Parboiling involves partial boiling of the paddy before milling it. Parboiling not only loosen the hulls of the grains, but it also increases the nutritive value of the milled rice.
Drying of paddy reduces the grain moisture content to a safe level for storage and improves the shelf life of the paddy. Therefore, it is important to dry the paddy within 24 hours of harvesting. With the innovation and technology in the milling industry, there are a lot of processes of parboiling and drying of paddy.
Let's have a look at them.
Different Process of Parboiling
Process for single boiled rice i.e. white belly rice involves:
Pre-cleaning
De-stoning
Transfer to overhead bins
Discharge raw paddy into temperature water in soaking tanks
Remove chaff and immature grains floating on the water surface
Soak for 6 to 12 hours
Circulate the water drain and tempering for 2 hours
Steam the paddy for 1-2 minutes
Discharge the paddy quickly from steaming tank into the cooler
Dry the paddy in drier
Unload the paddy to a storage bin
Process for double-boiled rice i.e. fully translucent rice
Pre-cleaning
De-stoning
Transfer to overhead bins
Discharge raw paddy into temperature water in soaking tanks
Steam for 5 minutes
Add water to steamed paddy
Circulate the water for 30 minutes
Remove floating chaff
Soak for 12 to 24 hours (depending on the variety of rice)
Drain the water and temper for 2 hours
Unload the paddy to a storage bin
Steam the paddy for 1 to 2 minutes after steam emergence
Discharge the paddy from the steaming tank into a cooler
Dry the paddy in Drier
Parboiling rice requires less time to cook. Therefore, it is important to do so. And, most of the milling industries offer parboiled rice.
Different Process of Drying of Paddy
As mentioned above, the primary purpose of the drying of paddy is to reduce the moisture content of the rice grain. High moisture levels in the grain will increase the temperature and accelerate mold growth and reduces starch and sugar content.
There are two methods of drying
Sun Drying
Mechanical Drying
Sun Drying: In this process, paddy is dried by keeping it under the sun for at least, 2 to 3 days.
Mechanical Drying: In this process, paddy is dried at 100-degree Celcius of hot air until the on-line moisture meter shows 20%. Reduce the hot air temperature to 80 degrees till the paddy moisture percent falls to 13%.
Final Thoughts
Both parboiling and drying of paddy are important to ensure the highest quality of rice. Depending on your requirements, you can choose the best process for yourself.
Nextech Solutions is the leading rice mill consultant in India and we offer complete grain milling solutions along with rice mill machinery solutions.
