Selected Non-Nutrients Flashcards
What are non-nutrients?
Substances that may occur in the diet and may have an affect on our health even though they are not nutrients
What type of compounds may have advantageous health effects when obtained in small doses?
Some toxic compounds found in plants
Name four selected non-nutrients.
- Phenols
- Polyphenols
- Sulphur containing compounds
- Alkaloids
What are phenols?
Hydroxyl group bonded to an aromatic hydrocarbon group
Where are phenols found?
In smoked foods
What can phenols act as?
Antioxidants
Phenols donate a ______ forming _______
Hydrogen
Radicals
What are polyphenols?
Compounds with more than one phenol ring
What rings in polyphenols are labelled A and B?
The two aromatic phenolic rings
What ring in polyphenols is labelled C?
The central heterocyclic ring
How do polyphenols differ from each other?
The oxidation status of the central heterocyclic ring
What are polyphenols also known as?
Flavonoids
What are polyphenols generally presented as in the diet?
Glycosides
Why do plants develop multiple polyphenols?
In response to stresses
- Against pathogens
- Against UV light
Name four polyphenols.
Flavanols
Flavonols
Isoflavones
Anthocyanidins
Give an example of a flavanol and name a source.
Catechin
Sources = wine, apples
Given an example of a flavonol and name a source.
Quercetin
Sources = onions, green tea
Give an example of an isoflavone and name a source.
Daidzein
Sources = soy beans, soy milk
Given an example of an anthocyanidin and name a source.
Cyanidin
Sources = blackcurrants, strawberries
How are interacting glycosides absorbed?
Interacting glycosides interact with transporters on the duodenum resulting in absorption
Name two interacting glycoside.
Glucoside
Galactoside
How are non-interacting glycosides absorbed?
They pass to the colon where they are degraded by bacterial glycosidases
Once hydrolysed it is absorbed
Name a non-interacting glycoside.
Rutinoside
What is a longitudinal study?
A study which follows subjects over time with continuous monitoring
What is a cross-sectional study?
A study which measures the health of a population at a specific time
Name three studies which looked at the relationship between polyphenol intake and CHD.
Zutphen Elderly study
Finish study
Caerphilly study
What is the oxidative hypothesis of disease?
Elevated free radicals and oxidative stress can lead to continuous damage of important biomolecules
What evidence of oxidative stress can be seen in the body?
CHD
Diabetes
Ageing
Neuro-degenerative disease
How do some phenols and polyphenols provide protection against disease?
The suppress radical-generating enzymes
They scavenge free radicals
They protect antioxidant vitamins
What are terpenes?
A selected non-nutrient that is fat soluble
What is the structure of a basic terpene unit?
Unsaturated branched five carbon chain
What is a six unit terpene called and what are its functions?
Triterpene
- Some boost the immune system
- Some are important in the eye (lutein and zeaxanthin)
What is an eight unit terpene called and what are its functions?
Teraterpene
- Sterols
- Stanols = reduce cholesterol absorption in the gut
What is cafestol and what is its function?
A terpene extracted only by the prolonged boiling of coffee
- Reversibly increases LDL cholesterol levels
Where are sulphur containing compounds found?
Onions
Chives
Garlic
When and how are sulphur containing compounds produced?
Enzymatically when tissue is damaged
How can the production of sulphur containing compounds be limited?
By soaking or cooking in vinegar
What do alkaloids contain?
Nitrogen
Name three alkaloids.
Caffine = mild stimulant
Quinine = anti-malarial
Solanum alkaloids = in potatoes - high levels produce a bitter taste and GI symptoms
