NBA9 Food matrix and digestion: bioactive compounds

28 important questions on NBA9 Food matrix and digestion: bioactive compounds

What is the plant matrix integrity and carotenoids bioavailability?

  • Cell clusters
  • Isolated cells
  • Chromoplasts

Where is the carotenoids deposition

Carotenoids deposition forms in plant chloroplasts

The chromoplasts structure and carotenoids deposition; in which order are the carotenoid released?

Release of carotenoid in the order: globules-tubules > crystalloids > thylakoids

light micrographs of carrot root and mango, papaya, and tomato fruit mesocarp. Arrows mark chromoplasts.
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The chromoplasts structure and carotenoids deposition; in which order are the carotenoid released?

Release of carotenoid in the order: globules-tubules > crystalloids > thylakoids

light micrographs of carrot root and mango, papaya, and tomato fruit mesocarp. Arrows mark chromoplasts.

Carotenois depositon forms in animal tissue, where can it be found?

  • Found in
    • eggs
    • milk and cheese
    • liver
    • salmon and prawns
  • bioavailability higher than carotenoids from plant

Carotenois depositon forms in animal tissue, where can it be found?

  • Found in
    • eggs
    • milk and cheese
    • liver
    • salmon and prawns
  • bioavailability higher than carotenoids from plant

The dietary modulators of carotenoids bioaccessibility: in fat

Olive oil

The dietary modulators of carotenoids bio accessibility: in dietary fibre

Image
  • ideal carotenoid micellaurization
  • limited access of lipase by pectin coatings
  • BS binding by pectin
  • Calcium-pectin interaction

What is the digestion of FUOH and FX?

P = digestion with pancreatin

P+O = digestion with lipase inhibitor orlistat

-P = digestion without pancreatin

Carotenoids esters

hydrolysed in free carotenoids by:

  • Cholesterol esterase
  • Pancreatic lipase
  • Membrane bound esterase

Which (poly)phenolics are there?

  • Non-flavanoids
    • phenolic acids
    • lignans
    • stilbenes
  • flavanoids
    • flavonols
    • flavones
    • isoflavones
    • flaconones
    • flacan-3-ols (flavanols)
    • anthocyanins

How are dietary polyphenols digested

Small intestine
  • hydrolysis of most glycosides (LPH, CBG)
  • conjugation reactions (methylation, glucuronidation, sulfation)


not absorbed --> colon
  • action of bacterial enzymes (alfa-rhamnosidases)
  • --> feces


aglycones from the small intestine and colon go to the liver
  • conjugation reactions
    • methylation
    • glucuronidation
    • sulfation

The microbial metabolism of flavanones

Absorption form the colon
  • 4-hydroxyhippuric acid
  • hippuric acid

What is the microbial metabolism of polyphenols

Relatively few intermediates and end-products
  • benzoic acid derivatives (from ring B)
  • Phenyl propionic acid and phenyl acetic acid derivatives (from ring B and phenolic acids)
  • phensyl Valerie acid and phenyl y-valerolactone derivatives (from ring B)
  • Phloroglucinol derivatives (from ring A)

Polyphenols up on consumption of Green tea

microbial metabolism in the gut increases bioavailability and change pharmacokinetics of phenolics!

in the large intestine the orange peak will come and go to the (liver)

Bioavailability of polyphenols; the stability in the GI tract

The larger the tmax the longer it took to go to the large intestine and by bacteria made available.

However you would expect phloroglucinaldehyde to have a higher tmax. So with this lower tmax the absorption took already place in the small intestine
  • some polyphenols are unstable and spontaneously decompose in SI, e.g. Anthocyanins

What is the bioavailability of polyphenols: interaction with the DF

  • Encapsulated
    • polyphenols may be entrapped in intact cells. Fraction released depends on the fraction of broken cells!
  • Cross-linked
    • polyphenols may be covalently bound to cell walls (e.g. Ferulic and p-coumaric acid in cereals). They are not released in SI!
  • Absorbed
    • after release from broken cells upon mastication or grinding, polyphenols rapidly and strongly interact with the DF in cell walls (or DF from other foods)

Polyphenols can have an interaction with proteins and starch

  • Polyphenols interaction with dietary protein, digestive enzymes and starch
  • HMW polyphenols (e.g. Tannins) interact more strongly

What is the physiological role of phenolic compounds during digestion?

  1. Reduce bioavailability and digestibility
  2. Inhibition of nutrients/bioactive oxidation
  3. Inhibition of lipid oxidation

How can you reduce the bioavailability and digestibility [physiological role of phenolic compounds during digestion]

  • Inhibition and precipitation of digestive enzymes
  • Interaction with dietary proteins/peptides and starch
    • shielding form enzymes
    • precipitation of hydrolysis products


Beef+ fruits&vegetables --> highest AID [apparent ill digestibility] compared to beef AND beef + phenolic extract from fruit&vegetables

The inhibition of nutrients/bioactive oxidation, how does this go [physiological role of phenolic compounds during digestion]

Bioavailability of oxygen sensitive compounds may be affected by the oxygen level in the GI-tract. O2 levels decrease from 58 Torr (stomach) to 3 Torr (distal colon).

BMT is some kind of antioxidant (as are pholyfenols)

The inhibition of lipid oxidation, how does this go [physiological role of phenolic compounds during digestion]

Polyphenols may protect from harmful secondary oxidation products:
  • inhibit formation in the stomach of secondary oxidation products (malondialdehyde, MDA; 4-hydroxynonenal, HNE)


LDL oxidation
Cell membrane oxidation

What are the factors affecting minerals bioavailability? In the chemical form

  • Chemical form of the mineral: e.g. Soluble organic slats/complexes > soluble inorganic salts > insoluble inorganic salts
  • Ex. Heme iron (animal foods) vs non heme iron (plants)

soluble organic complexes increase the bioavailability > soluble organic salts > soluble inorganic salts > insoluble inorganic salts

What are the factors affecting minerals bioavailability? In the chemical form

  • Chemical form of the mineral: e.g. Soluble organic slats/complexes > soluble inorganic salts > insoluble inorganic salts
  • Ex. Heme iron (animal foods) vs non heme iron (plants)

soluble organic complexes increase the bioavailability > soluble organic salts > soluble inorganic salts > insoluble inorganic salts

What are the factors affecting minerals bioavailability? In the structural integrity of plant tissues


iron and spinachbreakdown of cellular structures - frozen & vacuum-dried

digestion of cellular structure
  • fresh (no enzyme)
  • fresh (0.06% pepsin)
  • fresh (0.19% pepsin)

What is the impact of freeze dried?

Fast and slow freezing


fast freezing, no breaking of the cells

slow freezing, cells will brake --> more braking is beer bioavailability

What are the factors affecting minerals bioavailability? In digestive modulators?

  • Limited by insoluble, non-absorbable chelators: dietary fibre, oxalate, polyphenols, phytates, etc
  • Enhanced by soluble, absorbable chelators: certain peptides, phytoferritin, ascorbic acid, etc.
  • Modulated by competition between minerals for absorption

Which of the following statements is wrong?
  1. bioavailability of parent polyphenols is as high as 90-95%
  2. cooking spinach with butter increases beta-carotene bioavailability
  3. polyphenols interact with digestive enzymes in the GI tract
  4. bioavailability of carotenoids is higher in tomato juice compared to paste

  1. bioavailability of parent polyphenols is as high as 90-95%

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