Influence of location, elevation gradients, processing methods, and soil quality on the physical and cup quality of coffee in the Kafa Biosphere Reserve of SW Ethiopia

2-Methyloxolane as an effective bio-based solvent for the removal of βN-alkanoyl-5-hydroxytryptamines from Arabica green coffee beans

βN-alkanoyl-5-hydroxytryptamines (Cn-5HTs) are the main constituents of coffee wax and may be responsible for the increased severity of gastric disorders in sensitive consumers. Their removal from green coffee beans can result in a "stomach-friendly" brew. This work presents a green approach to Cn-5HTs extraction using the bio-based solvent 2-methyloxolane (2-MeOx). HPLC/DAD analyses on Arabica Brazil samples show that mild conditions (30 min at 50 °C) extract about 90% of the wax, without affecting the caffeine content of the beans, whereas almost complete removal is achieved in 60 min at reflux. 2-MeOx forms an azeotrope with water, its possible re-use has been demonstrated using aqueous 2-MeOx (95.5%) as the solvent. These preliminary results make 2-MeOx a possible candidate for the replacement of dichloromethane (DCM) in coffee dewaxing. The importance of fermentation in reducing Cn-5HTs by about 36% has been demonstrated in an analysis of green beans subjected to different post-harvest treatments.

Optimizing drip fertigation at different periods to improve yield, volatile compounds and cup quality of Arabica coffee

How to improve and regulate coffee bean yield and quality through split fertilization in the whole life cycle of coffee is still unclear and deserves further study. A field experiment of 5-year-old Arabica coffee trees was conducted for 2 consecutive years from 2020 to 2022. The fertilizer (750 kg ha^-1 year^-1, N-P₂O₅-K₂O:20%-20%-20%) was split in three times at early flowering (FL), the berry expansion (BE), and the berry ripening (BR). Taking equal fertilization throughout the growth cycle (FL₂₅₀BE₂₅₀BR₂₅₀) as the control check, variable fertilizations including FL₁₅₀BE₂₅₀BR₃₅₀, FL₁₅₀BE₃₅₀BR₂₅₀, FL₂₅₀BE₁₅₀BR₃₅₀, FL₂₅₀BE₃₅₀BR₁₅₀, FL₃₅₀BE₁₅₀BR₂₅₀, and FL₃₅₀BE₂₅₀BR₁₅₀. Leaf net photosynthetic rate (A _net), stomatal conductance (g _s), transpiration rate (T _r), leaf water use efficiency (LWUE), carboxylation efficiency (CE), partial factor productivity of fertilizer (PFP), bean yield, crop water use efficiency (WUE), bean nutrients, volatile compounds and cup quality, and the correlation of nutrients with volatile compounds and cup quality was evaluated. FL₃₅₀BE₂₅₀BR₁₅₀ had the maximum A _net and g _s, followed by FL₂₅₀BE₃₅₀BR₁₅₀. The highest dry bean yield and WUE were obtained from FL₂₅₀BE₃₅₀BR₁₅₀, which increased by 8.86% and 8.47% compared with FL₂₅₀BE₂₅₀BR₂₅₀ in two-year average. The ash, total sugar, fat, protein, caffeine and chlorogenic acid in FL₂₅₀BE₃₅₀BR₁₅₀ were 6.47%, 9.48%, 3.60%, 14.02%, 4.85% and 15.42% higher than FL₂₅₀BE₂₅₀BR₂₅₀. Cluster analysis indicated FL₁₅₀BE₃₅₀BR₂₅₀, FL₂₅₀BE₃₅₀BR₁₅₀, FL₃₅₀BE₁₅₀BR₂₅₀ and FL₃₅₀BE₂₅₀BR₁₅₀ under medium roasted degree increased pyrazines, esters, ketones and furans, FL₁₅₀BE₃₅₀BR₂₅₀ and FL₂₅₀BE₃₅₀BR₁₅₀ under dark roasted degree increased ketones and furans. The aroma, flavor, acidity and overall score of medium roasted coffee were higher than dark roasted coffee, while the body score of dark roasted coffee was higher than medium roasted coffee. The nutrient contents were correlated with the volatile compounds and cup quality. TOPSIS indicated that FL₂₅₀BE₃₅₀BR₁₅₀ was the optimal fertilization mode in the xerothermic regions. The obtained optimum fertilization mode can provide a scientific basis for coffee fertilization optimization and management.

