• Journal of Korean Medical classics
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• v.35 no.2
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• pp.33-49
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• 2022

Objectives : This paper aims to investigate the role of the sweet flavor within the contexts of 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin' and the meaning of the two concepts. Methods : Related contents in databases including the Siqu Quanshu were searched with 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin', whose understanding and application were examined. Results & Conclusions : The theories of 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin' originate from Cheng Wuji's comparison of the Gancaoqianjiangtang and Shaoyaogancaotang in the 29th verse of the Shanghanlun. The two terms first appeared in the Qing period among the Wenbing school. In other medical texts, the combination with sweet flavors could be found with salty, bitter and bland flavors other than with pungent and sour. The role of the sweet flavor in 'pungent and sweet becoming Yang' and 'sour and sweet becoming Yin' is to accomplish the dispersing and converging action slowly and effectively, by supplying energy in small amounts preventing it from happening too quickly, corresponding to its Earth nature of the Five Elements which harmonizes the Yin and Yang. While 'becoming Yin' and 'becoming Yang' could be understood as tonifying Yin and Yang, it could also be understood as 'doing Yin' and 'doing Yang', The specific actions differ according to herb and mixture. The point of distinction between the aforementioned tonification and that of medicinals that have Yin and Yang tonifying properties is that due to the other flavor that is matched with the sweet flavor, Qi is given motility which allows for tonification without stagnation.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.785-794
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• 2020

Food Codex regulations have set freshness limits for oils used to fry food, such as potato and fish products, and fried food itself; however, no such freshness limits have been set for meat products, such as sweet and sour pork. The freshness standard suggest that acid values (AVs) and peroxide values (POVs) for frying oil should be less than 2.5 and 50, respectively, whereas AVs and POVs for common fried food should be less than 5.0 and 60, respectively. Therefore, in this study, we investigate the effect of the number of frying cycles on oxidation-promoted changes in the oils used to fry sweet and sour pork and fried food itself during repeated frying over 10 d by determining their AVs and POVs, which were found to be highly correlated. Soybean, canola, palm, and pork lard oils could be reused approximately 37, 32, 58, and 87 times, respectively, to fry sweet and sour pork based on oil freshness, and 78, 78, 81, and 286 times, respectively, based on the freshness of fried food. Our data may help establish food-quality regulations for oils used to fry animal-based foods.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.203-210
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• 2023

Taste is classified into five types, each of which has evolved to play its respective role in mammalian survival. Sour taste is one of the important ways to judge whether food has gone bad, and the sour taste receptor (PKD2L1) is the gene behind it. Here, we investigated whether ʟ-pyroglutamic acid interacts with sour taste receptors through electrophysiology and mutation experiments using Xenopus oocytes. R299 of hPKD2L1 was revealed to be involved in ʟ-pyroglutamic acid binding in a concentration-dependent manner. As a result, it is possible to objectify the change in signal intensity according to the concentration of ʟ-pyroglutamic acid, an active ingredient involved in the taste of kimchi, at the molecular level. Since the taste of other ingredients can also be measured with the method used in this experiment, it is expected that an objective database of taste can be created.

• Journal of Welding and Joining
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• v.32 no.5
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• pp.13-20
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• 2014

A brief overview is given of the corrosion and hydrogen diffusion behaviors of high strength pipe steel in sour environment. Firstly, hydrogen adsorption and diffusion mechanism of the pipe steel is introduced. Secondly, the effect of iron sulfide film precipitated as a result of the corrosion reaction on the steel surface on hydrogen reduction reaction and subsequent hydrogen permeation through the steel is discussed. Moreover, the hydrogen diffusion behavior of the pipe steel under tensile stress in both elastic and plastic ranges is reviewed based on a number of experimental permeation data and theoretical models describing the hydrogen diffusion and trapping phenomena in the steel. It is hoped that this paper will result in significant academic contributions in the field of corrosion and hydrogen related problems of the pipe steel used in sour environment.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.171-176
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• 2016

Sour gas is natural gas or any other gas containing significant amounts of hydrogen sulfide ($H_2S$). Natural gas is usually considered sour gas if there are more than 5.7 milligrams of $H_2S$ per cubic meter of natural gas, which is equivalent to approximately 4 ppm by volume under standard temperature and pressure We have surveyed on the treatment and removal technology of sour gas, sour gas include a lot of hydrogen sulfide($H_2S$), Carbon dioxide($CO_2$), utane($C_4H_{10}$) and mercaptan($C_nH_{4n-1}SH$) etc. We need high technology for development for these kinds of raw gases and we should specially take care of treating and removal of theses raw gases. Therefor we are going to describe about these kinds of raw gases and about methods how to treat these kinds of gases.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.117-133
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• 2016

