Effects of Lipid on the Solubility of MPC during Storage

Abstract:

This study was focus on the effect of lipid on the protein solubility of milk protein concentrate，which lacks of intensive study now. A model system was established using fatty acid methyl ester with different melting points including methyl laurate and methyl myristate. The spray dried milk powder prepared with various lipids was storage at 45 ℃（RH 23%） for 30 days and at 35 ℃（RH 11%） for 30 days，respectively. The changes in the powder solubility under different conditions were studied and the mechanism of solubility decrease was explored. The effect of lipid on protein solubility was insignificant. The most prominent determinant for solubility decrease was related neither to lipid oxidation nor to protein oxidation. The interaction between caseins caused insoluble aggregates formation during storage，which decreased the protein solubility. The main driving forces for protein aggregation were in the prefer orders of hydrogen bond > disulfide bond > hydrophobic interaction.