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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Journal of Food Science and Technology
Journal Basic Information
Journal DOI :
Korean Society of Food Science and Technology
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Volume & Issues
Volume 32, Issue 6 - Dec 2000
Volume 32, Issue 5 - Oct 2000
Volume 32, Issue 4 - Aug 2000
Volume 32, Issue 3 - Jun 2000
Volume 32, Issue 2 - Apr 2000
Volume 32, Issue 1 - Feb 2000
Selecting the target year
Physicochemical Characteristics of Agastache rugosa O. Kuntze Extracts by Extraction Conditions
Lee, Boo-Yong ; Hwang, Jin-Bong ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 1~8
Fifty-seven extracts from flower, leaf and stem of Agastache rugosa O. Kuntze were prepared by varing extraction conditions: solvents (hot water, ethanol and NaCl solution); temp.
and solvent ratios (10 to 35 times per material). Lipid content of leaf was 9.54% and protein content of the flower where the essential amino acids were most abundant among all parts was 16.8%. Among six minerals (Na. Ca, Fe, P, K and Mg) detected from all parts of the plant, the content of K was the highest. Extraction yield rated higher in odor of water, ethanol and NaCl solution, respectively and the extractions reached eqilibrium in about 15 to 20 min, regardless of extraction conditions. pH values of all extracted solvents maintained neutral upon extraction and a few free sugars in forms of glucose and fructose were detected from ethanol extracts. Colors and organoleptic characteristics of the extracts which determine the properties of final products varied with extraction conditions.
Aroma Pattern Analysis of Various Extracts of Agastache rugosa O. Kuntze by Electronic Nose
Lee, Boo-Yong ; Yuk, Jin-Su ; Oh, Se-Ryang ; Lee, Hyeong-Kyu ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 9~16
Aroma of various extracts of Agastache rugosa O. Kuntze was analyzed by electronic nose with 32 conducting polymer sensor arrays. The 57 extracts were prepared by extraction solvents (hot water, ethanol and NaCl solution), extraction temperatures
, solvent mixture ratios of solvent (10 times 35 times) and parts of Agastache rugosa O. Kuntze(flower, leaf and stem). Aroma pattern of Agastache rugosa O. Kuntze extracts showed big difference in normalized pattern and odor intensity with extraction temperatures and parts, but showed no difference with extraction solvents. Especially in the case of ethanol extracts, because odor of ethanol itself was very strong, difference in aroma of extracts with extraction temperatures and parts did not show through the electronic nose. The organoleptic characteristics such as mint odor, grassy odor, mint taste, medicinal herb taste and sweetness for Agastache rugosa O. Kuntze extracts were determined by the profile test and the result of sensory evaluation by quantitative descriptive analysis was explained to QDA diagram. In correlation with the result of aroma analysis by electronic nose and the sensory evaluation, difference in aroma pattern among the extracts concretely brought to light definite characteristics such as mint odor and mint taste.
The Changes of Aroma in Wine Treated with Reverse Osmosis System
Lee, Seung-Ryong ; Lee, Kyu-Hee ; Chang, Kyu-Seob ; Lee, Suk-Kun ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 17~24
Reverse osmosis (RO) system was applied to improve wine quality. General wine (GEN) and wines containing different sugar levels
(RO-28) by removing pure water using RO system without sugar addition on brewing method. And they were compared by wine aroma analysis. The preparing method of analysis was LLCE (liquid-liquid continuous extraction). And volatile aroma compounds of different wines were prepared for raw, and diluted materials in same proportion. The wine aromas were described by trained twelve panelists for QDA (quantitative descriptive analysis) and showed for FD (flavor dilution)-chromatogram. Consequently, overall acceptability of RO-28 showed better than that of other treatments. Aromas of RO-28 also were represented the high contents of positive aroma compounds such as ethanol and ethyl acetate, which were identified by GC-O and GC-MS.
High Performance Liquid Chromatographic Analysis of Isoflavones in Soybean Foods
Kim, Chung-Sook ; Lee, Young-Sun ; Kim, Jin-Sook ; Han, Young-Hee ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 25~30
Phytoestrogen has been used as a suppliment of estrogen in order to treat osteoporosis. The representative phytoestrogens, isoflavones, are daidzein, genistein and formononetin which were present highly in our traditional soybean foods. The quantitative analysis of the isoflavone was done with a high performance liquid chromatography(HPLC) using a UV/VIS detector for the contents of the isoflavones in Astragali Radix, soybean sprouts, bean-curd(Tofu), soybean, soybean oil, pea, kidney pea, black bean(Yak-kong), soybean sauce(Ganjang). soybean paste(Doenjang), and fermented soybean(Maejoo). The content of free daidzein in soybean sprouts was
$ which was much higher than that in soybean,
, although total daidzein of fermented soybean was lower than that in soybean (Table 2. P<0.01). The amounts of free genistein in soybean sprouts, fermented soybean. and soybean paste were
, respectively. The level of free formononetin in soybean paste was the highest among the soybean products (P<0.01). The content of formononetin in Aatragali Radix,
, was about 160 times higher than that in soybean. Thus Korean traditional soybean products, black bean(Yak-Kong) and Astragali Radix can be a good choice of phytoestrogens.