Production and Inhibition of Acrylamide during Coffee Processing: A Literature Review

Coffee is the third-largest beverage with wide-scale production. It is consumed by a large number of people worldwide. However, acrylamide (AA) is produced during coffee processing, which seriously affects its quality and safety. Coffee beans are rich in asparagine and carbohydrates, which are precursors of the Maillard reaction and AA. AA produced during coffee processing increases the risk of damage to the nervous system, immune system, and genetic makeup of humans. Here, we briefly introduce the formation and harmful effects of AA during coffee processing, with a focus on the research progress of technologies to control or reduce AA generation at different processing stages. Our study aims to provide different strategies for inhibiting AA formation during coffee processing and investigate related inhibition mechanisms.

Medium Roasting and Brewing Methods Differentially Modulate Global Metabolites, Lipids, Biogenic Amines, Minerals, and Antioxidant Capacity of Hawai'i-Grown Coffee (Coffea arabica)

In the United States, besides the US territory Puerto Rico, Hawai'i is the only state that grows commercial coffee. In Hawai'i, coffee is the second most valuable agricultural commodity. Health benefits associated with moderate coffee consumption, including its antioxidant capacity, have been correlated to its bioactive components. Post-harvest techniques, coffee variety, degree of roasting, and brewing methods significantly impact the metabolites, lipids, minerals, and/or antioxidant capacity of brewed coffees. The goal of our study was to understand the impact of roasting and brewing methods on metabolites, lipids, biogenic amines, minerals, and antioxidant capacity of two Hawai'i-grown coffee (Coffea arabica) varieties, "Kona Typica" and "Yellow Catuai". Our results indicated that both roasting and coffee variety significantly modulated several metabolites, lipids, and biogenic amines of the coffee brews. Furthermore, regardless of coffee variety, the antioxidant capacity of roasted coffee brews was higher in cold brews. Similarly, total minerals were higher in "Kona Typica" cold brews followed by "Yellow Catuai" cold brews. Hawai'i-grown coffees are considered "specialty coffees" since they are grown in unique volcanic soils and tropical microclimates with unique flavors. Our studies indicate that both Hawai'i-grown coffees contain several health-promoting components. However, future studies are warranted to compare Hawai'i-grown coffees with other popular brand coffees and their health benefits in vivo.

Ecological quality as a coffee quality enhancer. A review

As both coffee quality and sustainability become increasingly important, there is growing interest in understanding how ecological quality affects coffee quality. Here we analyze, for the first time, the state of evidence that ecological quality, in terms of biodiversity and ecosystem functions, impacts the quality of Coffea arabica and C. canephora, based on 78 studies. The following ecosystem functions were included: pollination; weed, disease, and pest control; water and soil fertility regulation. Biodiversity was described by the presence, percentage, and diversity of shade trees. Coffee quality was described by the green bean physical characteristics, biochemical compounds, and organoleptic characteristics. The presence and diversity of shade trees positively impacted bean size and weight and reduced the percentage of rejected beans, but these observations were not consistent over different altitudes. In fact, little is known about the diversity of shade trees and their influence on biochemical compounds. All biochemical compounds varied with the presence of shade, percentage of shade, and elevation. Coffee beans from more diverse tree shade plantations obtained higher scores for final total organoleptic quality than simplified tree shade and unshaded plantations. Decreasing ecological quality diminished ecosystem functions such as pollination, which in turn negatively affected bean quality. Shade affected pests and diseases in different ways, but weeds were reduced. High soil quality positively affected coffee quality. Shade improved the water use efficiency, such that coffee plants were not water stressed and coffee quality was improved. While knowledge on the influence of shade trees on overall coffee quality remains scarce, there is evidence that agroecosystem simplification is negatively correlated with coffee quality. Given global concerns about biodiversity and habitat loss, we recommend that the overall definition of coffee quality include measures of ecological quality, although these aspects are not always detectable in certain coffee quality characteristics or the final cup.

