scholarly journals Effect of the Post-Harvest Processing on Protein Modification in Green Coffee Beans by Phenolic Compounds

Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 159
Author(s):  
Gustavo A. Figueroa Campos ◽  
Johannes G. K. T. Kruizenga ◽  
Sorel Tchewonpi Sagu ◽  
Steffen Schwarz ◽  
Thomas Homann ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Storage Protein ◽  
Protein Fraction ◽  
Protein Modification ◽  
Green Coffee ◽  
Processing Methods ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Modified Peptides ◽  
Cup Quality

The protein fraction, important for coffee cup quality, is modified during post-harvest treatment prior to roasting. Proteins may interact with phenolic compounds, which constitute the major metabolites of coffee, where the processing affects these interactions. This allows the hypothesis that the proteins are denatured and modified via enzymatic and/or redox activation steps. The present study was initiated to encompass changes in the protein fraction. The investigations were limited to major storage protein of green coffee beans. Fourteen Coffea arabica samples from various processing methods and countries were used. Different extraction protocols were compared to maintain the status quo of the protein modification. The extracts contained about 4–8 µg of chlorogenic acid derivatives per mg of extracted protein. High-resolution chromatography with multiple reaction monitoring was used to detect lysine modifications in the coffee protein. Marker peptides were allocated for the storage protein of the coffee beans. Among these, the modified peptides K.FFLANGPQQGGK.E and R.LGGK.T of the α-chain and R.ITTVNSQK.I and K.VFDDEVK.Q of β-chain were detected. Results showed a significant increase (p < 0.05) of modified peptides from wet processed green beans as compared to the dry ones. The present study contributes to a better understanding of the influence of the different processing methods on protein quality and its role in the scope of coffee cup quality and aroma.

Prediction of specialty coffee cup quality based on near infrared spectra of green coffee beans

Talanta ◽  
2016 ◽  
Vol 150 ◽  
pp. 367-374 ◽  
Author(s):  
Kassaye Tolessa ◽  
Michael Rademaker ◽  
Bernard De Baets ◽  
Pascal Boeckx
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Near Infrared Spectra ◽  
Coffee Beans ◽  
Specialty Coffee ◽  
Cup Quality

Profiling of phenolic compounds using UPLC–MS for determining the geographical origin of green coffee beans from Ethiopia

2016 ◽  
Vol 45 ◽  
pp. 16-25 ◽  
Author(s):  
Bewketu Mehari ◽  
Mesfin Redi-Abshiro ◽  
Bhagwan Singh Chandravanshi ◽  
Sandra Combrinck ◽  
Minaleshewa Atlabachew ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Geographical Origin ◽  
Green Coffee ◽  
Green Coffee Beans ◽  
Coffee Beans

scholarly journals Drying and sortation to improve green beans and cup quality of Wamena coffee

2021 ◽  
Vol 306 ◽  
pp. 03024
Author(s):  
Adnan ◽  
Martina Sri Lestari
Keyword(s):  
Simple Technique ◽  
Descriptive Analysis ◽  
Quality Score ◽  
Local Culture ◽  
Green Coffee ◽  
Green Beans ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Cup Quality

Drying and sortation are the most important steps to improve green coffee beans and cup quality. However, farmers very often neglect these steps. Therefore, a simple technique and soft approach are required to encourage farmers to implement drying and sortation technology. The study aim is to assess suitable drying and sortation technology to improve green coffee beans and cup quality to local culture in Jayawijaya Regency, Papua. The study was conducted using 2 factors; a. Combination of drying floor using a tarp and without sortation (DFWTS), b. Combination of drying tables and with sortation (DTWS). Drying tables were designed as two separate parts. The first part was the permanent tables, and the second part was removable boxes in dimension 80 x 80 cm located on top of the permanent tables. Descriptive analysis was conducted based on SNI 01-2907-2008 by the Indonesian Coffee and Cocoa Research Institute. The results show DTWS produce green coffee beans in compliance with SNI 01-2907-2008 at 4a grade, compared to DFWTS is rejected. Green coffee beans quality is likely to affect cup quality. DTWS obtain cup quality score 83.0 compare to DFWTS is 81.25. In conclusion, DTWS improve green coffee beans and cup quality.

scholarly journals Phenolic compounds in coffee

2006 ◽  
Vol 18 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Adriana Farah ◽  
Carmen Marino Donangelo
Keyword(s):  
Phenolic Compounds ◽  
Quinic Acid ◽  
Green Coffee ◽  
Phenolic Fraction ◽  
Related Substances ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Main Components ◽  
The Impact ◽  
Related Compounds

