Parboiled rice (from the English words partially boiled) is a kind of rice that has undergone a special treatment allowing to increase the rice content of microelements (vitamins and mineral salts), this process is scientifically called as hydrothermal process that may be defined as the gelatinization of starch within the rice grain. It has almost the same nutritional value as brown rice It will be enabling to achieve a better final cooking behaviour.
Necessity is the mother of invention
More than 1000 years ago Parboiling was done in simple clay pots in the earth to improve shelf life and resistance against insects. A first big boost to Parboiling production was given during World War II when the need to supply the troops with long term storage and high nutritional level foodstuff was imperative. Nowadays Parboiled rice is by far one of the most popular rice products in the world. Over the past few years’ people consume Parboiled rice in countries like U.S.A, Europe, and Nigeria and Asian countries.
Different types of parboiled rice can be prepared
The different process solutions the grains undergo, allow the millers to select specific process parameters to match different production requirements. It is therefore important to know what impact the different kinds of processes will have on different Paddy varieties and on the quality of the final product.
Different Types of Parboiling Rice :
1. Single Stage Single Steaming
Process :
Hot water filled in Soaking Tanks
Paddy fed to Soaking Tanks from Bin
Soaking in Hot water
Draining the water
Steaming
Discharge to Drier
2. Single Stage Double Steaming
Process :
Paddy fed to Soaking Tanks
Pre Steaming in Soaking Tanks
Soaking in Ambient water
Room Temperature water fed to Soaking Tank
Draining the water
Post Steaming in Soaking Tank Discharge to Drier
3. Three Stage Double Steaming
Process :
Paddy fed to Small Vessels from Bin
Pre Steaming in Small Vessels
Steamed Paddy fed to Soaking Tanks
Soaking in water
Draining the water
Soaked paddy Fed o small vessels
Post Steaming small vessel Discharge to Drier
Color :
Crystal White
Medium yellow
Golden parboiled
Another positive effect of parboiling is that rice turns out to be far more resistant to pest infestation since the steaming process sterilizes the grains so that they can be preserved longer. Parboiled rice satisfies even the most demanding consumer expecting perfect rice even in case of overcooking.
Through the lower release of starch in cooking stage, Parboiled grains do not stick together, are well separated and can be reheated without loosing their original characteristics. For these reasons Parboiled rice has met over the years an increasing success among consumers and it is by now among the simplest and versatile products the modern food industry might offer.
Advantages of Parboiled Rice :
Parboiled rice is 80% nutritional
The process imparts a hard texture and a smooth surface finish to the grain as a result which the broken in the milled rice is minimized
Insects find it more difficult to bite and eat their way through the hard and smooth surface of parboiled rice
The loss of solids in the gruel during cooking is also less in parboiled than in raw rice
Milled Parboiled rice contains more of B-vitamins than milled raw rice
Loss of B-vitamins is less in Parboiled rice, during washing and cooking, compared to that in raw rice
The cooking quality is different from that of raw rice. Parboiled rice is non-sticky and non-glutinous
Parboiled rice bran is relatively stabilized compared to raw rice
Through the lower release of starch in cooking stage, Parboiled grains do not stick together, are well separated and can be reheated without loosing their original characteristics. For these reasons Parboiled rice has met over the years an increasing success among consumers and it is by now among the simplest and versatile products the modern food industry might offer.
The Parboiling Process :
1. Pre Steaming
Paddy is subjected to steam before soaking. This process of pre steaming softens the achieve desire colour of Parboiled rice. It reduces the soaking time of the paddy, It also increases the capacity of Parboiled rice to absorb water during cooking.
2. Soaking
The paddy is soaked in the water Tank for a specific time and temperature for specific variety of Paddy. Special care is taken while paddy soaking in Hot water/Room temperature, with water circulation in between soaking time as different varieties requires different water temperature prevailing weather condition. This process increases vitamin B in rice and decreases percentage of broken grain in it. It also improves hardness of Par boiled rice which retains its shapes even after cooking.
3. Pre Steaming
The soaked paddy is then transferred to the steaming vessel where it is kept at a certain temperature for short time and discharged to drier. Steaming can change the Physical structure of Paddy and keep the nutrition to increase the production ratio and make Paddy easy to store or drying. It improves grain length and uniforms the colour of Parboiled rice.
