Post-harvestLosses of Grain

Definitions

‘Loss’ is a measurable decrease of the foodstuff whichmay be quantitative or qualitative.

‘Damage’ generally refers to the superficial evidence ofdeterioration, e.g. broken grains (which may laterresult in loss).

Loss precludes utilisation, damage inhibits utilisation.

TYPES OF LOSS

.

- Quantitative loss.

- Qualitative loss.

Farm production

-Cultivation practice-Irrigation-Weather-etc.

QualityQuantity

-Impurity-Moisture content-Milling yield

-Cultivation practice-Harvesting-Drying-Storage

-Paddy output/area

GAP

Weight loss•Weight loss results from the feeding of insects, rodentsand birds or from spillage, due to improper handling or bythe activities of pests.

• Moisture changes may lead to an increase in weight andin some cases production of water by and insectinfestation may partly offset the weight loss. In manyinstances weight loss may go undetected as the tradersells by volume.

Loss in quality

• Appearance, shape, size,

• Contaminants include soluble excretions of pests, oils,pesticides, pathogenic organisms spread by rodents, andtoxins arising from fungal infections.

• Chemical changes: the free fatty acid level leading torancidity in the oil.

Nutritional loss•Rodents and moth larvae: attack the germ of the grain thusremoving the protein and vitamin content, the carbohydratecontent.

• Many pests may eat the bran of cereals reducing vitaminssuch as thiamin.

• Moisture and fungal infection also lead to changes invitamin content.

Loss of seed viability

Loss in seed germination.

Insects that selectively attack the germwill cause a greater loss in germination than others.

Commercial losses

a) Monetary loss:Weight loss is an economiclossb) Loss of goodwill

c) Loss due to legal action

Sources of losses1.Mechanical Damage2.Heat3.Moisture4.Insect Pests5.Microorganisms6.Rodents7.Birds

Post-harvest losses of grains may occur inthe following areas:

• during harvesting• during transportation• during drying• during threshing• during processing• during storage

The postThe post--harvest pipeline for maize. harvest pipeline for maize.

Level of loss during post-harvest system

• Field drying and harvesting• Transport• On-farm drying• Threshing/shelling and cleaning• Milling• Storage• Marketing

Rice Post harvest Rice Post harvest ManagementManagement

Case study: Thai riceCase study: Thai riceByBy

ProfProf.. Athapol NoomhormAthapol NoomhormAsian Institute of TechnologyAsian Institute of Technology

F Rice is harvested from field in form of paddy.

Main Component:F HuskF BranF KernelF Mainly starchF AmyloseF Amylopectin

(Mixture of 2 starches determine cooking texture of rice.)1.Husk

2.Pericarp3.Seed coat 4.Aleurone layer 5.Endosperm 6.Scutellum7.Germ

3 Main Varieties

FIndica (long grain) : warm climate belt,Indochina, Thailand, India, Pakistan,Brazil

FJaponica (round grain) : cold climate,Korea, Japan, Northern China, and California

FJavanica (Medium grain) : only grown in Indonesia

FF Rice is largely produced and consumed in AsiaRice is largely produced and consumed in Asia..

FF In In 2000,2000, World paddy production was over World paddy production was over 590590million metric tons million metric tons ((MMTMMT),), or about or about 350350 MMT MMT milled rice basismilled rice basis..

FFOnly Only 2323 MMT MMT (6(6--7%)7%) ---->> Trade InternationallyTrade Internationally

FF Asia shared over Asia shared over 90%.90%. Paddy is usually kept by Paddy is usually kept by farmer for household consumption or for next farmer for household consumption or for next season seed or emergency savingseason seed or emergency saving,, what is left is what is left is sold to local market for extra cashsold to local market for extra cash..

FF Top Top 33 rice producers are Chinarice producers are China,, India and India and Indonesia Indonesia ((combined to over combined to over 60%).60%).

FF Top Top 33 rice exporters are Thailandrice exporters are Thailand,, Vietnam and Vietnam and USA USA ((combined to over combined to over 50%).50%).

