Coffee Science (E-Journal)
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Optimization of robusta green coffee fermentation using response surface methodology
Get PDFKombucha coffee is a fermented coffee bean, which is extracted using a combination of bacteria and yeast. Kombucha coffee can be obtained by optimizing the three variables, namely sugar concentration, incubation temperature and duration of fermentation using a response surface methodology (RSM). This study aimed to optimize the three variables that influence the fermentation of Robusta green coffee beans using a kombucha culture to obtain low caffeine content and high levels of chlorogenic acid. RSM calculation was used high-performance liquid chromatography (HPLC) on caffeine and chlorogenic acid that content in kombucha coffee. The results of modeling used a central composite experimental design (CCD). The results of the optimization study showed that the lowest concentration of caffeine and chlorogenic acid was obtained at sugar concentration of 6.77% (b/v), incubation temperature of 25°C and incubation for 18 days. Finally, the fermentation using RSM on kombucha coffee required an additional variable which is the amount of kombucha culture inoculums, as well as the variables of sugar concentration, incubation temperature and duration of fermentation.
Key words: Kombucha coffee; caffeine; chlorogenic acid.
Café in small towns: A picture of the weakening social engagement
Get PDFSmall towns in developing countries are grappling with the evolving global-brand and modern coffee shops (cafés) that have driven out the traditional coffee shop. New cafés have also encouraged a global coffee culture with its uniformity of coffee presentation and quality standard. Taking Indonesia as a case study, this study analyses the changing of coffee culture from the perspective of coffee shops culture in small towns of the developing country. In small towns and rural areas, coffee shops served not only as community meeting spots but also as centers of information and resource exchanges. Coffee shop helped to mediate people’s social interactions. Newly arrived café leaves the social dimension of the traditional coffee shop with the limited interaction among its patrons. Café becomes a mere economic establishment and a token of modern lifestyle. By using qualitative research with descriptive methodology and quantitative research (survey) as the baseline, the study reveals that even though the cafés improve the economy, the change reflects the changing of civic-bond in the society. It concludes that the changing of coffee consumption in rural Indonesia may not only signing the arrival of a globalised coffee culture but also, signing the change of social engagement of the society
Key words: Coffee for health; coffee culture; globalization; social engagement
Sensory Q-Grader evaluation of fermented arabica coffees by yeast (Saccharomyces cerevisiae) and lactic bacteria (Pediococcus acidilactici) cultures
Get PDFThe objective of this study was to evaluate sensorially, by professional Q-Grader, the beverage coffee from fermentation natural and fermentation with the use of yeasts and lactic acid bacteria as starter cultures in wet coffee processing. The Arabica coffee was harvested at two different altitudes in Espírito Santo State. Both coffees went through 04 treatments: inoculated with starter cultures Saccharomyces cerevisiae (YML) or Pediococcus acidilactici CCT 1622 (LAF), natural fermentation (NF) (not inoculated) and Control, without fermentation (WF). The coffee was processed by just the wet process. After process and roasting, the sensorial analysis was performed to understand the impact of fermentation processing in the coffee quality, and was performed by 6 Q-Graders, following SCA protocol. The study evidenced that the use of natural fermentation or starter cultures during post-harvest coffee contributed to obtain a quality beverage with pleasurable sensorial characteristics, punctuated by the tasters in the overall score obtained and also by the highsensory scores in attributes such as fragrance, acidity, aftertaste and the different perceived aromas. This work demonstrates for coffee growers that fermentation technology is not intuitive but requires an understanding of the relationship of the microorganisms with the coffee and the environment. In addition to the other chemical aspects of roasting and brew coffee.
