Melino, V.Soole, K.Ford, C.2010-09-092010-09-092009Australian Journal of Grape and Wine Research, 2009; 15(3):293-3021322-71301755-0238http://hdl.handle.net/2440/60440Background and Aims:  The majority of the acidity of a grapevine (Vitis vinifera L.) berry is a result of the accumulation of l-tartaric (TA) and l-malic acids (MA). TA is synthesised from l-ascorbic acid (Asc, vitamin C), the metabolism of which is poorly characterised in grapevines. In a distinct pathway, oxalic acid (OA) is also formed from Asc degradation. The aim of this study was to develop a single method whereby the distribution of Asc and its catabolites from fruit and vegetative sources could be determined. Methods and Results:  Effective recoveries of total Asc, TA, OA and MA were achieved with this extraction method, while chromatographic separation was accomplished with reversed-phase high-performance liquid chromatography (RP-HPLC). These results demonstrate that Asc and its catabolites TA and OA rapidly accumulate in immature berries, and that the Asc to dehydroascorbate ratio increases with berry maturity. Conclusions:  A method for the simultaneous analysis of Asc, TA, OA and MA in fruits is provided; moreover, we have demonstrated its use to study their distribution in fruits, rachis, leaves and roots. Significance of the Study:  This method enables accurate monitoring of the accumulation of Asc, permitting further research towards understanding acid metabolism during berry ripening.en© 2009 Australian Society of Viticulture and Oenology Inc.ascorbateberry developmentcatabolismmalic acidoxalic acidtartaric acidJournal article002009276910.1111/j.1755-0238.2009.00062.x0002701409000122-s2.0-7035034104937454Melino, V. [0000-0003-2742-5079]Ford, C. [0000-0003-1617-2977]