Avaliação de vitamina C e compostos fenólicos em suplementos alimentares à base de camu-camu (Myrciaria dubia) por HPLC-MS/MS

Abstract

The fruit Camu-camu (Myrciaria dubia) comes from Amazon and has been studied due to the presence of several bioactive compounds already identified in different studies. Both high amounts of vitamin C and phenolic compounds have been widely described, but the fruit is sour, so, there is some difficulty on its consumption in natura. In this context, its manufacture to be applied on dietary supplements becomes worthwhile. It is also necessary to quantify the nutrients present on such fruit to analyze the quality of those dietary supplements. So, firstly, a bibliographic review was carried out to verify which bioactive compounds are present in this fruit, as well as a survey of which techniques are most applied and which ones are the most sensitive to evaluate phenolic compounds and vitamin C in complex matrices. It was observed that liquid chromatography coupled with mass spectrometry is the most sensitive technique to evaluate different analytes in these matrices. Therefore, this research aimed at developing and validating an analytical method by high performance liquid chromatography coupled with sequential mass spectrometry (HPLC-MS/MS) as well as quantifying commercial samples of food supplements based on camu-camu. This method was optimized to quantify vitamin C, gallic acid and myricetin. Five samples of food supplements were evaluated, prepared by extractions with acidified methanol (10% v/v), using as mobile phase a mixture of acetonitrile and 1% formic acid (v/v) in a gradient system, chromatographic column C18 (250mm) x 4.6mm x 3.5µm) in chromatograph with MS/MS detection (sequential), with electrospray ionization (ESI), in negative mode. Due to the high sensitivity observed in the mass detectors, it was possible to quantify all compounds with precision and accuracy, in a linear range of the studied method. The results showed that there are significant amounts of vitamin C, gallic acid and myricetin in those studied food supplements. The method developed was precise, accurate and linear (R>0.99) for all analytes evaluated and it was possible to quantify the three compounds without matrix interference. Four of the five analyzed products showed expressive results for vitamin C (7.99; 6.15; 2.10 and 11.92 g/100g), as well as gallic acid and myricetin compounds. Thus, according to the obtained results, it is concluded that HPLC-MS/MS technique can identify and quantify compounds in complex matrices and it is a fast and very sensitive method to evaluate the bioactive compounds in camu-camu.