Transcript Document 7213657

Course
Module 3
Exercise
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
INFORMATION COLLECTION
Characteristic
Sample 1
Moisture content [%]
Oven
Meter
Grain dimensions [LW]
1000-grain weight [gm]
Degree of dockage [%]
Inert
Weeds
Insects
Cracked grains [%]
Discolored grains [%]
Immature grains [%]
Sample 2
Sample 3
Average
Course
Module 3
Lesson 1
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
The quality characteristics
Course
Module 3
Lesson 1
:
:
:
Grain Quality
Determining the Physical Characteristics of Paddy Rice
The quality characteristics
PADDY CHARACTERISTICS
List of characteristics
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Course
Module 3
Lesson 1
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
The quality characteristics
QUALITY CHARACTERISTIC: MOISTURE CONTENT
Moisture content has a significant
influence on all aspects of paddy
quality. To obtain high yields, it is
essential that paddy be milled at the
proper moisture content.
Paddy is at its optimum milling
potential when its moisture content
is 14%
Course
Module 3
Lesson 1
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
The quality characteristics
QUALITY CHARACTERISTIC: IMMATURE
Immature rice kernels are very
slender and chalky and result
in the production of excessive
bran, broken grains and
brewer’s rice
Course
Module 3
Lesson 1
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
The quality characteristics
QUALITY CHARACTERISTIC: VARIETAL PURITY
A mixture of varieties in a sample of
paddy causes difficulties in milling
and usually results in reduced milling
capacity, excessive breakage, lower
milled rice recovery, and reduced
head rice yields.
Course
Module 3
Lesson 1
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
The quality characteristics
QUALITY CHARACTERISTIC: DOCKAGE
Dockage includes chaff,
stones, weed seeds, soil, rice
straw, stalks and other foreign
matter. These impurities
generally come from the field
or from the drying floor.
Course
Module 3
Lesson 1
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
The quality characteristics
QUALITY CHARACTERISTIC: DISCOLORED
Water, insects and heat exposure
can cause paddy to deteriorate
through biochemical changes in the
grain which may result in the
development of off-doors and
changes in physical appearance
Course
Module 3
Lesson 1
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
The quality characteristics
QUALITY CHARACTERISTIC: CRACKED
Overexposure of mature paddy
to fluctuating temperature and
moisture conditions leads to the
development of crack in
individual kernels.
Course
Module 3
Lesson 2
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring moisture content
OVEN METHOD
This method weighs a sample
of the paddy and then removes
all the moisture by heating the
sample in an oven. After the
moisture has been removed,
the sample is re-weighed.
Course
Module 3
Lesson 2
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring moisture content
MOISTURE METER
This method weighs a sample of the paddy and then removes all
the moisture by heating the sample in an oven. After the moisture
has been removed, the sample is re-weighed.
Course
Module 3
Lesson 3
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring grain dimension and varietal purity
VARIETAL PURITY
Crops of a single variety are easier to manage because they
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have uniform stands
fill uniformly
ripen at the same time
Milling a mixture of varieties results in:
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reduced milling capacity
excessive breakage
lower milled rice recovery
reduced head rice yields
A measure of varietal purity is the L-W ratio of the grain
Course
Module 3
Lesson 3
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring grain dimension and varietal purity
Grain
Length (mm)
Width(mm)
1
2
3
4
5
6
7
8
Length to width ratio (L/W)
9
10
11
=
12
13
14
15
16
17
18
19
20
Total
Average [total/20}
[A]
[B]
Average paddy length [A]
Average paddy length [B]
Course
Module 3
Lesson 3
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring grain dimension and varietal purity
REVIEW
1.
2
3.
4.
Course
Module 3
Lesson 3
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring 1000-grain weight
1000-GRAIN WEIGHT
Procedure
1. Count 1000 grains of
paddy.
2. Weigh the 1000 grains.
3. This is the 1000-grain
weight.
Course
Module 3
Lesson 4
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring the amount of dockage
PADDY PURITY - DOCKAGE
Procedure
1. Weigh a sample of paddy (about 100gm) [A].
2. Separate the dockage from the paddy.
3. Weigh the dockage [B].
% Dockage =
Dockage in a paddy rice sample – less is better.
Wt of dockage [B]
Total wt of sample [A]
X 100
Course
Module 3
Lesson 4
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring the amount of dockage
DOCKAGE TYPES
Procedure
1.
2.
3.
4.
5.
Weigh a sample of paddy (about 100gm) [A].
Separate the insects from the paddy.
Separate the weed seed from the paddy.
Separate the inert material from the paddy.
Weigh the types of dockage [B], [C], and [D].
% Insects =
% Weedseed =
% Inertmaterial =
Wt of insects [B]
Total wt of sample [A]
X 100
Wt of weed seed [B]
Total wt of sample [A]
Wt of inertmaterial [B]
Total wt of sample [A]
X 100
X 100
Course
Module 3
Lesson 5
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring the percentage of cracked grain
CRACKED GRAIN PERCENTAGE
Crack detector
Procedure
1. Select a sample of about 25gm of paddy and weigh it [A].
2. Separate the cracked grains from the paddy.
3. Weigh the discolored grains [B].
% Cracked grains =
Wt of cracked grains [B]
Wt of sample [A]
X 100
Course
Module 3
Lesson 6
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring the percentage of immature grain
IMMATURE GRAIN PERCENTAGE
Procedure
1. Select a sample of about 25gm of paddy and weigh it [A].
2. Separate the immature grains from the paddy.
3. Weigh the immature grains [B].
% Immature grains =
Wt of immature grains [B]
Wt of sample [A]
X 100
Course
Module 3
Lesson 7
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Grain Quality
Determining the Physical Characteristics of Paddy Rice
Measuring the percentage of discolored grain
DISCOLORED GRAIN PERCENTAGE
Procedure
1. Select a sample of about 25gm of paddy and weigh it [A].
2. Separate the immature grains from the paddy.
3. Weigh the immature grains [B].
% Immature grains =
Wt of immature grains [B]
Wt of sample [A]
X 100
Course
Module 3
Review
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Grain Quality
Quality of paddy
QUIZ ANSWERS
1. Any four of moisture content. Varietal purity, cracked grain, immature
or discolored
2. Air-oven method, using moisture
3. All foreign matter in he paddy sample. Weeds, insects, stones, inert
4. The length width ratio is used because it measures varietal purity
5. Yellowing or black spots through change in the