Tamarind Kernel Powder Grades: What Textile Mills Look For

Tamarind kernel powder (TKP) is produced by decortication, kernel separation, milling, and sieving of dried tamarind seeds. It is used as a warp-sizing agent in textile mills and as a stabiliser or thickener in food applications. Grade — defined by mesh size, polysaccharide content, and viscosity — determines which application it suits. At KVM & Co., Mysore, we trade tamarind seeds separately from tamarind fruit at our APMC Yard, Bandipalya premises; buyers sourcing seed for TKP milling will find the background below useful when specifying what they need from a miller.

From tamarind seed to powder

Four steps convert raw seed into milled TKP, and each affects final grade.

1. Drying. Seeds must reach below 8% moisture before milling; damp seed gums the mill and compromises powder flowability.
2. Decortication. A roller or disc decorticator removes the hard outer testa, releasing the cream-coloured kernel. Incomplete decortication leaves hull fragments that darken the powder — a disqualifier for food-grade lots.
3. Kernel separation. Broken testa is aspirated and sieved out. The cleaned kernel is the TKP raw material proper.
4. Milling and sieving. The kernel is pin-milled or hammer-milled and sieved to target mesh. Coarser mesh for textile, finer for food and pharma.

Textile use: warp sizing

Warp sizing applies a protective film to yarn before weaving to reduce breakage from abrasion against heddles and reed. TKP forms a flexible, continuous film that withstands loom stress — it has been used in Indian cotton weaving for over a century. Against starch it offers more consistent adhesion and cleaner desizing (water-soluble, no enzyme treatment needed). Against synthetics (PVA, CMC), cost wins: Karnataka-origin tamarind seed is substantially cheaper per unit of sizing polymer.

Food use: stabiliser and thickener

The primary polysaccharide in TKP is a xyloglucan that behaves similarly to pectin. At 1–3% concentration it forms a viscous, shear-thinning gel used as a stabiliser in sauces, ketchups, and ice cream mixes. Approved under FSSAI regulations (fssai.gov.in) as a thickening agent, it also serves as a vegetarian alternative to gelatin in some stabilisation applications — though it does not set to a rigid gel at room temperature.

TKP grade hierarchy

Three commercial grades dominate the trade. The BIS standard IS 14826 specifies requirements for tamarind kernel powder for industrial and food use; request compliance documentation when sourcing.

Industrial / sizing grade

60–80 mesh. Polysaccharide above 60%. Colour is cream to light-tan; microbial counts are not controlled to food-grade limits. The largest-volume grade in Karnataka trade. Used in textile warp sizing and paper manufacture.

Refined / food grade

200+ mesh. Polysaccharide above 65%. White to cream colour; hull contamination essentially zero. Total Plate Count below 10,000 CFU/g is a typical buyer specification. Commands a 30–60% price premium over industrial grade.

Premium / pharma grade

200+ mesh with narrow, COA-tracked viscosity specification; heavy-metal testing included. Used in pharmaceutical tablet-coating formulations and nutraceuticals. Procurement is typically direct from the miller with full batch traceability.

Viscosity: the specification textile buyers must ask for

Polysaccharide percentage alone is not enough. For warp sizing, viscosity of the prepared paste at your working concentration is what matters. Industrial-grade TKP at 4% delivers 2,000–4,000 mPa·s (Brookfield LVT, 25°C, 30 rpm); well-decorticated, high-polysaccharide lots can reach 5,000–6,000 mPa·s. Mills on fine counts (80s and above) prefer the lower end for penetration; coarse-count weaving (20s–40s) benefits from higher viscosity for surface coating. Always request viscosity data at your sizing kitchen's concentration — the polysaccharide figure alone does not predict it.

Grade × application at a glance

Where KVM & Co. fits in this chain

We trade tamarind seed as a separate commodity from tamarind fruit at APMC Bandipalya, Mysuru — dried, in 50–70 kg bags, typically 5–20 tonne lots. Buyers who mill TKP in-house (several Coimbatore and Erode belt mills do this) source seed directly from yards like ours and handle decortication and milling at their own facility. We do not mill TKP. We supply quality-checked, correctly dried seed with lot-level documentation. See our produce page for current availability.