The effect of high pressure processing on colour, bioactive compounds, and antioxidant activity in smoothies during refrigerated storage.
The effects of high pressure processing HPP (450 and 600 MPa/3 min/20 degC) on the colour, carotenoids, ascorbic acid, polyphenols and antioxidant activity (FRAP and DPPH) of a smoothie were compared to thermal processing (80 degC/3 min) Stability during 45 days at 4 degC was also evaluated. HPP samples showed slight differences (p 0.05) in colour compared to untreated smoothies. Both HPP significantly increased the extractability of lycopene, b carotene and polyphenols compared to untreated samples. After HPP, ascorbic acid was retained by more than 92% of the initial content. The best results for antioxidant activity were obtained when HPP was applied at 600 MPa. FRAP and DPPH showed a high correlation with ascorbic acid (R(2) 0.7135 and 0.8107, respectively) and polyphenolic compounds (R(2) 0.6819 and 0.6935, respectively) but not with total carotenoids. Changes in bioactive compounds during the storage period were lower in the HPP smoothie than in the thermal treated sample.
Food chemistry