• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.8
• /
• pp.1204-1210
• /
• 2013

Various commercial vinegars of high-strength acidity (10% or more of total acidity) were investigated to compare their physicochemical and antioxidant properties. The total acidity of double-strength vinegars was relatively lower than triple-strength vinegars. Irrespective of the acidity, sugar and reducing sugar content ranged from $7.00{\sim}10.80^{\circ}Bx$ and 1.32~3,885.90 mg%, respectively. Free sugars were mainly composed of fructose and glucose, and were relatively high in double-strength vinegars. The content of acetic acid (a principal organic acid in vinegars) increased with acidity, but oxalic acid was not identified in commercial high-strength acidity vinegars. Double-strength vinegars using malt extracts were the highest in free amino acid content, showing 24 kinds of amino acids. The content of total phenolics and flavonoids was highest in apple vinegars of double-strength acidity, which affected the scavenging ability of DPPH and ABTS radicals. Overall, the quality of high-strength acidity vinegars was affected by its content and production methods, and double-strength acidity vinegar using apples showed the best antioxidant activities.

• Microbiology and Biotechnology Letters
• /
• v.14 no.3
• /
• pp.225-232
• /
• 1986

This study was to improve the quality of Kochuzang and utilize red pepper seed. Kochuzang were prepared with the addition of red pepper seed and garlic (2％), compared the changes in the various chemical components and enzyme activity during the aging period of Kochuzang, and also organoleptic values of the products. Enzyme activities of liquefying and saccharogenic amylase, protease and lipase were increased by addition of garlic pulp and the suvival activities of enzyme except liquefying amylase were lasted high the late period of aging. Also the addition of red pepper seed was effective in maintaining the enzyme activities Change of titration acidity and pH of kochuzang were little when red pepper seed was added, but in case of a garlic additive it showed no difference at the late period of aging. Total nitrogen and amino nitrogen were increased by the addition of red pepper seed or garlic until the late period of aging, and ammonia nitrogen also increased during the middle period of againg, but showed no difference at the late period. Alcohol content was decreased by the addition of garlic or red pepper seed. but crude lipid was increased by the audition of red pepper seed. but crude lipid was increased by the addition of red pepper seed. Generally, taste, flavor and color of garlic added group were superior to the non-garlic added group for the products which aged for 10 weeks. Therefore, The quality of Barley Kochuazng may be improved by adding 2％ garlic to the whole red pepper.

• Journal of Life Science
• /
• v.29 no.12
• /
• pp.1408-1414
• /
• 2019

Enzymes are widely used in industrial applications such as detergents, food, feed production, pharmaceuticals and medical applications and major contributors to clean industrial products and processes. To screen, identify, and characterize the enzymes the zymography techniques are routinely used. The zymography technique is a simple, sensitive, and quantifiable technique that is widely used to detect functional enzymes following electrophoretic separation in sodium dodecyl sulfate (SDS)-polyacrylamide gels. The method is a versatile two-stage technique involving protein separation by electrophoresis followed by the detection of enzyme activity in polyacrylamide gels under non-reducing conditions. It is based on SDS-polyacrylamide gel (PAG) copolymerization with substrates, which are degraded by the hydrolytic enzymes restored in enzyme reaction buffer after the electrophoretic separation. Any kind of biological sample can be applied and analyzed on zymography, including culture supernatants of microbes, plants extracts, blood, tissue culture fluids, enzymes in foods extracts and metaproteome. The advantage of zymography is that it is possible to directly detect the protein with activity on the electrophoretic gel as well as confirm the activity at the nanogram level. Thus, this zymography technology can be applied in various fields. However, these advantages are rather disadvantageous and can often lead to experimental errors. In this review, the advantages, disadvantages, and problem solving of zymography technique are described.

