2. Major factors for high production
2
1. Right Variety for given weather,
soil.. and other given conditions
2. Good environmental conditions
- Water –Irrigation
- Soil – fertilizer
- Prevention of harmful insects
- Good weather
- Weed control
------- etc
3. Major factors for high production
3
As a results, if we could produce 15% more than average
production.
We can say “Miracle!”
This is
“Primary
production”
4. 4
Simple Example of Rice Milling
Rice Milling system in South East Asia 2015
Rice Paddy → Brown Rice → Whitened rice
Head Rice + Large Broken
(35% ~ 50%)
Korea 72% vs 35~50% South East Asia
Believe or not !
5. 5
What is the Post-harvest technology ?
5
Objectives:
Minimize the loss of Agricultural Products during the post-
harvest(after harvest).
Learn related study which reduce the loss of agricultural Products.
Such as grain drying, storage, milling, …
vegetable storage, ….
6. Postharvest System Field
6
Major Field of Postharvest technology
•Cereal grain drying, storage, milling
•Feed processing technology and
•storage
•Food processing technology
•Storage of Fruits & Vegetables
•Design of agricultural processing plant
11. 1-3 Agricultural Mechanization in
Korea
Mechanization of rice farming: Spray Agricultural Chemicals
1990
2000
1970
2015
11
12. 1-3 Agricultural Mechanization in
Korea
Mechanization of rice farming: Combine Harvester
1970 Mower 1980 combine harvester with bags
2000
combine harvester
by bulk
12
15. 1-4 Traditional rice post-harvest
system
Farm mechanization program had started from 1965.
From the plowing operation to harvest were well done back to 1990.
However, post harvest of rice was far behind industry in Korea till 1990
.
Government policy maker thought;
- Weather of Korea during the fall is very good.
- Sun drying is very good.
- They underestimate importance of post harvest of rice.
15
16. 1-4 Traditional rice post-harvest
system
16
Cutting &
Threshing
Storage loss Milling loss
Average total
loss
1-2% 2-3% 4-6% 7-11 %
◆ Rice losses during the milling process by traditional system
◆ Max. possible milling rate : 72%
Milling rate by traditional milling system: 61 – 65%
17. Rice Drying, Storage and Milling Process Complex
Major process flow of RPC in Korea
17
25. 3-1Drying Theory-Basic concept
(4) Condition of Grain
a. Sound grain >> Unsound grain(Broken, fine, cracks)
** Moisture can easily move in and out.
** Insects or molds can be easily alive.
25
26. 3-1Drying Theory-Basic concept
(4) Condition of Grain
b. Environmental conditions
• Temp; by aeration wet spot
• Moisture: by drying
• Condition: by sorting & cleaning
26
27. (2) Safe Storage Period of Grains
◆ Moisture Content vs Safe Storage for General Cereal Grain
27
Moisture
%(wb)
Condition
15 Not safe for storage
14 Safe for storage , limited to winter months
13
Safe storage for one winter season
Hard to milling process.
Start to occur a rice crack and broken rice
12
Nearly 3 years but germination declined
A lots of crack occur
10
Good condition for 4 years storage
A lots of crack occur
** Criterion: visible mold growth
28. (2)Safe Storage Period of Grain
◆ Safety Storage Days and MC of Paddy Rice during the typical fall season in Korea
MC(%) 17 18 19 20 21 22
Safety Storage Period
(days), t = 15~25℃
25~30
days
15~20
days
15
days
10
days
3~5
days
0
days
28
29. 2. Type of drying
29
(1) Natural Air Drying
(2) Artificial air drying(heated air drying)
30. 2. Type of drying
30
2-1 Natural Air Drying:
1. takes long hours for drying
2. grain loss expect to occur
3. hard to uniform drying
31. 2. Type of drying
31
2-1 Artificial Drying:
1. Quick drying time
2. high cost for capital investment
and fuel cost
3. high temp. drying may cause
some problems such as crack.
** Temp. difference between the
surface and the inside of grain
35. 2-3. Dryer: In bin drying
35
Drying is the most economical way for
storage of grain, fruits, fish…
- It make possible to storage for long
period with low cost
- It is easy to regain
its taste & characteristics
even after the drying
39. 39
2-4. Rice milling
39
⑪ Color sorting
Removing the colored rice which are not white,
immatured rice, and rice having white belly...etc.
Basic concept of color sorter
