Interaction between cupric ion and camu camu fruit (Myrciaria dubia): Generation of free radicals

Guija-Guerra H.; Troncoso-Corzo L.; Guija-Poma E. · Nutricion Clinica y Dietetica Hospitalaria (2025) · DOI: 10.12873/451guija

Resumen

Introduction: Camu camu, a fruit from the Peruvian jungle, has a high content of vitamin C. This vitamin is highly antioxidant, but becomes pro-oxidant in the presence of transition metals, generating free radicals. Objective: To investigate the reactivity of bioactive compounds, such as vitamin C, of camu camu with cupric ions. Materials and methods: The reactivity of the cupric ions with the aqueous extract of camu camu was evaluated by thiobarbituric acid reactive substances (TBARS) method. The effects of Cu2 + concentrations ranged from 0.010 to 0.060 mM were observed. In order to inhibit the formation of TBARS the antioxidant capacity of thiourea, EDTA and mannitol was evaluated. The ascorbic acid content in camu camu was determined by the Jagota assay. Inferential statistics were used using the Pearson correlation coefficient (r) and simple linear regression. Results: The cupric ions reacted with the aqueous extract of camu camu through an increased generation of TBARS as a function of time. The presence of various concentrations of Cu2+ in the reaction medium increased the generation of TBARS through saturation kinetics. The antioxidant potency to inhibit the generation of TBARS by the effect of copper on camu camu decreased in the following order EDTA> thiourea> mannitol, whose protection constants were 9.6 x 10-6 M, 4.2 x 10-5 M y 4.7 x 10-3 M, respectively. Conclusions: The study showed that the reactivity of the cupric ions with camu camu generated TBARS and EDTA, thiourea and mannitol showed antioxidant activity through a concentration-dependent reaction. These generated free radicals should be taken into account when indicating some food combinations in the diet.

Instituciones: Universidad Nacional Mayor de San Marcos; Universidad de San Martín de Porres