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

Abstract

The production of coffee leaf tea (Coffea arabica) in El Salvador and the influences of processing steps on non-volatile compounds and volatile aroma-active compounds were investigated. The tea was produced according to the process steps of conventional tea (Camellia sinensis) with the available possibilities on the farm. Influencing factors were the leaf type (old, young, yellow, shoots), processing (blending, cutting, rolling, freezing, steaming), drying (sun drying, oven drying, roasting) and fermentation (wild, yeast, Lactobacillus). Subsequently, the samples were analysed for the maximum levels of caffeine, chlorogenic acid, and epigallocatechin gallate permitted by the European Commission. The caffeine content ranged between 0.37–1.33 g/100 g dry mass (DM), the chlorogenic acid was between not detectable and 9.35 g/100 g DM and epigallocatechin gallate could not be detected at all. Furthermore, water content, essential oil, ash content, total polyphenols, total catechins, organic acids, and trigonelline were determined. Gas chromatography—mass spectrometry—olfactometry and calculation of the odour activity values (OAVs) were carried out to determine the main aroma-active compounds, which are β-ionone (honey-like, OAV 132-927), decanal (citrus-like, floral, OAV 14-301), α-ionone (floral, OAV 30-100), (E,Z)-2,6-nonadienal (cucumber-like, OAV 18-256), 2,4-nonadienal (melon-like, OAV 2-18), octanal (fruity, OAV 7-23), (E)-2 nonenal (citrus-like, OAV 1-11), hexanal (grassy, OAV 1-10), and 4-heptenal (green, OAV 1-9). The data obtained in this study may help to adjust process parameters directly to consumer preferences and allow coffee farmers to earn an extra income from this by-product.

Combination of HPLC–orbitrap‐MS/MS and network pharmacology to identify the anti‐inflammatory phytochemicals in the coffee leaf extracts

“…The DCM‐L fraction contained the highest content of caffeine (303.04–769.41 mg/g extract), whereas the H 2 O‐L fractions contained the lowest caffeine (0.36–5.24 mg/g extract). The content of caffeine is related to the varieties of plants, age of leaves, tea‐processing methods, and seasonal variation (Deka et al., 2021; Steger et al., 2022). Chen et al.…”

“…whereas the H 2 O-L fractions contained the lowest caffeine (0.36-5.24 mg/g extract). The content of caffeine is related to the varieties of plants, age of leaves, tea-processing methods, and seasonal variation (Deka et al, 2021;Steger et al, 2022). Chen et al (2018) found that young coffee leaves have higher caffeine than mature leaves due to the decreased biosynthesis of caffeine in matured and aged leaves.…”

Coffee Leaf Tea Extracts Improve Hyperuricemia Nephropathy and Its Associated Negative Effect in Gut Microbiota and Amino Acid Metabolism in Rats

“…It is rich in chlorogenic acid, catechin, and other polyphenols, suggesting its beneficial effect on health. 12 However, its effect on hyperuricemia and HN remains to be investigated.…”

“…Coffee leaf tea can contain up to 80 mg/L caffeine, 100 mg/L chlorogenic acid, and 700 mg/L epigallocatechin gallate. 12 Compared to traditional tea (Camellia sinensis), coffee leaf tea is higher in polyphenols and antioxidants. 13 It has traditionally been used to alleviate various diseases or disorders such as anemia, edema, asthenia, diarrhea, intestinal pain, and fever.…”

“…Coffee leaf, one of these coffee byproducts, has been widely consumed as tea in coffee-growing countries including Indonesia, Jamaica, and Ethiopia since the 1800s and has been acknowledged to be a tea beverage in the EU since July 2020. Coffee leaf tea can contain up to 80 mg/L caffeine, 100 mg/L chlorogenic acid, and 700 mg/L epigallocatechin gallate . Compared to traditional tea (Camellia sinensis), coffee leaf tea is higher in polyphenols and antioxidants .…”