To investigate Oiji (traditional Korean cucumber pickles) with reduced sodium content based on the use of saline foods as a salt substitute, Oiji was prepared using glasswort powder (Salicornia herbacea L.), and its physicochemical properties and sensory evaluation were examined. The moisture content of Oiji was shown to be higher in those to which glasswort powder had been added compared to the control without addition of glasswort powder, and Oiji with 40% glasswort powder substitute showed the highest pH and lowest acidity, resulting in slow progression of fermentation. The salinity of Oiji among those containing glasswort powder substitute was significantly higher with increasing level of glasswort powder. The sodium content of Oiji was significantly reduced as addition of glasswort powder increased. The L value of Oiji decreased with increased addition of glasswort powder, whereas the a value was highest in the control. The hardness of Oiji was higher in the control than in Oiji containing glasswort powder. Taste acceptance was highest for Oiji with 20% glasswort powder substitute, whereas acceptance of appearance was higher for Oiji with 10% glasswort powder substitute. Flavor and texture acceptance was higher for the control. In the attribute difference test, significant differences were found in brownness, off-flavor, salty taste, and sourness. Based on the findings, 10-20% substitution of salt with glasswort powder did not significantly lower overall acceptance compared to the control while salinity of Oiji was maintained. Therefore, the potential production of low-sodium Oiji has been verified.
In order to study low salinity Oiji (cucumber pickled in salt) with a reduced content of sodium, which was accomplished by replacing the salt in this saliferous food, we produced Oiji using sea tangle and, then performed physicochemical and sensory evaluations. It was found that the moisture content of Oiji was decreased with increasing the amount of added sea tangle. The pH and acidity were significantly different between the samples made with sea tangle, and the pH and acidity showed no consistent tendency according to the amount of sea tangle powder added. The salinity of Oiji was the highest in the control Oiji (2.92%), and the higher the amount of sea tangle added, the lower was the salinity in the Oiji with the salt replaced by sea tangle (2.78 to 2.89%). The sodium content of Oiji was also the highest in the control Oiji (591.65 mg/ 100 g) and significantly decreased with the increasing addition of sea tangle (560.43~366.71 mg/100 g). The color value of Oiji showed a significant difference between the samples, with no consistent tendency according to the amount of added sea tangle powder. The hardness of Oiji was significantly greater in the Oiji with the salt replaced by 40% of sea tangle, with greater hardness noted as the amount of added sea tangle powder increased (217.70 g). As a result of the acceptance test of Oiji, there were significant differences between the samples in overall acceptance, appearance, and taste, showing that the Oiji with salt replaced by 30% of sea tangle was significantly highest in overall acceptance and taste. The attribute difference test showed a significant difference only for the brown color, while no significant differences were found between the samples for off-flavor, bitter taste, fermented taste, salty taste, sour taste, hardness and crispness. The above results demonstrated that when sea tangle was substituted for 30 to 40% of the salt content, the Oiji with a low content of sodium and low salinity can be produced with a high level of taste and overall preference. Therefore, this study firmly demonstrated that 30 to 40% of the salt can be replaced by sea tangle as a substitute in order to produce Oiji that has low salinity, a low sodium content.
To optimize the fermentation period of lightly salted Oiji, 3% salt was added to cucumbers that were fermented at 27±1°C for 3, 4, 5, 6, or 7 days, after which their physical properties (moisture content, salinity, pH, acidity, hardness) and sensory characteristics (acceptance test, difference test) were evaluated. The moisture content was highest at day 6. Hardness slowly increased as fermentation time increased, but not significantly. The pH was highest after 3 days of fermentation, and tended to decrease as fermentation time increased, with the largest drop occurring between 4 and 5 days, and the lowest pH occurring between 6 and 7 days. Acidity was lowest after day 3 of fermentation and highest after day 7. Acidity tended to increase as fermentation period lengthened. The L-value tended to decrease as salt concentration increased. The a-value declined from day 3 to day 5, then increased significantly by day 7. The b-value was highest after 7 days, with a tendency to increase as the fermentation progressed. Acceptance test results were highest for taste and overall acceptance after 5 days of fermentation. The difference test showed that the optimal lightly salted Oiji fermentation period was approximately 5 days. These results indicate that lightly salted Oiji fermented for 5 days produced the highest acceptance.