Agricultural Practices, Climate Resilience, and Socioeconomic Factors Influencing Coffee Value and Productivity in Vietnam

This study examines the factors affecting coffee value and yield among farming households in Vietnam’s Central Highlands. Utilizing data from the Vietnam Household Agriculture Research Survey and applying ordinary least squares regression, we examine how key variables such as Arabica cultivation, organic certification, input costs, labor, household characteristics, infrastructure access, and climate resilience impact coffee productivity and profitability. The results indicate that increasing the proportion of Arabica coffee significantly enhances both coffee value and yield. Efficient management of economic inputs, particularly irrigation and pesticide use, is found to be crucial in boosting productivity. Household characteristics, including education level and social organization membership, also positively impact coffee yield and profitability, reflecting the role of knowledge dissemination and community engagement.Conversely, high labor costs and remote farm locations negatively affect coffee productivity, while drought events significantly reduce coffee value, highlighting the vulnerability of coffee production to climate change. The findings provide empirical support for policy interventions aimed at strengthening Vietnam’s coffee sector through infrastructure investment, climate adaptation strategies, and the promotion of diversified coffee varieties. Additionally, the study underscores the importance of balancing economic inputs with sustainable farming practices to enhance both environmental and financial resilience. Key words: Coffee production; Arabica; organic certification; agricultural inputs; climate resilience

Antioxidant Activity and Phytochemicals of Freeze-dried and Spray-dried Soluble Coffee Brews

This study analyzed the antioxidant activity and the concentration of several phytochemicals i.e. polyphenols, caffeine, glutathione (GSH), and protein, of freeze-dried and spray-dried soluble coffee brews. Six types of coffee samples were analyzed i.e., 1) Spray-Dried Robusta instant coffee (SDR), 2) Freeze-Dried Robusta instant coffee (FDR), 3) Regular Robusta coffee powder (RR), 4) Spray-Dried Arabica instant coffee (SDA), 5) Freeze-Dried Arabica instant coffee (FDA), and 6) Regular Arabica coffee powder (RA). Antioxidant activity was determined using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging assay. Polyphenols, caffeine, glutathione, and protein were measured spectrophotometrically. Results showed that freeze-dried instant coffee (both robusta and arabica) in a concentration of 500 ppm demonstrated DPPH radical scavenger activity >80% and significantly higher (p<0.05) compared to spray-dried soluble coffee and regular coffee brews. This level was maintained in concentrations of 750 ppm, 1000 ppm, and 1500 ppm. The higher antioxidant activity of freeze-dried coffee brew was in line with the higher concentration of polyphenols, caffeine, GSH, and protein. In conclusion, freeze-dried instant coffee demonstrated more sensitive antioxidant activity, probably due to its more abundant polyphenols, caffeine, GSH, and protein. Key words: Caffeine; DPPH; Glutathione; Polyphenols; Protein

Enhancing bioactive compounds from coffee cascara via enzymatic treatment and microbial fermentation

Coffee cascara is rich in bioactive health-promoting compounds, particularly phenolic compounds with known antimicrobial, antioxidant, and anticancer properties and shows promise for utilization in the food and pharmaceutical industries. Enzymatic treatment and subsequent fermentation have emerged as a viable technique for enhancing the breakdown of complex plant cell structures, releasing phenolic compounds, and generating desirable flavors and active metabolites. This study aims to evaluate the effect of enzymatic treatment and subsequent microbial fermentation on the production of bioactive compounds in coffee cascara. Celluclast was determined to be the most effective for extracting phenolic compounds, yielding a total phenolic contentof 25.29 mg gallic acid equivalent/g (mg GAE/g) and demonstrating high antioxidant activity. Lactobacillus paracasei C13-treated cascara recorded the highest total phenolic content and antioxidant capacity, with caffeic acid levels 12 – 18 times higher than those observed in other treatments. Combining Celluclast treatment with fermentation by L. paracasei C13 significantly increased total phenolic content to 29.56 mg GAE/g and achieved the highest antioxidant activity of 15.40 mg ascorbic acid equivalent/g (mg AAE/g). This process improved the extraction of chlorogenic acid, protocatechuic acid, and caffeic acid to 151.95 mg/100 g, 27.99 mg/100 g, and 22.58 mg/100 g, respectively, while decreasing caffeine levels compared to L. paracasei C13 fermentation alone. Enzymatic treatment and subsequent microbial fermentation significantly enhanced bioactive compounds, demonstrating a feasible method for the production of functional food ingredients from coffee cascara. Key words: Coffee cascara; enzyme-assisted extraction; microbial fermentation; antioxidant capacity; health-promoting compounds

Development and characterization of edible cups made from wheat, sorghum, and coffee pulp flour

