Quantitative analysis of chemicals release into food cooked in polyethylene bags at Uganda industrial research institute (UIRI)

Abstract

The study was done to quantify the chemicals substances that are released into food when it’s cooked in polyethylene bags. Cooking food in polyethylene bags has of late substituted banana leaves in Uganda especially in the urban centres. However, this is a risky method of preparing food as chemical contaminants may migrate from the polyethylene bags into food during cooking, causing health complications. Therefore, this study was done to identify and quantify the levels of these chemical contaminants in polyethylene bags. Food with a case study on matooke was cooked and then wrapped in green polyethylene bags, incubated at temperatures of 70°C (T1), 80°C (T2), and 90°C (T3) in pre-set water baths for a period of 3 hours. Samples were obtained from all the water baths at the end of every hour. These samples were analysed for heavy metals using an Atomic Absorption Spectrophotometer and for phthalates and bisphenol A using a High Liquid Performance Chromatography. The results obtained indicated that the highest values that is BPA, Bisphenol A (0.042 ppm), Dibutylphthalate, DBP (0.90 ppm), Di-(2-ethyhexyl phthalate, DEHP (1.01 ppm), Butyl benzyl phthalate, BBP (1.12 ppm), Di-isononyl phthalate, DINP (1.23 ppm), lead (132.18 ppm), chromium (10.30 ppm), cobalt (14.36 ppm) and cadmium (14.68 ppm) were obtained at treatment temperature, T3 90°C after 3 hours’ incubation time. While, the lowest values; that is BPA, Bisphenol A (0.000 ppm), Dibutylphthalate, DBP (0.52 ppm), Di-(2-ethyhexyl phthalate, DEHP (0.63 ppm), Butyl benzyl phthalate, BBP (0.74 ppm), Di-isononyl phthalate, DINP (0.85 ppm), lead (25.79 ppm), chromium (3.49 ppm), cobalt (4.03 ppm) and cadmium (4.23 ppm) were obtained at treatment temperature, T1 70°C after 1 hour of incubation time. These values were compared with the World Health Organisation maximum contaminant levels. Lead had the highest concentrations followed by cadmium which was closely followed by cobalt and then chromium had the lowest concentrations. Chemicals were released at all incubation temperatures except for BPA at 70°C after 1 hour of incubation time and their concentrations increased with increasing time. The study revealed that the concentrations of the chemicals found in the food cooked in polyethylene bags were above the recommended limits by the WHO and thus it is dangerous for consumption of food cooked using this kind of method. It is recommended that The use of toxic chemicals in the manufacture of polyethylene be reduced and the toxic chemicals substituted with less toxic ones.