The search for alternatives for the control of microbiological contamination in foods has been the object of study in different scientific areas. This study aimed to evaluate the efficiency of lemon grass (Cymbopogon citratus) essential oil in controlling the growth of the fungus Aspergillus flavus in three types of analysis: first, by in vitro tests, in essential oil doses between 0.2 and 1.0 μL/ml; second, by serial microdilution to determine the minimum inhibitory concentration, in doses between 0.1 and 1.2 μL/mL; and third, by inhibition of fungal growth in corn kernels contaminated using essential oil doses of 0.4, 0.7, and 1.0 μL/mL, in the incubation times of 14, 28, and 42 days. The in vitro tests showed that the essential oil controlled the fungus from doses of 0.6 μL/mL, but the dose of 1.0 μL/mL controlled 100% growth until day eight of incubation, from which it decreased. The minimum inhibitory concentration for the microdilution analysis was 0.9 μL/mL. The evaluation of the corn kernels for all doses of essential oil and times tested showed 100% inhibition of the fungal growth.

Respiratory abnormalities among workers at coffee roasting and packaging facilities have already been reported; however, little is known about microbiological contamination inside coffee production facilities. This study intends to assess the microbial contamination (fungi and bacteria) in two coffee industries from Brazil with a multi-approach protocol for sampling and for subsequent analyses using four main sources of samples: filtering respiratory protection devices (FRPD) used by workers, settled dust, electrostatic dust cloths (EDC) and coffee beans. The fungal contamination in the assessed industries was also characterized through the molecular detection of toxigenic species and antifungal resistance. Total bacteria contamination presented the highest values in FRPD collected from both industries (7.45 × 104 CFU·m⁻²; 1.09 × 104 CFU·m⁻²). Aspergillus genera was widespread in all the environmental samples collected and sections with clinical relevance (Fumigati) and with toxigenic potential (Nigri and Circumdati) were recovered from FRPD. Circumdati section was observed in 4 mg/mL itraconazole. Sections Circumdati (EDC, coffee beans and settled dust) and Nidulantes (EDC, coffee beans and FRPD) were detected by qPCR. Some of the targeted Aspergillus sections that have been identified microscopically were not detected by qPCR and vice-versa. Overall, this study revealed that microbial contamination is a potential occupational risk in the milling stage and should be tackled when assessing exposure and performing risk assessment. In addition, a multi-sampling campaign should be the approach to follow when assessing microbial contamination and FRPD should be included in this campaign. Occupational exposure to mycotoxins should be considered due to high fungal diversity and contamination. A One Health approach should address these issues in order to prevent consumption of coffee crops and beans infected by fungi and, more specifically, to avoid widespread azole resistance.

The objective of this work was to evaluate the antifungal activity of the essential oil of Cymbopogon citratus in the control of Aspergillus brasiliensis in analysis in vitro and in stored corn kernels. Two in vitro tests were carried out. One of them, by diffusion in agar and the other by microdilution in wells. The concentrations used for the agar diffusion assay were 0.2; 0.4; 0.6; 0.8 and 1.0 µL mL-1. The concentrations used for the microdilution test were: 0.1; 0.2; 0.3; 0.4; 0.5; 0.6; 0.7; 0.8; 0.9; 1.0 and 1.2 µL mL-1. The mycelial growth was evaluated over time, using the Scott-Knott test at 5% significance. From the results obtained, it was verified that the application of the essential oil of Cymbopogon citratus interferes significantly in the fungal development of the species Aspergillus brasiliensis. The microdilution test in wells was used in a qualitative way, indicating absence of growth in doses from 0.8 µL mL-1. For the corn grain test, the essential oil dosages of 0.5; 0.8 and 1.0 µL mL-1 and were stored for 42 days. There was no significant difference in the different doses of essential oil over the storage period for this assay.