FF Top importers vary every year among IranTop importers vary every year among Iran,, ChinaChina,,IndonesiaIndonesia,, JapanJapan,, Brazil and Malaysia Brazil and Malaysia ((each about each about 11 MMTMMT).).

åThailand produced about 23.33 million tons (MT)paddy, which converted to about than 13 MT milled rice.

åOf this 13 MT milled rice,å60% --> local consumption or processing å40% --> exported in term of unprocessed rice.

å Thailand still prohibit exportation of paddy.

ø about 9.2 M Ha

ø 6 plains : upper northern, lower northern,central, upper northeastern, lower northeastern, southern

ø Different soil condition and climate:- each plain grow different rice variety

with different quality.

øø about about 9.29.2 M HaM Ha

øø 66 plains plains :: upper northernupper northern,, lower northernlower northern,,centralcentral,, upper northeasternupper northeastern,, lower lower northeasternnortheastern,, southern southern

øø Different soil condition and climateDifferent soil condition and climate::-- each plain grow different rice variety each plain grow different rice variety

with different qualitywith different quality..

• Upper northern plain:• used to grow high quality glutinous rice. "Snake fang”

• Lower northern plain:• second largest production plain • Currently Thai Fragrant rice is grown here.• mainly grows main crop with some parts capable to grow second or third crop.

• purely produces white rice and fragrant rice.

• Central plain:• largest production• can produce up to 3 crops per year• mainly for export

•• Upper northern plainUpper northern plain::•• used to grow high quality glutinous riceused to grow high quality glutinous rice.. ""Snake Snake fangfang””

•• Lower northern plainLower northern plain::•• second largest production plain second largest production plain •• Currently Thai Fragrant rice is grown hereCurrently Thai Fragrant rice is grown here..•• mainly grows main crop with some parts capable mainly grows main crop with some parts capable to grow second or third cropto grow second or third crop..

•• purely produces white rice and fragrant ricepurely produces white rice and fragrant rice..

•• Central plainCentral plain::•• largest productionlargest production•• can produce up to can produce up to 33 crops per yearcrops per year•• mainly for exportmainly for export

• Upper northeastern and lower northeastern plain:• produce same rice.• famous for Fragrant rice and glutinous rice.•due to poor weather and soil condition, it produce far less rice than the other plains.

• Southern plain:• smallest rice growing area • only for regional consumption

•• Upper northeastern and lower northeastern plainUpper northeastern and lower northeastern plain::•• produce same riceproduce same rice..•• famous for Fragrant rice and glutinous ricefamous for Fragrant rice and glutinous rice..•• due to poor weather and soil conditiondue to poor weather and soil condition,, it it produce far less rice than the other plainsproduce far less rice than the other plains..

•• Southern plainSouthern plain::•• smallest rice growing area smallest rice growing area •• only for regional consumptiononly for regional consumption

i Majority of Thai rice is grown during main crop,which starts planting between July-September,depending on climate, area, and variety.

i Traditional varieties yield about 25-35 tang/rai (1 tang is 10 kg, 1 rai is 1,600 m2., calculated = 2.2 MT/Ha).

i Recently, with modern allegation and better variety, some areas can attend 90-100 tang/rai (5.6-6.25 MT/Ha).

i This is still far less than Chinese or American standard but Thai people is happy with our result.

i High quality Thai rice is longer in grain and whiter in milling. -----> Jasmine RiceJasmine Rice and ChainatChainat

i total estimated paddy production is 23.33 MT --> about 80% is grown during main crop, the rest is grown in second or third crop.

i Over 90% of rice field is flooded field. Small percentage is hilly field which will not be discussed here.

i Total growing time, from seeding to harvesting is 100-160 days depending on field and variety.

Land preparationLand preparationLand preparation

Seed preparationSeed preparationSeed preparation

PlowingPlowingPlowing

CastingCastingCasting

RestingRestingResting

DrainingDrainingDraining

HarvestHarvestHarvest

• Harvesting practices, especially referred to by hand, machine and when long field exposure of the crop may result in heavy infestation by insects pests and damage by rodents, .

The magnitude of losses in traditional methods of field drying and harvesting varies greatly from country to country.

