FOOD MATERIAL CHACTERISTIC PAPER
Hydrophobic part of protein interact with lipid. The interaction can be strong and it is difficult for lipid to be removed from protein. When lipid has a flavor or if it reacts to produce flavor, the protein might be considered to contributed to the flavor of the prooduct. Most of the flavor compound are volatile and lipid soluble. Protein degradation also contribute to the flavor of the product. It is usually has a negative effect for the product and result in a bitter taste. Further degradation may lead to the formation of unpleasant odors. The interaction between protein and amino acid with fatty ...view middle of the document...
Carrageenan, a seaweed extract, is by far the most commonly used stabilizer in chocolate milk. Kappa carrageenan, which has found use in chocolate milk due to its ability to react with the milk proteins and form a three-dimensional network. When carrageenan is used as stabilizer, the chocolate milk must be cooled down below 25°C before filling.
Although carrageenan may interact with other casein fractions in milk, the binding is much weaker than that with casein, and does not result in gel formation. The presence of the other fractions, such as occurs in whole casein, in fact decreases the sharpness of the sol – gel transition.
K-casein and carrageenan is primarily the gel-forming. It exhibits a sol-gel transition with temperature. They are effective for the suspension of cocoa in chocolate milk. Gelation is required that the formation of gel may be a function of the carrageenan component of the carrageenan-casein complex.
The proteins in milk are a colloidal dispersion. The casein proteins in milk are combined with some of the minerals in milk and form micelles. Micelles are groups of molecules; the micelles in milk form a colloidal dispersion.
The serum proteins, also called whey, are in colloidal dispersion in the water content of milk and are coagulated by heat, but acids and salt do not coagulate them
Protein function in chocolate milk is also as emulsifier. First we should know the exact meaning of emulsion. Emulsion is a condition where liquid dispersed in liquid. This mixing liquid can be caused by its polarities. As we know, protein has a unique structure which contains 2 parts, hydrophobic and hydrophilic. So the hydrophobic part in the peak of one side, and the hydrophilic part in the peak of the other side. In chocolate milk, the presence of lipids may make the emulsion reaction when the milk is mixed with water. The protein here is used as emulsifier to stabilize the layer produce between water and lipid, as protein can partially soluble in both phases. Temperature also has a role in this emulsifier function of protein. The lower temperature may cause the water become more ordered, so there will be less energy difference between those 2 phases, it doesn’t break the emulsion but it may reduce the layer made by those 2 phases.
Proteins have been shown to stabilise emulsions by forming a viscoelastic, adsorbed layer on the oil droplets, which form a physical...