Based on coffee’s unique and fascinating flavor, coffee has become the most popular nonalcoholic drink in the world and is a significant agricultural economic crop in tropical- and subtropical-planted coffee countries and regions. It is also beneficial for human health because of its rich active compounds, such as caffeine, chlorogenic acids, trigonelline, tryptophan alkaloids, diterpenes, melanoidins, etc. These compounds often relate to the prevention of cardiovascular disease, Alzheimer’s disease, and antibacterial, anti-diabetic, neuroprotection, and anti-cancer activities. The formation of coffee’s flavor results from various influence factors, including genetics, shade, elevation, post-harvest processing, fermentation, roasted methods, etc. The first stage of coffee production is obtaining green coffee beans through the primary process. Fermentation is critical in the primary process of coffee, which is often related to yeasts, bacteria, and filamentous fungi. Therefore, microorganisms play a key role in coffee fermentation and coffee flavor. To provide an understanding of the role of microorganisms in coffee fermentation, the coffee fermentation overview and microbial characteristics in different coffee primary processing methods and different coffee fermentation regions were reviewed in this paper. Brazil and China are the main study countries in coffee fermentation, which contribute a large number of technologies and methods to improve coffee flavor by fermentation. Different primary processing methods (wet, dry, or semi-dry processing) and coffee producer countries had obvious microbial community characteristics. Moreover, the application of yeast and bacteria for improving coffee flavor by microbial fermentation was also introduced.

To stabilize Arabica coffee quality by enhanced fermentation with Pichia membranifaciens , high‐throughput sequencing, UPLC–MS/MS, HS‐SPME‐GC–MS, and SCA cupping protocol were employed for comprehensive analysis of the coffee fermentation process. Gene sequencing showed that the predominant microorganisms at the genus level were Weissella , Lactococcus , Trichococcus , Leuconostoc , and Massila for bacteria and Pichia , Hanseniaspora , Lachancea , Candida , and Cystofilobasidium for fungi. Meanwhile, 122 and 122 differentially changed nonvolatile compounds (VIP > 1, p < 0.05, FC > 1.5 or FC < 0.65) from 2275 nonvolatile compounds were found between PE2 versus PB2 and PE3 versus PB3, respectively. Furthermore, 26 differentially changed volatile compounds (VIP > 1, p < 0.05, FC > 2.0 or FC < 0.50) were found between PE and PB. Therefore, enhanced fermentation with P. membranifaciens inhibited the growth of other microorganisms and changed the chemical compounds during the fermentation to stabilize flavor quality.

Cadmium (Cd) in contaminated soil not only enters surface water via rainfall runoff but also penetrates groundwater, adversely affecting human health through the food chain. This research examined three kinds of soil from Luoping County in southwestern China, with different Cd pollution levels. Simulated rainfall and soil column leaching experiments were conducted to explore the risks and factors influencing Cd loss in surface runoff and underground leaching water at different ground slopes (6°, 12°, 18°, and 24°), rainfall intensities (30, 60, and 90 mm∙h⁻¹), and soil profile conditions. The results show that the risk of soil Cd runoff loss increased at a higher rainfall intensity or Cd pollution degree, reaching a peak at a ground slope of 18°. The main factor affecting soil Cd runoff loss was rainfall intensity followed by Cd soil pollution degree and slope. The risk of soil Cd leaching loss was mainly determined by the leaching time and soil depth. The primary factor affecting soil Cd leaching loss was leaching time, followed by soil depth. The soil organic matter (SOM) concentration and pH minimally affected soil Cd loss. The research results provide a theoretical basis for risk management and control of cadmium loss in contaminated soil, and indicate that the environment-friendly water treatment method of high concentration Cd polluted runoff deserves attention.

The planting altitude of coffee is one of the important influencing factors on coffee quality. The effects of four planting altitudes (1,000 m, AT1; 1,200 m, AT2; 1,400 m, AT3; and 1,600 m, AT4) on the microorganism community and the related metabolites in Coffea arabica cherries were investigated using Illumina-based amplicon sequencing and UPLC-MS/MS technologies, respectively. At tha same time, the contents of main flavor precursor substances (caffeine, trigonelline and chlorogenic acid) were analyzed using HPLC method. The results showed that planting altitude can significant influence the microbiomes’ characteristics and endogenous metabolites of coffee. The dominant bacterial genera, Sphingomonas and Pleomorphomonas were significant differences in four planting altitudes, with the maximum relative abundance in AT3. Cladosporium and Strelitziana were the dominant fungal genera, while Vishniacozyma and Setophoma were also important in AT1, Setophoma and Didymella in AT3. 22 (AT2 vs. AT1), 68 (AT3 vs. AT1), 38 (AT3 vs. AT2), 77 (AT4 vs. AT1), 57 (AT4 vs. AT2), and 116 (AT4 vs. AT3) differentially changed metabolites were found between different planting altitudes, respectively. Moreover, caffeine, trigonelline and chlorogenic acid content was the decreas with planting altitude increased. These changes with planting altitude indicted a potential chance to find more fermentation microorganisms.