LIBRO-CONGRESO-CITRUS

S21
flowers of different cultivars of citron and lemon were analyzed by HPLC/MS-MS. The dominant pigments in
fruits were cyanidin-3-glucoside and cyanidin-3-(6” malonil-glucoside) while in young leaves and flowers a
different pattern was observed. This is the first report of patterns of anthocyanins in the different organs of a
large number of genotypes of citrus.
S21P02
Organic acids metabolism in postharvest citrus fruit
Cheng Y.J., Sun X.H., Zhu A.D., Xu J., and Deng X.X.
Huazhong Agricultural University (H), Key Laboratory of Horticultural Plant Biology, Ministry of Education, China.
yjcheng@mail.hzau.edu.cn
Organic acids in citrus fruits play critical roles in their edible quality and sensibility to storage environments.
However, very limited information on postharvest acid metabolism in citrus fruit is available yet. In the
present study, organic acids metabolism in the pulp of 3 main pummelo cultivars (Citrus grandis), widely
planted in China, including ‘Guanximiyou’, ‘Shatianyou’, and ‘Hirado Bontan’, were systematically analyzed
in 3 successive growing seasons. Capillary electrophoreses, high performance liquid chromatography and
gas chromatography mass spectrometry were used for physiological and metabolic analyses. Moreover, an
8×15K mitochondrial microarray, composing of 1569 functional gene probes was designed. Based upon the
acid metabolic profiles, RNA was extracted from four key stages for the microarray assaying. Meanwhile, the
damage of mitochondrial membranes, as well as the contents of reactivate oxygen species was examined. Our
results demonstrated that during citrus fruit postharvest storage phase: 1) The metabolic profiles of organic
acid differed among cultivars; 2) Fluctuations of acid contents were inherent properties of in all sound citrus
fruits; 3) The dynamic equilibrium of organic acid content was determined by the status of acid synthesis,
degradation, transportation and storage, which were resulted from the synergistic actions of mitochondria,
vacuoles and peroxisomes; 4) Except tricarboxylic acid cycle (TCA), glutamine and γ-aminobutyric acid (GABA)
pathway, which linked the primary and secondary metabolisms, also played significant role in citrus fruit acid
regulation.
S21P03
Ethylene degreening treatment under commercial conditions does not cause loss of nutritional
and aroma quality of citrus fruit.
Sdiri S., Navarro P., and Salvador A.
Instituto Valenciano de Investigaciones Agrarias (I.V.I.A.), Centro de Tecnología Postcosecha, Spain. salvador_ale@gva.es
A significant volume of Spanish citrus fruit production is commonly submitted to degreening with ethylene
exposure prior to be exported to overseas countries under cold quarantine conditions. Many studies
have reported the effect of postharvest application of ethylene on internal quality fruit. Nevertheless,
information about the effect of degreening and quarantine treatments on the nutritional and aroma
volatile compositions in citrus fruit is scarce. This study aimed to evaluate the effect of degreening with
and without ethylene exposure followed by cold quarantine treatment on vitamin C, hesperidin, narirutin,
didymin, sinensetin, nobiletin, tangeretin content as well as antioxidant activity of ‘Navelina’ sweet orange
and ‘Clemenules’ and ‘Oronules’ mandarins. The levels of the most important aroma active compound in
citrus fruit (ethanol, acetaldehyde, ethyl butanoate, hexanal, α-pinene, myrcene, ethyl hexanoate, octanal,
limonene, linalool, nonanal and decanal) were also determined. The response to degreening process and
the posterior quarantine treatment depended on the variety. Although some changes were observed
in individual flavonoids compounds of ‘Clemenules’ mandarins and ‘Navelina’ oranges, the degreening
treatments followed by cold quarantine storage did not induce dramatic changes in nutritional and aroma
compounds. Nevertheless, ‘Oronules’ mandarins exhibited the highest response to ethylene exposure and
quarantine treatment with an increase in the level of flavonoids components as well as the level of some
volatile compounds.
356 - VALENCIA CONFERENCE CENTER, 18th-23rd NOVEMBER 2012