Rice bran is the most perishable thing a rice mill sells. Once the bran layer is milled off the grain, natural enzymes begin breaking its oil down into free fatty acids, so the age and handling of a lot matter as much as where it came from. Buy against a specification written for your use, oil extraction or feed, sample the lot properly, test it promptly, and agree in advance how freshness will be judged at delivery.
Key takeaways
- Free fatty acids (FFA) in raw bran can rise quickly after milling, so the time from milling to use belongs in the specification.
- Specify by use: oil content and FFA for solvent extraction; protein, fat, fibre, acid-insoluble ash and aflatoxin for feed.
- BIS IS 3648:2024 sets two grades for rice bran used as a livestock feed ingredient.
- Sample from many points, seal and time-stamp the sample, and test it quickly.
In this guide
What rice bran is
Bran is the outer layer of the grain, together with the germ, removed when brown rice is whitened. The Bureau of Indian Standards describes rice bran for feed as the pericarp or bran layer and germ of rice, with only as much hull fragment and broken rice as is unavoidable in regular milling. At SONIK, bran is recovered during whitening and polishing and sold in bulk for oil extraction and feed compounding. The whitening step is described in our guide to Sortex, grading and polishing.
Why freshness decides value
Milling breaks the cells of the bran layer and brings fat-splitting enzymes, lipases, into contact with the oil. The oil then breaks down into free fatty acids, which reduce the yield and quality of edible oil and make the bran rancid. Published research reports FFA in unstabilised bran rising by roughly 1 to 7% a day under favourable conditions, and a widely cited threshold treats bran with more than 5% FFA as unfit for human food use. The rate depends on temperature, moisture and handling, which is why no one can promise a fixed shelf life for raw bran.
Bran from parboiled paddy behaves differently. Parboiling heats the grain before it is milled, and as our comparison of parboiled and raw rice explains, that inactivates the enzymes that break down fats in the bran layer. An older BIS standard, IS 9867, even treats parboiled rice bran for feed separately. Specify which kind of bran you are buying.
Specify by use
| Point | For solvent extraction (rice bran oil) | For feed compounding |
|---|---|---|
| Main concern | Oil yield and oil quality | Nutrients, and safety for animals |
| Parameters to state | Oil content, FFA, moisture, sand and silica | Moisture, crude protein, crude fat, crude fibre, acid-insoluble ash, aflatoxin B1 |
| Reference | Your plant’s own acceptance criteria | BIS IS 3648:2024 for rice bran; IS 3593 for de-oiled bran |
| Freshness | Maximum time from milling, or maximum FFA on arrival | Free from rancid smell or taste, mould and insects |
For feed, BIS IS 3648:2024 sets these requirements:
| Characteristic | Grade 1 | Grade 2 |
|---|---|---|
| Moisture, max | 10% | 10% |
| Crude protein, min | 13% | 11% |
| Crude fat, min | 15% | 12% |
| Crude fibre, max | 10% | 12% |
| Acid-insoluble ash, max | 5% | 8% |
| Aflatoxin B1, max | 20 ppb | 20 ppb |
Acid-insoluble ash is mostly sand and silica, so a high figure often points to husk, dust or soil in the bran. It is a useful check on how cleanly the bran was separated, whatever the end use.
Sampling and testing
- Draw from many bags or many points in a heap, top to bottom, and mix before dividing. For feed, IS 3648 points to the sampling method in IS 2052.
- Seal and label each portion with the lot, the date and the time of sampling, and keep a counter-sample.
- Test FFA as soon as you can, because it keeps changing in the sample bag. Record the time between sampling and testing.
- Use a laboratory accredited for the tests you need, and name the methods in the contract.
Handling and delivery
Because raw bran keeps changing, plan collection close to milling, keep it dry and cool, and avoid holding it in large warm heaps. Fix in the contract how freshness will be judged at delivery, for example an FFA limit tested within an agreed time, rather than relying on a word such as “fresh”. When bran is supplied to IS 3648, the standard calls for clean, dry, sound jute or HDPE bags, marked with a batch number, the date of packing and a best-before date.
Bran is one of several streams from a paddy lot; our milling recovery guide shows how it fits with husk, broken rice and finished rice.
Frequently asked questions
Can a supplier guarantee FFA on arrival?
No supplier controls what happens to raw bran after collection, and FFA rises with time and temperature. What both sides can agree is the basis: when and where the sample is drawn, the test method and the acceptance limit.
Is de-oiled rice bran the same product?
No. De-oiled, or solvent-extracted, rice bran is what remains after the oil is extracted, and it has its own BIS standard, IS 3593. This guide is about bran as it leaves the rice mill.
SONIK sells rice bran in bulk from its mill at Ghentugachhi. Send your intended use, quantity in MT, packing or loading requirement, destination and the parameters you test through the bulk enquiry form.
Sources
- Bureau of Indian Standards. IS 3648:2024, Rice bran as livestock feed ingredient: specification.
- Dubey, B., Fitton, D., Nahar, S. and Howarth, M. (2019). Comparative study on the rice bran stabilization processes: a review. Research and Development in Material Science 11(2).
- Agriculture and Natural Resources 55 (2021), 816–825. Study of rice bran stabilisation, lipase activity and free fatty acid content.
