Psyllium husk extract

Sold across the trade as psyllium husk extract, this material is not a solvent extract at all — it is the cleaned, milled and air-classified seed coat of Plantago ovata Forssk. (isabgol), separated from the seed and graded by how much pure husk survives the separation. Thovek states that plainly because it changes the specification a buyer should be writing: there is no marker compound to assay, no solvent to declare and no extraction ratio. What is measured instead is purity, fibre content, swell volume and mesh. Around 85 per cent of the husk on a dry basis is total dietary fibre, and 70 to 80 per cent of that fibre is soluble — chiefly a highly branched, high-molecular-weight arabinoxylan that hydrates into a viscous gel. Purity grades run 85, 90, 95, 98 and 99 per cent, and higher is not automatically better. The 95 per cent grade is the commercially significant line, because it is the purity written into the US definition of psyllium husk at 21 CFR 101.81, which also caps protein at 3 per cent, light extraneous matter at 4.5 per cent and heavy extraneous matter at 0.5 per cent. Swell volume is the functional number: not less than 40 mL/g at 95 per cent and above, matching the Ph. Eur. Ispaghula husk swelling index of not less than 40, and around 35 mL/g on the 85 per cent grade. Mesh drives the process fit — 40 to 60 mesh hydrates slowly and flows well through sachet and canister lines, while 80 to 100 mesh suits capsule filling and tablet compression, where fill-weight consistency matters more than anything else. Two things need saying before a first order. Psyllium is a low-moisture agricultural commodity with a documented Salmonella history, so Thovek offers steam-treated grades carrying a validated pathogen reduction step alongside untreated lots for buyers running their own kill step. And psyllium dust is itself a recognised IgE-mediated occupational allergen: rhinitis, asthma, contact urticaria and anaphylaxis have all been reported in healthcare and pharmaceutical workers handling the powder, with one study of an exposed healthcare group finding 13.8 per cent sensitised and 8.6 per cent clinically allergic. The material carries none of the major food allergens, but dust extraction and respiratory protection at the charging point are a real requirement, not a formality. Buyers formulating for the US market should also note that soluble fibre from psyllium husk is the subject of an authorised health claim under 21 CFR 101.81, requiring at least 1.7 g of soluble fibre per reference amount; using that claim, and substantiating it, is the brand owner's responsibility.