forms a helix with negatively charged sulphate groups turning outwards. This helix interacts with the positively charged casein micelle. When carrageenan is used as stabilizer, the chocolate milk must be cooled down below 25°C before filling, or cooled down below 25°C during constant rotation if in can/in bottle sterilization is used. This is necessary for formation of the carrageenan network. Figure 2 across shows how the network is formed in a carrageenan stabilized chocolate milk. Further storage of the chocolate milk should be below 30°C as the formed network breaks down at higher temperature. The effect of the MCC/CMC complex Microcrystalline cellulose (MCC), or rather a MCC/CMC complex, also finds application in chocolate milk, however, often in combination with carrageenan. MCC is derived from plant fibres from which the crystalline part of the cellulose is extracted. When in dispersion the MCC forms a three-dimensional network due to formation of hydrogen bonds. Figure 2. Formation of carrageenan network in chocolate milk. Below 80°C a change in temperature only has limited effect on the functional properties of MCC, meaning that cooling and storage temperature is less critical when MCC is used. Consequently, MCC based products are recommended when cooling below 25°C is not applicable or if the storage temperature is higher than 30°C which is often the case in eg. South East Asia and the Middle East. MCC based products often gives more body and creaminess to the milk drink, which could be another reason for recommending a MCC based solution. Figure 3 below illustrates the network formation of MCC/CMC in which the cocoa particles are kept in suspension. Finding the right stabilizer dosage The dosage of the stabilizer is very crucial. Underdosing means sedimentation in the chocolate milk and overdosing results in heavy body and gelation. When working with carrageenan one has to be very careful as the margin between underdosing and overdosing is very narrow. The use of mono- and diglycerides together with carrageenan increases the dosage margin of carrageenan and at the same time reduces the amount of carrageenan needed for formation of a stable product. This is due to the fact that the mono- and diglycerides form a network between the fat globules and the whey proteins. Figure 3. MCC/CMC network. Further the dosage of the carrageenan depends on • The fat content of the milk. Higher fat demands less stabilizer • The cocoa content. Higher dosage less stabilizer • The heat treatment. Sterilization demands less stabilizer than UHT treatment which again demands less stabilizer than a pasteurised product Palsgaard Technical Paper, October 2010 3 How to make a delicious chocolate milk
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