Chandes of Cation Contents and Solubilities of Pectic Substances during Brining of Various Vegetables

Abstract

During pickling in brine, the changes of Ca^-, Mg^-, K^- and Na-contents and the compositions of pectic substances consisting of the water (W-P), the hot water (HW-P), the hexametaphosphate (HX-P) and the HCl-soluble (H-P) pectin fractions in various vegetables (leaf vegetables: chinease cabbage, crisp head type lettuse; edible roots: radish root, carrot root; fruits: cucumber, ) were comparatively investigated. The results obtained were as follows: (1) The total amounts of pectic substances in the ethyl alcohol-insoluble substances (AIS) prepared from various vegetables were little changed during brining for 14 days, though the composition ratio of HX-P was markedly decreased and those of W-P and HW-P were much increased. (2) The contents of Ca, Mg and K in AIS were apparently decreased during brining, while Na increased remarkably. From these findings, it is presumed that the permiation of NaCl into tissues of various vegetables during brining causes the ion exchanges of Na with Ca Mg and K of some components in AIS including pectic substances and releases Ca, Mg and K, which give rise to the increase of W-P and HW-P, decreasing HX-P, and H-P on the contrary.