When processing a hide, the level of crystallinity becomes lower when the hide is affected stronger during processing. In our case, the start and finish temperatures of the second endothermic effect coincide for both hide samples, which proves that collagen is not affected. The third endothermic effect is related to the destruction of hide tissue. After 22 days of storage, this results in lower starting and higher finishing temperatures compared with those samples which were stored for 1 day. The lower initial temperature indicates the beginning of the deterioration of the outer layers of the hide, but due to pressed collagen fibres, the thermal effect ends at a higher temperature. Summarising the results, it can be concluded that hide storage at 4uC under vacuum can prolong the storage duration to 3 weeks without any observable symptoms of hide tissue deterioration and without any changes to the hide collagen structure. Of course, one or other preservation methods can be validated only by checking the quality of the leather processed from hide preserved by this method. Since leather quality depends upon the condition of the raw material, the behaviour of the hide during processing and the properties of the leather produced from such hide confirm or deny the suitability of preserved hide for the manufacture of leather. As the main protein in hide is collagen, its condition determines the quality of the leather produced. This was why the changes in collagen were initially investigated. The processing of leather from hide samples stored for 5 and 19 days under vacuum was carried out. Such solutions were conjugated: liming and washing after liming; deliming-bating and washing after deliming-bating. These mixtures and pickling solutions were analysed with the aim of establishing the amount of collagen proteins removed. The results are presented in Table 6. It is known that the amount of collagen proteins removed during liming usually varies in the range 0.2�C0.5 g/kg of hide. When liming the vacuumed hide stored for 21 days, the amount of collagen proteins removed was higher than those removed from salted hide. Also, it somewhat exceeded the amount removed from Cefetamet pivoxil HCl unpreserved hide or that stored for a shorter period of time following vacuum. On the other hand, the amount of collagen proteins removed during liming was not higher than the above-mentioned value for any of the samples tested. Comparison of the total amount of collagen proteins removed during all beamhouse processes was very close to the results obtained for vacuumed or unpreserved hide. It can be concluded, therefore, that vacuumed hide is no more affected than unpreserved hide when it is processed. The second step was the investigation of hide properties during the chrome tannage process. Exhaustion of Ginsenoside-Ro chromium compounds, content of Cr2O3 in leather and distribution of chromium in separate leather layers were evaluated after tanning. Data are presented in Table 7. The comparison of chroming process indexes showed that better results were achieved when the hide samples stored for longer periods of time were processed. In such cases, the exhaustion of chromium compounds was higher. Accordingly, the amount of Cr2O3 in this leather was also higher. This 
can be explained on the grounds of more intense opening up of the derma structure in the case of hide stored for a longer period prior to processing. As a result, the derma of this sample was more accessible for chromium compounds, which led to the higher chromium exhaustion and to higher Cr2O3 content in the leather. Consequently, the higher content of Cr2O3 leads to higher shrinkage temperature, which is the main reason for the higher shrinkage temperature of the leather produced from the hide stored under vacuum for 19 days.