Several studies have reported the incidence of fungi and mycotoxins in coffee beans; however, there are few reports related to occupational exposure to these agents at coffee dry milling industries. The aim of this review was to identify and to analyze studies assessing occupational exposure to fungi and mycotoxins in coffee industries. Therefore, a systematic literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology and focusing on the assessment of occupational exposure to fungi and mycotoxins in the coffee industry. In these papers, different environmental matrices were considered in evaluating occupational exposure, but the most used matrix was airborne dust (four of the five studies). Airborne fungi were sampled using active (four of the five studies) and passive sampling. Only the most recent of the studies (2022) identified microorganisms by their genera and species, and only two groups of mycotoxins were analyzed in the studies considered, namely, Ochratoxin A and Aflatoxins. None of the studies reported data on both fungi and mycotoxins. The fungal genera identified in these occupational environments included Cladosporium, Paecilomyces, Aspergillus, Penicillium, and other genera. Among the mycotoxins, only aflatoxins and ochratoxin A were investigated. Occupational exposure to these biological agents may lead to several health effects. Fungal spores and fragments can cause respiratory diseases such as asthma, allergic rhinitis, bronchitis, and hypersensitivity pneumonitis. Additionally, the mycotoxins studied—particularly Aflatoxins and Ochratoxin A—are associated with serious toxicological effects. Coexposure to both fungi and mycotoxins may enhance health risks and should be carefully considered in occupational risk assessments. Considering the possible effects related to exposure to fungi and mycotoxins and the number of workers involved in this type of industry in the world, more studies should be developed. This is the first review to systematically consolidate data on occupational exposure to both fungi and mycotoxins specifically within the coffee industry, highlighting existing knowledge gaps and the need for targeted risk assessments in coffee-producing settings.

O gênero Cymbopogon é amplamente estudado por suas características medicinais, as quais são reconhecidas e utilizadas em todo o mundo. No entanto há a necessidade de se estudar a cinética de secagem, equilíbrio higroscópico e a alteração de cor das folhas de Cymbopogon flexuosus mediante a variação da temperatura de secagem. O objetivo deste trabalho foi estudar a cinética de secagem de folhas de capim-indiano, ajustar um modelo dentre os existentes na literatura que melhor representa o comportamento da isoterma de sorção, como também analisar o efeito do processo de secagem na coloração das folhas. As folhas de capim-indiano foram cortadas em comprimento de 0,2 m e submetidas às temperaturas de ar de secagem de 35, 45, 55 e 70 ºC em secador mecânico de camada fixa. Para o estudo do fenômeno de higroscopicidade foram utilizadas as temperaturas de 20, 30, 55 e 70 ºC com atividades de água entre 10,75 e 85,11%. O modelo que melhor representou as curvas de secagem foi o modelo de Midilli com R² de 0,99. O modelo que melhor representou a curva de equilíbrio higroscópico das folhas de capim-indiano foi o de GAB Modificado com R² de 0,94. Com o aumento da temperatura do ar de secagem houve escurecimento das amostras em temperaturas superiores à 45ºC.

A secagem de café por meio de secadores de camada fixa tem sido amplamente utilizada por cafeicultores brasileiros. Entretanto, frequentemente são relatados elevados gradientes de teor de água formados nestes secadores, bem como o aparecimento de microrganismos na massa de café. Desenvolveu-se o presente trabalho com a finalidade de monitorar a performance destes secadores e seu efeito na qualidade final do produto, comparando à uma adaptação feita em secadores de camada fixa convencional. Durante a secagem foram monitorados em diversos pontos na câmara de secagem as seguintes características: temperatura do ar de secagem, do ar intergranular, do ar de exaustão e do ar ambiente; umidade relativa do ar de secagem, do ar ambiente e do ar de exaustão e teor de água do produto em diferentes pontos e alturas na câmara de secagem (0,12; 0,36 e 0,60 m). Dentre as avaliações do produto seco, foram realizadas: análise de cor e análise microbiológica. De acordo com os resultados obtidos, a secagem com inversão do fluxo de ar resultou em um gradiente de teor de água de 0,4% (b.u.), enquanto a secagem convencional ocasionou um gradiente de 8% (b.u.). Em relação à coloração do produto nos diferentes manejos de secagem, a secagem com inversão resultou em produtos mais claros. Para a análise microbiológica, foram encontrados fungos dos gêneros Cladosporium, Fusarium e Aspergillus, dentre outros. Sendo que a média da incidência destes fungos foi maior nas amostras da secagem convencional que na secagem de camada fixa com inversão do fluxo do ar.