The main bitter compounds (nomilin, limonin and naringin) in the fruit tissues of ‘Guoqing No.1’ Satsuma
mandarin (Citrus unshiu Marc.) were determined throughout the fruit development of 3 consecutive
growing seasons. Although fluctuating largely at the corresponding developing stages of the 3 years,
the contents of these compounds in fruit tissues mostly displayed a declining trend, which implied that
the rhythm of the metabolism of these bitter compounds was not consistent among years and was largely
growing season dependent. Regarding their distribution, fruit flavedo might be a weak sink that contained
the lowest level of naringin, while the segment membrane accumulated large amount of limonin
and nomilin, which indicated a possible tissue bias pattern for biosynthesis or accumulation of those
compounds. Partial correlation coefficient analysis revealed a synergistic accumulation of naringin and
the two limonoid aglycones in fruit tissues during fruit development, indicating an integrated metabolism
of flavonoids and limonoids.
2013 Elsevier Ltd. All rights reserved.