Sectional Composition of Minerals in Domestic Deer Antler
Kim, Hye-Young ; Rhyu, Mee-Ra ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 31~36
The mineral compositions were analysed of the tip and the upper section of dried domestic antlers. The upper section was divided longitudinally into four parts. The tip and the upper section were divided traversely into the velvet and the spongy bone layers. The contents of ash, calcium, phosphorus and magnesium increased (p<0.05), and those of manganese, zinc, copper and iron decreased (p<0.05) downward from the tip both in the velvet and the spongy bone layers. The contents of ash, calcium, phosphorus, manganese and zinc of the spongy bone layer were significantly (p<0.05) higher than those of the velvet layer. The tip, which is the growth center of the antler, had the significantly (p<0.05) lowest proportions of Ca/ash, Ca/P and Ca/Fe ratios both in the velvet and spongy bone layers.
Analysis of Chemical Composition in leaf and foot of Acrorus calamus L.
Kim, Hye-Ja ; Kim, Se-Won ; Shin, Chang-Sik ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 37~41
This study has been carried out to investigate the chemical composition of Acorus calamus L., a wild plant (Chang Po) which has long been used as a medicine or a hair rinse in Korea and China. Potassium was found to be the most predominant mineral in leaf and root, followed by calcium, magnesium, and phosphorus, in a decreasing order. Contents of potassium in leaf and root account for 54a.65 mg% and 242.87 mg%, respectively. Contents of these minerals in leaf were higher value than that in root. Glucose and fructose were found to be the major free sugars in leaf and root. Malic acid was the most abundant organic acid of leaf and root, and followed by citric acid. Fourteen different kinds of fatty acids were identified from the leaf and root. Content of unsaturated fatty acids. such as linolenic, and linoleic acid ware higher than that of saturated fatty acids. Content of total amino acids was 3 times higher in leaf than that in root. Leucine was the major amino acid in leaf and glutamic acid in root.
A New Method for Analysis of Capsaicinoids Content in Microcapsule.
Jung, Jong-Min ; Kang, Sung-Tae ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 42~49
A new method for the quantitative determination of capsaicinoids in microcapsule has been developed. Among seventeen solvents tested for solubilizing wall material (gum arabic and modified starch) of microcapsule, dimethyl sulfoxide (DMSO) was selected as an optimal solvent. The most appropriate mixing ratio of microcapsule to DMSO for solubilizing wall material was 1 to 10(w/v). Appropriate carriersolubilizing temperature and time were
and 30 min, respectively. Also conditions for extracting oleoresin from the solubilized microcapsule were studied. The mixing ratio of ethanol to DMSO was optimal at 8 to 1(v/v). Optimized vortexing time was 5 min at 40㎐. Pecipitant was obtained by centrifugation at 21000 rpm for 15 min. The precipitant was reextracted with ethanol. The extracted supernatants were combined and adjusted to final volume of 25 ml. Extracted solutions were analyzed for quantitation of total capsaicinoids by employing HPLC and for quantitation of total carotenoids by spectrophotometric method. This method can be used to monitor changes of capsacinoid during manufacturing or storage of red pepper oleoresin microcapsule powder.
Stabilization to Sunlight of Natural Coloring Matter by Soluble Methyl-Hesperidin
Woo, Dong-Ho ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 50~55
Soluble methyl-hesperidin (MH) powder was prepared from crude MH, and was investigated on the stabilization to sunlight of natural coloring matter. Soluble MH powder was added to riboflavin, bixin, and paprika oleoresin solutions at concentration of 0.1 or 0.2%(w/w), and the absorbance of respective solutions was analyzed by spectrophotometer after exposing to sunlight for
hr. While coloring matter solutions without MH was faded completely with lapse of time, addition of MH retarded to fade natural coloring matters. According as amount of MH added increased, MH showed more excellent stabilizing effect on the coloring matters. Especially, vitamin C with soluble MH showed remarkable synergistic effect in paprika oleoresin solution during the exposure to sunlight for 8 hr. Consequently, it was found that MH plays a role as excellent stabilizer of natural coloring matters to ultraviolet of sunlight.
Volatile Compounds of Mustard Leaf (Brassica juncea) Kimchi and Their Changes during Fermentation
Pyo, Young-Hee ; Kim, Jung-Soo ; Hahn, Young-Sook ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 56~61
Fourteen volatile compounds isolated by distillation under reduced pressure from Mustard Leaf(Brassica juncea) Kimchi were identified by the GC/FID and GC/MSD. They were composed of 63% of hydrocarbons and acid and 30% of isothiocyantes and their related components in relative amount; Volatile isothiocyanates and their related components such as 2-phenylethyl isothiocyanate, benzothiazole, 2-methyl benzothiazole and 2-(3H)-benzothiazolone, which are reported to be responsible for the pungent flavor of mustard products, were found in Mustard Leaf Kimchi. These volatile components were remarkably decreased during the fermentation of Mustard Leaf Kimchi.
