The Effects of Ashed Egg Shell and Some Specialized Salt on the Hardness and Hardening Mechanism of Brined Ume Fruit
1992 Volume 39 Issue 12 Pages 1128-1134
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1992 Volume 39 Issue 12 Pages 1128-1134
To make clear the effect of ashed egg shell on the hardness of brined ume fruit (Prunes mume Sieb. et Zucc), ume fruit was brined with either regular salt (S1), or a specialized salt solution (S2), after an addition of lime (Calcium hydroxide) or ashed egg shell. After that, 1% S1 or S2 was added against the brined ume fruit once a day until their content in the fruit reached to 15% concentration. Six months after the final addition of S1 or or S2, the hardness and content of Ca and Mg in the brined ume fruit were measured with a rheometer and high performance liquid chromatography, respectively. The pectin content was also determined in the same relative samples. The results obtained were as follows: (1) The texture of the ume fruit softend with brining, but that brined with S2 was a little harder than that brined in S1. In addition, the lime or ashed egg shell suppressed the decrease of the hardness of the fruit brined with either S1 or S2; (2) Ca content of the fruit increased with the addition of lime or asked egg shell; (3) During the brining, the HSP (HCI soluble pectin) increased and WSP (Water soluble pectin) and HXSP (Hexametaphosphate soluble pectin) contents were decreased. But in the case of fruit brined with S1, WSP decreased and HSP and HXSP increased with the addition of lime or ashed egg shell. On the other hand, in the case of brining with S2, WSP decreased and HSP increased. As a result of these experiments, it was presumed that the increased amount of Ca ions in the tissue might form much more additional cross-linkage within the pectin molecules during brining with lime or ashed egg shell, which follows the decrease of WSP and increase of HSP or HXSP that was maintained by the hardness of texture.
