Impact of different varieties and mature stages on phytochemicals from Coffea arabica and Coffea robusta leaves

In the present study, we analysed the presence of anti-nutrients (tannins and phytates) in coffee leaves and subsequently explored the phytochemicals from Indian coffee leaves across different species, varieties and stages of maturity (young and mature). The phytochemicals investigated included total phenolics (TP), 5-caffeoylquinic acid (5-CQA), quercetin, caffeine, trigonelline and mangiferin. Our findings revealed that coffee leaves contained 0.83-1.18% phytates and 14.04-14.46% tannins. The highest levels of TP were recorded in the young leaves of Kent's (79.62 +/- 3.5 mg CQAE/g) and C x R (75.90 +/- 3.8 mg CQAE/g) varieties of Arabica and Robusta respectively. 5-CQA and quercetin were in the range of 5-20 mg/g and 2-14 mg/g while caffeine and trigonelline were found between 0.2 and 8 mg/g and 9.26-19.12 mg/g respectively. Mangiferin was observed to be present only in the Arabica varieties at the levels of 2-8 mg/g. The matured leaves exhibited a 50-60% reduction in phytochemicals compared to the young leaves. The principal component analysis (PCA) unveiled a substantial correlation between phytochemicals and antioxidant activities, with PC1 and PC2 accounting for 63.1% and 19.9% of the total variance, respectively. Our study highlights the influence of species, varieties and maturity level on the phytochemicals from coffee leaves. The leaves generated from coffee estate agronomic practices hold great potential for commercialization and the development of innovative value-added products, thereby contributing to a more sustainable coffee industry.