Key words: Fermentation; Microorganisms; Quality
Activity of robusta coffee on the expression of CRP and MMP-9 against hyperlipidemia
Get PDFHyperlipidemia especially LDL accumulation causing inflammation in blood vessel. CRP and MMP-9 are component that triggering in inflammation process. This study to know activity of robusta coffee against hyperlipidemia on this component. This study using male wistar rats were divided into three groups ; normal, hyperlipidemia and that were given coffee with high fat diet groups. Robusta coffee was given 3.6x10-6 m3 by intragastric gavage. Bloodcollection was carried out using infra-orbital for analysis of LDL levels. Furthermore, the experimental animals were sacrificed and coronary arteries were taken for CRP and MMP-9 immunohistochemical staining. Data were analyzed using ANOVA followed LSD test. Results show The highest expression score for CRP and MMP-9 within the hyperlipidemia group was 188.27 ± 1.8 and 277.56 ± 2.1. The decrease in the expression score of CRP and MMP-9 happened within the ones that were given coffee with 59.33 ± 1.5 and 116.7 ± 0.2 each. Results showed that were differences in the expression of CRP andMMP-9 in all groups (p <0.05). In conclusion, activity robusta coffee can decreases the expression of CRP and MMP-9 against hyperlipidemia.
Key words: Coronary disease; hyperlipidemia; robusta coffee
Effect of the impact of rigid rods on coffee fruit detachment efficiency by mechanical vibrations
Get PDFThe mechanization of field activities has been the response of coffee producers to the labor shortage, especially for fruit harvesting. The use of mechanical harvesters allows greater harvesting efficiency and ensures the economic viability of coffee plantations, which currently depend mainly on the reduction in production costs. The principle used for mechanized coffee harvesting is based on the principle of mechanical vibration. The objective of this studywas to analyze the dynamic behavior of the coffee fruit-peduncle-branch system under mechanical vibration and the impact of the vibrating rods on the fruit detachment process in association with this behavior. Fragments of coffee branches containing fruits in the unripe and ripe stages were used in this experiment. These samples were subjected to different frequencies (20, 30, 40, and 50 Hz) and amplitudes (0.002, 0.003, and 0.004 m). Another variableanalyzed was the form of vibration transmission to the fruits, with the vibrations being transmitted to the samples with or without the impact of the fiberglass rods. The fruit detachment efficiency increased as the ripening stage progressed from unripe to ripe. A higher detachment efficiency occurred with the increase in vibration frequency and amplitude because of the higher vibrational energy imposed on the fruit. The detachment efficiency was low when the vibration was transmitted without the impact of the rods. Conversely, the vibration in combination with impact achieved a mean detachment efficiency of approximately 90%.Key words: Coffee crop; dynamic behavior; harvester machine; mechanical harvesting
Quality assessment of coffee beans through computer vision and machine learning algorithms
Get PDFThe increasing market interest in coffee beverage, lead coffee growers around the world to adopt more efficient methods to select the best-quality coffee beans. Currently, coffee beans selection is carried out either manually, which is a costly and unreliable process, or using electronic sorting machines, which are often inefficient because some coffee beans defects, such as sour and immature beans, have similar spectral response patterns. In this sense, the present work aimed to assess coffee beans quality using both computer vision and machine learning techniques, such as Support Vector Machine (SVM), Deep Neural Network (DNN) and Random Forest (RF). For this purpose, an algorithm written in Python language was developed to extract shape and color features from coffee beans images. The obtained dataset was then used as input to the machine learning algorithms. The data reported in this study pointed to the importance of color descriptors for classifying coffee beans defects. Among the variables used, the components from RGB (Red, Green and Blue) and HSV (Hue, Saturation and Value) color spaces presented the most relevant contribution for the classification models. Also, the results reported in this study provides evidence that computer vision along with machine learning algorithms can be used to identify and classify coffee beans with a very high accuracy (> 90%).
