Processing and matrix effects on the antioxidant capacity of fruit‐based beverages

Fruits contain a variety of polyphenolic compounds with antioxidant properties. These compounds are associated with lower risk of chronic disease. Fruits are consumed as raw and in processed forms (e.g. beverages). The perishable nature of fruits/fruit‐based products demands processing strategies to enhance shelf‐life and assure food safety, while maintaining nutritional quality. Therefore, we proposed to develop a system to test standard and novel processing strategies on the antioxidant capacity (AC) of fruit‐based beverages containing appreciable amounts of polyphenolic compounds. In this study, strawberry (Str) formulated dairy‐(D) and non‐ dairy (ND) beverages were used to investigate the effect of high temperature‐short time (HTS‐72°C‐20 sec) and high pressure (HPP‐600 MPa‐1 min) processing on AC as measured by Oxygen Radical Scavenging Capacity (ORAC). Two dairy‐based beverages contained 0 or 10 g, freeze‐dried CA Str (D‐Ctrl, D‐Str), and 1 beverage contained Str (10 g) and water only (ND‐Str). HPP and HTS reduced ORAC of D‐Str and D‐Ctrl compared to their respective unprocessed beverages (D‐Str: 6.9±1.1 & 3.1±0.3 vs. 12.3±0.9 μMTE/mL and D‐Ctrl: 1.2±0.1 & 1.8±0.2 vs. 2.4±0.2 μMTE/mL, respectively, P<0.01). HPP did not affect ORAC of ND‐Str compared to unprocessed ND‐Str (11.1±1.0 vs. 10.6±1.1 μMTE/mL); however, HTS significantly reduced ORAC of ND‐Str (4.7±0.6 μMTE/mL) compared to unprocessed ND‐Str (P<0.01). These findings indicate a significant effect of processing and matrix on AC of fruit‐based beverages and support further work to determine the impact of these findings in in vivo systems.