Updating Nutritional Data and Evaluation of Technological Parameters of Italian Milk

Different technologically treated Italian milks (whole and semi-skimmed ultra-high temperature (UHT), pasteurized and microfiltered milk), collected from 2009 to 2012, were evaluated for nutritional and technological properties. No significant differences in calcium and sodium were detected (p > 0.05), while significant differences were observed concerning phosphorus content, between whole and semi-skimmed milk, and lactose content, between pasteurized and UHT milk (p < 0.05). In UHT milk, lactose isomerization occurred, and lactulose (from 8.6 to 104.0 mg/100 g) was detected. No significant differences (p > 0.05) were detected for choline, a functional molecule, between whole (11.3-14.6 mg/100 g) and semi-skimmed milk (11.1-14.7 mg/100 g), but there were significant differences (p < 0.05) in processing milk (UHT vs. pasteurized milk and UHT vs. microfiltered milk). Among the unsaponifiable compounds, only 13 cis retinol and trans retinol showed differences in technologically treated milk (pasteurized vs. UHT milk and microfiltered vs. UHT milk; p < 0.05). In this research, the greater was the "severity" of milk treatment, the higher was the percent ratio 13 cis/trans retinol (DRI, degree of retinol isomerization). The degree of antioxidant protection parameter (DAP), useful to estimate the potential oxidative stability of fat in foods, was significantly different between whole and semi-skimmed milk (p < 0.05). Finally, the evaluation of color measurement of whole milk showed a good correlation between beta carotene and b* (r = 0.854) and between lactulose and a* (r = 0.862).