Atividade biológica e quantificação de compostos bioativos em extrato de erva-mate e sua aplicação em hambúrguer de peixe

Yerba Mate (Ilex paraguariensis) Processing and Extraction: Retention of Bioactive Compounds

Ilex paraguariensis is a native tree from South America known for the presence of bioactive compounds, and its processed leaves are consumed as hot and cold infusions. After harvest (step 1), the leaves are subjected to flame blanching to inactive the enzymes (step 2), followed by drying and milling (step 3). The impacts of I. paraguariensis processing on leaf composition were investigated by extracting the major compounds (chlorogenic and isochlorogenic acids (3-CQA, 4-CQA, 5-CQA, 3,4-DQA, 3,5-DQA and 4,5-DQA), p-coumaric acid, caffeine and rutin) using different ratios of ethanol and water as extraction solvent (EW 25:75, 50:50, and 75:25 (w/w)). The solvent ratio of EW 50:50 was more effective in extracting the chlorogenic acids isomers, with retention of chlorogenic acids of 3463, 9485, and 9516 µg mL- 1 for steps 1, 2, and 3, respectively. Rutin and p-coumaric acid exhibited similar behavior with the increment of processing steps; however, p-coumaric acid was only detected in steps 2 and 3 for the solvent ratios EW 50:50 and 25:50. The caffeine extraction from I. paraguariensis varied from 936 to 1170 µg mL- 1 for all processing steps, with emphasis on its concentration extracted in step 1. The evolution of processing steps led to a higher retention of phenolic compounds from I. paraguariensis, which was not observed when using different solvent ratios, and the solvent ratio EW 50:50 was more effective for the extraction of chlorogenic acids. The successful extraction of chlorogenic acids from I. paraguariensis in this study proved to be a promising alternative for the use of yerba mate beyond the cuia cup.

Use of Bio-Waste of Ilex paraguariensis A. St. Hil. (Yerba mate) to Obtain an Extract Rich in Phenolic Compounds with Preservative Potential

In this work, a comparison between the extracts of dehydrated yerba mate (Ilex paraguariensis) and bio-waste of yerba mate leaves from the Brazilian industry was made. The incorporation of the functional extract as a preservative/functional ingredient in a pastry product (pancakes) was tested. The individual profile of phenolic compounds was determined by HPLC-DAD-ESI/MS, and the bioactive potential was assessed using in vitro assays for antioxidant, anti-inflammatory, antimicrobial, and cytotoxic activities. The yerba mate extracts revealed a high antimicrobial potential against the tested strains and a very promising antioxidant and anti-inflammatory action. Additionally, revealed a cytotoxic capacity for MCF-7, CaCo and AGS tumor cell-lines. In the three types of pancakes, after 3 days of storage, the chemical and nutritional characteristics remain unchanged, proving the preservative efficiency of the extract. This study showed the benefits of the use bio-waste from agro-industrial sector, focusing on sustainable production and the development of circular economy.

Stability of yerba mate extract, evaluation of its microencapsulation by ionic gelation and fluidized bed drying

Studies show that yerba mate (Ilex paraguariensis) has high antioxidant capacity occasioned by its high contents of total phenolic compounds. Microencapsulation, specifically ionic gelation, since it does not use heating during process, is considered as an alternative for preserving and applying the extract. The purpose of this study was to evaluate general characteristics and stability of hydroalcoholic extract of yerba mate, conduct the extract microencapsulation by ionic gelation followed by microparticle fluidized bed drying. The extract was evaluated for color stability, total phenolic compounds, and antioxidant activity for nine weeks and at three temperatures (5, 15, and 25 °C). From the extract, a double emulsion (W/O/W), generation of microparticles (ionic gelation by dripping), and fluidized bed drying were conducted. The extract had 32912.55 mg GAE/100 g of phenolic compounds and 2379.49 μmol TE/g of antioxidant activity. The main compound observed was chlorogenic acid (5-CQA) with 0.35 ± 0.01 g/100 mL. In the stability study, the temperature was observed to influence in phenolic compounds reduction, as well as in total color difference of the extract. Double emulsion has shown to be stable and appropriate for use. The values of microparticles total phenolic compounds and antioxidant activity were 423.18 ± 8.60 mg GAE/100 g and 21.17 ± 0.24 μmol TE/g, respectively. After drying, the moisture of microparticles was reduced from 79.2% to 19%. The extract had high total phenolic compound content and high antioxidant activity. Storage at the lowest temperature (5 °C) assured better preservation of extract total phenolic compounds. The dried microparticles showed content of total phenolic compounds and antioxidant activity with potential for commercialization and future application in food matrices.