Key words: Deep neural network; classification; artificial intelligence; image processing; granulometry
Behavior of the biochemical attributes of a Oxisol submitted to high doses of gypsum in the coffee culture
No full textThe objective of this study was to determine the influence of increasing doses of agricultural gypsum on the quality of the soil biochemical attributes in coffee cultivation (Coffea arabica L.) by two climatic seasons in the Brazilian Cerrado. Soil samples were collected in two collections (dry and rainy season), at 0 – 10 cm depth of a Oxisol, submitted to doses 0 (GSA); 3.5 (G3.5); 7.0 (G7.0) and 14 (G14) Mg ha-1 of agricultural gypsum in the coffee planting line. The biochemical attributes evaluated were: total organic carbon (TOC); microbial biomass carbon (MBC); soil basal respiration (SBR); absolute enzymatic activities [Urease, acid phosphatase, hydrolysis of fluorescein diacetate (FDA)]. TOC showed no differences between treatments. The significant effect (p ≤ 0.05) of gypsum doses was observed for MBC and SBR, which were higher in the treatment with G7.0 application. The enzymatic activities of Phosphatase and the FDA showed no differences between treatments. On the other hand, the specific enzymatic activities by MBC were to describe the differences between the doses of gypsum applied, generally with greater activity in treatments G7.0 and G14. The accumulated coffee productivity was higher in G14 treatment. The results presented to confirm that the biochemical attributes of the soil are sensitive in the evaluation of changes in soil use and that the increase in gypsum does favor activity and microbial biomass
Growth of robusta coffee after the application of herbicides to control Urochloa ruziziensis
Get PDFThe growth of coffee plants can be severely affected by competition with other plants, being necessary to the management of these, which can be performed by controls manual, mechanical, biological and chemical methods. This study aimed to evaluate the growth of coffee robusta due to no control of Urochloa ruziziensis (cv. Common) and control by manual weeding and herbicides in post emergence, seeking the most appropriate method. The experimental design was completely randomized, with four replicates of four treatments: control (no control of the U. ruziziensis); manual weeding; oxyfluorfen (1.44 kg a.i. ha-1); paraquat + diuron (0.40 + 0.20 kg a.i. ha-1) and glyphosate (1.92 kg a.i. ha-1), with the spray volume equivalent to 200 L ha-1. The herbicides were applied directly on the U. ruziziens plants 60 days after planting. 30 days after treatment, the following were evaluated: a, b and total chlorophyll content, stem diameter, plant height, number of leaves, leaf area, orthotropic and plagiotropic branches, dry shoot biomass, dry root biomass and root growth. U. ruziziens, when not controlled, caused a 42% reduction in the leaf area of robusta coffee in relation to those that were controlled through manual weeding. The herbicide oxyfluorfen and weeding were the most suitable for the control of U. ruziziens in the cultivation of coffee, since they did not affect seedling growth. Failure to control U. ruziziens or weeds leads to reduced growth of robusta coffee plants, except in the height due to the etiolation caused by competition with U. ruziziens.
Key words: Coffea canephora Pierre ex Froehner; Coffee seedlings; Brachiaria; Chemical control
REVIEW Coffee berry borer (Coleoptera: Curculionidae): An opening for fungi and toxins?
Get PDFCoffee is one of the most consumed beverages in the world. Studies on coffee quality are important, because the occurrence of defective grains can affect its microbiological and sensory quality. The insect Hypothenemus hampei, when perfurating the fruits in the crop, causes coffee berry borer defects to reduce the weight of the grains and can also favor the entry of fungi, some of them toxigenic, that under ideal growth conditions are capable of producing toxins. The present article is a review of the general aspects of coffee, its defects, the coffee berry borer and the possible relationship with ochratoxigenic fungi and ochratoxin A production in coffee.
Key words: Coffee pest; Hypotenemus hampei; Endosulfan; Fungi; Ochratoxin A
Spatial correlation between the chlorophyll index and foliar npk levels in coffee crop
Get PDFDetection of spatial variability of data that can improve crop management is a key factor for precision agriculture. In agriculture, there is a need for tools to assist farmers in making decisions about the proper nutrient management, aiming their full productive potential. The use of portable and easy-to-use sensors has facilitated the collection of data, as they are more agile and cost-effective. Thus, the SPAD® chlorophyll meter is an alternative to generate the chlorophyll index (CI), which is easily obtainable and non-destructive sampling. In this context, this study aimed to determine the spatial correlations between the CI and nitrogen, phosphorus and potassium (NPK) foliar contents in the coffee crop using geostatistical tools. The CI showed a moderate spatial correlation with N, showing potential to be used in precision coffee farming. Differently, for potassium, the use of CI is not recommended, as they presented the lower spatial correlation. As a tool that performs an indirect measurement, the results should be validated by field measurements to local calibrations.
Key words: Optical sensor; precision agriculture; mapping; geostatistics; Coffea arabica L