Phenolic compounds are secondary metabolites generally involved in plant adaptation to environmental stress conditions. Chlorogenic acids (CGA) and related compounds are the main components of the phenolic fraction of green coffee beans, reaching levels up to 14 % (dry matter basis). These compounds have a number of beneficial health properties related to their potent antioxidant activity as well as hepatoprotective, hypoglycemic and antiviral activities. The main groups of CGA found in green coffee beans include caffeoylquinic acids, dicaffeoylquinic acids, feruloylquinic acids, p-coumaroylquinic acids and mixed diesters of caffeic and ferulic acids with quinic acid, each group with at least three isomers. During coffee processing, CGA may be isomerized, hydrolyzed or degraded into low molecular weight compounds. The high temperatures of roasting also produce transformation of part of CGA into quinolactones and, along with other compounds, melanoidins. This review focuses on the chemical characteristics, biosynthesis, and distribution of CGA and related compounds in coffee. The influence of genetic, physiological and environmental factors as well as processing on the chemical composition of coffee beans is discussed. The impact of CGA composition of green coffee on cup quality is also approached. Despite the existence of substantial published information on the total levels of CGA in coffee, more research is needed on the composition of minor phenolic compounds and specific CGA isomers (and related substances) in green and roasted coffee beans, as well as their impact on coffee quality.

scholarly journals The Role of Microbes in Coffee Fermentation and Their Impact on Coffee Quality

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Mesfin Haile ◽  
Won Hee Kang
Keyword(s):  
Fermentation Process ◽  
Positive Impact ◽  
Starter Culture ◽  
Starter Cultures ◽  
Green Coffee ◽  
Comprehensive Overview ◽  
Processing Methods ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Culture Development

Coffee is one of the most important and widely used commercial crops in the world. After ripe coffee cherries are harvested, coffee must pass through several steps to become (green) raw coffee beans. Commonly, there are three different processing methods used to obtain green coffee beans from coffee cherries, namely, the wet, dry, and semidry methods. Microorganisms (yeasts and bacteria) play a major role in coffee fermentation process by degrading mucilage by producing different enzymes (pectinase), acids, and alcohols. Starter culture development is crucial and is done by selecting microorganisms that have certain characteristics, such as mucilage degradation ability, tolerance to stress during fermentation, the ability to suppress the growth of pathogenic fungi, and a positive impact on the sensory quality of the coffee. Currently, green coffee beans obtained from farms that use any of the above processing methods are fermented with selected microorganisms to improve the flavour and aroma of the coffee. This is the result of a new insight into the development of unique flavoured coffee and into engaging with the coffee market to better benefit. This review gives a comprehensive overview of the fermentation process, microorganisms and starter cultures, and fermentation’s impact on coffee quality. Future prospects are also discussed through the incorporation of recent research.

scholarly journals Comparison of the Antioxidant Activities and Volatile Compounds of Coffee Beans Obtained Using Digestive Bio-Processing (Elephant Dung Coffee) and Commonly Known Processing Methods

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 408
Author(s):  
Mesfin Haile ◽  
Hyung Min Bae ◽  
Won Hee Kang
Keyword(s):  
Antioxidant Activity ◽  
Volatile Compounds ◽  
Green Coffee ◽  
Roasted Coffee ◽  
Green Beans ◽  
Processing Methods ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Roasted Coffee Beans ◽  
Elephant Dung

There are different types of coffee processing methods. The wet (WP) and dry processing (DP) methods are widely practiced in different parts of coffee-growing countries. There is also a digestive bioprocessing method in which the most expensive coffee is produced. The elephant dung coffee is produced using the digestive bioprocessing method. In the present experiment, the antioxidant activity and volatile compounds of coffee that have been processed using different methods were compared. The antioxidant activity, total phenolic content (TPC), total flavonoid content (TFC), and total tannin content (TTC) of green coffee beans from all treatments were higher as compared to roasted coffee beans. Regarding the green coffee beans, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of elephant dung coffee beans was higher as compared to that of the DP and WP coffee beans. The green coffee beans had higher DPPH activity and ferric reducing antioxidant power (FRAP) value compared to the roasted coffee beans. The green beans of elephant dung coffee had a high TPC than the beans obtained by WP and DP methods. TFC in elephant dung coffee in both green and roasted condition was improved in contrast to the beans processed using dry and wet methods. The elephant dung coffee had an increased TTC in comparison to the DP and WP coffee (green beans). About 37 volatile compounds of acids, alcohols, aldehydes, amide, esters, ethers, furans, furanones, ketones, phenols, pyrazines, pyridines, Heterocyclic N, and pyrroles functional classes have been found. Some of the most abundant volatile compounds detected in all treatments of coffee were 2-furanmethanol, acetic acid, 2-methylpyrazine, 2,6-dimethylpyrazine, pyridine, and 5-methylfurfural. Few volatile compounds have been detected only in elephant dung coffee. The principal component analysis (PCAs) was performed using the percentage of relative peak areas of the volatile compound classes and individual volatile compounds. This study will provide a better understanding of the impacts of processing methods on the antioxidants and volatile compounds of coffee.

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