Safety evaluation of certain food additives: WHO food additives series 42. Glucono-delta-lactone and the calcium, magnesium, potassium, and sodium salts of gluconic acid
The results of the new study of acute toxicity provided no evidence of toxicity in rats given single doses of 500, 1000, or 2000 mg/kg bw sodium gluconate.
In two new four-week studies in rats, sodium gluconate was administered orally either by gavage at doses of 0, 500, 1000, or 2000 mg/kg bw per day or by feeding at doses of 0, 1, 1.25, 2.5, or 5% w/w (equal to 1000, 2000, and 4100 mg/kg bw per day). A further group received 1.35% w/w sodium chloride (equal to 1100 mg/kg bw per day), equivalent to the concentration of sodium in 5% sodium gluconate. After gavage, a significant increase in the relative weight of the kidneys (unilateral) was seen in males at 1000 or 2000 mg/kg bw per day. No treatment-related or dose-related effect was observed on any of the other parameters examined in this study. The effects observed in the feeding study, i.e. increased water intake, increased prothrombin time, and increased relative kidney weights, were not dose-related. Qualitative urine analyses revealed effects in both four-week studies that were considered by the Committee to be related to the high sodium intake arising from the sodium gluconate.
Evaluation.
On the basis of a re-evaluation of data previously considered by the Committee and new-data on the short-term toxicity of sodium gluconate, the Committee extended the previous ADI `not specified' for glucono-delta-lactone to a group ADI for glucono-delta-lactone and the calcium, magnesium, potassium, and sodium salts of gluconic acid..