INFLUENCE OF METAL IONS ON THE OXIDATIVE STABILITY OF HEATED MILK: STUDY BY ATR-FTIR SPECTROSCOPY AND CHEMOMETRICS

The present study demonstrates the effect of metal ions (stainless steel, Cu2+, andFe(2+)), and their catalytic activity in the lipid oxidation of the milk samples. Milk fat is one of the complex fats and highlysensitive to auto-oxidation. To amplify the effect of metal ions, milk is subjected to temperature treatment, leading to various chemical and biochemical changes in the lipid fraction of the heated milk. Metal release were monitored by HG-AAS for the metaldetermination in milk samples. In this current investigation, the effect of metals ions on heated milk was determined using Ekomilk Scan for physicochemical analysis and ATR-FTIR Spectroscopy for the determination of lipid oxidative status, in combinationwith the chemometric PCA (Principal Component Analysis), which was not reported in earlier investigations. The heating process resulted in decreases in the areas of intensity ratios of 1746/2923 and 1737/2923 cm(-1). Principal component analysis and hierarchical cluster analysis confirmed that stainless steel has a higher effect on lipid oxidation than copper and iron. These results demonstrate that the metal in milk solution and their ions impact lipid oxidation during the heating. This research also indicateds that oil oxidation could be easily and rapidly monitored by ATR-FTIR spectroscopy