CHANGES IN THE CHARACTERISTIC PROPERTIES OF EGG-SHELL DURING ASHING PROCESS AND ITS EFFECT ON HARDNESS OF BRINED UME FRUIT

Physico-chemical components, characteristic properties and maintenance in hardness of brined'' ume'' fruits by dried egg shells (DES) were c ompared with those of ashed egg shells (AES) under various ashing temp eratures. Calcium (Ca) content of the main inorganic ingredients from DES was about 38%, and its content of AES increased to 70 approximatel y 71% in AES-800 (ignited at 800-degrees-C) and AES-900. Observation o f particle surfaces of AES-750, AES-800 by scanning electron microscop y (SEM) revealed the acceleration of the growth of pores and projectio ns. At this temperature, fine particles in a size range from 750-degre es-C to 800-degrees-C were formed and then the phase change of morphol ogical construction occurred. The weight loss of DES measured by therm ogravimetry (TG) trailed a shoulder at about 670-degrees-C gradually a nd then paralleled at about 820 approximately 835-degrees-C (weight lo ss ratio 44.0%). Also, differential thermal analysis (DTA) of DES show ed a weak exothermic reaction with a peak at about 330-degrees-C, and a large endothermic reaction with a peak temperature at about 805 appr oximately 810-degrees-C. By X-ray diffraction analysis, the main inorg anic compound of DES was 93.96% of CaCO3 (m.p. 825-degrees-C), and the formation of fine particles after the phase change of morphological c onstruction at about 820 approximately 835-degrees-C concluded 99.48% CaO. The experimental results of the changes of egg shells under vario us ashing temperatures are shown in a reaction formula (CaCO3-->CaO CO2) at about 820 approximately 830-degrees-C, and it was concluded fr om the experiment obtained by X-ray diffraction, TG and DTA, atomic ab sorption spectrometry (AAS) and observation with SEM. Also, it was fou nd that the brined ''ume'' fruits increased in yield and hardness main tained was with the addition of AES ashed at over 700-degrees-C. Espec ially in the case of using AES above 800-degrees-C, the effect was rem arkable.