ABSTRACT
Research into microbial interactions during coffee processing is essential for developing new methods that adapt to climate change and improve flavor, thus enhancing the resilience and quality of global coffee production. This study aimed to investigate how microbial communities interact and contribute to flavor development in coffee processing within humid subtropical climates. Employing Illumina sequencing for microbial dynamics analysis, and high-performance liquid chromatography (HPLC) integrated with gas chromatography-mass spectrometry (GC-MS) for metabolite assessment, the study revealed intricate microbial diversity and associated metabolic activities. Throughout the fermentation process, dominant microbial species included Enterobacter, Erwinia, Kluyvera, and Pantoea from the prokaryotic group, and Fusarium, Cladosporium, Kurtzmaniella, Leptosphaerulina, Neonectria, and Penicillium from the eukaryotic group. The key metabolites identified were ethanol, and lactic, acetic, and citric acids. Notably, the bacterial community plays a crucial role in flavor development by utilizing metabolic versatility to produce esters and alcohols, while plant-derived metabolites such as caffeine and linalool remain stable throughout the fermentation process. The undirected network analysis revealed 321 interactions among microbial species and key substances during the fermentation process, with Enterobacter, Kluyvera, and Serratia showing strong connections with sugar and various volatile compounds, such as hexanal, benzaldehyde, 3-methylbenzaldehyde, 2-butenal, and 4-heptenal. These interactions, including inhibitory effects by Fusarium and Cladosporium, suggest microbial adaptability to subtropical conditions, potentially influencing fermentation and coffee quality. The sensory analysis showed that the final beverage obtained a score of 80.83 ± 0.39, being classified as a specialty coffee by the Specialty Coffee Association (SCA) metrics. Nonetheless, further enhancements in acidity, body, and aftertaste could lead to a more balanced flavor profile. The findings of this research hold substantial implications for the coffee industry in humid subtropical regions, offering potential strategies to enhance flavor quality and consistency through controlled fermentation practices. Furthermore, this study contributes to the broader understanding of how microbial ecology interplays with environmental factors to influence food and beverage fermentation, a topic of growing interest in the context of climate change and sustainable agriculture.
ABSTRACT
BACKGROUND: The Amazon region hosts several species of exotic fruits with great functional potential which are important sources of nutrients and biologically active compounds. These fruits are widely consumed by the local population, but unknown to the general population and the scientific community. In addition, the seasonality inherent in these fruits limits their consumption. In this context, the processing of food products is one of the main tools for improving sensory quality and increasing the useful life of fruits. This work aims to make use of all parts of the gabiroba fruit in the form of preserves with the replacement of commercial pectin by passion fruit albedo, as well as the characterization of the fruit and the processed product. METHODS: To optimize the preserves, a response surface methodology was used with a complete factorial design 23 with 11 formulations and 3 independent variables, citric acid concentration, pulp/sugar ratio and albedo concentration, which were subjected to microbiological analysis, sensory analysis and physical-chemistry analysis. RESULTS: The results showed that the gabiroba fruit has a low lipid content, 1.09%, in addition to 51.20 g/100 g vitamin C, 4.09% fiber, 79.83% moisture, 1.29% protein, 13.23% carbohydrates, 019% titratable acid and 0.47% ash. The result of the sensorial analysis indicated an optimal formulation with smaller amounts of citric acid and albedo and a lower pulp/sugar ratio. CONCLUSIONS: The gabiroba fruit was suitable for its full use in preserve processing. Processed preserves showed desirable physical-chemical characteristics, with consumer preference for formulations with a lower pulp/sugar ratio indicating the impact of consumer unfamiliarity with the fruit on their decision to consume it.
