Abstract: This text research quality and physiological change law of activation of red earth grape fruit by Chitosan, Is it preserve temperature , Chitosan density and scribble time three factor impact on red earth grape Fresh-keeping at the same time. The experimental result indicates, temperature is the main factor influencing grapes to keeping fresh. The results show the fourth is the best method for grapes fresh-keeping too. This method is putting the grape in the density 1% of the chitosan with 1 min and preserving the 0.5℃. Fall grains of rate, rotten rate, rate of weight loss at the same time, solubility firm shape content of thing reduce, the hardness dropsied. quality drops SOD enzyme activation reducing, the content of MDA increasing, respiratory intensity and PG enzyme presenting a peak, and the activation of POD enzyme strengthen, this means the fruit is old and feeble gradually.

Key words: Chitosan, Red Globe Grape, Fresh-keeping, Physiological activation