• Applied Biological Chemistry
• /
• v.22 no.2
• /
• pp.65-90
• /
• 1979

This study was conducted to establish the brewing method which would be useful for the production of Kochuzang. Kojis, which were made from various materials and microorganisms under a covered condition, were investigated and compared. Yeasts (Saccharomyces rouxii and Torulopsis versatilis) were added to Kochuzang, and the enzyme activity, microflora, chemical composition, nitrogen content, alcohol content and free sugars of Kochuzang were investigated and analysed. The results obtained are as follows: 1. Koji making (1) Glutinous rice-soybean group was superior to glutinous rice group in the saccharogenic and liquefying amylase activities of three day-Koji. (2) Protease activity (acid, neutral and alkaline) of glutinous rice-soybean Koji, which was inoculated with Aspergillus oryzae A, was increased till the 5th day, while other groups showed maximum activity after the 3rd day. (3) The maximum cellulose activity of Aspergillus oryzae B-Koji and A-Koji was observed after the 2nd day and the 3rd day, respectively. High cellulose activity of Aspergillus oryzae B-Koji and A-Koji was respectively shown in glutinous rice group and glutinous rice-soybean group at maximum. (4) Compared with glutinous rice Koji, glutinous rice-soybean Koji gave larger number of yeast and aerobic bacteria. 2. Kochuzang Fermentation (1) Each Kochuzang group shoved different liquefying and saccharogenic amylase activities. The highest activities were generally shown in 10 to 40 days after mashing and remarkably reduced in the last stage of aging. (2) Protease activities of each group were strong in order of acid, neutral and alkaline protease. Especially acid protease showed highest activity at the 40th to 50th day Kochuzang. (3) Each group showed maximum cellulase activity in the 40th and 50th day-Kochuzang and then decreased. (4) Osmophilic yeast of yeast-added Kochuzang after one-month aging was distinctively outnumbered compared with non-yeast-added Kochuzang, but two groups were similar after two months. (5) Yeast-added group and non-added group gave almost the same number of halophilic lactic acid bacteria in Kochuzang, but the non-added group gave slightly larger number of aerobic bacteria than the yeast-added group. (6) Amino nitrogen contents in all test group were increased rapidly till the 60th day of Kochuzang aged. After that the contents were increased slowly. (7) Ethyl alcohol contents of 20day-fermented Kochuzang were high in order of Saccharomyces rouxii-added group, Torulopsis versatilis-added group, Saccharomyces rouxii and Torulopsis versatilis mixed group and non-yeast-added group. But all test group showed about 2% in ethyl alcohol content after 40days of aging. (8) Alcohol content in the 7 month-aged Kochuzang of all test groups was high in order of ethyl alcohol, n-butyl alcohol, n-propyl alcohol and iso-propyl alcohol. Torulopsis versatilis-added group had the highest value of ethyl alcohol, n-propyl alcohol and n-butyl alcohol. (9) Reducing sugar in Kochuzang was increased after 20 days of aging compared with the 10days-ferment. The reducing sugar content in Saccharomyces rouxii-added group was distinctively small compared with that of other groups, decreasing after 30days of aging. (10) Rhamnose, fructose, glucose and maltose were isolated from the 10 day fermented Kochuzang. Raffinose was also found after 300 days-aged group, and fructose content was high in the 300days-aged Kochuzang. However, glucose content was smaller than that of 10days-fermented Kochuzang. (11) For the organoleptic tests of Kochuzang, taste, flavour and color of yeast-added group were superior to the non yeast-added group. Especially the complex yeast group among the yeast added groups were the best of all. Yeast-added group after 300 days of aging took higher paint in flavour test than that of non-added group. Therefore, brewing method like complex yeast added group seems to be advantageous for short time brewing Kochuzang.

