Physical defects in green coffee: effect on bioactive and volatile compounds of the beverage

ABSTRACT Physical defects in coffee beans represent a critical factor that can influence both the sensory quality and the bioactive properties of coffee beverages. In this context, the present study evaluated the impact of six common physical defects (sour, total black, cherry, bitten, mild coffee berry borer, and severe coffee berry borer) incorporated into specialty-grade green coffee using an integrated analytical approach combining the analysis of bioactive compounds, volatile organic compounds (VOCs), and near-infrared (NIR) spectral characteristics. Coffee beverages were analyzed to determine antioxidant capacity using the DPPH and ABTS assays, total phenolic content using the Folin–Ciocalteu method, and phenolic profiles using high-performance liquid chromatography (HPLC). VOCs in roasted and ground coffee were characterized using gas chromatography coupled with mass spectrometry (GC–MS), while NIR spectroscopy was applied directly to defective beans to examine spectral variations associated with bean composition. Results showed lower antioxidant capacity and total phenolic content across most defect types, except for total black beans. Differences in phenolic profiles were also observed among defect categories, indicating variations in the chemical composition of defective beans. A total of 96 VOCs were detected and classified into eight major chemical classes, including pyrazines, ketones, furans, aldehydes, hydrocarbons, esters, phenols, and alcohols. Some compounds showed associations with specific defect types, suggesting their potential relevance as chemical indicators of coffee deterioration. NIR spectral analysis revealed differences among defect types, particularly within the 1900–2500 nm region associated with moisture, proteins, and carbohydrates. Overall, these results indicate that physical defects are associated with measurable changes in the chemical, bioactive, and aromatic composition of coffee. This integrated analytical approach provides new insights into the influence of bean defects on coffee quality and highlights its potential for supporting quality control strategies and the valorization of defective beans.