Optimisation of an HPLC method for the simultaneous quantification of the major sugars and organic acids in grapevine berries

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Vol. 885-886; pp. 43 - 49
• Main Authors: Eyéghé-Bickong, Hans A., Alexandersson, Erik O., Gouws, Liezel M., Young, Philip R., Vivier, Melané A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.02.2012
• Subjects: Berries; Carbohydrates - analysis; Carboxylic Acids - analysis; chloroform; Chromatography; Chromatography, High Pressure Liquid - instrumentation; Chromatography, High Pressure Liquid - methods; equations; Extraction; fructose; Fruit - chemistry; Grapevine berries; Grapevines; High performance liquid chromatography; ion exchange; Linear Models; malic acid; Mathematical analysis; Organic acids; refractive index; Reproducibility of Results; small fruits; Sugars; sulfuric acid; Vitis; Vitis - chemistry; Wine - analysis; Grapevine berries; Sugars; Organic acids; High performance liquid chromatography
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/j.jchromb.2011.12.011

► High performance liquid chromatographic method optimised and validated. ► Simultaneous quantification of major sugars and organic acids in grapevine berries. ► Samples directly injected after sample extraction. ► Extraction step downscaled to allow the use of milligrams of sample material. ► A set of equations proposed to calculate concentrations of malic acid and fructose. A high performance liquid chromatographic method was developed to profile major sugars and organic acids in grapevine berries. Sugars and organic acids in grapevine berries were extracted by chloroform/polyvinylpolypyrrolidone purification. The extracts were chromatographed on an Aminex HPX-87H ion-exchange HPLC column with 5mM sulphuric acid as mobile phase. Chromatography was visualised via a diode array detector combined with a refractive index detector. The analysis was calibrated using external standard calibration and a novel equation was used to calculate the concentrations of malic acid and fructose from unresolved separation. For the method to be utilised for analysing a large numbers of berry samples, each sample was directly injected after sample extraction and the extraction step was downscaled to allow the use of small amounts of sample material. The concentrations of sugars and organic acids in grapevine berry samples were normalised to the internal standard concentrations obtained after extraction of an internal standard mixture. The analysis method exhibits a good precision and a high analyte recovery from samples spiked with the standard mixture and is suitable for the profiling of major sugars and organic acids in grapevine berry samples at different stages of berry development. This is the first report on the combined profiling of the major sugars and organic acids in grapevine berries using milligram amounts of plant material with direct injection after sample extraction.