• Applied Chemistry for Engineering
• /
• v.21 no.6
• /
• pp.621-626
• /
• 2010

Anion exchange membranes can be used for reverse electrodialysis for electric energy generation, and capacitive deionization for water purification, as well as electrodialysis for desalination. In this study, anion exchange membranes of poly((vinylbenzyl) trimethylammonium chloride-2-hydroxyethyl methacrylate)/poly(vinyl alcohol) were prepared through the polymerization of (vinylbenzyl)trimethylammonium chloride and 2-hydroxyethyl methacrylate in aqueous poly(vinyl alcohol) solutions, esterification with glutaric acid, and cross-linking reaction with glutaraldehyde. We investigated electrochemical properties for the anion exchange membranes prepared according to experimental conditions. Ion exchange capacity and electrical resistance for the membranes were changed with a variation in the monomer ratio in polymerization. Water uptake and conductivity for the membranes decreased with an increase in the content of glutaric acid in esterification. The change in the time of crosslinking reaction with the formed film and glutaraldehyde affected electrochemical properties such as water uptake, conductivity, or transport number for the membranes. Chronopotentiometry and limiting current density for the anion exchange membranes prepared were measured.

• Korean Journal of Microbiology
• /
• v.27 no.3
• /
• pp.216-220
• /
• 1989

As the bsic study about protoplast fusion of amylolytic fungus Aspergillus oryze and nonamyloytic sugar fermenter, Saccaromyces cerevsisae, the intraspecific protoplast fusion of A. oryzae was carried out and the properties of the obtained fusants were investigated. For protoplast fomation from mycellia of auxotrophs, Novozyme 234 as lytic enzyme was the most effective and optimal pH was determined to be pH 5.5-6.0. When the two types of protoplasts were treated with a fusogen including 30% PEG4000, they fused effectively and most of fusants were heterokaryons. Protoplasts aggregated with 30% PEG4000 after fusion treatment were observed by the microscope. Protoplast regeneration frequency was 1.46 to 13.8% and complementation frequency of fusion was 0.12 to 0.16. Fusant strains had a 1.5-fold DNA content compared to that of parent strain. And amylase activity was intermediate between those of parent strains.

• The Korean Journal of Mycology
• /
• v.39 no.1
• /
• pp.88-89
• /
• 2011

To investigate liver toxicity of traditional rice wine, traditional rice wine was prepared by using cooked rice, Rhizopus stolonifier No. 17 nuruk and Saccharomyces cerevisiae. After concentrated the traditional rice wine, it was orally administered into Sprague-Dawley(SD) rats and then changes of its body weight and biochemical parameters of the blood were investigated. All of male and female SD rats did not show any changes in its body weight during two weeks after administering the traditional rice wine concentrates and also biochemical parameters such as aspartate aminotransferase (AST or GOT), alanine aminotransferase (ALT of GOT) and alkaline phosphatase activity were not different compared to control. This results indicated that the traditional rice wine has not any toxicity.

• Applied Biological Chemistry
• /
• v.43 no.4
• /
• pp.253-259
• /
• 2000

In order to study the effects of the maturing temperature of kanjang(Korean traditional soy sauce) mash on the distributions of chemical compositions and sensory characteristics of kanjang, test kanjang mash prepared by mixing one part of meju and three parts of 20% salt solutions was matured at 15, 30 and $45^{\circ}C$ for 60 days respectively. It was found that although the higher the maturing temperature upto $45^{\circ}C$ for 60 days of maturing the higher total nitrogen, total free amino acids and pigment content in kanjang could be obtained, better quality kanjang containing the lower acetic acid, butyric acid and pyroglutamic acid with the higher ratio of the glutamic acid to the total free amino acids and the higher sensory evaluation scores could be prepared by maturing kanjang mash at $15^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.27 no.6
• /
• pp.964-971
• /
• 1995

Volatile flavor compounds and free amino acids in untreated and hydrolysate pen shell by-product produced with APL 440 protease were compared by vacuum simultaneous steam distillation-solvent extraction/gas chromatography/mass spectrometry. A total of 109 volatile flavor compounds were detected in hydrolysate (65 compounds) or the 109 volatile flavor compounds were detected in untreated pen shell by-product (88). These compounds were composed of aldehydes(16), ketones(17), alcohols(31), nitrogen containing compounds (16), aromatic hydrocarbon compounds(8), esters(3), and miscellaneous compounds (17). Levels of aldehydes and aromatic hydrocarbons decreased after hydrolysis, whereas levels of nitrogen containing compounds increased 3 times than in untreated pen shell by-product. Taurine, known to be having a physiological function, was accounted for 31.25% of total amino acids in hydrolysate.

