3. Discussion
To the best of our knowledge, this is the first study to demonstrate the metabolism of phenolic compounds of juçara juice in humans. Phenolic acids, anthocyanins, flavanonols, flavonols, stilbenoids, flavan-3-ols, and flavones were detected in juçara juice. Secondary metabolites of plants can be divided into flavonoids and non-flavonoids [In this study, the two main anthocyanins observed in the juçara juice were cyanidin 3-The present study measured anthocyanins and their metabolites only in urine. Nonetheless, the presence of anthocyanins in plasma is recognized to be very low, with only trace amounts reaching the bloodstream and being excreted with urine (<0.1% in human studies) [Although we did not measure metabolites in plasma, HA was identified as one of the major metabolites of cyanidin-3-glucoside in urine, reaching a maximum concentration of 6058.0 µmol/mmol creatinine. According to the literature, we may speculate that HA is formed via PCA metabolism, which is the product of spontaneous degradation of cyanidin-3-glucoside in the small intestine and circulation [HPA appeared in urine as the second major metabolite of cyanidin-3-glucoside, reaching a maximum concentration of 3340.9 µmol/mmol creatinine. Such a metabolite could be produced from the breakdown of anthocyanin aglycone to form dihydrophenylacetic acid, with further dehydroxylation to HPA [The juçara juice decreased the TOS values at 0.5 h, 1 h, and 2 h after the juice intake. These findings corroborate the previously published study, which showed positive effects after an acute intake of juçara juice on lipid peroxidation in 11 healthy subjects [Antioxidants play a role against free nitrogen and oxygen radicals formed in tissues and biological fluids [According to a recent review, the effects of intervention with juçara on antioxidant enzymes remain controversial [As investigated in the present study, other crossover clinical trials also examined the effects of juçara juice intake on healthy subjects [Our study and the three trials that assessed the antioxidant effects of açaí (As strengths of this study, it should be mentioned that this was the first study to evaluate the absorption, excretion, and pharmacokinetic parameters of the main phenolic acids and anthocyanins of juçara juice in the urine of healthy subjects after acute intake. On the other hand, the primary limitations concern the absence of urine sample collection at timepoints after 6 h, losing some metabolite detection. The lack of measuring metabolites in plasma has also been considered a limitation of this study. However, it is well-known that the maximum concentration of anthocyanins in humans occurs at 0.5–4 h after intake. The average urinary excretion is between 0.03% and 4% of the ingested dose, eliminated between 1.5 and 3 h [