Variation in Bioactive Flavonoid Content of Commercial Brands of Orange Juices

Abstract

Orange juice is an important source of bioactive compounds like flavonoids and the main human dietary source of antioxidant compounds in developed countries. Citrus flavonoids possess chemo-preventive and anti-inflammatory properties as well as the ability to lower cholesterol and modulate the immune function. In this study, we examined flavonoid content of “concentrated” (n = 12) and “Not-From Concentrate (NFC)” (n = 14) commercial orange juices by an HPLC method to investigate the brand to brand differences and differences within the brand (various types). Correlation between flavanonoid content (mg) and price per unit volume was also evaluated. Significant (P = 0.05) differences among the brands were observed in the flavanoid content of both NFC and concentrated orange juices. Total flavonoid content was significantly higher in concentrated juices compared to the NFC juices. However, higher content of didymin was found in NFC juices. Within the brand, no significant differences in the total flavonoid content were observed in juice types containing antioxidant vitamins compared to the juice types devoid of these vitamins. Price did not correlate with the total flavonoid content for either NFC (r = 0.057) or concentrated (r = -0.49) orange juices. Hesperidin was the major flavonoid and followed by narirutin and didymin. Their content (mg/100 mL) in concentrated and NFC juices ranged between 18-55 (Hesperidin); 3-8 (narirutin); and 1-2.5 (didymin), respectively. This study provides valuable information on flavonoid composition of orange juices commonly available in the US market.