It could be as less as 5 percent for relatively drier areas, to 50 percent

HarvestingHarvestingby humanby human

Manual threshingManual threshing

ThreshersThreshers

HarvestingHarvesting by by machinemachine

JJ Harvest at Moisture content Harvest at Moisture content 2121--2424 %%------>> Highest Head YieldHighest Head Yield

JJ Combine Harvester about 3,000 Combine Harvester about 3,000

JJ Road condition and Transportation Road condition and Transportation ProblemProblem

Relationship between paddy moisture Relationship between paddy moisture content at harvest and content at harvest and %% head yield head yield

Transport

Losses due to transport of the crop to, within, and off-farm depend on:

• Type of transport facility used

• Efficiency of transport facility

• Quantity of crop transported

• Ground conditions and surface of the terrain, etc.

Transport losses are generally small, ranking 1 to 2 percent.

The complexity of the rice supply chain

• Adulteration• Risk to damage• High logistics

cost

Development of transportation model of rice supply chain system

Farm (Paddy production)

Middleman

Rice mill

Pick up truck 4 wheels truck 6 wheels truck

10 wheels truck

6 wheels truck 10 wheels truck

Trailer truck

Transportation model

Table 4.20: The data of transportation for calculation Transportation cost (baht/Trip)

Engine Volume Max. Load a+b*W+(c+d)*2D+[(e*D*W+f*2D)*F] Vehicle

Mode (cc.) (m3) (ton) a b c d e f

Pick up 2,500 3.57 2 20 15 1.77 0.31 0.0167 0.0667

4 wheel truck 4,000 8.86 6 25 15 1.77 0.31 0.0069 0.0833

6 wheel truck 6,000 14.36 10 30 15 2.00 0.31 0.0033 0.1667

10 wheel truck 7,900 34.31 15 35 15 3.60 0.31 0.0027 0.1818

Trailer >8,000 68.62 21 125 15 3.40 0.31 0.0018 0.2326

Transportation cost (baht) = [a+b*W+(c+d)*2D+ ((e*D*W+f*2D)*F)]*n Whereas; a = Weighing charge (baht/trip) b = Unloading charge (baht/ton) c = Maintenance +Depreciation (baht/km.) d = Driver cost (baht/km.) e = Fuel consumption (liter/km./ton) f = Fuel consumption (lit/km.) W = Weight (ton) D = Distance (km.) F = Fuel Price (baht/lit) n = Trip

• Newly harvested paddy (21-24%mc) -->reduce moisture < 14% to prevent damage during storage and processing

Moist Paddy(20-24 %)

Heat

WaterWater

Low moisture paddy( < 14 %)

Factors in DryingFactors in Drying•• Hot Air TemperatureHot Air Temperature•• Grain TemperatureGrain Temperature•• Evaporation rate at surfaceEvaporation rate at surface

On-farm drying

Traditional drying methods can cause:

• The crop is exposed to proliferation of fungi, moulds and bacteria and soil reducing its quality.

• The crop is also exposed to attacks of domestic animals and birds causing qualitative and quantitative losses.

• Estimation of losses in traditional drying and storing in a raised barn for up to 4-5 months has been between 7 to 14 percent. Improved drying technique, as the crib, can reduce losses losses mainly due to fungi and insects in approximately 2 percent. Average on-farm drying losses are 3 -6 percent.

Sun Drying Sun Drying

•• Low costLow cost•• Slightly effect on head yieldSlightly effect on head yield•• Cannot operate in raining season Cannot operate in raining season --

-->> use dryeruse dryer

Sun DryingSun Drying

Mechanical Dryer

•• Use hot Air Use hot Air -------->> remove water form remove water form paddypaddy

•• Should clean paddy before dryingShould clean paddy before drying

•• Tempering Tempering ------> reduce energy consumption > reduce energy consumption and %breakageand %breakage

Foreign MatterForeign MatterCleanerCleaner

Dryer Chamber

Control unit of Flowing

Bucket conveyorBucket conveyor

Dried GrainDried Grain

Recir

culate

dRe

circul

ated

Moist GrainMoist Grain

Batch-in-bin dryer

Continuous-flow dryer

Recirculating batch dryer Rice DyersRice Dyers

Column DryerColumn Dryer

Good storage practices prevent rice quality loss byGood storage practices prevent rice quality loss by::

