The present invention relates to a molecular press dehydrating agents for vegetative tissues comprising starch hydrolysates or their derivatives. Preferably, the starch hydrolysates of the present invention may be maltodextrin specifically, and the derivatives of starch hydrolysates may be a modified starch, main component of which is starch sodium octenyl succinate. The molecular press dehydrating agents of the present invention may comprise sodium caseinate of low molecular weight additionally. The molecular press dehydrating agents of the present invention can cause cytorrhysis phenomenon and dehydrate plant tissues by mixing them together. While the molecular press dehydrating agents of the present invention show superior dehydration and drying effect in a similar level to existing dehydrating agents, there are no limitations for food use in legal, social and economical aspect, and it can be supplied in large quantities. Therefore, the dehydrated tissues and exudates obtained by using the dehydrating agents of the present invention may be usefully applied to various fields of manufacture such as foods and beverages, feeds, beauty materials, medicines, flavorings, agricultural chemicals, coloring agents, etc.