Food-grade tamarind kernel powder is refined to remove more of the seed coat, made under food hygiene controls and tested for microbes, aflatoxin and contaminants. Textile-grade TKP is sold mainly on viscosity, colour and price, and is not made or tested as food.
Both start from the same tamarind seeds. The differences lie in seed selection, how well the kernel is cleaned, the plant's hygiene and the paperwork that comes with it.
How the grades are made
Processors heat or roast the seed so the hard brown coat (testa) can be separated from the kernel. The kernel is then broken and ground. In textile grades, some coat often remains, giving a light brown or speckled powder. Food or refined grades are cleaned more thoroughly, sometimes with further purification of the polysaccharide.
Key differences
- Purity: food grades aim for little or no seed coat. Textile grades tolerate more.
- Colour: food grades are usually whiter. Textile grades are often off-white to light brown.
- Hygiene: food grades come from plants with a food safety system and an FSSAI licence. Textile plants may not have either.
- Testing: food grades are tested for microbiology, aflatoxin, pesticides and heavy metals. Textile grades usually are not.
- Performance: textile grades are judged on paste viscosity, film strength and wash-out.
- Documents: food grades need a full certificate of analysis and food compliance statements.
Food legality comes first
Before you buy food-grade TKP, check that tamarind seed polysaccharide is permitted in food in your market, and for which uses. It is used as an additive in some Asian markets, but it is not one of the familiar E-number thickeners in the EU. A supplier calling a powder "food grade" does not make it legal in your country.
If it is permitted, ask for the specification that your regulation or customer expects, and confirm the plant can meet it batch after batch.
Risks to watch
General checks for adulteration are covered in how to avoid adulteration when buying spices from India, and the same approach works for TKP.
- Textile grade sold as food grade: the most serious risk. Check the plant's licence and the test reports.
- Aflatoxin: seeds stored damp can develop mould. Test every food lot.
- Mixing with cheaper flours or starches: check viscosity and, if in doubt, test for starch.
- Inconsistent viscosity between lots, which disrupts textile and food processes alike.
Choosing the right grade
If you use TKP for sizing or print paste, a well-made textile grade at a steady viscosity is the right buy. Paying for food grade adds cost without benefit. If any of the product goes into food, or into something that touches food, buy food grade from a food plant and test it.
How Creston & Co handles this
We visit the plant to confirm it really makes the grade it offers, check its licences on site and test samples at an NABL-accredited lab. Ask for a free sourcing review.