Phenolic Compounds and Metals in Some Edible Annonaceae Fruits.

The concentrations of 3,4-dihydroxybenzoic acid, caffeic acid, catechin, chlorogenic acid, epicatechin, gallic acid, p-coumaric acid, quercetin, rutin, ferulic acid, and the major metals in graviola (Annona muricata), atemoya (A. squamosa x A. cherimola), fruta do conde (A. squamosa), biribá (Rollinia mucosa), and the North American pawpaw (Asimina triloba) were determined by UPLC-ESI (-)-MS/MS. It enabled the identification and quantification of phenolic compounds. Catechin was only found in atemoya, at a concentration of 38.6 µg/g-dw. Only 3,4-dihydroxybenzoic acid was found in the fruit pulps of all five fruits analyzed. Atemoya stands out for not only having catechin but also for having much more epicatechin (239 µg/g-dw) than the other fruits. At the same time, graviola had more p-coumaric acid (62.6 µg/g-dw), and the North American pawpaw had more chlorogenic acid (48.1 µg/g-dw) than the other fruits. Metals were determined by ICP equipped with axially viewed plasma. All five fruit pulps had relatively high levels of potassium, with concentrations ranging from 7640 to 15,000 µg/g-dw, with pawpaw being the lowest and atemoya being the highest. The concentrations of other metals ranged from Ca 547 to 1110, Na 14.3 to 123, P 1210 to 1690, Mg 472 to 980, Mn 1.86 to 5.27, and Zn 5.55 to 7.32 µg/g-dw. All five fruits in the Annonaceae family that were analyzed in this study have several phenolic compounds in them and were good sources of potassium, calcium, phosphorus, and magnesium.

Chlorogenic acids and flavonoid extraction during the preparation of yerba mate based beverages.

This study determined the content of chlorogenic acids (CA) and rutin during successive aqueous extraction of yerba mate for tererê and chimarrão from four yerba mate types (smooth, native, traditional and coarse ground). Aqueous extracts were prepared aiming to simulate homemade procedure by partially (chimarrão) or completely (tererê) immersing the herb into hot (chimarrão) or cold (tererê) water (30 times consecutively). The content of CA and rutin in the aqueous extracts was compared to those in methanolic extracts (exhaustive extraction). Tererê aqueous extracts gave higher amounts of all phenolic compounds (2.5 to 6 times higher than chimarrão). Among chimarrão, course-ground aqueous extracts had on average 15% more PC (phenolic compounds). By comparing the content in aqueous and methanolic extracts, after 30 successive extractions, on average 14% of the total amount of CA in yerba mate leaves and 9% of rutin were transferred to the chimarrão extracts, whereas tererê achieved between 40% and 100% of transference. Thus, this study shows that CA and rutin are continuously extracted during the preparation of aqueous extracts of chimarrão and tererê, favoring a high intake of these antioxidant species by consumers.

Optimization of the Preparation Conditions of Yerba Mate tea Beverage to Maximize Chlorogenic Acids Extraction.

The beverage obtained from the yerba mate tea, besides being the most consumed in Brazil, has high concentrations of chlorogenic acids. In this study, a central composite design was employed to establish the best infusion time, temperature and water volume to maximize the extraction of chlorogenic acids 5-caffeoylquinic (5CQ), 3.4-dicaffeoylquinic (3.4 DQ), 3.5-dicaffeoylquinic (3.5 DQ) and 4.5-dicaffeoylquinic (4.5 DQ), from the leaves and stems of yerba mate tea (beverage ready for consumption). Analyses were performed by high-performance liquid chromatography and the optimum conditions were obtained through the use of the desirability function of Derringer and Suich. The maximum chlorogenic acids content in the beverage was obtained when the infusion was prepared with 2 g of mate tea, in 300 mL of water at 95 °C, under infusion for 16 min. The optimal conditions were applied for the preparation of beverages from 15 commercial samples of yerba mate tea, and it was observed that the sum of the concentration of the four compounds showed variation of up to 79 times between the average of the samples, which can be attributed to climatic conditions of cultivation of the plant and/or of processing.