Risk Assessment of Caffeine and Epigallocatechin Gallate in Coffee Leaf Tea

Abstract

Coffee leaf tea is prepared as an infusion of dried leaves of Coffea spp. in hot water. It is a traditional beverage in some coffee-producing countries and has been authorized in 2020 within the European Union (EU) according to its novel food regulation. This article reviews current knowledge on the safety of coffee leaf tea. From the various ingredients contained in coffee leaves, only two were highlighted as possibly hazardous to human health, namely, caffeine and epigallocatechin gallate (EGCG), with maximum limits implemented in EU legislation, which is why this article focuses on these two substances. While the caffeine content is comparable to that of roasted coffee beans and subject to strong fluctuations in relation to the age of the leaves, climate, coffee species, and variety, a maximum of 1–3 cups per day may be recommended. The EGCG content is typically absent or below the intake of 800 mg/day classified as hepatotoxic by the European Food Safety Authority (EFSA), so this compound is suggested as toxicologically uncritical. Depending on selection and processing (age of the leaves, drying, fermentation, roasting, etc.), coffee leaf tea may exhibit a wide variety of flavors, and its full potential is currently almost unexplored. As a coffee by-product, it is certainly interesting to increase the income of coffee farmers. Our review has shown that coffee leaf tea is not assumed to exhibit risks for the consumer, apart from the well-known risk of caffeine inherent to all coffee-related beverages. This conclusion is corroborated by the history of its safe use in several countries around the world.

Coffee Leaf Tea from El Salvador: On-Site Production Considering Influences of Processing on Chemical Composition

“…Von Pröpper observed in 1882 [ 6 ] that “The leaves of the coffee plant, roasted and poured over with hot water, make an excellent tea, which has long been one of the staple foods of the entire Indian archipelago, and is said to be not inferior in effect to the true Chinese tea, but apparently has not yet come into commerce” (authors’ translation from German). Further mentioned in the literature are the countries Ethiopia, West Sumatra, Jamaica, Java, and South Sudan [ 7 , 8 ]. Novita et al [ 9 ] described the traditional production of “Kahwa daun”, a herbal tea from coffee leaves produced in West Sumatra.…”

Risk Assessment of Chlorogenic and Isochlorogenic Acids in Coffee By-Products

“…While the direct consumption of large amounts of coffee by-products is unlikely, it is important to recognize the various ways in which individuals can be exposed to chlorogenic and isochlorogenic acids. These compounds can enter the body through a variety of sources, including food, health products, medications, or processed products that contain coffee by-products as ingredients [ 4 , 10 , 15 , 22 ]. For example, coffee by-products may be used in the production of dietary supplements, functional foods, or pharmaceutical formulations [ 35 , 51 , 118 ].…”

“…Coffee is particularly cultivated and produced in tropical and subtropical regions along the equator (the so-called “coffee belt”), where ideal growth is possible due to the constantly warm temperatures and humid climate without extreme weather fluctuations. The most important coffee producers include Brazil, Vietnam, Colombia, Indonesia, Ethiopia, and India [ 2 , 3 , 4 ]. In addition to the main ingredient, caffeine ( 1a ), the purine alkaloids theophylline ( 1b ) and theobromine ( 1c ), the diterpenes kahweol ( 2 ), cafestol ( 3a ), and 16- O -methylcafestol ( 3b ), as well as the flavonoid epigallocatechin gallate ( 4 ) and the polyphenolic chlorogenic acids ( 5 ) are present in coffee; these are shown in Figure 1 [ 4 , 5 , 6 ].…”

“…The most important coffee producers include Brazil, Vietnam, Colombia, Indonesia, Ethiopia, and India [ 2 , 3 , 4 ]. In addition to the main ingredient, caffeine ( 1a ), the purine alkaloids theophylline ( 1b ) and theobromine ( 1c ), the diterpenes kahweol ( 2 ), cafestol ( 3a ), and 16- O -methylcafestol ( 3b ), as well as the flavonoid epigallocatechin gallate ( 4 ) and the polyphenolic chlorogenic acids ( 5 ) are present in coffee; these are shown in Figure 1 [ 4 , 5 , 6 ].…”

Toxicological Assessment of Roasted Coffee Silver Skin (Testa of Coffea sp.) as Novel Food Ingredient

“…There are approaches to make use of these by-products, but legal regulations to bring foods onto the European market must be considered. The coffee leaves and coffee cherry pulp (or cascara) can be used for various purposes [ 9 ] and were approved as traditional foods from third countries [ 10 , 11 ]. The cascara was used in several forms of spiced or unspiced, aqueous or milk-based infusions in Yemen, where the infusion is called Qishr, but also in Ethiopia and Bolivia.…”