Study of Antioxidant Capacity and Quality Parameters in An Orange Juice-Milk Beverage After High-Pressure Processing Treatment

The aim of this study was to obtain a beverage with a high content of bioactive compounds. Therefore, a mixture of orange juice and milk was prepared. The effect of high-pressure processing (HPP), four different pressures (100, 200, 300, and 400 MPa), four treatment times for each pressure (120, 300, 420, and 540 s) on antioxidant compounds, and quality parameters was studied. The effects of HPP treatment were compared with those of thermal treatment (90 degrees C for 15, 21 s and 98 degrees C for 15, 21 s). Ascorbic acid retention in the orange juice-milk beverage was higher than 91% in all cases after HPP. There was a significant increase (p<0.05) in phenolic compounds at 100 MPa/420 s, however at 400 MPa/540 s, it was observed a non-significant decrease. Total carotenoid content was significantly higher in all samples treated by HPP when treatment time was 420 and 540 s. Color changes increased when pressure and treatment times were higher, with the highest difference appearing at 400 MPa/540 s, but HPP had a smaller effect on total color changes than thermal processing. A 5-log reduction of Lactobacillus plantarum CECT 220 was obtained in the orange juice-milk beverage after HPP (200 MPa, 300 s), and this was compared with treatment at 90 degrees C (15 s), the heat treatment most effective at preserving ascorbic acid.