Fresh-Squeezed Orange Juice Properties Before and During In Vitro Digestion as Influenced by Orange Variety and Processing Method

This study aims to analyze the influence of processing and orange variety on initial quality, antioxidant activity, total polyphenol content (TPC), and ascorbic acid content of fresh-squeezed orange juice during in vitro digestion. Fresh-squeezed orange juice was made from Fukumoto Navel, Lane Late Navel, Olinda Nucellar Valencia, and Campbell Valencia oranges, and was processed thermally and nonthermally. Antioxidant activity (FRAP and ABTS assays), TPC (Folin-Ciocalteu method), and ascorbic acid were analyzed before and after gastrointestinal digestion. Bioaccessibility was calculated by comparing the measured values after digestion with the initial value for each juice. Orange variety significantly influenced pH, acidity, and total soluble solids (P < 0.0001). Antioxidant activity by FRAP was significantly higher (P < 0.0001) in Fukumoto Navel orange juice (16.0 +/- 0.4 mM Trolox) than the other juices (range: 9.1 to 10 mM Trolox). TPC was significantly influenced by orange variety (P < 0.0001) and ranged from 521 +/- 6 (Campbell Valencia) to 800 +/- 11 mg gallic acid/L (Lane Late Navel). Processing method did not influence antioxidant and polyphenol bioaccessibility (P > 0.05). However, antioxidant activity by ABTS and ascorbic acid bioaccessibility were significantly influenced by orange variety (P < 0.0001). These results indicate that fruit variety and nutrient bioaccessibility should be considered to optimize processing and formulation parameters.