• Korean Journal of Environmental Agriculture
• /
• v.16 no.3
• /
• pp.227-232
• /
• 1997

Visible injury appeared 7 days after ultraviolet-B(UV-B) irradiation, but did not show any significant decline of growth in cucumber plant. However the growth of the first leaves of fertilized plants was suppressed by UV-B irradiation. Especially the most effective growth retardiation appeared when supplied with nitrogen rather than phosphate and potassium. These results suggest that UV-B may play an important role in inhibiting nitrogen metabolism. Therefore we examined the effect of activity of nitrate reductase, and found that the nitrate reductase activity of the first leaves was increased by UV-B irradiation for 7 days and fertilization. We examined the effect of plant hormone on the inhibition of growth in the first leaves. Benzyladenine promoted the growth of discs excised from the first leaves by fertilization and without UV-B, but did not promote the growth of leaf discs from UV-B irradiated plants. We conclude that the UV-B-induced decrease in the growth of the first leaves could be related to reduction in sensitivity to plant hormones.

• Food Science and Preservation
• /
• v.7 no.3
• /
• pp.313-320
• /
• 2000

In order to improve the functionality of Korean soybean paste the changes of microorganisms, enzyme activity and physiological functionality of five types of Korean soybean paste prepared with various concentrations of Ginseng extracts. The pH of Korean soybean paste was decreased during fermentation but total acidity was increased. NaCl concentrations was increased up to 15.67~16.90% until 30~45days of fermentation and amino acidity was increase of the mixture ratio of Ginseng extract. Reducing sugar content was increased up to 45days of fermentation and total sugar content was increased up to 16.92~20.01% until 30days of fermentation, but decreased after that. The number of bacteria was highest in all sample after 45days fermentation, while that of mold was decreased during fermentation. Amylase and protease showed the highest activity at 30days of fermentation. Tyrosinase activity was increased during fermentation. Antimutagenic activities of Korean soybean paste (10% Ginseng extract) were 80.90%, 62.46% against MNNG, NPD on S. typhimutium TA100 and 51.96%, 58.88% against NQO, NPD on S. typhimutium TA98.

• Food Science and Preservation
• /
• v.20 no.5
• /
• pp.608-613
• /
• 2013

The physicochemical characteristics and antioxidant capacities of 15 red wines (Cabernet Sauvignon) from the US (5) and Chile (10) were investigated. The contents of soluble solid, reducing sugar, titratable acidity, and $SO_2$ were measured. Antioxidant capacities were examined by DPPH, ORAC assay, and total phenolic contents. In addition, polyphenols composition were analyzed by HPLC. The contents of soluble solid, reducing sugar, and acidities were 7.03~8.6 $^{\circ}Brix$, 2.7~6.7 g/L, and 0.7~0.8%, respectively, and showed no differences between wines from the two countries (p<0.05). The $SO_2$ content of Chile wines was 50% higher than that of US wines (p<0.05). Antioxidant activities by DPPH assay ranged 5.58~9.80 mM and 6.77~9.48 mM in the US and Chile wines, respectively. The ORAC values of the US and Chile wines ranged 2.17~18.08 mM and 4.55~33.77 mM, respectively. The total phenolic content ranged from 1,315 to 2,651 mg/L among the US red wines, and from 1,653 to 2,493 mg/L among Chile red wines. Gallic acid, catechin, syringic acid, p-coumaric acid, quercetin, and kaempferol were identified by HPLC. The polyphenol contents of the Chile red wines were higher than those of the US red wines(p<0.05). There were no differences in the physicochemical characteristics and the antioxidant capacities of the wines from US and Chile, but only in their $SO_2$ and polyphenol contents (p<0.05).

• Food Science of Animal Resources
• /
• v.23 no.3
• /
• pp.262-268
• /
• 2003

Kefir is a traditional fermented milk in Caucasusian area and is made mainly of milk fermented with lactic acid bacteria and yeasts. Six typical kefir grains were selected from ten kefir grains collected from different locals in Korea. Kefir grains were gelatinous in texture and had various shapes of villi, grapes, leaves, hulled millets, and towels. To investigate predominant microflora of kefir grains, SPC, MRS, M17, Rogosa, and APT agar media were used for viable cell count MRS, SPC, and Rogosa media were most acceptable for bacterial cell counts of the selected kefir grains. From one or two of the SPC agar plates which contained around 25∼50 colonies, all grown colonies were isolated and identified. Most predominant bacteria was identified as Lactobacillus fermentum by API 50 CHL kit. The proportions of Lb. fermentum and Lb. brevis among the total identified bacteria were around 41~88% and M4%, respectively. To select the best preservation method for kefir grains, refrigeration, freezing, and freeze drying were compared. Freeze drying was found most suitable for the preservation of kefir grains, based upon their acid-producing activities and production of off-flavors.

