From Plantation to Cup: Changes in Bioactive Compounds during Coffee Processing

Abstract

Coffee is consumed not just for its flavor, but also for its health advantages. The quality of coffee beverages is affected by a number of elements and a series of processes, including: the environment, cultivation, post-harvest, fermentation, storage, roasting, and brewing to produce a cup of coffee. The chemical components of coffee beans alter throughout this procedure. The purpose of this article is to present information about changes in chemical components and bioactive compounds in coffee during preharvest and postharvest. The selection of the appropriate cherry maturity level is the first step in the coffee manufacturing process. The coffee cherry has specific flavor-precursor components and other chemical components that become raw materials in the fermentation process. During the fermentation process, there are not many changes in the phenolic or other bioactive components of coffee. Metabolites fermented by microbes diffuse into the seeds, which improves their quality. A germination process occurs during wet processing, which increases the quantity of amino acids, while the dry process induces an increase in non-protein amino acid γ-aminobutyric acid (GABA). In the roasting process, there is a change in the aroma precursors from the phenolic compounds, especially chlorogenic acid, amino acids, and sugars found in coffee beans, to produce a distinctive coffee taste.

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

“…These are capable of undergoing a nucleophilic addition to proteins e.g., thiol and free amino groups, thereby covalently modifying the proteins. The green coffee beans have been shown to possess polyphenol oxidase (PPO) activity [ 17 ]. Therefore, their proteins are liable to this type of modification [ 18 ].…”

“…According to Rogers et al, only 1.1 and 0.2% of the amino acid content can be allocated to cysteine and methionine, respectively. Further, it was recently shown that the dry processing of the coffee beans may increase the content of the non-protein amino acid γ-aminobutyric acid [ 17 ]. In the soluble protein fraction of the 11S protein, glutamate and glutamine are the most abundant amino acids in coffee beans.…”

“…The coffee beans are an excellent source of antioxidants, which include phenolic compounds such as chlorogenic acid [ 17 , 20 ], an ester formed between caffeic-and quinic acid. They appear in the form of caffeoylquinic acids (CQA), its corresponding three isomers (3-CQA, 4-CQA, and 5-CQA), dicaffeoylquinic acids (diCQA) with its respective three isomers (3,4-diCQA, 3,5-diCQA, and 4,5-diCQA), and feruloylquinic acids with the known three isomers (3-FQA, 4-FQA, and 5-FQA) representing further derivatives of hydroxycinnamic acids found in coffee beans [ 21 ].…”

Effect of Dewaxed Coffee on Gastroesophageal Symptoms in Patients with GERD: A Randomized Pilot Study

“…It has been reported that, in medium roasts, a 60% loss of CGA has been observed and up to 100% loss in a dark roast. The optimal roasting condition for coffee is medium above which there is a significant reduction of bioactive compounds [50][51][52]. In general, the most studied CGAs in coffee are the three main CQA isomers, whereas diCQAs and FQAs have been barely investigated.…”

Potential Antimicrobial Properties of Coffee Beans and Coffee By-Products Against Drug-Resistant Vibrio cholerae

“…Nevertheless, the efficacy varies, depending on the species, degree of roasting, brewing procedure, and decaffeination ( 45 ). Coffee varieties from various origins differ significantly in terms of their constituents, and multiple agricultural geography conditions of the coffee plant, such as the soil type, altitude, and harvest season, as well as the pre- and post-harvest management practices, influence coffee bean bioactivity ( 46 , 47 ).…”