Optimisation of analytical methods for the characterisation of oranges, clementines and citrus hybrids cultivated in Spain on the basis of their composition in ascorbic acid, citric acid and major sugars

Abstract

Summary Three HPLC methods were optimised for the determination of citric acid, succinic acid and ascorbic acid using a photodiode array detector and fructose, glucose and sucrose using a refractive index in twenty eight citrus juices. The analysis was completed in <16 min. Two different harvests were taken into account for this study. For the season 2011, ascorbic acid content was comprised between 19.4 and 59 mg vitamin C/100 mL; meanwhile for the season 2012, the content was slightly higher for most of the samples ranging from 33.5 to 85.3 mg vitamin C/100 mL. Moreover, the citric acid content in orange juices ranged between 9.7 and 15.1 g L−1, while for clementines the content was clearly lower (i.e. from 3.5 to 8.4 g L−1). However, clementines showed the highest sucrose content with values near to 6 g/100 mL. Finally, a cluster analysis was applied to establish a classification of the citrus species.

Comparative Study of Bioactive Components and Quality from Juices of Different Mandarins: Discriminant Multivariate Analysis of Their Primary and Secondary Metabolites

“…Table 2 shows the total vitamin C content determined by the HPLC method (expressed as mg•100 mL −1 values) and the TAA is expressed as L-ASC equivalents (mg•100 mL ) determined by ABTS method. The total vitamin C levels ranged from 19.57 to 59.30 mg•100 mL −1 , which is in agreement 1 Data are expressed as mean (n = 3 -9); different letters in the same column, indicate significant differences (p < 0.05); 2 As vitamin C total determined by the HPLC method; 3 Total antioxidant activity from the hydrophilic fraction expressed as L-ASC equivalent determined by the ABTS method; 4 TAA/Vit C total. 5 β-cryp = β-cryptoxanthin, and β-car = β-carotene; 6 Value expressed as retinol equivalents L −1 .…”

“…Herein the organic acid profile was determined and three acids were quantified ( Table 3). Ellendale exhibited the highest levels of citric acid (26. , similarly to those reported previously [4] [23]. Sugar composition was determined and three sugars were quantified in all the arieties studied ( Table 3).…”

A Size Exclusion HPLC Method for Evaluating the Individual Impacts of Sugars and Organic Acids on Beverage Global Taste by Means of Calculated Dose-Over-Threshold Values

“…Eyéghé-Bickong et al [11] reported unresolved separation peaks between malic acid and fructose for the analysis of grapevine berries, using also an Aminex cation-exchange column with 5 mM aqueous H2SO4, as the isocratic mobile phase. The same interference was also found by Carballo et al [20], for a two-run analysis, using a polymeric anion exchange column (with 80 mM aqueous solution of NaOH as the eluent) and an ion-exclusion column in hydrogen form (using 5 mM aqueous solution of H2SO4 as the eluent). However, few of these works report HPLC analytical method validation [11][12][13]20], and only one reports the simultaneous quantification of sugars and organic acids in a single run [11].…”

“…Each standard mixture was prepared independently by measuring the appropriate mass of each compound in order to obtain the concentration ranges reported in the previous subsection. Due to co-elution issues reported in the literature [11][12][13]20], between some sugars and organic acids, additional assays were carried out. To study possible interferences between tartaric acid and glucose or malic acid and fructose, new standard solutions, with different concentrations, were prepared by mixing seven of the eight compounds under analysis, each solution without one of the above-mentioned two organic acids or two monosaccharides.…”

“…Sugars and organic acids concentrations in beverages are usually quantified using liquid chromatography in a single run [8][9][10][11] or separate runs [12][13][14][15][16][17][18][19][20]. The use of ultraviolet (UV) or photodiode array (DA) detectors and a refractive index (RI) detector or an evaporative light scattering detector (ELSD) enables quantifying organic acids and sugars, respectively.…”