•• keeping rice below a moisture which corresponds to keeping rice below a moisture which corresponds to a a 65%65% equilibrium relative humidityequilibrium relative humidity,,

•• keeping rice temperature within keeping rice temperature within 1010ooF of the F of the average monthly air temperature and below average monthly air temperature and below 6060ooF as F as long as possible during the yearlong as possible during the year,,

•• designing and operating aeration system to maintain designing and operating aeration system to maintain uniform rice moisture and temperatureuniform rice moisture and temperature,,

•• storing only well cleaned ricestoring only well cleaned rice..

Milling ProcessingMilling Processing

MillingThe milling operation produces: husk, milled rice, germ, bran and broken, coming out as mixed products, depending on the rice mill used. The ideal moisture content for milling is 14 percent, as wet soft grain results in a powdery product, while very dry brittle grains result in broken and powdery material.

Causes of losses during milling include:

• incorrect adjustment of milling equipment

• spillage in traditional hand-pounding and

• under- or over-dried paddy

Complete Rice MillComplete Rice Mill

~The largest Thai industry in term of number of factory is rice milling. There are over 20,000 rice mills of various sizes.

~Smaller ones mills 10-20 MT paddy per days.

~Larger ones are 100-200 MT paddy per day with the largest one of few thousand MT paddy per day.

~White rice, glutinous rice and fragrant rice are milled similarly.

7 % Loss

3% Impurities

20% Husk

10% Bran and tips

3% 7% 9%Broken

48% Head Rice

CleanerCleaner

Foreign matter separatorForeign matter separator DeDe--stonerstoner

HuskerHusker

Brown Rice

Paddy

Whitener

StorageStorage losses depend upon the following:

• Physical factors, e.g. damage during harvesting, transportation and shelling. This make maize susceptible to attacks by insect pests, mites and moulds

• Temperature and humidity may encourage mould formation and create conditions for insect population growth. The losses could be: minimal in cool dry areas, marked in hot dry areas, high in cool damp conditions and very high in hot damp climates.

• Type of storage structures or containers used

• Duration of storage

• The storage management effected prior to and during storage.

Bulk StorageBulk Storage

Bag Bag StorageStorage

MarketingBefore marketing and consumption, grain is subjected to a whole range of loss-agents discussed above as a result of which the following attributes get affected:

• Reduction in Quantity and quality of the crop

• Reduction in nutritive and germinative attributes

• Reduction in commercial and economic value

The traceability system of rice supply chain

Traceability in rice supply chain

Seed Company

- Seed Company ID - Variety - Genetic Traits

Seed Lot

Producer

- Producer ID - GAP Data

Producer Grain

Seed Lot

Elevator

- Elevator ID - Grain Mix Record - Storage Data

Elevator Grain Lot

Producer Grain

Seed Lot

Rice Mill

- Mill ID - Receiving Record - Processing Data

Milled Rice Lot

Producer Grain Lot

Seed Lot

Elevator Grain Lot

Certified seed Tag data

GAP Certificate of Analysis

Grain test

RFID application in traceability system

Diagram of connection of RFID, software and database part

Transponder (Tag)

Data

Identification Data

RFID Part

Verify data from reader

Reader

Connect with database

Data

Software Part

Specific Data

Database

Database Part

Data from database

Show user data

Writing the data onto RFID tag

• Rice variety• Receiving

month• Receiving date• Group of

quality• Rice type• Sizing

Quality Check ListQuality Check List::•• Percentage of ImpurityPercentage of Impurity

•• Appearance and Yield of Brown RiceAppearance and Yield of Brown Rice

•• Moisture ContentMoisture Content

•• Milling Yield Milling Yield (%(% Total and Head YieldTotal and Head Yield))

From surveying, most of rice mill will evaluate quality of paddy in physical properties.

