Flashcards
Grain Quality
Cards in this deck (31)
- 1how are grain cleaners different from gravity separatorswork using sieves rather than vibration
- 2malting barley requires...low N <1.65% hence get on early
- 3skinning is...the loss of hull from barley - bad!
- 4why is skinning badcan cause grain to go mouldy
can cause too early germination or not at all if endosperm is lost - 5what can gravity separation improve?HFN and specific weight
Germination - removes poor germinating seed - 6disadvantage to gravity separatorscan lose good grains just because they're small
slow and expensive - 7a grain contains...starch
protein
non starch polysaccharides (sugar)
lipids - 8wheat germ is in wholemeal flour, a disadvantage of this is...high oil content so can go rancid
- 93 components of wheat qualityprotein
HFN
specific weight - 10Protein quality determined by...genetics
- 11protein concentration determined by...genetics and N
- 12Hard or soft depends on...how starch is held in protein matrix
- 13hard ideal for bread as it...hold more water
- 14Friabilin - difference between hard and softHard - doesn't work so can crack across starch grain causing protein damage hence holds more water
Soft - becomes friable hence allows easy separation of starch grains - 15HFN is...a measure of alpha amylase activity
- 16HFN is a indicator of...sprouting
- 17Alpha amylase does what?degrades starch into simple sugars
- 18Starch Hydrolysis...detects alpha amylase
- 19what is used in starch hydrolysishydrolytic enzymes
- 20what do hydrolytic enzymes do?they break down the large storage molecules into smaller, active molecules
- 21what does the starch breakdown do...produces alpha amylase
- 22HFN should be greater than...250seconds
- 234 reasons for low HFN...post maturity sprouting
pre-maturity alpha amylase
pre maturity sprouting
retained pericarp alpha amylase - 24why should milling wheat be harvested first?to reduce possibility of rain after dormancy break
- 25what triggers pre maturity alpha amylasecool shock - approx. 12C at flowering
- 26what causes pre maturity sprouting?OBM damage or prolonged rain in early grain growth
- 27retained pericarp alpha amylase occurs when...in late tillers, hence green grains harvested
- 28how can retained pericarp alpha amylase levels be reduced?glyphosate prior to harvest
storage - 29why would green areas of a crop be harvested separately?to reduce risk of spoiling whole crop due to high retained pericarp alpha amylase levels
- 30specific weight is..a simple measure of weight to volume
- 31low specific weight is caused by..lack of starch from a lack of sun
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- PHT Flashcards on Grain Quality, created by labradorlass on 06/06/2013.
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- labradorlass
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