Ozone Combined with Ultrasound Processing of High-Sugar Concentrated Orange Juice: Effects on the Antimicrobial Capacity, Antioxidant Activity, and In Vitro Bioaccessibility of Carotenoids.

The objective of this work is to evaluate the effects of ozone combined with ultrasound (ozone+US), pasteurization (PT), and high-temperature short-time sterilization (HTST) on antimicrobial capacity, antioxidant activity, carotenoid distribution and in vitro bioaccessibility of carotenoids in high-sugar concentrated orange juice. The enhancement of cellular membrane permeability and the leakage of cytoplasmic contents in Penicillium citrinum and Saccharomyces cerevisiae induced by ozone+US treatment were confirmed by fluorescence and FTIR spectrum. Ozone+US treatment exhibited higher antimicrobial activity than PT, and ozone+US treatment could decrease 4.22 ± 0.08 log CFU/mL of P. citrinum and 4.49 ± 0.10 log CFU/mL of S. cerevisiae. Additionally, ozone+US treated samples showed significantly lower peroxidase and polyphenoloxidase residual activity, higher bioactive compounds, and antioxidant capacity of orange juice as compared to thermal treatment. Among these treatments, ozone+US-treated orange juice showed the highest retention rates of carotenoid content and carotenoid bioavailability of 3.76 ± 0.05 mg/L and 24.53 ± 1.37%, respectively. Interestingly, particle size reduction and uniform distribution of carotenoids in ozone+US-treated samples enhanced the bioaccessibility of carotenoids. Compared with those thermal treatments, ozone+US treatment would be an alternative to improve microbial safety and decrease the degradation of antioxidant components in high-sugar concentrated orange juice. [ABSTRACT FROM AUTHOR]