Coffee was first introduced to Colombia around the same time Jesuit priests first began arriving from Europe in the mid 16th century. The leaders of Colombia tried to encouraged people to grow coffee, but they met with resistance. Worried that a coffee tree takes five years to provide its first crop, they wondered how they were going to survive during this period?
Last month we briefly discussed the role of chlorogenic acid (CGA) and its decomposition during roasting. This month we’ll focus in a bit more on CGA’s secondary compounds and introduce citric acid in an effort to understand its affect on overall quality.
Discovered in 1932, chlorogenic acids (CGA) represent a large family of esterified compounds present in green and roasted coffee. During roasting, CGA's slowly decompose to form caffeic and quinic acid with about 50% of the original CGA being destroyed in a medium roast.
In the past two series of articles we briefly discussed a handful of important chemical components. This month we will zoom in organic acids and explore their role in flavor development in coffee.
Think humans are the only living creatures that are hooked on caffeine? Well think again. Scientists at the University of Haifa (Israel) found that bees may actually prefer nectar traced with caffeine and nicotine over nectar without.
Coffee has a long and varied history and historians are not exactly sure where coffee began before being spread across all part of the world. But there is strong evidence to suggest that coffee originated in the mountains region of Abyssinia, or current day Ethiopia, some over 2,000 years ago.
In both arabica and robusta coffee, free and bound proteins account for roughly 10 to 13% of coffee’s dry matter. Since proteins are made of smaller components called amino acids - these can vary significantly within each coffee based on a number of factors.
Perhaps the single most important factor in determining coffee quality is the care taken during post-harvest processing. A single mistake can have serious implications, at times, capable of spoiling en entire batch of coffee. But before we discuss the various processing methods, lets take a look at the coffee bean itself.
Although arabica and robusta coffee may appear similar appearance - there are a number of differences that significantly differentiate these two popular species of coffee. The following list points out a few basic differences.
How much caffeine is in green coffee beans?
There are over 60 species of coffee currently in existence, but only two are of main commercial value. Namely, Coffee Arabica or "Arabica" and Coffee Cenaphora or more commonly known as "Robusta" coffee. On average caffeine content in Arabica is 1.2% (range 0.9-1.4%) and 2.2% in Robusta (1.8-4.0%).
How much caffeine is in my cup of coffee?
Caffeine content varies widely in various beverages due to beverage serving size and beverage strength. The table below summarizes caffeine content in common foods and beverages:
Source: NCA, August 1999, www.coffeescience.org
There are number of other variables such a the species of the coffee, grind level, duration of brew, water brew temperature, etc. that greatly vary total caffeine in the final beverage.
Why is coffee "bitter"?
Contrary to popular belief, coffee is not bitter due to caffeine, but rather due to the formation of several protein containing compounds created during roasting. In fact, its been estimated that less than 10% of coffee's 'bitterness' can be attributed to caffeine alone.
What are "melanoidins"?
Melanoidins are brown colored polymetric compounds created during roasting process and responsible for giving coffee it characteristic brown hue. It accounts for approximately 25-30% of coffee's dry beverage and has been identified as a potent antioxidant, generally higher in medium color roasts.
Whats the most common method of decaffeination?
Methylene chloride (CH2Cl2) is the most common method of decaffeination, representing 50-75% of the decaf market. The method is sometimes referred to as the KVW method or European process. A large percentage of the coffee is still decaffeinated in Germany since this is where much of the technology originated.
What is chemical free decaffeination?
"Chemical free" decaffeination refers to the removal of caffeine without the use of traditional chemicals, namely methylene chloride or ethyl acetate.
There are several "chemical free" methods currently on the market with the most popular being the patented Swiss Water method, Mexican Water process, and Super Critical Carbon Dioxide method. The first two use water as a solvent used to extract caffeine from the bean, whereas the super critical method uses naturally occurring compressed CO2 gas as the solvent.
What is "naturally decaffeinated" coffee?
Naturally decaffeinated coffee is coffee decaffeinated using ethyl acetate (C4H8O2), a naturally occurring compound created during the ripening of several fruits.
Although manufactures label coffee as "naturally decaffeinated" the truth is that the solvent is produced synthetically. In pure form ethyl acetate exists as a clear volatile liquid with a fruity smell. It is also used in a number of industries including perfumes, nail removers, and in the storage of insects (entomology).
What is OTA?
Produced by a mycotoxin Aspergillus ochraceus, OTA is short for "Ochratoxin A". Thus far, researchers have identified three distinct strains of the toxin: ochratoxin A, B and C, though only ochratoxin A has been associated with coffee.
OTA has been under extensive research over the past decade, since studies have shown to cause renal tumors in animal models. Currently the toxicity of OTA has been debated, since studies have shown its inability to form reactive intermediates in humans.
OTA formation in coffee has been correlated with poor manufacturing practices, namely: poorly stored cherries, improper drying, and rewetting of the beans on drying patios. Cases have also been found in poorly processed decaffeinated coffee samples.
Although OTA exposure from coffee is minor, it accounts for an estimated 4% - much behind its occurrence in other products, including cereals (44%), wine (10%), and beer (7%).