The Bio Basics Guide to Parboiled Rice

Answers to FAQ on Parboiled Rice
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How to use this Guide

This part of the Bio Basics Guide Series addresses all your questions related to Parboiled Rice.

If you are short of time, simple head to The “Quick Guide” section. Scroll over and click on your burning question to get quick, concise answers.

However, if you wish to get more details, or you have more time at hand, you could go over to the “Detailed Guide” section. You can also access detailed answers to questions from within the Quick Guide by clicking on “Read more” available at the end of every short answer.

We hope you will enjoy discovering answers to all your questions and clear all your confusion ranging from difference between parboiled rice and red rice, how to cook it, nutrition related information, etc.

Parboiled rice is paddy that is partially boiled, dried and then milled.

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The parboiling process involves soaking the grain, then draining the water out and cooking the paddy within the husk. It is then sun-dried to remove the moisture.

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Parboiling results in the starch within the grain becoming gelatinised and then hardening again, giving it a translucent appearance.

Cooked parboiled rice is firmer and less sticky, and has better food and nutrition value.

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Thiamine (or Vitamin B1) deficiency unknown in communities consuming unpolished parboiled rice.

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In double boiling, the steaming process is repeated a second time after soaking paddy post first boiling.

Double boiled rice takes longer to cook, but is said to have an even lower Glycaemic Index than parboiled rice.

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Yes, “Idli rices” (like Ambasamudram Idli Rice) are parboiled rice varieties. The general practice is to use parboiled rices for making idli. However, idli can be made out of raw rice or even millets.

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Yes, red rice (also synonimously called “brown rice”) is much much more nutritious than polished white rice.

The red bran layer contains almost 95% of the minerals and dietary fibre contained in the rice. This invaluable portion of paddy is completely lost when rice is fully polished.

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Yes. Parboiled rice (like raw rice) can be processed into unpolished (red / brown) rice, semi-polished rice and fully polished (white) rice.

Unpolished red / brown rice is the most nutritious, and polished white rice is the least nutritious.

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Polished white rice, although nutritionally deficient, became popular because it can be kept longer without going rancid. This is due to removal of the bran, which, is nutrient-rich, but is vulnerable to insect attack and rancidity.

But today, many have come to realise short-comings of fully polished rice and are switching to healthier red / brown rice.

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To look up research papers, documents  and articles related to parboiled rice click below

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Detailed Guide

What is Parboiled Rice?

Parboiled RiceWhen paddy is partially boiled, dried and then milled, the resultant rice is called par boiled rice. So, the word “Parboiled” is a combination of the words partial and boiled.

Parboiled rice is said to have a lower Glycaemic Index compared to its raw rice counterpart.

How is Parboiled Rice Made?

The parboiling process involves the following:

  1. Soaking the grain.
  2. Draining the excess water
  3. Steaming the soaked paddy within the husk and very little water
  4. Sun-drying to remove the moisture
  5. Hand-pounding or milling to remove husk.

These days, rice mills have steam cookers in which the par boiling process is undertaken without too much manual effort.

Parboiling improves the nutritional profile of the rice and also made it easier for the traditional hand pounding. Because it makes the rice harder there is less breakage.

For an in-depth reading of the parboiling process click here

What happens during a Parboiling process?

The process of parboiling causes the nutrients to move from the bran to the endosperm. It results in the starches within the grain becoming gelatinised and then hardening again. This results in the rice getting a translucent appearance and makes it hard.

The result that it makes the cooked rice firmer and less sticky, resulting in grains of the steamed rice being distinct and separate. Parboiled rice is also proven to have better food and nutrition value.

 

Is Parboiled Rice more nutritious?

In the 19th century, it was discovered that sailors who consumed parboiled rice escaped beriberi whereas their compatriots who consumed raw rice were inflicted by the dreaded deficiency disease. Beriberi is a disease caused by a deficiency of vitamin B-1. This is also known as a thiamine deficiency. This disease is documented to be unknown in communities consuming unpolished parboiled rice.

Parboiling causes in the nutrients to move from the bran to the endosperm. Parboiling results in the starches within the grain becoming gelatinised and then hardening again. This results in the rice getting a translucent appearance and makes it hard. It also makes the cooked rice firmer and less sticky resulting in grains being distinct and separate. Par-boiled rice has proven to have better food value.

What is “Double Boiled Rice”?

The process of parboiling rice can  be undertaken at two levels of boiling.

  • Parboiling: Boiling is undertaken only once. Gelatanisation takes place, but to a lower level.
  • Double boiling: After first boil, paddy is once more soaked in water. After draining the water, paddy is steamed once more. It is then dried and milled.

Double boiling results in higher level of gelatinisation. The rice gains are much more translucent, compared to parboiled rice.

Most people in Kerala prefer the double boiled rice. This takes longer to cook, but provides a firmer grain and is said to have an even lower Glycaemic Index than parboiled rice.

 

Is Idli Rice a Parboiled Rice?

Ambasamudram Parboiled Idli Rice
Ambasamudram Parboiled Idli Rice

The general practice is to use parboiled rices for making idli. Therefore, “Idli rices” (like Ambasamudram Idli Rice) are parboiled rice varieties.

However, it is not an essential rule that idli can be made only of parboiled rice alone; raw rice can also be used to make idli. For that matter, even millets can be used as a partial or complete replacement of rice for making idli and dosa.