The use of plastic containers is increasing enormously, raising concerns about their improper disposal and their contribution to environmental pollution. The study aimed to develop and characterize edible cups made with wheat and sorghum flour, incorporating coffee pulp flour into their formulation. Percentages used of these flours in the three treatments studied were T1: 50-38-2 %; T2: 40-45-5 %; and T3: 30-52-8 %, respectively, and 10 % of cornstarch in all of them. Color, hardness, water absorption capacity, liquid resistance (distilled water at 20-25 and 75-80 °C), biodegradability, and fiber and protein analysis of the obtained containers were analyzed. Both one-way analysis of variance and the Tukey mean test were done at p˂0.05. The results, in comparison with a commercial edible cup, showed an acceptable cup color and a high protein (~11.8 %) and fiber (~3.62 %) content; hardness values (~37N for T1 and T2 and ~42N for T3) were lower. T2-T3 exhibited the low water absorption capacity and liquid resistance at 25°C (~28% at 30 min and ~165 minat 25°C, respectively), while T2 and T3 had the high-water stability at 80°C (~110 min). The developed edible cups exhibited the high biodegradability rate (~63%), decomposing in ~12 days. Including coffee pulp flour as an ingredient in the manufacture of edible cups allows obtaining containers with good structural integrity and physical properties superior to those of commercially available edible containers. Key words: Comestible mugs; physical properties; biodegradable; coffee husk

Prediction of coffee sensory attributes using near-infrared spectroscopy

Cup tasting is the traditional method for evaluating coffee beverage quality. However, sensory analysis has several limitations, including subjectivity, high costs and the challenge of establishing desirable limits for different quality attributes. Therefore, this study aimed to predict coffee sensory attributes based on near-infrared (NIR) spectra of roasted and ground coffee samples. For that, an experiment was conducted during the 2020-2021 harvest season in the Zona da Mata region of Minas Gerais State, Southeastern Brazil, involving seven arabica coffee fields. A total of 180 coffee samples were harvested, processed, and evaluated through sensory analysis following the Specialty Coffee Association protocol. Subsequently, regression models using NIR spectra (1000 to 2500 nm) coupled with Partial least squares (PLS) and PLS-OPS (ordered predictors selection) were developed. The PLS-OPS models yielded the best results, with correlation coefficients (rP) ranging from 0.78 to 0.82 and prediction errors (RMSEP) between 0.15 and 0.13 for aftertaste, overallperception, body, and balance. While predictions for aroma, flavor, and acidity require further improvement, the other attributes showed performance comparable to more complex analytical techniques. These findings demonstrate that NIR spectroscopy, combined with advanced chemometric modeling, offers a promising, cost-effective alternative for predicting coffee sensory quality. Key words: Coffea arabica L.; cup quality analysis; digital agriculture; proximal sensing

Engineering Innovation for Cherry Coffee Wet Processing Using Circulation System and Agitator Grading Machine

Coffee cherry grading technology is currently advanced, but it is necessary to adjust the sorting method and factors such as the condition of the coffee plantation location which has a limited water source to process wet processing such as semi-wash and full-wash. This study is an innovation of coffee cherry grading machines with semi-wash and full-wash methods that focuses on technology that can be applied to coffee plantation environments that have limited water sources so that the quality of water filtration, water quantity, and quality of coffee beans produced by this innovation are observed. The method used is to design and then measure the performance of the machine including filtration performance, the quantity of soaking media, and the quality of the coffee beans produced. The results of this innovation were successfully carried out by the application of effective water filtration, namely during the semi-wash process, the turbidity value in the Main Tube was 10.42 NTU and the Water Storage was 5.32 NTU. In the full wash process, the turbidity value at the Main Tube is 15.65 NTU and Water Storage is 7.70 NTU. This machine has a capacity of 7 kg of coffee with a volume of 306.79 liters of water required during the process. The quality of the green beans produced following SNI 01-2907-2008 and the visualization of coffee bean results according to the semi-wash green bean standard, which is bluish-green, and the full-wash result looks yellowish-green. Key words: Grading; coffee cherry; semi-wash; full-wash; turbidity

Effect of Microwave Use on Kawa Daun Production: Production, Composition, and Antioxidant Properties: Kawa Daun

Kawa daun tea is a drink made of dried coffee leaves from Western Sumatra, offering refreshing benefits for the body. The use of a microwave in the drying process proves to be an effective method due to its significantly high efficiency. Therefore, this study aimed to investigate the impact of varying drying time using microwave on the characteristics of coffee leaves, kawa daun tea, and drinking water, as well as to determine effect of microwave treatment. This study uses a complete random design with ANOVA (Analysis of Variance) and followed by a DNMRT (Duncan’s News Multiple Range Test). The results showed that the difference in drying times significantly affected properties of coffee tea leaves, specifically on the total water-soluble substance test. However,there was no substantial impact on the yield, water level, polyphenols level, caffeine level, and antioxidant activity. The length was also affected by polyphenols level, total soluble solidity, and water solubility antioxidant activity, but did not impact caffeine content test. The maximum time for optimal drying coffee leaves was two minutes with a yield of 35.99% hydration, 4.33% water level, 48.56 mgGAE/g total polyphenols level, 0.56% caffeine level, 63.43% oxidative activity, and 4.61% total water-soluble material. In the chemical analysis of drinking water, the results obtained were total polyphenol content of 28.1 mg GAE/g, caffeine content of 0.45%, total dissolved solids of 1.87%, and antioxidant activity of 88.79%. Thus, it is also concluded that there is no negative effect of drying coffee leaves with a microwave. Key words: Antioxidant; caffeine; robusta coffee leaves; microwave drying; polyphenols

