Acetylated oxidized starch is a chemically modified root or grain starch. It is produced by oxidation of a slurry of starch granules in alkaline hypochlorite at low temperature (21–38 °C). The alkaline medium is neutralized with sodium bisulfite, and the resulting organic salts are removed by washing with water. The oxidized starch is then esterified with acetic anhydride under mildly alkaline conditions. The product is neutralized with hydrochloric acid, washed, and dried.

Acetylated oxidized starch is proposed for use as a binding agent in soft confectionery, in which the product is to be mixed with water, sugars, and flavours in a batch process until a clear solution with a dry-solid content of 70% is obtained. The important characteristics of the end-product for confectionery use are gel strength and clarity. Acid hydrolysis produces relatively unclear starch products, whereas oxidized starch products result in overly soft confectionery products. Acetylation of oxidized starch enhances the important properties, resulting in a gummy, clear jelly. This starch product is to be used in confectionery at a concentration of about 30%. It can be used as a substitute for gelatin or gum arabic and would replace a large amount of sugar.

Acetylated oxidized starch has a stable configuration in food under normal conditions. It is hydrolysed slowly in the presence of strong acids, yielding glucose, gluconic acid, and acetic acid. No degradation products are expected or known to result from storage or use of this substance in the preparation of foods at neutral pH. The substance is not known to sequester minerals, nor does it interact with proteins or vitamins. It has no known effect on other nutrients.

Acetylated oxidized starch has not been evaluated previously by the Committee.

A 14-day range-finding study was performed with acetylated oxidized starch in rats according to GLP (a statement of quality assurance was included). Groups of five male Wistar rats received a diet containing 10, 30, or 50% acetylated oxidized starch (equivalent to 0, 5000, 15 000, or 25 000 mg/kg bw per day) at the expense of native wheat starch, for 14 days. One group received basal diet, and another received 50% unextruded acetylated oxidized starch (equivalent to 2500 mg/kg bw per day). The mean body weight of the animals at the start of treatment was 190 g.

No deaths or clinical signs were observed. Behaviour, appearance, body weight, food intake, and food efficiency were not significantly different from those of controls. Rats given 50% acetylated oxidized starch had soft faeces from day 2 onwards. The absolute and relative caecal weights were increased in animals given 30 and 50% acetylated oxidized starch and 50% unextruded acetylated oxidized starch. At the end of the study, macroscopic examination showed dilated caeca in animals at 30 and 50% acetylated oxidized starch. The caeca of animals given 50% acetylated oxidized starch were flabby. The NOEL was 10% acetylated oxidized starch in the diet, equivalent to 5000 mg/kg bw per day, on the basis of increased caecal weights and dilatation of the caeca (Til & Kuiper, 1993).

A 90-day diet study was performed with acetylated oxidized starch in rats according to GLP and OECD Guideline 408. A statement of quality assurance was included. Groups of 10 male and 10 female Wistar rats received diets containing 0, 5, 10, or 30% acetylated oxidized starch for 90 days, equal to 0, 3000, 5900, and 18 000 mg/kg bw per day for males and 0, 3400, 6600, and 20 000 mg/kg bw per day for females. At the start of treatment. the mean body weights were 155 g for male rats and 116–117 g for females. Condition and behaviour were monitored twice daily on working days and once daily at weekends and holidays, and all clinical signs were noted. Ophthalmoscopy was carried out on all rats before the study and on all rats at 0 or 30% at the end of the study. Body weight, food intake, and food efficiency were recorded weekly. Haematological examinations were performed on all rats at day 85, urinary analysis on day 87, and clinical chemistry at autopsy. At termination, all rats were examined macroscopically, and about 30 tissues from all rats at 0 or 30% were examined microscopically. In addition, the kidneys, liver, lungs, and gross lesions from all animals at 5 and 10% and the urinary bladders of all male animals at 5 and 10% were examined microscopically.

No deaths were seen. The behaviour, appearance, ophthalmoscopic parameters. The body weights of males at 5% and 30% were slightly lower than those of controls, but no effect was seen in males at 10%, and the body weights of females were comparable in all groups. The food intake of males at 30% was generally higher than that of controls. Food efficiency was equivalent. Haematological examination showed no significant changes. A slightly increased mean corpuscular haemoglobin concentration in males at 10% was not found in those at 30% and was therefore considered biologically irrelevant. Clinical chemistry and urinary analysis revealed no significant changes.

The absolute and relative weights of empty and filled caeca were statistically significantly increased at 30% acetylated oxidized starch. The mean relative weights of the adrenals and kidneys of males at the lowest concentration were significantly increased, but no change was seen at the two higher concentrations or in organ weights in females. Therefore, the changes in the weights of the adrenals and kidneys in males at 5% were considered to be of no biological significance. One male rat at 30% had a dilated caecum.

Microscopy showed focal hyperplasia of the epithelium of the urinary bladder in four male rats at 30% (Table 1). This effect was not seen at lower concentrations, in controls, or in females at 30%. Hyperplasia of transitional epithelium in the kidney was seen in several animals (see Table 1). The total incidence in females at 30% was higher than those in other groups although not statistically significant. In addition, the incidence of mineralization was slightly higher in animals at 30% (see Table 1). Mineralization occurred especially in the pelvic area but also in the cortex and the medullary zone. A statistically significant increase in the frequency of small aggregates of reticulo-endothelial cells in the liver only in males at 5% acetylated oxidized starch was considered to be a fortuitous finding because no dose–response relationship was observed and it is a common finding in rats of the strain and age used. The NOEL was 10% in the diet, equal to 5900 mg/kg per day, on the basis of microscopic changes in the kidney and urinary bladder (Til & Kuiper, 1993).

