VOLATILE PROFILE DIFFERENTIATION OF HEALTHY, DISEASED, AND ROTTEN COCOA BEANS: IMPLICATIONS FOR AROMA QUALITY

A number of pests affect cocoa, including black pod and witches' broom. These diseases are responsible for around 30% of losses in global production. In light of the growing demand for cocoa and the production losses caused by these diseases, mixing healthy and diseased fruits is a common practice in some producing regions. However, these pests compromise fermentation and favour the formation of undesirable compounds, which directly impact the sensory profile. Nevertheless, there is little data demonstrating this impact on quality. The objective was to characterize and compare the volatile profiles of healthy, diseased, and rotten cocoa beans, as well as mixtures containing equivalent proportions of these samples, in order to evaluate the impacts on aroma composition. Five samples were analyzed: beans from healthy fruits (FSH), diseased fruits (FSD), rotten fruits (FSR), a 1:1 mixture of healthy and diseased beans (FSH-D), and a 1:1 mixture of healthy and rotten beans (FSH-R). Volatile compounds were extracted by solid-phase microextraction (SPME) and analyzed by gas chromatography coupled with mass spectrometry (GC-MS). Identification was confirmed by linear retention indices (LRI) and mass spectra. Principal component analysis (PCA) revealed clear separation among groups. For FSH, the volatile profile showed low intragroup variability, with predominance of desirable compounds such as methyl-pyrazine, phenylacetaldehyde, and short-chain aldehydes associated with floral and chocolate notes. In contrast, FSD presented elevated concentrations of ketones (butanone, heptanone, propanone) and furfural, typical markers of poor fermentation and oxidative degradation. The FSH-D treatment showed partial overlap between FSH and FSD, reflecting greater heterogeneity and loss of aromatic quality. Similarly, comparison between FSH, FSR, and FSH-R indicated significant separation among groups (PERMANOVA, p < 0.01). While FSH maintained higher proportions of pyrazines and aldehydes associated with pleasant aroma, FSR and FSH-R were characterized by lipid oxidation and thermal degradation products, such as aldehydes and ketones. The dendrogram corroborated these findings, clustering healthy beans separately, while samples containing rotten seeds grouped together in a distinct branch. In conclusion, healthy beans exhibited a more homogeneous volatile profile, rich in positive aromatic compounds, whereas the inclusion of damaged seeds, even in reduced proportions, resulted in increased levels of undesirable markers and decreased sensory quality. These results reinforce the importance of rigorous bean selection to ensure an excellent final product.