Heat damage evaluation in ultra-high pressure homogenized milk

The evaluation of heat damage in ultra-high pressure homogenized (UHPH)-treated samples has been studied by analyzing different thermal indicators such as compounds that absorb at 340 nm, hydroxymethylfurfural, free sulphydryl content, furosine, lactulose and whey protein denaturation. Milk was treated at 200 and 300 MPa with inlet temperature of 30 and 40 °C and was compared to high-pasteurized milk (PA; 90 °C, 15 s) and to commercial UHT, in bottle-sterilized and pasteurized milks. UHPH samples were differentiated from PA milk, basically by the determination of absorbance at 340 nm and β-Lactoglobulin denaturation. Both parameters indicated a reduced thermal effect in UHPH samples over PA milk. Comparison of UHPH samples with UHT and sterilized milks showed an increase of all heating indicators when severe heat process was applied. Overall, in spite of the increase of temperature during UHPH treatments, heat damage was lower compared to PA milk, suggesting the potential of this technology as an alternative to pasteurization.