Novel Approach of Using Nutraceutic-Directed Caloric Antioxidant Density and Ion-Ratio for Evaluating Fruit's Health Quality

Seven kinds of indigenous fruits and five imported fruits were compared for their “health quality.” Methods including the calorific, antioxidant, and ion ratios were carried out. Results indicated the order of content (in mg/100g) was: Ca²⁺, Murcott orange (218.2) > Kiwifruit (200.0) > pineapple (138.5) > Golden kiwi (117.6); Mg²⁺, Pitaya (192.2), banana (88.0), Kiwifruit (63.4), and Golden kiwi (58.4); Zn²⁺, Pitaya (19.53) > pear (10.8) > Kiwifruit (6.09) > Irwin mango (4.58). Cu²⁺, Kiwifruit (0.70) > Red globe grape (0.67) > Golden kiwi (0.65) > Irwin mango (0.42) ≈ Pitaya (0.40). In terms of ion ratio, Pitaya showed Zn²⁺/Cu²⁺ (48.8), Mg²⁺/Ca²⁺ (6.7) and uniquely possessed selenium 0.002 mg/100 g; for pear, Zn²⁺/Cu²⁺ = 37.2, while Kyoho grape, Red globe grape, and Golden kiwi revealed extremely high Fe²⁺/(Co²⁺+Ni²⁺) ratios. On the other hands, Irwin mango and Pitaya astonishingly contained huge amount of inositol, reaching 3523.2 mg/100 g and 1998.7 mg/100 g, respectively. To evaluate the “health quality” of fruits, an overall ranking method by combining (a) the Function-directed Caloric Antioxidant Density (CAD) and (b) the ion ratio was developed. The finalized ranking of these selected fruits was: Pitaya > cherry > Irwin mango > Murcott orange = pineapple > banana > Golden kiwi > pear > Kiwifruit > Red globe grape > apple > Kyoho grape. Conclusively, this evaluation method is novel, contemporary and scientific, which could more clearly assess the “health quality” of fruits in view of nutritional, calorific, and antioxidant balance.