The migration of propylene glycol, mono-, di-, and triethylene glycols from regenerated cellulose film into food.

Chocolates, boiled sweets, toffees, cakes and meat pies were wrapped in regenerated cellulose films (with or without coatings) that contained various mixtures of glycol softeners and which had been specially formulated for particular food applications. Samples were unwrapped at intervals (up to the end of the usual maximum shelf-life for the food) and analysed for their glycol content. Analysis involved homogenization of the food in hot water, removal of fats with hexane, precipitation of sugars with calcium hydroxide and analysis of the glycols by capillary gas chromatography with flame ionization detection (GC/FID) after trimethylsilyl (TMS) derivatization. Triethylene glycol was analysed by selected ion monitoring GC/mass spectrometry (GC/MS) as interference problems occurred with the GC/FID approach. The results of the study showed that higher levels of migration occurred for propylene glycol than for triethylene glycol and the presence of a coating reduced the migration of both softeners. Generally, mono- and diethylene glycol levels in the food samples were below 10 mg/kg, although some samples wrapped in polyethylene glycol-softened films contained levels approaching the current statutory limit of 50 mg/kg.

Gas chromatographic determination of monoethylene glycol and diethylene glycol in chocolate packaged in regenerated cellulose film.

A method for the quantitative determination of monoethylene glycol (MEG) and diethylene glycol (DEG) in chocolate is described. The procedure involves dissolving the chocolate in hot water, defatting with hexane, removing sugars by precipitation, and analyzing as trimethylsilyl (TMS) ether derivatives by capillary gas chromatography. The use of butan-1,4-diol as an internal standard corrects for recovery, which is between 50 and 60%, to give a relative standard deviation of 10-11% for the determination of both glycols at the level of 50 mg/kg. The presence of MEG and DEG in chocolate is confirmed by full scanning gas chromatography/mass spectrometry of the TMS derivatives.

Changes in plasma growth hormone in diabetic and nondiabetic subjects during the glucose clamp.

A group of 22 newly diagnosed noninsulin-dependent diabetic subjects and seven nondiabetic subjects underwent a glucose clamp at plasma glucose 100 mg/dL with insulin infusion rates of 1.0 and 10 mU/kg/min. During both insulin infusion rates, there was a sustained rise in plasma growth hormone (GH) above basal in 18 of the 22 diabetic subjects. Basal GH values were 2.37 +/- 0.67 ng/mL, rising above basal during the lower insulin infusion (6.1 +/- 3.3 ng/mL, P = 0.05) with a further rise at the higher insulin level (8.58 +/- 2.0 ng/mL, P less than 0.001). There was no rise in GH in any of the nondiabetic subjects. In neither group was there any rise above basal in cortisol, prolactin, glucagon, or somatostatin (SRIH). In a group of three nondiabetic subjects, a rise in GH similar to that seen in the diabetic group was induced by elevating the plasma glucose to 200 mg/dL for 60 minutes prior to the euglycemic clamp procedure. However, it is unlikely that changes in plasma glucose account totally for the changes in plasma GH described in the diabetic subjects since a rise in plasma GH was also seen in four diabetic subjects clamped at their fasting plasma glucose. We conclude that in newly diagnosed noninsulin-dependent diabetic subjects there is a rise in plasma GH during the euglycemic clamp procedure, which may be due to both the prior lowering of plasma glucose and the high plasma insulin levels.

Serum immunoreactive insulin responses to a glucose load in Asian Indian and European type 2 (non-insulin-dependent) diabetic patients and control subjects.

The serum immunoreactive insulin response to an oral glucose load was estimated in 15 Asian Indian and 29 European non-diabetic subjects, and in 45 Asian Indian and 72 European Type 2 (non-insulin-dependent) diabetic patients. In the non-diabetic group, basal insulin values were higher in the Asian Indians than the Europeans (16.7 +/- 3.0 vs. 6.9 +/- 0.7 mU/l, p less than 0.001), and remained higher throughout the glucose tolerance test. Total insulin response was also higher in the Asian Indians (p less than 0.001), and linear regression analysis revealed basal insulin, body mass index and race to be important predictors of insulin response. Amongst the diabetic patients, basal insulin values were again higher in the Asian Indians compared with the Europeans (18.0 +/- 5.0 vs. 11.5 +/- 0.9 mU/l, p less than 0.05). Total insulin response was also greater (p less than 0.01). Linear regression analysis revealed the basal insulin value to be the only significant predictor of insulin response. The results demonstrate higher insulin levels in Asian Indians than Europeans in both normal subjects and Type 2 diabetic subjects. The insulin response to a glucose load is also greater in the Asian Indians. In the control subjects, ethnic differences contribute to this response, whereas in the diabetic patients this is a function of the elevated basal insulin values of the Asian Indians.