Abstract: In order to investigate the presence of non-thermal effect in the microwave irradiation heating hemp degumming process, two hemp degumming methods, microwave heating and water bath heating are compared within different times and different temperature conditions. The capable hemp residual gum content was used to determine the non- thermal effect during the heat processing. The results revealed that the capable hemp residual gum content of microwave heating was lower than that of water bath heating. With the increasing heating time and the heating temperature, the residual gum rate gap first increase and followed by the decreasing trend which indicated that in the microwave heating processing, there was some non-thermal effect except thermal effect with water bath heating.

Key words: miceowave, water bath, hemp degumming, non-thermal effect, residual gum content