Insights into yerba mate components: Chemistry and food applications

Abstract

Ilex paraguariensis A.St.-Hil. is a native plant of the subtropical regions of South America whose leaves, after being treated (dried and roasted), are known as yerba mate (YM). YM is produced in Argentina, Brazil, and Paraguay, where “mate,” the infusion prepared from YM, is an integral part of the people's diet and culture. YM contains different chemical compounds, including nutrients: proteins, carbohydrates, minerals (potassium, magnesium, phosphorus, calcium, sulfur, manganese, zinc, iron, and copper), and vitamins (primarily C, B1, B2, and B6). It also contains phenolic compounds, mainly represented by chlorogenic acid and its derivatives, flavonoids, and saponins, which are the subject of considerable research interest. The leaves of YM have been used for centuries by the native population of America to prepare medicinal beverages for consumption. In the last few years, an increasing number of published articles have shown a variety of healthy properties of YM, which are attributed to its bioactive compounds and antioxidant activity. The benefits include antidiabetic, antiobesity, hypocholesterolemic, antihypertensive, cardioprotective, antiinflammatory, antimutagenic, antibacterial, antifungal, antiviral, and antiparasitic effects. In addition, the positive effect on bone tissue and neuropsychiatric conditions such as anxiety, depression, as well as Parkinson's disease are described. As a result, YM is categorized as a functional food due to its medical benefits. Thus, the use of YM or its derivatives as additives to increase the nutraceutical value of food is being increasingly evaluated. Many studies were carried out to extract, stabilize, and encapsulate bioactive compounds from this natural source, being the solvent selection, the application of physical treatments (such as sonication or microwave), and the choice of the conditions/material of encapsulation were some of the principal analyzed factors. In this context, the aim of this chapter is to summarize the recently reported YM bioactive compounds and their food applications. Different methods of extraction and encapsulation of YM bioactive compounds are also analyzed.Widespread knowledge about YM may increase its consumption and the incorporation of different derivatives in food products. In addition, research about by-products of YM processing has not been fully explored yet, so it represents an interesting area for future work.