Ground green coffee beans as a functional food supplement - Preliminary study

•The grinding characteristics of green coffee beans was studied.•The sensory properties of bread enriched with green coffee beans flour were evaluated.•Digestion in vitro released the antioxidant compounds from green coffee beans.•Bread enriched witch green coffee possessed higher antiradical activity than control.•Phenolics released during simulated digestion were highly bioavailable in vitro.

The paper presents the study on possibilities of using green coffee beans (GCB) from Ethiopia, Kenya, Brazil and Colombia as a functional additive. The dominant compound identified was 5-caffeoylquinic acid. Caffeine content was comparable in all samples and averaged from 4.36 mg/g dw to 4.99 mg/g dw. The grinding characteristics of GCB was studied and the sensory properties of bread enriched with GCB flour were evaluated. GCB was characterized by high grinding energy requirements. Phenolics released during simulated digestion were highly bioavailable in vitro. Simulated digestion released phytochemicals acting as chelating and reductive agents, free radical scavengers and lipid-preventers. Results of a preliminary study concerning the proposed functional product indicate that phenolic compounds from bread enriched with powdered GCB were highly mastication-extractable, which may predict their high bioaccessibility and bioavailability. The content of phenolics was strongly correlated with powdered GCB addition. The sensory characteristics linking results indicated that a partial replacement of wheat flour in bread with up to 3% ground GCB powder gives satisfactory overall consumer acceptability. Bread enriched with GCB possessed higher antiradical activity than control samples. The results of our study clearly show that powdered GCB may be used directly, without extract preparation, for food supplementation.