Retention of Ascorbic Acid, Retinol, β-Carotene, and α-Tocopherol in Milk Subjected to Pressure-Assisted Thermal Processing (PATP)

Thermal treatments can cause undesirable sensory quality and nutritional changes in food, whereas high-quality retention has been widely reported for high-pressure processing (HPP). The aim of this study was to assess the retention of whole-fat milk vitamins after pressure-assisted thermal processing (PATP). The retention of ascorbic acid (AA), retinol, beta-carotene, and alpha-tocopherol was determined by HPLC after 0.5 to 10 min treatments at 46 to 75 degrees C and 95 to 705 MPa. AA content was particularly sensitive to PATP treatments, particularly at 705 MPa and 75 degrees C for 5 min, reaching a loss of 55.1 +/- 0.9%. Liposoluble vitamin losses were much lower than those observed for AA. For all treatments, retinol loss remained below 10.2 +/- 1.7% and it was independent of the processing times tested (0.5, 5, and 10 min) for treatments at 400 MPa and 75 degrees C with losses of 6.3 +/- 1.3, 6.1 +/- 1.5, and 8.1 +/- 3.2%, respectively. For PATP treatments at 75 degrees C, 5 min, and 95-705 MPa, alpha-tocopherol losses were minor and ranging from 5.0 +/- 2.1 to 6.4 +/- 0.6%. These values were similar to those observed after conventional thermal pasteurization. Low beta-carotene losses were also observed at 75 degrees C for all PATP treatments with losses of -0.6 +/- 2.9 to 4.4 +/- 0.5% for 95-705 MPa/5 min and 2.4 +/- 0.3 to 4.9 +/- 2.1% for 400 MPa/0.5-10 min treatments. This study showed that in whole-fat milk subjected to PATP treatments, AA is significantly more sensitive than retinol, beta-carotene, and alpha-tocopherol.

Automated summary

It was found in the study that in whole-fat milk subjected to pressure-assisted thermal processing, ascorbic acid (AA) is more sensitive to the processing, while losses of liposoluble vitamins are lower.