Excellent nutritional value in fruits of three guava cultivars in Taiwan

In Taiwan, guava is one of the fruit crops under consideration for international export markets due to its high nutritional values. This study was aimed to investigate the exporting potential of three locally bred guava cultivars by evaluating their nutritional values. Results from this study showed that 'Rainbow' guava had the highest ascorbic acid content with a value of 391.5 mg 100 g^-1 FW, followed by 'Jen-ju' and 'Di-Wang'. Based on the ascorbic acid content analyzed in guava, consuming one guava can obtain equal amount of ascorbic acid as eating 70 apples or 20 kiwifruit. The content of total phenolic compound (TPC) in 'Rainbow' guava was significantly higher than that of the other two cultivars with a value of 3064 μg g^-1 FW in 'Rainbow' and 2468 μg g^-1 FW in 'Jen-ju'. The antioxidant capacity (FRAP and DPPH) and nitrite scavenging activity in guava fruits were also higher than those in apple and kiwifruit. Results from this study indicated that it took only 0.01-0.02 mL of guava juice to scavenge 50% nitrite, while 0.23 and 0.12 mL of apple juice and kiwifruit juice, respectively, were required to obtain the same result. Overall, guava is not only rich in Vitamin C but also in a variety of other nutrients and therefore is an excellent candidate for overseas market.