The review, published in the Elsevier journal Food and Chemical Toxicology, provides useful data for companies to formulate products without any safety concerns over the ingredient.
HPMC, also authorised to be labelled as carbohydrate gum in the US, is used extensively in the food industry as an emulsifier, film former, protective colloid, stabiliser, suspending agent, and thickener.
The ingredient is approved for food uses by the European Union (EU), US Food and Drug Administration (FDA), and the joint FAO/WHO Expert Committee on Food Additives (JECFA). However, no specified acceptable daily intake (ADI) for the ingredient has been established.
The new assessment, by George Burdock from Florida-based Burdock Group, compared data from animal studies regarding potential toxicity with the estimated human consumption (0.047 mg HPMC per kg of body weight per day).
"Comparing the [no-observed-adverse-effect level] NOAEL of 5000 mg/kg/day from a 90-day feeding study in rats and an estimated consumption of 0.047 mg HPMC/kg body weight/day, a theoretical safety factor of greater 100,000 exists," stated Burdock.
"These data indicate that at the current level of intake, HPMC does not pose a health risk to humans," he concluded.
Thickeners, along with emulsion stabilisers, suspending agents, gelling agents, thickeners, fibre sources, mouthfeel improvers, fat replacers and processing aids all come under the umbrella of hydrocolloids, a market that has grown signficantly in the past 20 years in parallel to an increasingly complex food processing industry.
The food industry's most frequently used hydrocolloids include: agar, alginates, arabic, carrageenan, Carboxy Methyl Cellulose (CMC), gelatin, konjac flour, locust bean gum (LBG), Methyl Cellulose and hydroxypropyl Methyl Cellulose (MC/HPMC), microcrystalline cellulose (MCC), pectin, starch and Xanthan.
Source: Food and Chemical Toxicology (Elsevier)
Published on-line ahead of print, doi:10.1016/j.fct.2007.07.011
"Safety assessment of hydroxypropyl methylcellulose as a food ingredient"
Author: G.A. Burdock