Exploring Secondary Metabolites in Coffee and Tea Food Wastes

Coffee and tea are popular beverages worldwide, and therefore generate large amounts of waste. Here we describe the caffeine content and phenolic profile in three types of teas and coffees, and how they vary with two successive extractions. Although the first extraction was far more efficient than the second, green tea also showed a high content of flavanols in the second extraction, as did mate tea for phenolic acids. Black tea could also be a good option since caffeine content was highest in both extractions. Water also proved to be the most effective solvent in almost all cases, which represent a major benefit for urban horticulture, as it is a simple extraction method from an easily accessible source. Coffee and tea residues are a rich source of caffeine and phenolic compounds that could potentially be used as alternatives to conventional pesticides.

Automated summary

The study investigated the caffeine content and phenolic profile of different types of teas and coffees with two successive extractions. Green tea showed high flavanol content in the second extraction, while mate tea's phenolic acid content increased. Black tea had the highest caffeine content in both extractions, and water was the most effective solvent in most cases for extracting these compounds.