As a general rule, use of unpolished rice (raw or parboiled), or unpolished millets will result in healthier idlis.

Is Unpolished (Red) Rice more nutritious?

Brown Rice vs White Rice - Nutrient ComparisonTraditionally, paddy is used after hand pounding. This leaves most of the bran intact, and gives it the red colour. Today, milling of rice is almost completely machinery driven. However, results similar to hand pounding can be still obtained by reducing the polishing. This is effected by managing the spacing between the rollers of the rice mill

This nutrient rich grain, full of fibre and energy giving starch, sustained many a generation of our ancestors.Conservation initiatives of traditional rice varieties have established beyond doubt that, traditionally, red rice (also synonymously called “brown rice”) that was grown in the Southern Peninsula of India.

The red bran layer contains almost 95% of the minerals and dietary fibre contained in the rice. This invaluable portion of paddy is completely lost when rice is fully polished. For an exhaustive read on nutrition of red rice, read the following:

  1. Brown Rice – Hidden Nutrients
  2. Brown Rice-Beyond the Colour Reviving a Lost Health Food – A Review

There are two other not-so-well-known economic and ecological benefits of using red rice:

  1. Avoiding polishing and whitening, reduces the energy requirement for milling by up to 65%.
  2. Since the bran and the nutrient-rich embryo is intact, there are fewer broken grains. Therefore, rice recovery from paddy is higher than white rice, by up to 10%.

Red rice has a nutty flavour. The world over, consumption of red rice is on the increase. Those of us who complain that the red colour is daunting would do well to remind ourselves that if we choose to use red rice with bran, we don’t need to run away from rice in fear (of getting diabetes or of becoming over weight).

Are there Unpolished  (Red) Parboiled Rices ?

Rice categorisationLike raw rice, parboiled rice can also be processed into the following types:

  1. Unpolished Rice: Where the bran is left intact with no polishing. They are also referred to as red or brown rice.
  2. Semi-polished Rice: Where part of the bran is removed, retaining anything from 30% to 70% of the bran. These are generally off-white or yellowish in colour.
  3. Polished Rice: Where no bran or germ is left on the rice. These are white in colour.

It goes without saying that nutrition and fibre content reduces in the same sequence, with unpolished rice having the most and polished rice having the least.

In that case, why is Polished White Rice so popular?

Polished rice became popular because it can be kept longer without going rancid. Unpolished and semi-polished rice has oil naturally found in the bran, which makes them more attractive to insects and also causes rancidity. This results in reduced shelf life of unpolished / semi-polished rice once milled .

Unpolished and semi-polished rice is also more expensive, because millers sell the nutritious bran removed from fully polished rice for making other products (including nutritional supplements that we pay exorbitant amounts for). And we now consume rice bran oil, purportedly to get those same nutrients that are naturally available in semi-polished and unpolished rice but removed from polished white rice.

Therefore, fully polished rice is a result of convenience and low cost trumping over better health and plain common sense.

But today, there is an increasing segment of the population that have come to realise these short-comings of fully polished rice and understand that it devoid of nutrients.

 

References & Further Reading

  1. Brown Rice – Hidden Nutrients. PA, Vetha varshini, K, Azhagu sundharam and P, Vijay Praveen. 2013. s.l. : Journal of Bio-science & Technology, 2013, Vol. 4(1), pp. 503-507.
  2. Brown Rice-Beyond the Color Reviving a Lost Health Food – A Review. Babu, P Dinesh, et al. 2009. s.l. : IDOSI Publications, 2009, 2009, American-Eurasian Journal of Agronomy.
  3. McKevith, Brigid. Nutritional aspects of cereals. British Nutrition Foundation. [Online] https://www.nutrition.org.uk.
  4. Ministry of Human Resource Development, Govt. of India. Parboiling of Rice. [book auth.] E-PG Pathshala. Food Science & Nutrition.
  5. Nutritional and medicinal values of some indigenous rice varieties. Rahman, Shakeelur, Sharma, MP and Sahai, Suman. 2006. s.l. : Indian Journal of Traditional Knowledge, October 2006, Vol. 5(4), pp. 454-458 .
  6. Rice in Health and Nutrition. Rohman, et al. 2014. [ed.] 13-24. s.l. : International Food Research Journal 2, 2014, Vol. 21(1):.
  7. Whole Grains. The Nutrition Source. [Online] Harvard Chan School of Public Health. https://www.hsph.harvard.edu/nutritionsource.
 Milagi Semi-polished Parboiled Rice

Milagi Semi-polished Parboiled Rice

 Sigappu Kavuni Semi-polished Parboiled Rice

Sigappu Kavuni Semi-polished Parboiled Rice

 Mapillai Samba Par-boiled Red Rice

Mapillai Samba Par-boiled Red Rice

 Kullakar Par-boiled Red Rice

Kullakar Par-boiled Red Rice

 Thondi Par-boiled Red Rice

Thondi Par-boiled Red Rice

 Uma Par-boiled (Kerala Red Rice)

Uma Par-boiled (Kerala Red Rice)

 Khichdi Samba Parboiled Semi-polished Rice

Khichdi Samba Parboiled Semi-polished Rice

 Kalanamak Semi-polished Parboiled Rice

Kalanamak Semi-polished Parboiled Rice