Effects of the Low Temperature and Low Salt Solution on the Quality Characteristics of Salted Chinese Cabbage

저온-저염 절임기술이 절임배추의 품질 특성에 미치는 영향

The principal objective of this study was to evaluate the influence of temperature and salt concentration on the physicochemical properties of salted Chinese cabbage. Salted Chinese cabbage samples were prepared with various concentrations of salt(4, 5, 6 and 7%), and were stored for 10 days at three temperatures(8, 14, and $25^{\circ}C$). The salting ratio of Chinese cabbage evidenced a decreasing trend regardless of the salting temperature and salt concentration, and their decrement appeared relatively high as the salting temperature increased. The period required to achieve a critical salting ratio(85%) decreased with increases in the salt concentration at $25^{\circ}C$, and a similar trend was observed at lower temperatures(8 and $14^{\circ}C$). The salinity of all samples evidenced an increasing trend during the salting period, and at $25^{\circ}C$, in particular, a continuous increment was observed. At salt concentrations of 4%, the critical salinity(2.2%) was not achieved regardless of the temperature and salting period. The pH of salted Chinese cabbage achieved critical pH in 3 days at a salting temperature of $25^{\circ}C$, but the critical pH 5.5 of samples at 8 and $14^{\circ}C$ appeared after a long period of approximately 4 to 10 days. The average hardness values of salted Chinese cabbage at a salting ratio of 85% were approximately 1.49 MPa, 1.87 MPa, and 1.97 MPa, respectively, at three temperatures($25^{\circ}C$, $14^{\circ}C$, and $8^{\circ}C$). The initial reducing sugar content of cabbage juice was 11.8 mg/$m{\ell}$, and this value decreased substantially to 3 to 5 mg/$m{\ell}$ on day 1.