Table 1. Incidences of relevant microscopic lesions in rats given acetylated oxidized starch in the diet

Data on the intake of acetylated oxidized starch were provided to the Committee by AVEBE, Research and Development, Netherlands. The substance is used as a binding agent for sugar confectionery and particularly for clear soft jelly. The data submitted indicated that if acetylated oxidized starch were used at a concentration of 30% in jelly confectionery, the daily intake would be 60 g/day or 1 g/kg bw per day, assuming an intake of 200 g of jelly confectionery and an average body weight of 60 kg (AVEBE, 2000).

The potential intake of acetylated oxidized starch from its use in jelly confectionery was also predicted on the basis of individual dietary records from the Australian population, assuming that consumption of confectionery would generally be higher in developed than in developing countries. The predicted mean intake for consumers of acetylated oxidized starch was 11 g/day, with a median of 6 g/day and consumption at the 95th percentile of 40 g/day, assuming use of the substance at 300 g/kg in all jelly confectionery. The predicted consumption of acetylated oxidized starch by 13–18-year-olds was higher (Table 2), but consumption of jelly confectionery at the 95th percentile in this age group did not exceed 200 g/day. These records were based on 24-h recall which tends to overestimate high consumption on a long-term basis (Gibney, 1999; Lambe et al., 2000).

If acetylated oxidized starch is used only in jelly confectionery at a concentration of 300 g/kg (30%), at a maximum consumption of 200 g/day of jelly confectionery, the maximum intake would be 60 g/day.

In a 14-day range-finding study in rats, administration of a diet containing acetylated oxidized starch at a concentration of 30 or 50% increased the weights of full and empty caeca, and dilated caeca were found at autopsy. At 50% in the diet, soft faeces were also seen. The NOEL was 10% in the diet.

In a 90-day study in rats, increased full and empty caecal weights were seen at the highest dietary concentration of 30%. Macroscopic examination showed a dilated caecum in one male rat. Microscopy did not reveal changes in the caecal wall or other parts of the digestive tract. Increased caecal weights are a known response to high dietary concentrations of poorly digested carbohydrates in rats, due perhaps to an increased osmotic load of short-chain fatty acids produced by microbial degradation and the associated water retention. Focal hyperplasia of the epithelium in the urinary bladder was seen in 4/10 male rats at 30% in the diet but not in males at other concentrations, in controls, or in females. The change was probably treatment-related and a consequence of irritation of the urinary bladder by calculi. The NOEL was 10% in the diet, equivalent to 5900 mg/kg of body weight per day.

If acetylated oxidized starch is used only in jelly confectionery at a concentration of 300 g/kg (30%) and if the maximum consumption by consumers is 200 g of jelly confectionery per day, the maximum intake of acetylated oxidized starch would be 60 g/day.

The effects seen in the 14-day and 90-day studies in rats have also been observed with high dietary concentrations of slowly digested carbohydrates and have commonly been seen in dietary studies with other modified starches. Because of the nature of acetylated oxidized starch and its similarity to other modified starches with similar non-systemic effects, the Committee established an ADI ‘not specified’¹, based on the known uses of acetylated oxidized starch as an ingredient in confectionery products.

AVEBE (2000) Datasheet on acetylated oxidized starch. Unpublished data dated 30 November 2000. Submitted to WHO by AVEBE, Foxhol, Netherlands.

Gibney, M.J. (1999) Dietary intake methods for estimating food additive intake. Regul. Toxicol. Pharmacol., 30, S31–S33.

Lambe, J., Kearney, J., Leclercq, C., Berardi, D., Zunft, H.F.J., De Henauw, S., De Volder, M., Lamberg-Allardt, C.J.E., Karkkainen, M.U.M., Dunne, A. & Gibney, N.J. (2000) Enhancing the capacity of food consumption surveys of short duration to estimate long term consumer-only intakes by combination with a qualitative food frequency questionnaire. Food Addit. Contam., 17, 177–187.

Scientific Committee for Food (1995) Opinion on acetylated oxidised starch expressed on 2 June 1995, Annex 4 to document 111/5373/95; CS/ADD/AMI/35-final), Brussels: European Commission.

Til, H.P. & Kuper, C.F. (1993) Range-finding (14-day) and sub-chronic (90-day) feeding studies with Perfectamyl GEL45 in rats (final report). Unpublished report number V 93.537 from TNO Nutrition and Food Research, Zeist, Netherlands, dated December 1993. Submitted to WHO by AVEBE Research & Development, Product Regulation, Foxhol, Netherlands.

¹ ADI ‘not specified’ is used to refer to a food substance of very low toxicity, which, on the basis of the available data (chemical, biochemical, toxicological, and other) and the total dietary intake of the substance arising from its use at the levels necessary to achieve the desired effect and from its acceptable background levels in food, does not, in the opinion of the Committee, represent a hazard to health. For that reason, and for reasons stated in individual evaluations, the establishment of an ADI expressed in numerical form is not deemed necessary. An additive meeting this criterion must be used within the bounds of good manufacturing practice, i.e., it should be technologically efficacious and should be used at the lowest level necessary to achieve this effect, it should not conceal food of inferior quality or adulterated food, and it should not create a nutritional imbalance.

    See Also:
       Toxicological Abbreviations
       ACETYLATED OXIDIZED STARCH (JECFA Evaluation)