Rennet coagulation of casein micelles and heated casein micelles in presence of sucrose or lactose

MIRYAM PIRES, CARLOS A. GATTI, GABRIELA A. ORELLANA , ENRIQUE MORALES

FOOD RESEARCH INTERNATIONAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2004 vol. 37 p. 95 - 101

0963-9969

The effects of sucrose and lactose on the kinetics of the aggregation step of milk enzymic coagulation were studied by turbidimetric measurements for casein micelles previously heated (HCM) or not heated (CM). The initial aggregation rate showed an initial destabilizing effect by addition of polysaccharides, which could be attributed to preferential exclusion of the same, from the micellar surface, followed by an inspecific stabilization due to the medium viscosity increase. The initial aggregation rate increased linearly as a function of the temperature/viscosity ratio, for CM and HCM, up to 33 C for sucrose and to 38 C for lactose, suggesting the constancy of initial aggregation constant (k2). Sharp inflexions to lower slopes were observed in all the cases besides these temperatures, evidencing a marked diminution of k2, attributable to an abrupt increment of the stability coefficient W . This sudden stability increment could be likely related to the formation of condensation complexes characteristic of the earlier stages of the Maillards reaction.