Metal ions vegetable tissue

The ability of metal ions to modify the texture of fruit and vegetable tissue has been studied since 1939, when Kertesz (l) found that calcium ions improved the firmness of tomatoes. A very simplified generalization of the effects of metal ions on fruit and vegetable texture is that monovalent cations, usually Na+ and K, cause tissue softening. Examples of this softening effect include results with peas (2.31, dried peas (4), carrots (5), potatoes (6) and green beans (7). On the other hand calcium, a divalent cation,... 

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