Quality Equipment CheckingF Percentage of

ImpurityF Paddy Cleaner F Sampling 200 g of paddy and

put in cleaner, Weigh thecleaned paddy and calculate%Impurity

Quality Equipment CheckingF Percentage of

ImpurityF Paddy Cleaner F Sampling 200 g of paddy and

put in cleaner, Weigh thecleaned paddy and calculate%Impurity

Quality Euipment CheckingF Appearance

and yield ofbrown rice

F Rubber Roll Husker F Sampling 200 g of paddy,remove husk by husker, weighand check appearance ofbrown rice

Quality Euipment CheckingF Appearance

and yield ofbrown rice

F Rubber Roll Husker F Sampling 200 g of paddy,remove husk by husker, weighand check appearance ofbrown rice

Quality Euipment CheckingF Moisture

ContentF Moisture Meter

(Resistance orCapacitance type)

F Sampling paddy and measuremoisture content usingmoisture meter

Quality Euipment CheckingF Moisture

ContentF Moisture Meter

(Resistance orCapacitance type)

F Sampling paddy and measuremoisture content usingmoisture meter

Quality Euipment CheckingF Milling Yield F Whitener (Abrasive

or Friction type)F Sampling paddy 100 g and put

in whitener, mill paddy 30-35sec and separate broken forwhole kernel by grader, weighand calculate milling yield

Quality Euipment CheckingF Milling Yield F Whitener (Abrasive

or Friction type)F Sampling paddy 100 g and put

in whitener, mill paddy 30-35sec and separate broken forwhole kernel by grader, weighand calculate milling yield

64.58+

/-1.26b

65.85+

/-1.05b

63.52+

/-1.84a

61.79+

/-3.11a

596061626364656667

Total

Yield

(%) .

2nd Crop Main Crop KDML105 Sticky Rice

64.58+

/-1.26b

65.85+

/-1.05b

63.52+

/-1.84a

61.79+

/-3.11a

596061626364656667To

tal Yi

eld (%

) .

2nd Crop Main Crop KDML105 Sticky Rice

38.26+/-3.28b

37.11+/-3.30b

30.80+/

-4.98a

36.92+/-4.05b

28

30

32

34

36

38

40

42He

ad Yi

eld (%

) .

2nd Crop Main Crop KDML105 Sticky Rice

38.26+/-3.28b

37.11+/-3.30b

30.80+/

-4.98a

36.92+/-4.05b

28

30

32

34

36

38

40

42He

ad Yi

eld (%

) .

2nd Crop Main Crop KDML105 Sticky Rice

64.28+

/-1.28b

64.11+

/-0.91b

62.64+

/-1.67a

61.79+

/-3.30a

59

60

61

62

63

64

65

66To

tal Yi

eld (%

) .

2nd Crop Main Crop KDML105 Sticky Rice

64.28+

/-1.28b

64.11+

/-0.91b

62.64+

/-1.67a

61.79+

/-3.30a

59

60

61

62

63

64

65

66To

tal Yi

eld (%

) .

2nd Crop Main Crop KDML105 Sticky Rice

43.69+

/-3.45b

43.76+

/-2.52b

42.74+

/-3.12b

40.23+

/-3.31a

35

37

39

41

43

45

47He

ad Yi

eld (%

) .

2nd Crop Main Crop KDML105 Sticky Rice

43.69+

/-3.45b

43.76+

/-2.52b

42.74+

/-3.12b

40.23+

/-3.31a

35

37

39

41

43

45

47He

ad Yi

eld (%

) .

2nd Crop Main Crop KDML105 Sticky Rice

• Rice production and quality are affected by:• Varieties• Climatic and seasonal difference• Management practices in field and off field

• Processing method ie. drying, storage and milling

• The infrastructure of all involved agencies should be linked to come up with the efficiency of the the rice production system in three sections;

• Marketing• Production • Processingto meet the objectives of the higher yield with better quality.

• The existing technology on both harvesting and postharvest should be improved for better performance.

• The quality of paddy, milled rice and by products should be clean and safe.

• The added value of rice products should be developed.

• Plane and policies of rice production,marketing and processing should be established.

