摘要 : The status of complexation between casein and whey protein on direct or indirect UHT processing of skim milk at 126 or 145 degrees C for 4 s was analysed for optimum physico-functionality of the complexed protein structures. Diffe... 展开 The status of complexation between casein and whey protein on direct or indirect UHT processing of skim milk at 126 or 145 degrees C for 4 s was analysed for optimum physico-functionality of the complexed protein structures. Different properties were analysed: pH-profiles of the micellar surface hydrophobicity (SHP) to assess both the extent of complexes formed and their stability in acidic environment; the degree of denaturation of beta-Lactoglobulin ( beta-Lg); and the enzymic accessibility of sugar-free caseinomacropeptide (n.-g. CMP) inside of the micelles. Results from the CMP analysis were verified further through investigations into rennetability and gel matrix formation. The colloid-chemical findings provide evidence for the formation of perfectly complexed micelle structures only on indirect heating at 126 degrees C for 4 s. The inherent structural status implies an exceptionally high SHP (indicating suitable emulsification properties) irrespective of the pH value and was paralleled by 59% beta-Lg denaturation and total non-coagulability since 38.7% of n.-g CMP remained inaccessible to enzymic cleavage. It is suggested that this complexation might be an alternative treatment to make use of milk with poor gelation induced by oxidative stress. 收起