• Applied Biological Chemistry
• /
• v.34 no.3
• /
• pp.262-264
• /
• 1991

In order to establish the optimum storage period of rice, storability of rice for 1, 2. 3 and 4 years was investigated. Fat acidity of stored rice for 1, 2, 3 and 4 years was measured to 12.4, 23.6, 30.8 and 41.1 KOHmg/100g, respectively. Reducing sugar of those was analized to 0.31, 0.41, 0.57 and 0.68%. Germination of the stored rice for 1, 2 and 3 years was 97, 93 and 85%, respectively, but that of stored for four years was very low 32%. The longer storage period the higher, the lower water uptake ratio and expanded volume and much the lower total solid in residual liquid and intensity of starch iodine blue value of residual liquid, and the worse panel scores in color, stickness, taste and smell.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.7
• /
• pp.771-776
• /
• 2005

In recent days, there is much interest in the biocidal activity of silver since silver is known to be safe and effective as disinfectant and biocidal material against coliforms and viruses. In particular, nano silted silver particles which can be used as effective biocidal material received more attention. Accordingly, it is important to investigate antimicrobial activity and mechanism of nano sized silver particles prepared in a cost-effective manner. In this study, nano sized silver particles were prepared via photoreduction of a silver salt ($AgNO_3$) in the bulk phase of $PEO_{20}-PPO_{70}-PEO_{20}$ (Pluronic 123) block copolymer The antimicrobial efficacy of silver nano particles against E. coli was investigated and compared with that of silver ion as the concentration of silver nano particles, pH ($5.6{\sim}8.2$), temperature ($4^{\circ}C{\sim}35^{\circ}C$) varied in aqueous system. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) was used to examine the nature of damaged microorganism with nano sized silver particles and silver ion. This study showed that antimicrobial efficacy of silver nano particles was approximately one twentieth than that of silver ion. It was more biocidal at higher pH in contrast with silver ion. In addition, nano silver particles was demonstrated to disrupt the outer membrane of E. coli, subsequently causing their aggregation. On the other hand, silver ion diffused into the cell damaging the cytoplasmic membrane without disrupting the outer membrane of E. coli.

• Journal of the Korean Chemical Society
• /
• v.34 no.6
• /
• pp.569-581
• /
• 1990

It is generated in DMF by activated catalysts of superoxo cobalt(III) complex, such as [Co(III)(Schiff base)(L)]O$_2$ (Schiff base; SED, SOPD and o-BSDT, L; DMF and Py) which mole ratio of oxygen to metal is 1:1 that oxidation major product of 2,6-di-tert-butylphenol by homogeneous oxidatve catalysts of oxygen adducted tetradentate Schiff base cobalt(III) is 2,6-ditert-butylbenzoquinone (BQ). And oxidation product of 3,3',5,5'-tetra-tert-butyldiphenoquinone (DPQ) is generated by activated catalysts such as $\mu$-peroxo cobalt(III) complex; $[Co(III)(SND)(L)]_2$$O_2$ (L; DMF and Py) which mole ratio of oxygen to metal is 1:2. It is difficult to identify these homogeneous activated catalysts such as superoxo and $\mu$-peroxo cobalt(III) complexes in DMF and DMSO solvents. But we can identify by P.V.T method of the oxygen absorption in pyridine solvent and by the reduction process occurred to four steps including prewave of O$_2$- in 1:1 oxygen adducted superoxo cobalt(III) complexes and three steps not including prewave of O$_2$- in 1:2 oxygen adducted $\mu$-peroxo cobalt(III) complexes by the cyclic voltammetry with glassy carbon electrode in 0.1 M TEAP as supporting electrolyte solutidn.