Time for coffee and tea
The dietary fiber content of coffee
Research carried out by Elena and Saura-Calixto at the Instituto del Frio in Spain took a look into the amount of dietary fiber that can be passed from coffee bean into the coffee drink. They took a look into the amount of soluble dietary fiber that was passed into coffee using different preparation and brewing methods. the three main methods of preparation were espresso, Filter coffee and Instant coffee.
The results from the research showed that brewed coffee has a large amount of soluble dietary fiber. Interestingly it was found that instant coffee contained a higher amount (0.75g per 100 ml) than espresso (0.65g per 100 ml) or filter coffee (0.47g per 100ml). This is thought to be as a consequence of the 200 degrees celsius temperatures that are used to extract soluble compounds from roasted coffee in the production of instant coffee. This results in a coffee that becomes totally soluble in hot water, whereas grinds from filter coffee need to be discarded. Interestingly it was found that coffee has a higher amount of dietary fiber than that what is found in either wine or orange juice.
In Europe the average dietary fiber intake is in the range of sixteen to twenty one grams per person every day. As a standard cup of coffee contains from half to three quarters of a gram of soluble dietary fiber it can be seen that people who drink three or four cups of coffee a day may be getting as much as 15% of their dietary fiber intake from coffee.
The two main types of dietary fiber constituents in brewed coffee are galactomannan and arabinogalactan II. It was found that galactomannan made up 70% of the dietary fiber found in roasted coffee. Additionally the authors of the paper found that brewed “coffee contained significant amounts of [sic] polyphenols”; these are well known for their antioxidant properties. The authors therefore hint that as dietary fiber is associated with these polyphenols that their presence may also help to explain some of the known antioxidant properties associated with drinking coffee.
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