Interesting Facts
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Women metabolise caffeine slower than men.
Coffee is slightly acidic (pH 5.0–5.1).
Used coffee grounds may be used for composting or as mulch.
The best effects are to be found drinking black coffee without sugar.
Coffee (Caffeine & Trigonelline) Health Benefits
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The European Food Safety Authority state for healthy adults with no medical
issues, 300-400mg/daily is deemed as safe, 200mg max single dose is OK only when exercising.
Low to moderate caffeine intake is generally associated with increased
alertness, learning capacity, exercise performance, and perhaps better mood,
Caffeine increases the metabolic rate and may increase fat burning during exercise.
Caffeine blocks the inhibitory neurotransmitter (adenosine), increasing noradrenaline and dopamine production, and neuron activity that can improve brain function.
Coffee contains high levels of antioxidants [phenolics] (200-550ml/6floz cup)
- a level far exceeding that of green tea [catechins], although their strength is weaker.
Invitro and animal studies suggest the trigonelline has a potential to inhibit cancer cells and may improve memory by regenerating axons and dendrites in the brain.
Coffee (Caffeine & Diterpenes) Health Risks
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The half-life of caffeine in your body is about six hours. Drinking 200mg
of caffeine at 3:00 p.m. will leave about 100mg in your system at 9:00 p.m.
High doses can produce anxiety, tachycardia and insomnia during its half-life.
Caffeine can increase blood pressure in non-habitual consumers and may reduce control of fine motor movements.
Caffeine stimulates the CNS, raising blood sugar, causing an overproduction of insulin – thereby negatively effecting glucose tolerance, glucose disposal, insulin sensitivity, and impairing blood sugar control.
Increases production of adrenal stress hormones such as cortisol that prevent other hormone systems from working properly, causing increased anxiety,
irritability, muscular tension, indigestion, insomnia, and decreased immune function.
Cafestol and kahweol (diterpenes) from consumption of unfiltered coffee can raise serum LDL cholesterol levels – negatively affecting cardiovascular health.
Caffeine can lead to minor physical dependence, withdrawal symptoms range from headache, fatigue, depression and anxiety, to nausea, vomiting and
physical pains.
COFFEE
What about Instant Coffee?
● Made by brewing coffee beans and then removing the water through freeze-drying.
● Less caffeine than fresh ground coffee per cup.
● Processes may improve antioxidant availability.
The Bottom Line:
The worlds’ most favoured beverage certainly contains some interesting ingredients.
Caffeine and trigonelline appear to have some valid health benefits, like increased
alertness, exercise performance and antioxidant capacity. However, caffeine can
destabilise blood sugar levels and also negatively affect health with increased anxiety
and ‘stress hormone’ production, which is worsened by excessive consumption. As with
any stimulant it is best consumed in moderate quantities and strengths, and not drank
after midday to avoid problems sleeping.
Welcome to Vacherin’s food in focus.
Each month our nutritionist Gary Baverstock will
provide some basic science and will help
to demystify certain foods in our diet.
Coffee
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Coffee is one of the most popular drinks in the world with a distinct aroma and flavour.
It is prepared from roasted coffee beans – seeds from the berries of the Coffee plant.
Cultivated in the equatorial regions of the Americas, Southeast Asia, India and Africa.
The two most commonly grown plants are the highly regarded Arabica and the less sophisticated, but stronger and hardier Robusta.
Once ripe, coffee beans are picked, processed (wet or dry), fermented then dried.
They are then roasted to varying degrees, depending on the desired flavour, before being ground and brewed to create coffee.
The caffeine content of Robusta is almost double that of the more
delicate Arabica. Roasting Coffee
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Roasting influences the taste by changing the bean both physically and chemically.
The bean decreases in weight as moisture is lost and increases in
volume, becoming less dense which will influence the strength of
the coffee.
Roasting begins when the temperature inside the bean reaches
approximately 200 °C.
Different varieties of seeds differ in moisture and density and will roast at different rates.
During roasting, caramelisation occurs as intense heat breaks down starches, changing them to simple sugars that begin to brown, altering the colour of the bean.
Sucrose is lost during the roasting process and may disappear entirely in darker roasts.
During roasting, aromatic oils and acids weaken, changing the flavour; at 205 °C other oils start to develop.
One of these oils, caffeol, is largely responsible for coffee’s aroma
and flavour.
Darker roasts are generally bolder because they have less fibre content and a more sugary flavour.
Lighter roasts have a more complex and therefore perceived stronger flavour from aromatic oils and acids otherwise destroyed by longer roasting times.
Roasting does not alter the amount of caffeine in the bean, but does give less caffeine when the beans are measured by volume due to the expansion caused by roasting.
Chemical Composition of Coffee
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Main chemicals present in coffee are Trigonelline and Caffeine
Trigonelline, a bitter alkaloid, contributes to the main bitterness
of coffee.
Trigonelline concentration is higher for Arabica than Robusta and serves to produce important aroma compounds.
During roasting trigonelline partially degrades to produce two
important compounds - pyridines (a volatile oil) and nicotinic acid
(niacin - Vitamin B3).
Caffeine is a methylxanthine with bitter characteristics; however, it is responsible for no more than 10% of the perceived bitterness.
Caffeine is a central nervous system (CNS) stimulant, having the effect of temporarily warding off drowsiness and restoring alertness.
Cafestol and kahweol are fat-soluble compounds known as diterpenes, which are present in the oil derived from coffee beans.
The amount of caffeine in your blood stream peaks 15-45 minutes
after ingestion.
Caffeine Content of Common Coffees & Other Products
Product
Caffeine Range (mg)
Brewed coffee (8floz) [250ml]
65-120
Instant coffee (8floz) [250ml]
60-85
Decaffeinated coffee, brewed (8floz) [250ml]
2-4
Decaffeinated coffee, instant (8floz) [250ml]
1-4
Espresso coffee (1floz) (or in cappuccinos)
30-50
Red Bull (12floz) [320ml]
80
Diet Coke (12floz) [320ml]
45
Decaffeination
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Beans are decaffeinated when they are still green.
All methods involve either soaking the green seeds in hot water
(the “Swiss water process”) or steaming them, then using a solvent to dissolve caffeine-containing oils.
Often done by processing companies – the extracted caffeine is
usually sold to the pharmaceutical industry.
Coffee Nutrition
Typical chemical composition per 100 ml of coffee brew from medium roasted coffee.
Caffeine
50-380mg
Protein
100mg
Chlorgenic acids
35-500mg
Lipids (Fats)
0.8mg
Trigonelline
40-50mg
Lipids (Fats)
10mg
Soluble Fibre
200-800mg
Melanoidins
500-1500mg