LAUSR

Carryover color in the whey fluid is one of the major challenges faced by the cheese manufacturing industry. In this study, we describe a solvent-mediated high-pressure process to complexate bixin and casein micelles as a novel strategy for color delivery. High pressures (120 and 240 MPa) and added ethanol resulted in change in casein hydrophobicity by exposure of tryptophan residues, as confirmed by spectroscopic methods. The incorporation of bixin resulted in a marked quenching of the fluorescence peak associated with tryptophan. A simulated coagulation study has shown that pressure-treated complexes resulted in whey powder with significantly lower a* values than unbleached whey, whereas no significant differences were observed for b* values. The results suggest that complexes can produce curds with a color similar to that using commercial annatto powder and whey powder with equal or superior color quality than obtained with chemical bleaching.