Exploring the Impact of Infusion Parameters and In Vitro Digestion on the Phenolic Profile and Antioxidant Capacity of Guayusa (Ilex guayusa Loes.) Tea Using Liquid Chromatography, Diode Array Detection, and Electrospray Ionization Tandem Mass Spectrometry

Abstract

Guayusa tea is derived from the leaves of the Ilex guayusa Loes. plant, which is native to the Amazon rainforest. Beyond its pleasant sensory properties, Guayusa tea is rich in antioxidants, phenolics, and minerals. In this study, the effects of infusion time, temperature, and solvent conditions on the color, antioxidant capacity, total phenolic content, phenolic profile, and antimicrobial activity of Guayusa (Ilex guayusa Loes.) tea were investigated. Guayusa tea samples were prepared using two different solvents, ethanol and water, with 4, 6, and 8-h infusions at 60 and 70 °C. Liquid chromatography, diode array detection, and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) were used to determine a comprehensive profile of phenolic compounds and to detect differences due to infusion conditions. Moreover, after the Guayusa tea infusion with the highest bioactive properties was determined, the effects of in vitro gastrointestinal digestion on the total phenolic content, antioxidant capacity, and phenolic compounds of the Guayusa tea infusion were measured. Phenolic profile analysis identified 29 compounds, among which chlorogenic acid and its derivatives were predominant. The increase in infusion time was correlated with an elevation in total phenolic content. Significant differences were observed between water and ethanol infusions of Guayusa in terms of phenolics and antioxidants. The total amount of phenolic compounds in the samples prepared with both solvents was found to increase after oral intake, depending on the digestion stage; meanwhile, the amounts of flavonoid compounds and di-O-caffeoylquinic acid derivatives decreased during digestion.

Phytochemical Analysis, Biological Activities, and Molecular Docking Studies of Root Extracts from Paeonia Species in Serbia

“…The high percentage of released methyl gallate in the digested tea samples was due to the high recovery of total phenolic acid derivatives (56.53-86.30%). A high recovery of phenolic acid derivatives after GID was also observed by Kelebek et al [83] for Guayusa tea. These results may contribute significantly to the future evaluation of the biological activity of peony root tea, as methyl gallate has been shown to have a variety of biological functions [87].…”

“…These results are higher or similar to those reported by Qin et al [ 79 ] and Koláčková et al [ 80 ] for the recovery of total phenolic compounds of green tea infusion after GID (68.71% and 62–84%, respectively), but they are significantly higher than the recovery of total phenolic compounds of teas prepared from the flowers of P. lactiflora (21.25%) [ 81 ] and P. suffruticosa (12.63%) [ 82 ]. On the other hand, an increase in the total amount of total phenolic compounds was found for Guayusa after an in vitro GID of 3% [ 83 ]. However, the recovery for each identified compound was different and was highly dependent on their structure, their tendency to react with digestive enzymes, solubilization in the digestive cocktail, and their presence in the initial sample [ 84 , 85 , 86 ].…”

Five Underutilized Ecuadorian Fruits and Their Bioactive Potential as Functional Foods and in Metabolic Syndrome: A Review

“…Other species of interest have traditionally been sources of food and medicine, but have not attained staple status, and also provide important nutrients and phytochemicals. Examples among these species that are being made known in global markets are Alibertia patinoi , regarded as an aphrodisiac and energizer; Ilex guayusa, of which the energizing properties have made it into popular drink products; and Euterpe oleracea, which has attained the dubious “superfood” status [ 20 , 21 , 22 ]. This status is a marketing and consumer culture term, not a science one.…”