Memoria CD.indd - ISHAM

in Arábica and 0.9% Robusta varieties), which are decompose and turn into nicotinic acid or niacin.The content of free acid is relevant for coffee’s organoleptic properties, mainly when it results inthe formation of acetic, citric or phosphoric acid. Phosphoric acid content (same as pyroglutamic acidderived from glutamic acid) becomes considerably higher during the roasting process (9).Quinic and vinidinic acids’ content, which varies between 0.3% and 0.5% in green beans andincreases during treatment, but from a biological point of view its byproducts are more important.One of them is n-chlorogenic acid, whose proportion and byproduct depend on the bean’s degree ofroasting (10,11).Coffee quality depends largely on the relative proportion of monochlorogenic and dichlorogenicacid. To much dichlorogenic acid might result in a metallic and bitter taste associated with a coffeethat has been heated for to long. Such flavor results from an increase in quinic acid, lactone formationand diminishes of pyridine concentration (11).Regarding coffee’s mineral content, the one found in large proportion is potassium (around 80 milligramsin a cup of instant coffee). Although cupper concentration tends to be low, its content is muchmore higher in Robusta coffee, which led to argue that such content might explain this variety’s higherresistance to fungi due to copper’s fungicidal activity.It can be say then:• Coffee’s composition is very complex, including more than a thousand substances;• Not all coffee components that have been identified possess physiological effects, being caffeinethe most widely known among them.• In order to validate experimental results of studies done in animals, the following criteria must beconsidered:• Dose used• Length of coffee’s administration;• Metabolic characteristic of each animal species• Caffeine is the most widely-known alkaloid amongst those known to produce significant physiologicaleffects; others such as theophylline and theobromine cause also significant biological effects.• Coffee’s metabolism is complex. Its physiological effects may in part be explained by three mechanisms:• Antagonism of adenosine receptors;• Phophorodiesterase inhibition; and• Intracellular calcium mobilization• The only neurological effects being clearly demonstrated so far are increased mental alertnessand delayed of onset of sleep. Coffee content produces vasoconstriction of brain vessels, whichis why it is present in several pharmaceutical products used for migraine treatment. Caffeine alsoboosts the analgesic effect of some drugs,• Coffee enlarges short-term memory, alertness and mental sharpness;• Coffee regular consumption in moderate quantities does not affect normal cardiovascular functioingor systolic and diastolic arterial pressure• The gastric or intestinal intolerance regularly attributed to coffee is usually linked to somepeople’ssensibility to coffee and has not been successfully reproduced in any experimentalstudy;• Coffee exerts a cholecystokinetic action and increases pancreatic secretion;• Coffee regular consumption does not cause respiratory apparatus associated diseases;• Endocrine functions are not modified by consuming coffee;• Consuming coffee does not have any important effect on muscle function;• It has not been demonstrated that consuming coffee increases the risk of bone fractures;• Coffee is a good source of potassium, magnesium and fluoride;• Coffee consumption increases energy metabolism in the hours following its ingestion, but does notmodify the total energy expenditure;• Coffee consumption has no harmful effects on reproduction or fertility;• Coffee (in the regular amounts consumed by human) has no teratogenic effect; and• In the habitual amounts consumed by humans, has no genotoxic, mutagenic or carcinogenic potential.131