Coffee Flower as a Promising Novel Food—Chemical Characterization and Sensory Evaluation

Abstract

The use of the flowers (blossoms) of the coffee plant (genus Coffea) has been neglected over the years, as the focus has primarily been on the cost-efficient production of coffee beans. Because of societal changes and economic pressures, there is an increasing demand for sustainability, so the focus has also widened towards the various by-products of the coffee production. The coffee flower is a by-product because it can be harvested following pollination without any risk to the bean production. The coffee flower can be used as a whole or as floral water in some food and cosmetic products. The flower can also be prepared as a tea-like beverage with hot water infusion. Another side-chain product in coffee plantations is the so-called coffee flower honey, which is rarely monofloral due to the short flowering period. To date, there have been few studies on coffee flowers and their sensory characterization. In this work, various compounds in Coffea arabica, C. canephora, and C. liberica flowers were identified and quantified by high-performance liquid chromatography (HPLC) with diode array detection (DAD), nuclear magnetic resonance spectroscopy (NMR), and near-infrared (NIR) spectroscopy. Caffeine, chlorogenic acids, organic acids, trigonelline, and sugars were quantified. Additionally, the sensory testing of coffee flower infusions according to the German norm DIN 10 809 was performed. With the acquired data, a principal component analysis (PCA) was performed in which hay, hops, sage, dried apricot, and honey were identified as major flavor descriptors in addition to the floral coffee flower flavors. The coffee flower is judged as a promising ingredient, which needs to be further assessed regarding its possible approval within the novel food regulations of the European Union.

Keywords

• coffee by-products
• coffee flower
• coffee blossom
• tea
• infusion
• analysis