Abstract
Carrots were cooked in a conventional cooker, a pressure cooker and a microwave oven. Viscosity and pH of the carrot extracts were measured.
Water soluble pectin was extracted from the carrot and then alcohol-insoluble substances (AIS) were taken from it. The contents of galacturonic acid and methoxyl group in AIS were measured, and the properties of pectin jelly made from AIS were examined.
The results obtained were as follows:
1) Viscosity of the carrot extract cooked in a microwave oven was a little higher than that obtained by other methods.
2) The pectin jelly became increasingly hard in a conventional cooker, a pressure cooker and a microwave oven, and got softer with an increase of cooking time.
3) The amount of galacturonic acid which was soluble in the carrot extract increased along with a lengthening of cooking time.
4) The amount of methoxyl group in pectin which was soluble in the carrot extract decreased with a lengthening of cooknig time.
5) The amount of methoxyl group correlated with the hardness of pectin jelly.