Karakteristik Fisikokimia dan Kapasitas Antioksidan Kopi Liberika dari Kabupaten Tanjung Jabung Barat, Jambi

Liberica coffee is one of the coffee species in commercial trade in Indonesia. The coffee is produced in Tanjung Jabung Barat Regency, Jambi, Indonesia which distributed into 5 sub-districts (Betara, Bram Itam, Kuala Betara, Pengabuan, Senyerang). Information about liberica coffee from Jambi is still limited, thus more exploration is needed. The objectives of this study were to characterize the morphology of the leaf and fruit, the physicochemical characteristics which include the dimension (length, width, thickness), mass, bulk density, colour (L*, a*, b*), moisture contents, TSS (total soluble solids), pH, and antioxidant capacity (DPPH IC50, FRAP) of green and roasted (commercial level) liberica coffee from the above 5 sub-districts. The studies showed that liberica coffee from 5 sub-districts in Tanjung Jabung Barat Rgency, Jambi had various leaf and fruit appearances which were characterized by various size and colour of coffee cherries. Green coffee from different sub-districts owned various physicochemical (width, volume, mass, bulk density, moisture content, TSS) and antioxidant capacity of green coffee. Green coffee from Betara and Pengabuan were associated with high TSS, L* and b* value, while green coffee from Bram Itam and Senyerang were associated with high mass, moisture content and a* value. The highest anti-oxidant capacity was produced by green coffee from Betara and Kuala Betara (DPPH IC50). Meanwhile, roasted coffee produced from green coffee from the 5 sub-districts with similar roasting level (similar L*) produced similar a*, b* value, mass and TSS. However, physicochemical characteristics (length, width, volume, bulk density, moisture content) and antioxidant capacity of these roasted beans varied.

Shaded-Coffee: A Nature-Based Strategy for Coffee Production Under Climate Change? A Review

Coffee is deemed to be a high-risk crop in light of upcoming climate changes. Agroforestry practices have been proposed as a nature-based strategy for coffee farmers to mitigate and adapt to future climates. However, with agroforestry systems comes shade, a highly contentious factor for coffee production in terms of potential yield reduction, as well as additional management needs and interactions between shade trees and pest and disease. In this review, we summarize recent research relating to the effects of shade on (i) farmers' use and perceptions, (ii) the coffee microenvironment, (iii) pest and disease incidence, (iv) carbon assimilation and phenology of coffee plants, (v) coffee quality attributes (evaluated by coffee bean size, biochemical compounds, and cup quality tests), (vi) breeding of new Arabica coffee F1 hybrids and Robusta clones for future agroforestry systems, and (vii) coffee production under climate change. Through this work, we begin to decipher whether shaded systems are a feasible strategy to improve the coffee crop sustainability in anticipation of challenging climate conditions. Further research is proposed for developing new coffee varieties adapted to agroforestry systems (exhibiting traits suitable for climate stressors), refining extension tools by selecting locally-adapted shade trees species and developing policy and economic incentives enabling the adoption of sustainable agroforestry practices.

The effects of trade cost components and uncertainty of time delay on bilateral export growth

This paper measures the trends, specifically for exporters, in bilateral trade costs and more specifically for costs associated with policy barriers. The study further examines the effects of different trade cost components on bilateral export flows via the dynamic panel gravity model. Empirical evidence shows that trade costs generally have a declining trend globally, however, in the case of emerging countries, this rate of decline is very low. The costs associated with non-tariff barriers in emerging countries have a greater role in the continuation of higher trade costs, in comparison to tariff barriers' costs. Likewise, the two-steps system GMM model's results suggest that the infrastructure quality, transportation costs, volatility of exchange rate, and uncertainty in time (days) delay are major hurdles in the sustainable growth of exports and indeed have rendered the exports uncompetitive in the world market, those are also sturdily supported by the prediction of the theory.