Reading the trade figures when you care about grade. HS 1302.32 takes in every grade of guar gum, and the heading also covers thickeners made from locust beans, so the table above can't tell you how much of India's trade was food grade. The yearly series is still useful. India's exports under the code rose from USD 339.4 million in 2021 to USD 508.1 million in 2022, then eased to USD 401.4 million in 2023 and USD 417.3 million in 2024. Volume moved less than value: about 240,637 MT in 2021, 266,165 MT in 2022, 211,412 MT in 2023 and 239,920 MT in 2024. The average value per kilogram therefore jumped by roughly a third between 2021 and 2022 and has stayed above the 2021 level since. That pattern is typical of a market where one demand stream, oilfield use, can swing sharply while food and technical demand stays steadier.
From split to powder: where the two grades part company
The guar seed has three parts: the husk, the germ and the endosperm. The endosperm holds the galactomannan, the long-chain polysaccharide that makes water thick. Processors crack the seed, strip out germ and husk, and sell the cleaned endosperm halves as refined guar split. The split is then hydrated, flaked, milled and screened into powder.
Up to that point the two grades can share a route. After it they diverge:
- Food and pharma grade is milled from well-cleaned split under hygiene controls, and some processors wash the gum with ethanol or isopropanol to cut the microbial load. JECFA's specification allows this washing and caps the residual solvent at 1%. Every lot is tested against a food-additive specification before it is released.
- Industrial grade is milled for performance. For hydraulic fracturing that usually means fast hydration and a predictable response to crosslinkers. For paper, textile printing, explosives and mining, it means a stable viscosity and good dispersion in the customer's process. Microbiology and heavy metals are not usually specified, because the product never enters food.
Some industrial customers buy chemically modified guar (derivatives made by further reaction), which is a different product again. If your specification sheet names a derivative, send it with the enquiry, because plain guar gum powder will not match it.
What does the cP viscosity figure on a certificate really measure?
Viscosity is the number both grades are bought on, and it is only meaningful alongside its test conditions. A guar gum viscosity is normally read on a rotational viscometer, often a Brookfield, from a dilute solution of stated strength, after a set hydration time at a set temperature. Change any of those and the figure changes:
- Concentration. Viscosity rises steeply with concentration, so a small difference in how the solution is made up gives a large difference in cP.
- Hydration time. Guar keeps building viscosity after it disperses. A reading taken soon after mixing and one taken the next day on the same lot are not comparable.
- Instrument, spindle and speed. Guar solutions thin under shear, so the reading depends on how fast the spindle turns.
- Temperature and water quality. Warm water speeds hydration, and dissolved salts and pH shift the result.
Our standard food-grade range runs from 3000 to 6000 cps, and industrial grades start at 5000 cps and go higher, each tested per batch. Oilfield buyers often care less about the final number than about how quickly viscosity builds in the first few minutes, because blending on a frac site happens on the move. Food buyers usually care about the final viscosity and its consistency from lot to lot, because that controls mouthfeel and stability in the finished product.
Mesh size and hydration speed
Mesh is the second grade parameter. Powder is sold at 80, 100, 200 or 300 mesh, where the higher number means finer particles. Finer powder offers more surface to water and hydrates faster, which is why oilfield and continuous-process users often choose 200 mesh or finer. Coarser powder disperses more easily without lumping, which suits batch mixing in food plants that don't use high-shear equipment.
Write mesh as a percentage passing a stated sieve (for example, a minimum share passing 200 mesh), not just as a name. Two lots called "200 mesh" can have quite different particle-size distributions, and the tail of coarse particles is what slows hydration.
Scenario: a sauce maker adding powder by hand to a batch kettle orders 100 mesh, because 200 mesh lumps before it disperses. A frac-fluid blender orders 200 mesh, fast-hydrating, because its gel has to build within the few minutes the fluid spends in the blender. The same mill can supply both, and both are correct for their process. Dosage is the other application check: in the US, 21 CFR 184.1339 caps guar gum at 0.35% in baked goods, so a single 25kg bag is the legal maximum for about 7.1 tonnes of bakery product, while a frac blender uses it at whatever loading its fluid design needs.
Purity and microbiology in the food-additive specification
Food-grade guar gum is additive INS 412 (E 412 in the EU). The Joint FAO/WHO Expert Committee on Food Additives (JECFA) publishes its specification, and many national rules follow the same pattern. The JECFA monograph sets these limits:
| Parameter | JECFA limit (guar gum, INS 412) | What it tells you |
|---|
| Loss on drying | Not more than 15.0% (105°C, 5 h) | Moisture; our export lots are held tighter, at ≤12% |
| Total ash | Not more than 1.5% | Mineral residue from soil and husk |
| Acid-insoluble matter | Not more than 7.0% | Husk and other insoluble residue left from milling |
| Protein | Not more than 10.0% (N × 6.25) | Germ carried into the endosperm; high protein means poorer separation |
| Borate | Absent | Rules out crosslinked material in a food lot |
| Residual ethanol / isopropanol | Not more than 1% | Applies to solvent-washed gum |
| Lead | Not more than 2 mg/kg | Heavy-metal contamination |
| Total plate count | Not more than 5,000 CFU/g | General hygiene of milling and packing |
| Yeasts and moulds | Not more than 500 CFU/g | Storage and moisture history |
| E. coli / Salmonella | Negative in 1g / negative in 25g | Pathogen control |
National rules add their own layer. In the United States, 21 CFR 184.1339 lists guar gum as GRAS, requires it to meet the Food Chemicals Codex specification and sets maximum use levels by food category, from 0.35% in baked goods to 2.0% in fats and oils and processed vegetables, with 0.5% for categories not listed. In the EU, food-grade guar gum from India also travels with a PCP (pentachlorophenol) analytical report endorsed by SHEFEXIL. Some buyers also test food-grade lots for pesticide residues against their market's maximum residue limits (MRLs), since guar is a field crop. Your market may add more, so send your specification sheet and we will test to it.
What drilling and technical buyers specify instead
An industrial specification reads like a performance test rather than a purity list. For fracturing grades the usual items are:
- Hydration rate: viscosity at a few set times after mixing, often within minutes, to show how quickly the gel builds.
- Final or base-gel viscosity: under the buyer's own concentration, temperature and instrument conditions.
- Crosslink response: guar gels with borate, which is the basis of many frac fluids. JECFA uses the same reaction as an identity test, and it is why borate must be absent from a food lot.
- Insoluble residue: residue left after the gel breaks can reduce flow in the formation, so drilling buyers watch it closely.
- Moisture, pH and particle size: these control dosing and dispersion in field equipment.
Paper, textile-printing and mining buyers each have their own short list, usually viscosity at their own concentration plus mesh and moisture. None of them normally asks for a microbiology panel. If yours does, say so, because it changes how the lot is milled and tested.