Psyllium husk (Isabgol)

Psyllium husk is the seed coat — the episperm and the collapsed layers immediately beneath it — stripped from the seed of Plantago ovata Forssk., the plant the Indian trade calls isabgol or ispaghula. The supply chain is unusually concentrated: India grows the overwhelming majority of the world crop, most of it in north Gujarat around Unjha, Sidhpur and Patan and in adjoining Rajasthan, and the milling and grading industry sits in the same districts. Grading is done not by assay of an active but by how much light extraneous matter survives winnowing, which is why purity and extraneous matter are two readings of a single number: 99% USP husk carries 1% maximum light extraneous matter, 98% carries 2%, 95% carries 5% and 85% carries 15%. Thovek quotes the grade on the same line as the price, because the two move together and a 95% offer held against a 99% specification is the most common source of dispute in this trade. What buyers are really specifying is swell volume. The USP monograph and the European Pharmacopoeia monograph for ispaghula husk both put the floor at 40 — a minimum of 40 mL per gram in USP terms, a swelling index of not less than 40 in Ph. Eur. terms — and husk that misses it is not pharmacopeial material whatever its purity grade says. The behaviour comes from a gel-forming arabinoxylan mucilage held in the epidermal cells, reported at up to roughly 30% of the husk, which hydrates on contact with water into a stiff gel that does not dissolve. That is a food-technology property as much as a nutritional one: the same water binding that makes psyllium a fibre-fortification ingredient in sachets, effervescents and beverage powders is what makes it a structure and moisture-retention aid in gluten-free bakery, where it stands in for the dough network wheat gluten would otherwise provide. Whole husk ships as brittle buff flakes at 40 mesh; milled powders run 60, 80, 100 and 200 mesh with a minimum of 95% through the stated screen. Two commercial points decide most orders. The first is gluten. Psyllium is intrinsically gluten-free, but it is grown in rotation with wheat, harvested with shared equipment and handled in the same yards, so a gluten-free declaration on psyllium is a tested result and never an assumption; Thovek releases gluten-free lots against R5 ELISA below 20 mg/kg, the threshold used by Codex and by Regulation (EU) No 828/2014. The second is how microbial counts are brought down. Ethylene oxide is not used on Thovek material — residues of ethylene oxide and its 2-chloroethanol breakdown product have driven repeated EU border rejections across the botanical trade — and where a lower count is required, saturated-steam treatment is applied and the method is stated on the certificate of analysis. Beyond that the product is vegan and vegetarian, wholly plant-derived, with no bovine, porcine, marine, milk, egg, soy, nut, sesame or crustacean input anywhere in growing, milling or packing, and every lot ships with a CoA covering purity grade, swell volume, loss on drying, ash, foreign matter, heavy metals, pesticide residues and full microbiology.