Colorimetric determination of carbohydrates in some brands of beer in Ghana as an indication of their glycemic index in the management of diabetes type II

Abstract

There is worldwide campaign against the consumption of sugar said to be a possible cause of obesity and diabetes. The major sources of added sugars are regular soft drinks, beers, sugar candies, cakes, cookies, pies, fruit drinks, dairy desserts and milk products (ice cream, sweetened yogurt and sweetened milk), and other grains. The use of sugar in brewing is widespread and the consumption of beer is a matter of concern as one of the possible causes of diabetes type II. The 6 brands of beer produced in Ghana namely Guinness, Stone (produced from rice), Root Extra (produced from cassava), Star, Gulder, Club were therefore analysed for their total carbohydrate contents. The phenol-sulphuric acid method was employed and the absorbance was measured at 485nm. The total carbohydrate contents of the 6 beer samples expressed in terms of glucose ranged from the maximum of 34.58 + 1.5 g/L for Guinness equivalent to 15 cubes of sugar per litre to a minimum of 12.60 + 1.5g/L for Stone beer equivalent to 5 cubes of sugar per litre. The average value of 23.30 + 0.3g/L was recorded for Root Extra beer which was equivalent to 10 cubes of sugar per litre. The other brands namely, Star, Gulder and Club had values 19.01+ 1.4 g/L, 22.10 + 0.5g/L and 24.05 + 2.7g/L equivalent to 8.5, 9.6 and 10.5 cubes of sugar per litre respectively.The amounts of carbohydrates in the 6 brands of beer investigated though variable were too high and could cause significant increase in glycemic index leading to poor control of blood glucose levels in people with diabetes type II conditions.