For the successful of handling for rice production, it is not drying operation, the different areas of research studied should be cooperated and investigated as the following area:

• Paddy Harvest and Post-harvest process

• Paddy procurement

• Paddy Drying

• Paddy storage at rice mills

• Milling Technology

• Parboiling

• Grading Standard

• Rice Processing Machinery

• Products and by-product utilization

• Information System

Interpretation of broken in milled rice

Specifications

• 14% Moisture Content (MC) • 95% purity • Not more than 7% damaged and yellow kernels • Rice varieties • Free from infestation

Laboratory Test method for Milled rice

The laboratory grading based on the following factors for quality assessment:

•Moisture Content•Impurities and Foreign matter•Damaged and Yellow Kernels

•Immature and chalky Grains

•Red Rice

•Varietals Purity

TEST METHODS

1. Preparation of working sample:1.1 Pass the representative sample at least three

times through a laboratory mixer or divider to ensure homogenous mixing.

1.2 Prepare the following working samples for three trials for each test.

1.2.1 For Paddy Grading3 - 150 gms. - for moisture content determination 3 - 100 gms. - for purity determination3 - 100 gms.-for immature, chalky, discolored, damaged and red kernels3 - 250 gms.- for potential milling recovery

The laboratory grading based on the following factors for quality assessment:

•Moisture Content•Impurities and Foreign matter

•Damaged and Yellow Kernels

•Immature and chalky Grains•Red Rice

•Varietals Purity

For Milled Rice Grading

3 -150 gms. - For moisture content determination3 - 100 gms. - for headrice, brokers and brewers3 - 100 gms. - for discolored, damaged, red, red streaked, chalky, immature and foreign matter

Moisture Content Determination:

• Determine the moisture content from the 150 gram sample using a properly calibrated moisture tester appropriate for the grain being tested,

• or use standard air-oven method or any other method which gives equivalent results. (The weight of the working sample may vary depending upon the requirement of the moisture tester.)

PADDY GRADING

Purity Determination

• Using the 100-gram paddy working sample, separate the weed seeds using a sieve.•Pass the remaining paddy twice through a laboratory aspirator to separate other impuritiessuch as chaffs, hulls, stones, stalks,weed seeds, etc.

• Gather and weigh all the impurities except the weed seeds. •Sorting out of weed seeds and other impurities can also be carried out manually by handpicking.

Calculate the following % using the following formula:

Determination of Potential Milling Recovery

• Aspirate more than 250 gram working sample and weigh 250 grams (capacity of laboratory mill) of the pure paddy.

• Dehull the pure paddy and mill the resulting brown rice to well milled rice using a laboratory testing mill

• Weigh the resulting milled rice and calculate the percentage milling recovery

Milling recovery = Wt. of milled rice x 100

Wt. of paddy

Rice Milling Test Machines

TESTING HUSKER• The Satake Testing Husker

is designed to provide rapid, accurate results in determining husking yields. It is manufactured to meet the requirements of laboratories, research and educational institutions.

TEST MILL

• The Satake Testing Mill is a compact and handy machine that can be used to determine the approximate total white rice recovery in the whitening process. The machine is widely used throughout the world, especially in laboratories, research stations and educational institutions.

THICKNESS GRADER

• The Satake Testing Thickness Graderis designed for use at a laboratory and rice mills for grading grains according to their thickness. It can be used for paddy, brown rice and milled rice by simply changing the hexagonal cylinder.

RICE GRADER

• The Satake Testing Rice Grader provides easy operation and precision grading. Accurate results are provided in the shortest possible time. The machine also features rapid indented cylinder replacement.

Rice Milling Meter

• Satake Corporation has developed a new milling meter that simultaneously measures the degree of milling, comparative whiteness and degree of transparency of milled rice samples.

• This advanced measuring system uses both reflected and absorbed light, producing far greater accuracy than can be obtained with conventional whiteness meters, which measure only reflected light.

Testing Dryer

• The machine is designed for drying samples of grain. Up to 48 separate samples of grain can simultaneously dried by means of hot air (a smaller 24 sample machine is also available).

Handy Moisture Meter

• This newly designed automatic temperature calibration device eliminates troublesome correction work for both ambient and grain temperature. The display shows the average value of the measure. The machine can measure the moisture content of paddy, brown rice, polished rice, barley, wheat and naked barley. The measuring range is 10%-40% (depending on product).