This study was to investigate the quality characteristics of sourdough bread made with 4 kinds of kamut sour starter. Kamut sour starters were made according to dough yield of sour starter and yeast adding on sour starter. We exmanined pH level, fermentation rate, specific volume, CrumbScan, moisture content, color value, texture analyzer, shelf-life test and sensory evaluation for observing quality characteristics of sourdough bread. From the results of pH measurement, kamut sourdough breads had lower pH value in dough and crumb pH than CON. In the experiment of dough's fermentation rate, CON had the rapidest fermentation rate among the samples initially, but the experimental groups also expanded as much as CON grew in spite of its slow fermentation. Specific volume and CrumbScan results suggested that CON had the largest volume. In addition, CM and TM had smaller volume than Pool and Biga. The sample that had the highest moisture content was Pool because its sour starter had the most amount of water. In color value test, CON had lighter crumb and crust color than other specimens. As a result of the TPA and shelf-life tests, CON had the softest hardness after 24 hours. However, Pool had similar hardness with CON after 72 hours. The result of the acceptance test of sourdough breads indicated that people prefered Pool and Biga to TM and CM. Difference test showed similar results with prior experiments. As the final outcome, Poolish was chosen as the optimal formula for kamut sour starter.

• Corrosion Science and Technology
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• v.17 no.5
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• pp.249-256
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• 2018

Metallic structures in the oil and gas production undergo severe degradation due to sweet and sour corrosion caused by the presence of $CO_2$ and $H_2S$ in the fluid environment. The corrosion behavior of 304 austenitic stainless was investigated in the presence of varying concentrations of $CO_2$ or $H_2S$ and $CO_2+H_2S$ to understand the effect of the parameters either individually or in combination. Potentiodynamic polarization study revealed that a small amount of $CO_2$ aided in the formation of calcareous deposit of protective layer on passive film of 304 steel, while increase in $CO_2$ concentration ruptured the layer resulting in sweet corrosion. The presence of $S^{2-}$ damaged the passive and protective layer of the steel and higher levels increased the degradation rate. Electrochemical impedance studies revealed lower polarization resistance and impedance at higher concentration of $CO_2$ or $H_2S$, supporting the outcomes of polarization study. XRD analysis revealed different types of iron carbides and iron sulphides corresponding to sweet and sour corrosion as the corrosion products, respectively. SEM analysis revealed the presence of uniform, localized and sulphide cracking in sour corrosion and general corrosion with protective carbide layer amid for sweet corrosion.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.41-47
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• 2017

Genetic differentiation and antioxidant activities in ethanolic extracts from leaves of Bouea macrophylla Griffith were determined. The result revealed genetic differentiation among sour ma-praang, ma-yong and sweet ma-praang of B. macrophylla Griffith (${\phi}_{PT}=0.772$, p-value=0.000). In addition, high genetic diversities were found in sour ma-praang and sweet ma-praang populations (P: 51.4 and 57.1 %; He: 0.1900.035 and 0.2240.036, respectively), but low genetic diversity was found in ma-yong population (P: 8.6 %; He: 0.0350.021). Total phenolic contents of sour ma-praang, ma-yong and sweet ma-praang were estimated as $680.51{\pm}89.81$, $701.03{\pm}59.89$ and $530.85{\pm}41.23mg$ gallic acid/g extract, respectively. Free radical scavenging activities of sour mapraang, ma-yong and sweet ma-praang were found (1/EC50=4.17, 1.43 and 1.37, respectively) corresponding with metalchelating activities (1/EC50=0.83, 0.65 and 0.17, respectively). Therefore, the obtained data may be applied to cultivation and utilization of their leaves as source of natural phenolics and antioxidants.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.829-836
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• 2008

This study was carried out to investigate the properties of mul-kimchi made with allium victorialis. Chemical and sensory characteristics were determined during fermentation at $4^{\circ}C$ for 4 weeks. The pH decreased with an increase in total acidity. Mul-kinchi showed salinity properties ranging within $1.0{\sim}1.5%$ during fermentation. Hunter's color L, a-values were gradually decreased, but b-value was increased. In the texture, hardness and strength decreased as the aging time increased. The numbers of total- and lactic bacteria cells rapidly increased up to the second week, and this slowly increased thereafter. Sensory evaluation of mul-kinchi was favored for appearance, flavor, taste, texture and overall acceptability during the second week. Sensory properties of well ripened odor and sour taste negatively correlated with physicochemical properties of pH and hardness. Sour odor and sour taste were positively correlated with acidity and total- and lactic acid bacteria.

• Journal of the Korean Society of Food Culture
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• v.20 no.3
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• pp.315-322
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• 2005

Kimchi noodle have a original taste and characteristics. This noodle was used for sour kimchi, kimchi taste powder, red bean fiber and emulsified oil etc. with RS(resistant starch) premix as blended wheat flour mixed to resistant starch. For manufacturing process of this kimchi mixed dry noodle, suitable kimchi of $pH3.70{\sim}3.80$ was required storage period during $4{\sim}5days$ at room temperature. At this point, the suitable treating amount of sour kimchi was about 20%(w/w) level. Manufacturing of kimchi noodle could be at the suitable manufacturing condition from use of kimchi taste powder and red bean fiber etc. Calori of this kimchi noodle was 308.17Kcal/100g as low level than wheat flour noodle as 355.82Kcal/100g, decreasing effect of calori was about 13.39%. This kimchi noodle had a characteristic sour and hot taste, that wasn't required the special seasoning and/or soup at this result.