Determination of chemical composition of sour pickled cabbages collected from northeast of China

Sour pickled cabbage is a traditional Chinese food mainly fermented by lactic acid bacteria. Sour pickled cabbage is home-made product by individual families with different material and processing, so the flavor, nutrition or safety of pickled cabbage may vary. In order to investigate the relationship between chemical composition and quality of pickled cabbage, the acidity, total sugar, nitrite, protein and sodium chloride levels of five naturally fermented sour pickled vegetables were detected using acid-base titration method, direct titration, hydrochloric acid naphthalene ethylenediamine kieldahl method, and indirect precipitation titration method, respectively. The results showed that the acidity of pickled cabbage were between 0.283% and 0.891%, the total sugar content were between 3.96% to 4.37%, the nitrate content were from 0.167 g/kg to 0.267 g/kg, the protein content were between 0.0169% and 0.0218%, the sodium chloride content were between 0.412% and 0.447%, respectively.