolate will increase, making flow more difficult. Especially in an ice-cream chocolate this is a disadvantage, as higher dosages of emulsifier will improve the water binding Palsgaard Technical Paper, September 2009 Troubleshooting emulsifiers for ice-cream coatings 3
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