Extraction of Total Anthocyanins from Sicana odorifera Black Peel Fruits Growing in Paraguay for Food Applications

Abstract

Sicana odorifera is a native fruit of South America large in size. Its dark-colored skin constitutes a useful byproduct for obtaining bioactive molecules because it is rich in polyphenolic compounds, such as anthocyanins. Obtaining appropriate extracts for obtaining anthocyanins can be useful for multiple applications in the food industry or for obtaining phytopharmaceuticals. In this work, the fruit and its peel composition were evaluated, an anthocyanin extraction system was designed and optimized, and the extract obtained was characterized. The peel composition of S. odorifera ripe fruits from the black accession growing in Paraguay was rich in polyphenol compounds and anthocyanins. Ultrasound-assisted extractions of total anthocyanins were studied, and the extraction variables were optimized. First, a screening design was considered to analyze time, pH, liquid–solid ratio, solvent concentration, and temperature. From the screening design, the significant variables were considered in a Box–Behnken design, and a response surface methodology was applied. The resulting total anthocyanin extract was characterized by UPLC-DAD-MS / MS-ESI. The most efficient system for the extraction of anthocyanins from the peel was at 15 min, 20 °C, pH = 6, 60% ethanol, and 80 mL/g of liquid–solid ratio. The highest concentration obtained was 61.908 mg C3G/g peel extract. In the extract, 12 main compounds were tentatively identified, including five anthocyanin derivatives, five flavonol derivatives, and two flavonol aglycones. This study provides information for the obtention of an anthocyanin-based dye from black kurugua peel, possibly useful for future applications as a natural colorant in high-added-value foods due to its antioxidant characteristics.

Nutritional and Bioactive Characterization of Sicana odorifera Naudim Vell. Seeds By-Products and Its Potential Hepatoprotective Properties in Swiss Albino Mice

“…However, the antioxidant activity values by the ABTS method in the seeds were higher than those reported (13.9 ± 2.87 µM TEAC/g) in the seeds of the ripe fruit, by the same authors [ 49 ]. In our previous work on pulp [ 13 ], we found lower concentrations of TPC in the mesocarp (37.2 mg GAE/100 g FW), whereas the epicarp (100 mg GAE/100 g FW) and dry seeds (206 mg GAE/100 g) showed higher levels of TPC [ 13 , 50 ]. The seeds, under our experimental conditions, showed 5.9 mg/g of cyanidin 3-glucoside in monomeric anthocyanins content.…”

“…Finally, the total antioxidant activity was also measured by inhibition of the radical ABTS, where the detected compounds may participate in its scavenging. The total antioxidant capacity value found in the seeds (18.44 μM TEAC/g FW) of S. odorifera is higher than that reported for the pulp (4.39 μM TEAC/g FW) and skin (0.201 μM T/g FW) [ 13 ].…”

“…The seeds, under our experimental conditions, showed 5.9 mg/g of cyanidin 3-glucoside in monomeric anthocyanins content. Compared to the other parts of the fruit, higher concentrations have been found in kurugua peel (19.7 mg/g of cyanidin 3-glucoside) and lower concentrations in the pulp (2.64 mg/g of cyanidin 3-glucoside) [ 13 ]. Anthocyanins are widely distributed metabolites also found in other Cucurbitaceae seeds [ 43 ].…”

“…Regarding the UHPLC-MS analysis of the seeds, eleven compounds were detected under our experimental conditions. In a preview study of our group, twelve main compounds were tentatively identified, including five anthocyanin derivatives, five flavonols derivatives, two flavonol aglycones, and two unidentified compounds in S. odorifera peels [ 13 ]. In this work, two phenolic acids, compounds 1 and 2, as far as we know, are both described for the first time in S. odorifera seeds.…”

“…This bio-residue could have a great economic impact for the industrial processing of the pulp in the value chain, being, together with the peel, its main waste [ 11 ]. Studies on the use of its peel as a potential source of natural colorants have been published [ 13 ]. In S. odorifera seeds, insect repellent activity has been reported with aromatic properties.…”