Effect of Oxidative and Non-Oxidative Media on Coffee Torrefaction and Uncondensed-Gas Properties

This research aims to examine the effect of atmospheric media variations on the uncondensed gas characteristics produced from the torrefaction and cooling processes of coffee beans. The process involved using air, N2, and Ar at a speed of 1 l/min as atmospheric media. Arabica green beans were torrefied for 60 min at 235±8oC and later cooled at the same rate and medium in a fixed-bed torrefier but stopped after the temperature reached 50oC. The volatile gases from the process flowed to the condenser, followed by the separation of the uncondensed gas from the liquid product, and subsequently flowed through the chimney. Furthermore, thermocouples that are connected to the Artisan visual roaster scope as an interface as well as the Artisan 2.4.2 software on a computer to measure and record changes in drum and bean temperatures (oC) over time (min). The uncondensed-gas yield was calculatedaccording to the mass balance principle, and their characteristics were determined directly in the form of temperature distribution (oC) and CO emission (ppm) by placing the testo 310 gas analyser sensor on the chimney. According to the findings, oxidative atmospheric caused greater temperature fluctuations in the drum and beans during the processes than non-oxidative media. The variations in atmospheric media led to differences in yield, and uncondensed-gas temperature distribution, as well as the CO emission. There was an increase in CO emission as the temperature was increased. The CO produced from torrefaction using non-oxidative is lower than using oxidative media. The cost factor and supporting of absorbent uncondensed-gas recycling technology must be taken into account when using non-oxidative media. This application will not only yield product variants but also reduce CO emissions and the coffee industry’s carbon footprint. Key words: Arabica-green-bean; coffee torrefaction; nitrogen; argon; condenser

Impact of mass-to-volume ratios on beverage quality in coffee blends

The discrimination of sensory attributes in coffee blends is complex due to the subjective nature of panelist evaluations and the intrinsic chemical heterogeneity of each variety. This study focuses on the influence of blend composition on the sensory evaluation of Robusta coffee, particularly its bitterness and astringency, depending on the proportion used. For specialty and commercial arabica coffees, positive attributes such as flavor and appearance are emphasized. The study also considers the impact of preparation concentrations, specifically the ratio of ground coffee (in grams) to water (in milliliters). We investigate coffee blends composed of different proportions of commercial roasted and ground Arabica coffee (CAC), Robusta coffee (RC), and a genotype of the Arabica specialty coffee (ASC) of the cultivar Yellow Bourbon, processed by both dry and wet methods. The blends were prepared at two concentrations: 7% (70 g ground coffee per 1,000 mL of water) and 10% (100 g ground coffee per 1,000 mL of water). Through predictive statisticalmodeling, this research investigates the sensory outcomes of coffee blends, considering implications previously associated with chemical variables in the literature. It was found that blends prepared at 10% concentration (m/v) with intermediate proportions of CAC and RC achieved a balance in bitterness and flavor attributes for both dry and wet processed Yellow Bourbon. Including brew concentration in the models improved predictive power substantially, increasing R² from approximately 75% to over 90%. Therefore, this concentration can be recommended to ensure a balanced sensory profile without disproportionate influence from any single attribute. Key words: Arabica coffee; robusta coffee; sensory analysis; mixture models; simplex regression

Phenolic content and α-glucosidase inhibition of tubruk-brew kalosi coffee processed by different post-harvest processing

Brewed coffee contains phenolic compounds, a class of bioactive compounds known for their ability to inhibit the alpha-glucosidase enzyme. This study investigates the influence of post-harvest processing on the phenolic content and alpha-glucosidase inhibitory activity of brewed coffee using tubruk method. Arabica coffee from Kalosi Enrekang was utilized, processed using three post-harvest methods: natural, honey, and full-washed. The beans were roasted to a medium level and brewed using the tubruk method. Results revealed that coffee brewed from beans processed using the natural method exhibited the highest phenolic content (3.02 g GAE/100 g) and alpha-glucosidase inhibitory activity (18.48%), compared to those processed with honey and full-washed methods. These findings highlight that post-harvest processing significantly impacts phenolic compound levels and their associated bioactivity. A higher phenolic content in brewed coffee corresponds to an enhanced ability to inhibit the alpha-glucosidase enzyme. Thus, post-harvest processing methods play an important role in determining the functional quality of coffee. Key words: Arabica Enrekang Coffee; bioactive compound; natural processing; full-washed processing; honey processing