Optimizing the functional quality of coffee (Coffea arabica cv. 'Catidiaf 21′) Pulp: Impact of cultivation system, ripening stage, and drying method on valorization for food industry applications

Coffee pulp, a major by-product of the coffee industry, represents a significant environmental challenge but also a potential source of valuable compounds. This study aimed to optimize the functional quality of coffee pulp (Coffea arabica cv. 'Catidiaf 21′) by evaluating the impact of agronomical practices, maturity stages and post-harvest factors. A 2 × 3 × 2 factorial design was implemented, assessing two cultivation systems (shade-grown at Rancho Arriba vs. full-sun at Juncalito), three fruit ripening stages (semiripe, ripe, overripe), and two drying methods (sun-drying vs. oven-drying at 41 °C). Results showed that all factors significantly influenced the pulp's chemical composition. Full-sun cultivation (Juncalito) yielded higher concentrations of sugars, polyphenols (including hydroxycinnamic acids and flavonols), and caffeine. Conversely, shade-grown pulp (Rancho Arriba) was richer in organic acids and minerals like K, Ca, Fe, and Mn. The ripening process led to a decrease in polyphenols, caffeine, and most minerals, while sugars accumulated, peaking at the overripe stage. Oven-drying proved superior for preserving organic acids, sugars, and bioactive compounds compared to sun-drying. These findings demonstrate that specific combinations of cultivation, harvest timing, and processing can maximize the concentration of target compounds, paving the way for the valorization of coffee pulp into customizable ingredients: for instance, high-sugar, low-caffeine flours (Juncalito, overripe, oven-dried) or potent antioxidant extracts (Juncalito, semiripe, oven-dried) suitable for the food industry.