• Korean Journal of Food Science and Technology
• /
• v.16 no.1
• /
• pp.1-6
• /
• 1984

The three kinds of Kochujang were prepared with liquid koji equivalent to 30%, 50%, and 70% of brewing water. The qualities of the Kochujangs during aging at $25^{\circ}C$ for 4 months were compared with those of the control group which was made from solid koji. There were no significant differences in the contents of moisture, crude protein, crude fat, NaCl and ethyl alcohol between test groups. The contents of amino nitrogen, soluble nitrogen, reducing sugar and pH of each test group during Kochujang aging were high in the order of control group. 70% liquid koji group, 50% liquid koji group and 30% liquid koji group. The pH of control group was over 5.0 during aging period. The titratable acidity of Kochujang was high in the 50% liquid koji group and the 30% liquid koji group.

• Korean Journal of Food Science and Technology
• /
• v.22 no.7
• /
• pp.743-747
• /
• 1990

Glucose, arabinose and total non-cellulosic neutral sugar contents of alcohol-insoluble substance were increased during maturation of persimmon, but arabinose, galactose and total non-cellulosic neutral sugar contents were decreased in soft persimmon. The main non-cellulosic neutral sugars of cell wall were galactose, arabinose and glucose. Arbinose and galactose contents were decreased during maturity and this tend was remarkable in soft persimmon. Pectic fraction contained $70{\sim}82%$ of uronic acid, and galactose, arabinose and uronic acid of pectic fraction were decreased. The main non-cellulosic neutral sugars of hemicelluloses were glucose, xylose, and galactose. Galactose was decreased during maturation and postharvest, and contents of non-cellulosic neutral sugar were decreased in soft persimmon.

• Journal of the Korean Ceramic Society
• /
• v.41 no.7
• /
• pp.555-559
• /
• 2004

Ceramic foams were prepared by a self-blowing process of a polysiloxane with A1$_2$O$_3$ as a filler. The release of water and ethanol vapor during the condensation reaction of the polymer triggered the pores in the polymer melt. The size. interconnectivity and shape of the pores in the ceramic foams were strongly dependent on the viscosity of the polymer melt, which could be varied by the content and size oi the filler. When the content of the filler inceased and the size of the filler decreased. the size of the pores were decreased and the thickness between the pores were increased. In the addition, the viscosity of polymer melt increased by the pretreatment at 130$^{\circ}C$ for Ire intermolecular cross linking thereby stabilizing the foam structure. The density and compressive strength of the ceramic foams were affected by the heating rate during the blowing process.

• Korean Journal of Food Science and Technology
• /
• v.22 no.1
• /
• pp.50-55
• /
• 1990

Differences in the major components between non-greening and greening garlic bulbs were compared, and the several factors to be affected on the greening were investigated to study on the greening phenomenon occured in garlic puree made from stored garlic bulbs. From the several chemical analyses it was found that the contents of total nitrogen and lipid were lower in the greening than in the non-greening bulb but the contents of pyruvic and succinic acid were not. The content ratio of glutamic acid to total amino acid and the composition ratios of linoleic and linolenic acid were high in the greening bulb in comparsion with the non-greening. The protein pattern of the greening bulb by SDS-PAGE was significantly differed from that of the non-greening, especially in molecular weight ranges of 45.0-66.2 Kd. From the studies on the effects of pH, temperature and duration on the development of green color in the garlic powder solution, the optimum pH for the greening was 5.5 and maximum degree of the greening in the pH adjusted solution was shown after 30 min at $50^{\circ}C$.