W3 - L2 -Wheat Quality Flashcards
what is the purpose of wheat quality (4)
- Feed - non-ruminants
- Breadmaking
- ‘Biscuit’ making / many niche markets
- Seed
wheat quality has a very important part of what (2)
Wheat quality has a very important genetic part – varieties are suitable for certain uses and an equally important environment part – weather /
season / yield-protein balance
what % of wheat is utilised as Worldwide
* Human Food
* Livestock Feed
* Seed
* Other
- Human Food - 65%
- Livestock Feed - 21%
- Seed - 8%
- Other - 6%
Wheat and Grain Protein Content
for breadmaking
breadmaking – >11% at 15%mc
Wheat and Grain Protein Content
for biscuit
9-10% at 15% mc
Wheat Quality for Breadmaking (7)
- High flour extraction
- Good flour colour
- Good Protein Content
- Good Protein Quality
- Acceptable starch quality
- No sprouting
- Good breadmaking result
milling steps for breadmaking
- High flour extraction
- Good flour colour
baking steps for breadmaking
- Good Protein Content
- Good Protein Quality
- Acceptable starch quality
- No sprouting
what is the general criteria For Breadmaking
- requires acceptable protein content and protein quality
- NOTE - wheat has characteristically low protein content and high carbohydrate levels
what is the specific criteria for breadmaking
- 75-85% of the total wheat protein is in the gliadin and glutenin components of the storage protein : this is the gluten forming part
- the other 15-25% of the total protein is the non gluten forming proteins albumin and globulin
what is the gluten forming part of bread making
the gliadin and glutenin components of the storage protein
what % of protein is in the gliadin
and glutenin components of the storage protein
75-85%
what % of the total protein in the non-gluten forming proteins albumin and globulin
the other 15-25% of the total protein is the non gluten forming proteins albumin and globulin
what are the unique properties of wheat gluten (3)
- does not exist in the mature wheat kernel nor in the flour derived from wheat endosperm
- gluten is produced when the flour is mixed with water and subjected to a small mechanical input
- the gluten complex encloses gas cells created in the dough by yeast fermentation and being both gas retentive and extensible allows the
dough to rise
what does not exist in the mature wheat kernel nor in the flour derived from wheat endosperm
wheat gluten - unique properties
when is gluten produced
gluten is produced when the flour is mixed with water and subjected to a small mechanical input
what does the gluten complex enclose
encloses gas cells created in
the dough by yeast fermentation
what allows the dough to rise
the gas retentive and extensible allows the dough to rise
what are the key aspects of wheat gluten (4)
- Good breadmaking wheat varieties have strong gluten
- Higher protein content means more gluten content
- Gluten can be damaged by high temperature grain drying – protein is denatured
- Gluten quality has many lab tests to evaluate extensibility and elasticity and other properties
what sort of gluten has good breadmaking wheat varieties
strong gluten
what does high protein content mean
Higher protein content means more gluten content
what can gluten be damaged by?
what happens the protein
Gluten can be damaged by high temperature grain drying
The protein is denatured
what is gluten quality lab tests for
to evaluate extensibility and elasticity and other properties
Sprouting : alpha-amylase activity
and the Hagberg Falling Number Test
- the hagberg falling no. test measures the viscosity of a mixture of water and ground wheat (at high temp.)
- measures the level of alpha amylase enzyme present in the wheat sample
- excess alpha amylase results in bread with sticky crumb and poor texture ( as starch is broken down to sugar)
- Wheat with Hagbergs of 300+ are ideal for breadmaking, - min. of 220 secs ( key figure)
what does the hagberg falling number test measures
the viscosity of a mixture of water and ground wheat (at high temp.)
what will increase yield
Fertiliser Nitrogen use will
increase yield - e.g. apply
180-200 kg/ha for a 10 t/ha
grain yield
what is high N uptake required during grain fill for
High N uptake is required during grain fill for high grain protein % for good
breadmaking quality
what does early season N applications increase
yield
Later N applications primarily increases
protein
when are later timings for N applications
later timings are GS 39, 59, 69+ etc
what does each 40 kg/ha of N increase the protein content by what %?
0.5%
by what % does a programme combining mid season and late season applications lift protein content by?
up to 1%
what does the accompanying yield increases comfortably to cover the
cost of the?
the accompanying yield increases comfortably cover the cost of the applications and the increase in protein content is a bonus
why is Breadmaking wheat production in ireland a struggle
- We grow high yields
- High yield crops have lower grain protein
- A Classical Inverse relationship between yield and protein in wheat
- So farmer thinks why grow a ‘bread’ wheat if the protein will be too low (<10.5% protein)
- Breadmaking wheat varieties yield a few % less
- If wet summer / wet harvest – wheat crop starts to sprout and wont meet HFN standard – RISK
- For many farmers feed wheat is more profitable and price premium for quality is uncertain
what has higher yielding crops of wheat
why is it a struggle
have lower protein
- struggle for breadmaking
what sort of relationship is there between yield and protein in wheat
A Classical Inverse
what happens to wheat if there is a wet summer/wet harvest
wheat crop starts to sprout and
wont meet HFN standard – RISK
what is a good HRN number
225
- higher the number, the better - no sprouting
why is breadmaking wheat production in Ireland a good policy(5)
- Food security
- Local product for local market
- It can be done successfully – there are no technical barriers
- Focus would be more on spring wheat and production in the
south east – climatic advantages
o Spring wheat 7-9t/ha
o Winter wheat 14-15t/ha - Wholemeal flour
what are the challenges of breadmaking wheat production (3)
- Large scale international competition – cheap imported flour
- Weather uncertainties and risks in wet years
- Price premium uncertainties ( bread v feed wheat )
what is an irish grist
combination of wheats milled
together to make a flour
what % of a grist protein content do irish millers seek to maintain
11%
what does the make up of grist depend on
the make up of a grist will depend on the price and quality of the available wheat
how many wheats will a typical grist have
which ones are:
Low protein/ lower price
high protein
high price
a typical grist will have wheat from 4-5 sources
e.g. 15% Irish - low protein/lower price
10% English
25% French
20% German - high protein
30% Canadian / Eastern Europe - high price
Wheat Quality for Biscuit making (6)
- Low water absorption
- Low starch damage (soft milling)
- soft wheat is a feed wheat
- Moderate -low Protein Content
- Weak extensible dough
- Suitable protein quality/type
- Low-moderate sprouting (alpha/amylase)
difference between bread wheat and biscuit wheat
bread wheat:
- Hard wheat
– hard textured
- high water absorption
- high protein
- strong gluten
- high HFN (v low sprouting)
Biscuit wheat
- Soft Wheat
- soft textured
- low water absorption
- low to moderate Protein
- weak gluten
- moderate HFN
what does lower protein mean in terms of price
lower protein = lower price
higher protein = higher price
what sort of product is bread
bread is an energy product
what does more N mean for protein
more N = more protein
