“…However, after squeezing or heating, ponkan juice exhibits an increase in bitterness just like other citrus fruits, which limits the industrial production of ponkan juice. Limonin (a limonoid) and naringin (a flavonoid) are recognized as the main reason for the bitterness of citrus juices (Cavia-Saiz, Muniz, Ortega, & Busto, 2011;Kola, Kaya, Duran, & Altan, 2010;Stinco et al, 2013). Our previous study showed that the content of narigin in ponkan juice was very low, and limonin was the main component of bitterness in ponkan juice (Bao, Yuan, Zhao, Liu, & Gao, 2013).…”