BIOACCESSIBILITY OF BIOACTIVE COMPOUNDS AND SENSORY EVALUATION OF BREAD ENRICHED WITH GREEN COFFEA CANEPHORA EXTRACT

Green coffee corresponds to unroasted beans, and it stands out for its high content of phenolic compounds, especially chlorogenic acids (CGAs), which exhibit antioxidant properties and functional potential, in addition to their technological application as natural food ingredients. This study aimed to incorporate an aqueous extract of green robusta coffee (Coffea canephora) into pan bread to evaluate its impact on proximate composition, sensory characteristics, and in vitro bioaccessibility of caffeine and CGAs. To obtain the extract, green beans were ground, sieved and subjected to percolation in water at 90°C. Three formulations were developed: F0 (control, without extract), F50 (50% water replacement with extract), and F100 (100% water replacement). Regarding proximate composition, oven drying at 105 °C was used for moisture, Soxhlet extraction with petroleum ether for lipids, the Kjeldahl method (conversion factor of 5.7) for proteins, incineration at 550 °C for ash, and total carbohydrates calculated by difference. Caffeine and CGA levels were quantified by HPLC. Sensory analysis involved acceptance tests using a 9-point structured hedonic scale to evaluate color, aroma, flavor, texture, and overall impression, under two conditions, a blind test and an informed test (providing the health benefits of green coffee), along with purchase intent evaluation during the informed test. Bioaccessibility was assessed using an in vitro gastrointestinal digestion simulation, comprising oral, gastric, and intestinal phases. Data were analyzed using ANOVA, Tukey’s and Student’s t-test (p<0.05). No differences (p>0.05) were found in the proximate composition among treatments (39.46% moisture, 1.25% lipids, 6.26% proteins, 1.9% ash, and 51.13% carbohydrates). In the blind test, formulation F50 achieved the highest scores for color (8.2), aroma (7.7), flavor (7.5), and overall impression (7.6), without differing from F0, whereas F100 showed lower acceptance. However, in the informed test, F100 exhibited significant increases in color (7.6 versus 7.3), aroma (7.6 versus 7.3), flavor (7.4 versus 7.0), and overall impression (7.5 versus 7.2), demonstrating the positive effect of the information. Texture did not vary across treatments under either condition (7.4). Purchase intent fell between “maybe I would buy it/maybe I would not buy it” and “I would probably buy it” (3.5-3.7; p>0.05). After in vitro digestion, a reduction (p<0.05) occurred in the free contents of caffeine and CGAs. The bioaccessibility indices were 0.77 (F50) and 0.91 (F100) for caffeine, and 0.62 (F50) and 0.74 (F100) for CGAs. This reduction was attributed to pH changes, enzymatic hydrolysis, and chemical interactions between phenols and both the gluten network and starch matrix formed during processing. However, it was noted that most of these compounds resisted the simulated conditions of the gastrointestinal tract. Results confirm technological feasibility of developing pan bread enriched with green coffee, combining industrial innovation with preservation of bioaccessible bioactive compounds.

Acknowledgment: CAPES; FAPES (#763/2024; #680/2024).