Επισκόπηση της μικροβιακής οικολογίας και των διαδικασιών ζύμωσης κόκκων καφέ – Επίδραση στην ποιότητα του αφεψήματος.

Abstract

Coffee is one of the most popular beverages in the world and this largely justifies the fact that it has been at the center of scientific interest for many decades. The per capita consumption of coffee drinks is increasing every year and, according to the available data, Finland, Norway and Iceland are the leaders, followed by Denmark, the Netherlands and Sweden. The economic and commercial importance of coffee is very great, as it is the most important agricultural commodity, after oil. The popularity of coffee is mainly due to the unique organoleptic characteristics, but also to the mild stimulating action of the drink attributed to the presence of caffeine and similar compounds. Coffee is produced from the seeds of coffee trees belonging to the genus Coffea of the family Rubiaceae, one of the largest families of flowering plants, with about 500 genera and 6,000 species. Of all the different species, the most economically important are Coffea arabica L. and Coffea canephora var. robusta. The unique identity of the different varieties of coffee begins to form during the growth of the plant, as well as during the post-harvest handling and the processes that follow the harvest of the fruits. Environmental factors, such as geographical origin, climate, altitude, temperature and plant nutrition, significantly affect the quality of coffee. The action of enzymes on sperm components, such as proteins, carbohydrates and phenolic compounds, is also considered to be particularly crucial. An important role in this process is played by microorganisms (yeasts, bacteria, fungi), which produce a variety of metabolic products, mainly alcohols and acids. The character of coffee is further modified during roasting, during which Maillard reactions predominate, leading to the production of aromatic and flavor compounds. The aromatic ingredients produced during roasting are, without a doubt, the most decisive factor in the quality of coffee. Volatile compounds characterize not only the different varieties, but also the geographical origin of coffee. To date, more than 1,000 volatile components have been identified. However, few of them seem to be important to the aroma and taste of coffee. According to some researchers, the peculiar aroma of a type of coffee is formed, for the most part, by a group of 20-30 individual volatile ingredients.