Abstract：This experiment to sour pickled cabbage as raw materials, mainly studies different drying methods, different drying conditions in the process of the sour pickled cabbage dry moisture in sauerkraut, flavor substances. This experiment, the hot air drying, freeze drying and vacuum drying of three drying methods, and studied again each of these three kinds of pickled vegetable moisture content in drying process, lactic acid content, free amino acid content, the change of nitrite content and flavor substances. Experiment with fresh pickled sour pickled cabbage as raw material, using method of titration, ninhydrin, gracy spectrophotometry for determination of the sour pickled cabbage, lactic acid, free amino acids, nitrite content. In freeze drying, for example: before and after freeze drying, lactic acid content was 0.18%, 0.17%, respectively. Free amino acid content was 0.7477/mL and 0.7342/mL, respectively. Nitrite content were 9.2889/mL and 9.2889/mL. The results show that the hot air drying of sauerkraut lactic acid content, free amino acid content, nitrite content and flavor of most influence and impact on the quality of pickles. To the maximum extent and freeze drying effect is best, reserve the original quality sauerkraut.
Keywords Pickled vegetable Hot air drying Freeze drying Vacuum drying Moisture Lactic acid Free amino acid Nitrite Flavor substances...