Vitamin C content, anthocyanins and antioxidant capacity of fruits of Rubus glaucus Benth. (mora de Castilla) with and without prickles grown in Risaralda, Colombia

Abstract

“mora de Castilla” is a native shrub of the Andean tropics and can be found in Colombia, Ecuador, Mexico, and other countries of this region. In Colombia, this fruit is cultivated by small producers and is an important source of income and rural employment. “mora de Castilla” is in great demand for domestic consumption as well as for export because it can be consumed fresh or processed and because of its extraordinary organoleptic and nutritional attributes. Risaralda is one of the departments in which Rubus glaucus Benth. is cultivated; there, plants with and without prickles are widely distributed. Although some studies have been carried out on these cultivars, it is necessary to evaluate and compare some of their attributes as an approach to recognize potential uses in agribusiness. Therefore, a physicochemical characterization was performed, the vitamin C content was evaluated, the amount and profile of anthocyanins were determined, and the antioxidant capacity of fruits of “mora de Castilla” with and without prickles was analyzed. The physicochemical parameters evaluated were weight, pH, soluble solids and titratable acidity. The content of vitamin C was evaluated using the 2-nitroaniline spectrophotometric method, and anthocyanins were evaluated using 2 methods: spectrophotometry (pH differential) and chromatography (HPLC). Finally, the antioxidant capacity was determined using the FRAP and DPPH methods. Significant differences were found between the municipalities as well as between the materials with and without prickles with regard to antioxidant capacity and vitamin C and anthocyanin content, with the highest values for fruits grown in the municipality of Pereira, Risaralda. The results obtained indicate that “mora de Castilla” with and without prickles is a fruit of high quality and promise because of its high content of bioactive compounds (vitamin C and anthocyanins), its relevant function as an antioxidant and its valuable organoleptic attributes.