Study of bioactive molecules of three cactaceae (Stenocereus pruinosus, Pachycereus weberi and Escontria Chiotilla) and their betalaina extraction in aqueous two-phase systems

Abstract

Mexico has a great diversity of cacti, however, many of their fruits have not been studied in greater depth. Several bioactive compounds available in cacti juices extract have demonstrated nutraceutical properties. Two little-studied cactus species are interesting for their biologically active pigments, which are chico fruit (Pachycereus weberi (J. M. Coult.) Backeb)) and jiotilla (Escontria chiotilla (Weber) Rose)). In the country, production of pitaya (Stenocereus pruinosus) 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, sustainable methods for betalains quantification and extraction in cacti fruits for rural communities will be necessary. Betanin in pulp of chico fruit (Pachycereus weber), jiotilla (Escontria chiotilla) and pitaya (Stenocereus pruinosus) were quantified using three different analytical methods. The techniques were of Spectrophotometry UV-vis (SCC), high-performance liquid chromatography (HPLC) and molar extinction coefficient (SEC). In this case SEC method represents the best option to reduce costs, time and solvents. In the three methods, coefficient of variation between measurements obtained are below 15%. Bioactive compounds and mineral content were evaluated in P. weberi and E. chiotilla. Then, clarified juices extracts were evaluated for their antioxidant activity and cytotoxicity (cancer cell lines) potentialities. Based on the obtained results, Chico fruit extract was found to be a good source of vitamin C (27.19 ± 1.95 mg L-Ascorbic acid/100 g fresh sample). From the cytotoxicity perspective against cancer cell lines, the clarified juices extracts of chico showed cytotoxicity (%cell viability) in CaCo-2 (49.7 ± 0.01%) and MCF-7 (45.56 ± 0.05%). While jiotilla extract had cytotoxicity against HepG2 (47.31 ± 0.03%) and PC-3 (53.65 ± 0.04%). In this study, low sugar betaxanthin and betacyanins preparations were obtained from clarified juices extracts from yellow pitaya and jiotilla using aqueous two-phase systems (ATPS). This work focuses on the effect of tie line length (TLL), phase volume ratio (Vr), and clarified juice extracts percentage on the partitioning of betaxanthins and sugars. In betaxanthins the correlation with Vr, clarified juices extracts, and TLL was determined by multiple linear regression. The desirability function was used to identify an ATPS (TLL = 37.7 %, Vr = 0.3, and 7 % crude extract) yielding a top phase with minimum total sugar (2.8 %) and maximum betaxanthin content (52.3%). These results demonstrated that Pitayas are excellent resources of betaxanthins.