The use of permitted additives and heat‐treatment to optimize the heat‐stability of skim milk and concentrated skim milk

Changes in heat stability induced by forewarming and addition of permitted stabilizers have been investigated for skim milk, concentrated (22·5 per cent total solids) skim milk and reconstituted skim‐milk powder. Forewarming slightly reduced the heat stability of skim milk, but markedly improved the heat stability of concentrated skim milk. The effect of stabilizer addition was largely dependent on the initial pH of the milk and its position on the coagulation time/pH profile with respect to the maximum heat stability in the curve. It was shown that the combination of forewarming and addition of suitable stabilizers could induce a large increase in the heat stability of both skim and concentrated skim milk. Addition of stabilizers could likewise increase the heat stability of reconstituted ‘high‐heat’ skim‐milk powder, but was ineffective in improving the basic heat stability of non‐forewarmed milk and reconstituted ‘low‐heat’ skim‐mlk powder.