National Agricultural Research Institute
Copies of this leaflet can be obtained from:
Parboiling of Paddy Rice
The Publications Section
National Agricultural Research Institute
Wet Lowlands Mainland Programme
PO Box 1639
LAE 411
Morobe Province
Telephone: (675) 475 1033/475 1228
Facsimile: (675) 475 1034
Email: [email protected]
NARI TOKTOK
RGP008
April 2003
PARBOILING OF PADDY RICE
Benefits of parboiling
Parboiling of paddy rice:
Introduction
Parboiling is a method used to partially cook
the paddy rice prior to storage, milling and
consumption. Parboiling gelatinizes the starch
within the rice grain, causing it to swell and fuse.
In the process, the paddy is soaked, steamed
and re-dried before milling. This process
greatly affects the milling, storage, cooking and
eating qualities of rice. Parboiling can be
mechanized or carried out in simple traditional
forms.
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prolongs storage life
allows easier dehulling of the grains
makes the grain harder
produces less brokens during milling
reduces insect attack on the grain
increases vitamin B content of grain
is prefered by some people for its taste
Caution
To parboil your paddy, follow the steps below.
Parboiled paddy cannot be used as seed so
put aside some seeds before heating the
grains.
Step 1: Soak the paddy in water
Acknowledgement
Soak the paddy in water to increase the
moisture content to about 30–35 %. This can
be done in a ½ cut 44-gallon (200 Litre) drum
overnight.
Thanks to Carolyn Pia’afu and Katleen
Terrence, both of the PNG University of
Technology, Lae for help received.
Use 50kg of paddy with 2 buckets of water.
Do not use more water because the grains
might germinate in the process.
Compiled by Joel G. Waramboi
Rice and Grain Programme
April 2003
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Step 7. Milling of parboiled paddy
Step 2: Producing hot steam
Milling can be done using the traditional motar
and pestle method called “tongtong”. You can
also use commercial mills if available.
Heat enough water in another ½ cut 200L drum.
Place 3-5 sheets of banana leaves on the
mouth of the drum to create a leaf-joint.
Source: McInnes, D (1998), Rice from seed to food.
Trukai Industries Pty Ltd, page 23
Milling should be done with the aim of getting
a higher head rice yield. This means that the
milling process should give you more whole
milled grains with less % of broken grains.
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Source:
FAO, (1994), Improved upland rice farming systems,
Rome, page 107
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Step 3: Steaming of paddy
Step 6. Storing of parboiled paddy
Place the drum containing the soaked paddy
on-top of the banana leaves. Steam the paddy
for 10-15 minutes.
Store the paddy in a dry place. Do not mill all
of them in one go because the milled rice may
go bad during storage. You can use bags, metal
bins, plastic containers, drums or cementplastered bins.
Do not steam for too long to avoid complete
gelatinization and discoloration of the grains.
Step 4: Cooling of paddy
Drain off the water in the drum. Remove the
parboiled paddy and pour them onto a dry
canvas.
Make sure they are clean and dry before use.
The storage medium should also be able to
keep out water, rats and insects.
Cool them slowly. Let excess water to drain
off from the paddy.
Step 5: Drying of parboiled paddy
Slowly dry the rice in the sun to 13% moisture
content. Drying should be done for at least 6
hours per day for 5 days.
Turn the paddy every 1-2 hours to ensure even
drying of the grains. You can use a smooth
wooden plank do this.
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