Evaluation of three methods for betanin quantification in fruits from cacti

Abstract

In México, production of cacti fruits has increased. These fruits have high concentration of betalains (pigments), and market has increased interest in food with natural ingredients. In the near future, a sustainable method for betanin quantification in cacti fruits for rural communities will be necessary. Betanin in pulp of garambullo (Myrtillocactus geometrizan), chico fruit (Pachycereus weber), jiotilla (Escontria chiotilla) and pitaya de mayo (Stenocereus pruinosus) were quantified using three different analytical methods. The techniques were of Spectrophotometry UV-Vis (SCC), High-Performance Liquid Chromatography (HPLC) and Spectrophotometry technique using Molar Extinction Coefficient (SEC). The accuracy and intermediate precision were evaluated in SEC, SCC, and HPLC with the four cacti´s fruit. The means betanin concentration in the pulps were 0.68±0.05 (mg/g dry weight) garambullo, 1.28±0.06 (mg/g dry weight) chico fruit, 1.84±0.34 jiotilla and 2.0±0.25 pitaya de mayo (mg/g dry weight). The concentration of betanin in garambullo pulp measured by the three methods did not differ significantly (P >0.05). In this case, SEC method represents the best option to reduce costs, time and solvents in this way this method is aligned with green chemistry. In the three methods, coefficient of variation between measurements obtained are below 15%. • Robust method to quantify betanin and evaluate intermediate precision • Validation parameters such as LOD, LOQ, accuracy, intermediate precision, and HorRat were considered • The developed method enriches the valorization of underutilized national agricultural sources of Mexico

Keywords

• Betanin
• Molar extinction coefficient
• Cactus fruits