• Journal of Life Science
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• v.33 no.5
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• pp.436-444
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• 2023

Scientific training, diet, and ergogenic aids are widely used to overcome the limits of humans' physical abilities and to achieve excellent sports records. The adoption of nutritional strategies is important for athletes to perform at their highest level, and one of the main factors determining endurance ability is increased fat metabolism. A ketogenic diet (high fat, low carbohydrates) has thus been proposed as an alternative strategy to maximize fatty acid oxidation during prolonged periods of exercise. However, studies have shown mixed results regarding the ergogenic value of a ketogenic diet. For this reason, exogenous ketone supplements (EKS, ingestible forms of ketone bodies, ketone esters, and/or salts) have been suggested to obtain nutritional ketosis, an acute transient increase in circulating acetoacetate (AcAc) and b-hydroxybutyrate (bHB) concentrations, without limiting carbohydrate intake. Some studies have suggested the beneficial effects of EKS on the performance of endurance exercises by providing an additional fuel substrate for peripheral tissues, such as cardiac and skeletal muscles, sparing carbohydrates/increasing fat oxidation and post-exercise recovery by increasing glycogen resynthesis in the liver/muscle, attenuating protein degradation, stimulating protein synthesis in the skeletal muscle, etc. However, many studies have failed to observe the beneficial effects of EKS as an ergogenic aid. As such, this review summarizes the theoretical basis of, as well as the proposed and proven effects of EKS on exercise performance and recovery to date.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.935-941
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• 2011

The growth inhibitory effects of kimchi prepared with solar salt were investigated. Chinese cabbages were brined with purified salt, four year-old solar salt, and Topan solar salt, and then mixed with other ingredients. The final salt concentration was adjusted to 2.2~2.4% (w/v) for each salt, and the kimchi was fermented at $7^{\circ}C$. When the acidity reached around 0.5~0.6%, the kimchi was used as a sample for further experimentation. MTT assay was used to measure the growth inhibitory effect of kimchi extracts (water, methanol) on BJ human foreskin normal cells, AGS human gastric adenocarcinoma cells, and HT-29 human colon carcinoma cells. Water extracts of all the kimchi samples showed growth inhibitory effects on cancer cells; however, there was no significant difference among the used salts. Methanol extracts of all the kimchi samples showed higher growth inhibitory effects compared to the water extracts. The methanol extracts of four year-old solar salt kimchi (AGS: 73%, HT-29: 48%) and Topan solar salt kimchi (AGS: 62%, HT-29: 46%) showed higher growth inhibitory effects than that of purified salt kimchi (AGS: 52%, HT-29: 39%). In addition, morphological changes of cancer cells (AGS, HT-29) and decreased cell numbers were observed when methanol extract of four year-old solar salt kimchi was treated to AGS and HT-29 cells. However, none of the kimchi extracts showed any growth inhibitory effect on BJ normal cells.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.105-114
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• 1974

Identification and change of microflora during the fermentation of anchovy Engraulis japonica, under the halophilic circumstance were investigated. The change of salinity and pH in meat and juice which decide the environment for microorganism and decomposition of nitrogenous compound which functions as a nutrient source were also discussed by measuring the content of total-N, amino-N, nonprotein-N, TMA and VBN, The fresh anchovy was mixed with rock salt (20 percent w/w) and stocked for six months. Through the fermentation lag phase of viable cells extended for 20 days that was obviously larger compared with other circumstances, hereafter increased to reach the maximum value of $5\times10^4$ total count per gram at 35 day stock. The stationary phase proceeded for 25 days. 540 strains were isolated and among them 11 genus of bacteria, 3 genus of yeasts, were identified and other 2 yeast strains of unidentified. At the initial stage of fermentation, Pseudomonas, and Helobacterium prevalently grew, at the middle stage, they disappeared rapidly and Pediococcus and yeasts completely dominated, where they are assumed to get directly involved with fermentation of fish, The PH value tended to decrease in the progress of fermentation and at 100 day stock it showed the minimum value of 5.5 to 5.6 in both meat and juice. The highest salinity of meat decreased to 18 percent, while in juice it decreased to 28 percent since 50 days stock. The content of total-N in meat gradually decreased to 2.8 percent, while in juice it increased to 2.3 percent at 100 day stock, However nonprotein-N was 1.8 percent and amino-N was 1.1 Percent. Since 100 days stock, the increasing rate of amino-M is too low it could be judged to entered the final stage of fermentation, In the first 20 days stock, the increase of VBN and TMA can be explained by the growth of putrefactive bacteria such as pseudomonas on the meat before salts penetrate into the fish meat, while reincrement after 100 days stock, is explained by decomposition of free amino acid due to the reactions of bacteria and enzymes.