Effects of Production-line Squeezing Techniques and Heat Treatment on Functional Components of Citrus kawachiensis (Kawachi bankan) Fruits

Abstract

We previously reported that Citrus kawachiensis peel is abundant in auraptene (AUR), 3,5,6,7,8,3′,4′-heptamethoxyflavone (HMF), nobiletin (NBT), naringin (NGIN), and narirutin (NRTN). All of the above are known as citrus functional components, and a part of these is extracted from the peel into the juice during fruit squeezing. In the present study, we demonstrated that while squeezing method did not affect the composition of compounds in the juice, the contents were affected. Heat treatment for a longer duration led to AUR decomposition, while HMF, NBT, NGIN, and NRTN did not decompose. These 5 components were stable in hot ethanol after 24 h.