Minor components of grains Flashcards
What is the role of phytic acid in grains? where is it found typically?
1) storage form of phosphorous (not bioavailable)
2) chelating agent
-found in the bran
Phytic acid binds to minerals and proteins, reducing nutrient absorption.
Why phytic acid classified as an anti-nutritional factor? what is its problem in the animal industry?
its chelating abilities bind to nutrients and minerals to make them bio-unavaible
In addition it:
-mitigates starch and protein digestion (cross links proteins + fibers)
-mitigates mineral digestion
in the animal industry it is an issue as many animals eat grains, this can increase risks of deficiency (decreased feed conversion efficiency)
What is the affect of phytase?
phytase cleaves ester bonds to release phosphate + inositol (vitamin)
What are the benefits of sprouting grains?
- Breaks down phytic acid
- Releases minerals
- Improves digestibility (enzyme release during germination)
- Increases nutrient bioavailability
What is the importance of phenolic compounds in grains? how are they typically found?
they act as antioxidants
-found bound (travel with dietary fiber to apply antioxidant effects)
What is the difference between free and bound phenolic acids?
- Free phenolics: Readily available; minor portion
- Bound phenolics: Most abundant form; require fermentation or enzymatic treatment to release
What effect does ferulic acid have on arabinoxylan?
Reduces solubility of AX
Impairs xylanase action and limits fiber functionality.
How do phenolic-protein interactions affect digestibility?
They form complexes that reduce protein digestibility by inhibiting protease access
In cereal-based food products, what is the functional effect of cross-linked arabinoxylan?
It forms insoluble, rigid networks, reducing water absorption and impairing dough rheology
What benefit does enzymatically released ferulic acid offer beyond dough improvement?
It can act as an antioxidant, contributing to gut health when fermented in the colon
What vitamins are primarily found in grains?
- B-complex vitamins (e.g., thiamine, riboflavin, niacin, folate)
- Vitamin E (tocols)
What are the anti-nutritional factors in grains?
- Sterols
- Lignans
- Saponins
- Tannins
- Lectins
- Trypsin inhibitors
How can you induce enzyme secretion in cereal grains?
By germination/sprouting
What tissue in grains is responsible for enzyme secretion?
The aleurone layer
