Quality and sensory characteristics of tofu prepared with concentrated to 8 oBrix deep ground sea-like water (SW) were investigated to check the availability for coagulants. The tofu was coagulated with three kinds of commercially coagulant, such as MgCl2, CaSO4 and glucono-δ-lactone. Different amounts of SW and soybean milk were added: SW-20 g/L, SW-25 g/L and SW-30 g/L. The moisture content and pH were significantly lower in which preparation with glucono-δ-lactone coagulated tofu, and others has not significantly difference each other. The mineral contents in the coagulant influenced the mineral content of the tofu, which contained larger quantities of major minerals. However, the mineral content of the tofu was not affected of the mineral concentration in the coagulant. The L and b values of the tofu prepared with SW were not significantly different. The hardness of the tofu prepared with the commercial coagulants was significantly lower than that of the tofu produced with the SW. The sensory property was lower when the hardness was lower and higher. In conclusion, the quality characteristics of SW-prepared tofu were not significantly different from those of the tofu prepared with the commercial coagulants, but the texture and the taste of the SW-prepared tofu were excellent.

Ground seawater quality was investigated, and the algal growth potential (AGP) tests were performed along the Tongyeong coast to examine the inflow of materials, which is needed for the red tide species Cochlodinium polykrikoides to grow. The study was conducted to determine the mechanism for C. polykrikoidesred tides. Water temperature, salinity, pH, and dissolved oxygen (DO) ranged from 16.05 to 20.74°C, 18.20 to 32.11 psu, 6.00 to 7.61, and 3.41 to 7.91 mg/L (41.4– 96.1%), respectively. No seasonal variation was observed in water temperature. The salinity, pH, and DO saturations at most stations were lower than those of coastal seawater at Tongyeong. The NH4 +-N, NO2+3 --N, PO4 3--P concentrations ranged from 0.43 to 16.00μM, 1.50 to 132.38μM, and 1.30 to 6.29μM, respectively; the values at some stations were much higher than observed in Tongyeong coast seawater. Using seawater from station B, C. polykrikoides grew consistently, with a high growth rate, similar to the red tide in nature. This seawater appeared to contain materials needed by C. polykrikoides to grow. Therefore, C. polykrikoides red tides seem to occur wherever the ground sea water contains materials that are needed for its growth.

One hundred and thirty two ground water samples from the Ulsan area were divided into urban and non-urban groupings and were assessed between 1993 and 1996. The results of statistical analysis were as follows: There were significant differences between the two groupings in the average value of the following water quality parameters: total hardness, nitrate, pH, iron, ammonia and chloride ion in the order of Z-score. Because total hardness, nitrate, and pH were also significant in ANOVA test, these three parameters can be regarded as the most sensitive parameters of artificial pollutants. By the comprehensive comparison of Ulsan water quality to that of Kangwon-do, all of the major parameters(pH, KMnO_4 consumption, sulfate, chloride and hardness except nitrate) were confirmed as being significantly increased levels.