• Journal of Korean Society on Water Environment
• /
• v.26 no.4
• /
• pp.614-621
• /
• 2010

A indigenous freshwater bivalve Unio douglasiae was introduced to compare the differences in the efficacy of algal bloom control and the appearances of mussel-mediated adverse effects between two different reservoirs such as mesotrophic (Shingu r.) and hypertrophic (Seokmun r.). We constructed the study mesocosm in the shore of each reservoir, stocked the mussel at density of $30indiv./m^3$ for 7 days, and measured daily the phytoplankton density and water quality. In mesotrophic reservoir, even though approximately 38% of suspended solids and chlorophyll-a was reduced by stocked bivalves for the first 3 days, algal density, ammonia and soluble reactive phosphorus gradually increased with increasing mussel death. In hypertrophic reservoir, mussels strongly inhibited suspended solids and chlorophyll-a by the termination of study with no increase of mussel death and nutrient, especially ammonia concentration. In both reservoirs, a strong selectivity showed mussels preferred to diatom rather than cyanobacteria and green algae without algal density and nutrient level. Our results indicate that an introduction of freshwater bivalve U. douglasiae is more strategic to improve water quality of hypertrophic than mesotrophic reservoir, but many preliminary studies on the treatment method and the selection of target water system are required.

• Journal of the Korean Society of Food Culture
• /
• v.18 no.1
• /
• pp.28-36
• /
• 2003

The purpose of this study was to investigate the effects of different moisture addition and sugar on the quality of Nokcha-julpyun, during 24hrs. As the result of the Hunter's color values, lightness, redness and yellowness were increased slightly or not after 24hrs and showed middle levels in $30%{\sim}40%$ moisture addition groups. It seemed that the addition of sugar to Nokcha-julpyun affected the redness and yellowness of 40% and 45% moisture addition groups more than the other groups. In texture profile, springiness of Nokcha-julpyun was not different significantly among all the groups during storage. Cohesiveness was getting higher by increase of moisture level and getting lower by storage. Sugar addition seemed to lower the rate of decrease of cohesiveness. Chewiness and hardness were getting lower by increase of moisture level and getting higher during storage. In this case sugar addition seemed to interfere the Nokcha-julpyun to be hard. Adhesiveness showed to be decreased during storage, but didn't show any correlations with water level. Sugar addition to Nokcha-julpyun seemed to increase springiness and adhesiveness slightly. 35% moisture and sugar addition group had the lowest values in springiness, hardness and cohesiveness. Both 40% groups and 45% moisture and sugar addition group had high values in springiness, cohesiveness and adhesiveness but had the lowest values in hardness and chewiness. In sensory evaluation, $30%{\sim}40%$ moisture addition groups showed good preferences in color, flavor, taste, tenderness and chewiness, and the 35% moisture and no sugar addition group showed the best overall acceptance among the groups. Above results indicated that moisture addition level with $30%{\sim}35%$ seems to give the best quality to Nokcha-julpyun added green tea powder with 6% level, and for the purpose to reduce the changes of texture profiles during storage, it is benefit to add sugar a little to Nokcha-julpyun.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.17 no.2
• /
• pp.85-94
• /
• 1988

This experiment was carried out to obtain the basic data for removal the astringency and off-flavor in soybean milk, by means of soaking of soybean in NaOH and $NaHCO_3$ solutions. The changes of phenolic compounds in soybean during soaking were investigated with HPLC and also the changes of flavor and sensority of soybean milk, prepared from soaked soybean were studied. Phenolic compounds of soybean were identified as chlorogenic, p-hydroxybenzoic, p-coumaric, ferulic and gentisic acid and, chlorogenic acid content was greater than the others. The chlorogenic acid of soybean was mainly neutral type and the other compounds were almost acidic type. Up to 85% of the chlorogenic acid was removed by soaking of soybean in 0.1% of NaOH solution for 8 hrs. Phenolic compounds of soybean was almost removed by soaking in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr. Chemical composition of soybean milks prepared from soaking of soybean in water, 0.1% NaOH and 0.5% $NaHCO_3$ solution were similar. Hexanol content of beany flavor in soybean milk was increased by soaking of soybean in NaOH solution, where as hexanal, propanal, pentanal contents were removed up to 60%. Color of soybean prepared from soaking of soybean in NaOH solution at high temperature were deep yellow but were high whiteness in soybean milk prepared from soaking of soybean in water at low temperature. Sensority of soybean milk prepared from soaking of soybean in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr was more favorable than the others.

• Journal of Animal Science and Technology
• /
• v.46 no.3
• /
• pp.427-436
• /
• 2004

The current study was conducted to determine the effect of suspension method on satisfaction level of Korean consumers and objective meat quality traits in Hanwoo longissimus dorsi(LD), triceps brachii(TB) and semimembranosus(SM) muscles. Eighteen Hanwoo steers were slaughtered and alternative sides were hung either by pelvic bone(TS) or Achilles tendon(Al). Sensory characteristics, WB-shear force, sarcomere length, water-holding capacity, saroomere length and cooking loss were determined after a 7-d chiller ageing. Higher carcass quality grade received significantly(p < 0.05) greater eating quality for LD, but the grade did not affect eating quality for both TB and SM. TS did not influence objective and subjective meat quality for TB, but that significantly(P < 0.05) improved eating quality for LD and SM. The most noticeable result was that when SM was tenderstretehed, eating quality was equivalent to that of nonna1ly hung LD. In relationship between objective and subjective meat quality assessments, eating qualty for LD had a significant(P < 0.05) relationship with intramuscular fat content, while that for SM was greatly(P < 0.05) related to saroomere length. The current study indicated that pelvic hanging was an effective way to improve eating quality both LD and SM, and carcass quality grades did not greatly reflect eating quality of SM and TB. The data also implied that instnunental measurements poorly estimated the satisfaction level of Korean conswners.