Lecture 7 Flashcards
What is the primary goal of processing grain?
The primary goal is to increase the digestibility of the starch
What is the basic structure of a cereal grain?
Fibre on the outside with starch on the inside. The starch is embedded within a protein matrix.
What are the ways to increase the starch digestion?
- Improve the enzyme efficiency (this is done through increasing starch hydration and the gelatinisation of the starch granules) 2. Expose endosperm to microbes and enzymes (cracking of pericarp and chemical treatments) 3. Increase the surface area that is exposed to microbes and enzymes (particle size reduction)
What does a hammer mill do?
Results in the shattering of the grain
What is clipping and what grain is it normally used for?
Normally used for oats and involves taking the end of
What species is chemical processing generally used for?
Generally used for ruminants.
What are the advantages of chemical processing?
1.Softens the grain husk 2.Doesn’t expose endosperm to rapid fermentation means lowered risk of acidosis 3.Reduced palatability means decreased risk of gorging
What are the potential disadvantages of using chemical processing?
- Cost 2. Reduced palatability 3. Potential toxicity
How does thermal processing improve enzyme efficiency?
- Increases starch hydration 2. Gelatinisation of starch granules
What three factors contribute to good pellet quality?
1.Sticky ingredients e.g. molasses 2. Sufficient time in conditioner to absorb moisture 3. Sufficiently high mash temperature
What is involved in the process of micronisation?
Grain is soaked then passed through an infrared burner and then rolled.
What is involved in the process of extrusion?
The feed is ground up. Then heat, moisture and pressure is added. These all function to improve the starch digestibility.
