Whey-off

Sodium carboxymethylcellulose (commonly known as CMC) was introduced in 1945 by Josephson and Dahle 10) for use in ice cream. It is cold water-soluble, will not react with acid, and has excellent water-binding properties. When properly processed, it is easily dispersible and quickly soluble in the mix. These properties make it well suited for high temperature-short time (HTST) mix. When used alone, it has a tendency to cause separation or wheying off in the mix. Irish moss extract is used with CMC to eliminate this condition. From 0.15 to 0.25% CMC is most often used in ice cream mix. 

In addition to their role in primary stabilization related to viscosity increase, some hydrocolloids (particularly carrageenan) are traditionally used as secondary stabilizers. Many of the primary stabilizing hydrocolloids, including locust bean gum and carboxy methyl cellulose induce precipitation of the milk proteins in the mix. This phenomenon in ice cream mix is known as wheying-off, and may be due to direct protein-polysaccharide binding and/or protein-polysaccharide incompatibility in the water phase40. The latter phenomenon may be due to decreased solvent quality due to the competition between protein and polysaccharide for solubilisation. 

The economic operation of a condensed milk business is of course seriously affected by any increase in loss due to spoiling of cans. Very bad milk will be detected at the condensery. In the hotrwell or in the pan it may curdle, whey off, or develop granular material, but these are not the worst problems of the milk condensery. The most serious loss is experienced in the spoiling of condensed milk after it is shipped and has passed into the many channels of trade. The manufacturer must stand this loss and also the damage to the good name of his product. 

K-Carrageenan is added to ice cream mixes in small amounts (about 0.02%) to prevent wheying off. Rather than remaining uniformly mixed, milk proteins and stabilizers tend to separate into separate regions of the matrix, because it is energetically favourable for them to be in contact with like molecules rather than unlike ones. K-Carrageenan forms a weak gel that hinders the coalescence of... 

Wheying off The phase separation of milk proteins and stabilizers in the matrix. 

For fermented milks, for example yoghurt, acidophilus milk and bifido products, stabilisers are widely used in many countries to improve viscosity and prevent wheying-off. Several types of stabilisers (e.g. gelatins, starch, pectins, carrageenans and cellulose derivatives) are used. The choice depends on the characteristics wanted and the technology used. The main parameters to be considered in the choice of stabiliser for fermented milks are heat stability and sensitivity towards low pH and salts. The effect of stabilisers on the activity of starter cultures must also be taken into consideration (Kalab et al., 1983). 

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