IMPACT OF MINERAL ELEMENTS (Ca, Mg AND Fe) ON MAILLARD REACTION IN MODEL SYSTEMS WITH CASEIN

Non-enzymatic browning, known as Maillard reactions (MR), occurs in many foods, including dairy products. The initial reactants are the amino compounds and reducing sugars. However, the MR in the real food systems proceeds in presence of other macroand micro-components. The task of the work was to determine the influence of Ca, Mg and Fe on the browning characteristics of the MR model systems consisting glycine or casein and lactose or glucose, and to estimate the interaction of the elements with the high molecular weight (HMW) products formed during MR. The extent of browning in MR solutions was evaluated by measuring absorbance at 420 and 550 nm. The HMW melanoidins were separated by means of dialysis. It was determined that Ca, Mg promote, and Fe slows down the formation of colored MR compounds in the lactose–casein as well as in glucose–casein model systems by thermal treatment to 12 h at boiling temperature. The amount of Ca in the non-dialyzable part of the systems increased over a longer time of interaction from 28–38 to 62–71 %, while the amount of non-dialyzable Mg stays fixed about 26%. The peak of non-dialyzable Fe (~50%) was found in the first hour of interaction. The results demonstrate the possible involvement of Ca, Mg and Fe in the thermal changes of dairy products and the impact of Maillard reactions on the solubility and supposed bioavailability of the elements.