Changes in Quality and Nutritional Parameters During Refrigerated Storage of an Orange Juice–Milk Beverage Treated by Equivalent Thermal and Non-thermal Processes for Mild Pasteurization

Abstract

The effects of high-pressure (HP) treatment (400 MPa at 42 °C for 5 min) and pulsed electric field (PEF) processing (25 kV/cm at 57 °C for 280 μs) on ascorbic acid, total carotenoids, total phenolic compounds and total antioxidant capacity (TEAC and ORAC) of an orange juice–milk (OJ-M) beverage along the storage time at 4 °C were compared with a conventional heat preservation technology used in industry (90 °C for 15 s). During storage, ascorbic acid, total carotenoids and antioxidant capacity (TEAC) depleted with time regardless of the treatment applied. Instead, total phenolic content and antioxidant capacity measured by the ORAC method increased at the end of the storage. Non-thermal-treated beverage had less non-enzymatic browning than the thermally pasteurized one. There were no significant variations in the hidroxymethylfurfural (HMF) content of the HP- and PEF-treated OJ-M, whilst a significant increase was obtained after thermal treatment. During refrigerated storage, HMF was always below the maximum values established. The HP treatments reduced the L* value of the treated beverages immediately after processing and during refrigerated storage and induced an increase in total colour differences of beverages treated by HP compared with PEF and thermally processed orange juice–milk. Hence, alternative methods such as HP and PEF may give new opportunities to develop orange juice–milk with an equivalent shelf life to that of thermally treated orange juice mixed with milk in terms of microbial, physicochemical and nutritional characteristics.