Fructo-oligosaccharides (FOS)

Fructo-oligosaccharides are the short end of the fructan family: 1-kestose (GF2), nystose (GF3) and 1F-fructofuranosylnystose (GF4), built from fructose units joined by beta-(2 to 1) fructosyl-fructose bonds on a terminal glucose. CAS 308066-66-2. Two industrial routes exist and they are not interchangeable on a label. Short-chain FOS is made by transfructosylation of sucrose using a fungal beta-fructofuranosidase, classically from Aspergillus niger or A. oryzae, a route Meiji Seika pioneered commercially. Oligofructose is made instead by controlled enzymatic hydrolysis of chicory inulin. Thovek states the route on the specification sheet at order stage, because the raw material declaration, the organic certification path and the botanical-origin statement all follow from it. The purified P-type spray-dried powder assays at 95% minimum total FOS on dry matter; the G-type syrup grade runs near 55% with glucose and sucrose making up the balance, and the two should never be quoted against the same price. Against the GB/T 23528 trade standard the 95% powder carries GF2 at 45-65%, GF3 at 20-45% and GF4 at up to 10%, with residual glucose, fructose and sucrose at 5% maximum, moisture 5% maximum, pH 4.5-7.0, sulphated ash 0.1% maximum, lead 0.5 mg/kg maximum, arsenic 1 mg/kg maximum and total aerobic count 1000 CFU/g maximum. Sweetness lands at roughly 30-50% that of sucrose with a clean profile and no lingering aftertaste, so the material does real formulation work as a bulking agent and partial sugar replacer as well as serving as a fermentable substrate. FDA has issued no-questions letters on a series of FOS GRAS notices, beginning with GRN 44 for short-chain FOS in November 2000 and continuing through GRN 623, 797 and 990. Origin and allergen status is clean but route-dependent, and buyers should record which they have bought. The material is vegan and vegetarian with no bovine, porcine or marine input, and free from milk, egg, fish, crustacean, mollusc, soybean, wheat and gluten-containing grains, peanut, tree nut, sesame, celery, mustard, lupin and sulphites. Sucrose-route product traces back to cane or beet; inulin-route product traces to chicory, an Asteraceae plant, which some brands choose to declare. The enzyme is fungal and is inactivated and removed downstream, and a separate enzyme and processing-aid statement is issued on request for buyers running fungal-sensitivity or vegan-audit programmes. One practical warning for tropical shipping: FOS is markedly more hygroscopic than inulin, so foil-lined drums with desiccant are the safer pack for long sea legs.