Effect of Conjugated Linoleic Acid Additives on Quality Characteristics of Pork Patty
Joo, Seon-Tea ; Lee, Jeong-Ill ; Hah, Kyung-Hee ; Ha, Yeong-Lae ; Park, Gu-Boo ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 62~68
Effects of conjugated linoleic acid (CLA) on physico-chemical properties of cooked ground pork patty were investigated for 11 days at
. Pork patties containing 0, 1, 2, and 3% CLA were cooked at
for 30 min. The contents of crude protein and fat did not change whereas the content of ash and water decreased as the level of CLA enhanced. Lipid oxidation as measured by thiobarbituric reactive substances of patty was inhibited by addition of CLA. CLA treatment also reduced nitrite and cholesterol content and changed fatty acid composition. Consequently, given these positive effects of CLA, it may be assumed that CLA could be used as a fat additive for value-added pork patty.
Varietal Differences in Quality Characteristics of Yukwa(Fried Rice Cookie) made from Fourteen Glutinous Rice Cultivars
Kang, Mi-Young ; Sung, You-Me ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 69~74
Varietal difference in physicochemical characteristics of glutinous rice grain and interrelationships between these properties and the quality characteristics of Yukwa(fried rice cookie) were investigated on fourteen rice varieties, to obtained the basic informations for diversifying the utility of glutinous rice grain and for developing various glutinous rice cultivars adaptable to glutinous rice food processing. Among physicochemical properties of glutinous rice grain, the content of released reducing sugar during soaking treatment was the most positive correlation between the adaptability to Yukwa processing quality. CB243 and Sandong 71 were the most adaptable glutinous rice cultivars to make the Yukwa, because of its tested score in expansion volume, crispiness and sensory preference was higher than other glutinous rice cultivars.
Comparison of Some Characteristics Relevant to Rice Bread made from Eight Varieties of Endosperm Mutants between Dry and Wet Milling Process
Kang, Mi-Young ; Han, Ji-Yeun ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 75~81
The processing properties for rice bread were examined using eight kinds of endosperm mutant rice. The varietal differences among eight kinds of endosperm mutant rice having the respective sugar contents and amylose contents were studied. The water absorptions of these eight cultivars were observed to have significant differences among the cultivars, revealing the water absorption ability of Shrunken(shr.) was 61.5%, and that of Punchilmi(fl) was 48.4%. In addition, the experiments using Whachungbyeo, Nampungbyeo and their mutant cultivars showed that the maximum water absorption was tend to be negatively correlated with the amylose content of each rice cultivars. This study also showed that the rice breads made by dry-milling was better in shape, mechanical properties(hardness, springiness, adhesiveness, chewiness) and texture tested using sensory evaluation than that made by wet-milling.
Comparison of Some Characteristics Relevant to Rice Bread made from Eight Varieties of Endosperm Mutants between Brown and Milled Rice
Kang, Mi-Young ; Koh, Hee-Jong ; Han, Ji-Yeun ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 82~89
Relationship among the properties of rice, such as amylose contents of endosperm starch, sugar content and amylogram characteristics, and processing properties for rice bread was studied. The amylose content of the rice cultivars decreased in order of Nampungbyeo, Whachungbyeo>Punchilmi(fl)>Nampung CB243> Whachung du-I, Nampung EM90>Whachung-chalbyeo>shr. Protein contents of rice tested in this study were almost same level, however, shr, the high sugar rice, showed the highest protein content scored as 8.2%. The study showed that the amylose contents of rice cultivars were negatively correlated with their protein contents. The starting temperatures for gelatinization of the flour of Punchilmi(fl) and Shurunken(shr) were low, however, in case of Whachungbyeo and Nampungbyeo plus their mutants derived from the both, the stickiness and the hardness of the flours were shown to be positively correlated with the amylose contents. In addition, loaf volume tested using sensory evaluation and overall quality showed the same tendency. Among the rice cultivars tested in this study, breads made from white rice had good qualities in bread making process than those made from brown rice. The bread made from Nampungbyeo was demonstrated to have highest score e in overall quality, as well as the lowest retrogradation index during storage at
Studies on Optimum Cooking Conditions for Commercial Continuous Rice Cooker
Lee, Eun-Young ; Jung, Jin-Hoon ; Shin, Hae-Hun ; Lee, Seok-Hoon ; Pyun, Yu-Ryang ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 90~96
The optimum cooking conditions for large scale continuous gas cooker were studied with three varieties of rice. Optimum soaking time for the cooker was estimated to be 30 min at cooking temperature above
, while 60 min at cooking temperature below
. The ratio of water-to-milled rice giving the best eating quality was founded to be
, and corresponding moisture content of cooked rice ranged from 60 to 62% for different rice varieties. The optimum ratio of water to milled rice. (Chucheong) decreased from 1.50 to 1.37 with increase in the amount of milled rice from 4.0 to 6.5 kg in a cooking vessel. However, actual water uptake by rice (g water absorbed per g rice) on cooking was nearly constant value of 1.13, which means that evaporated water during cooking increases with decreasing the amount of rice in a cooking vessel.
Characteristics of Waste Brine from the Salting Process of Chinese Cabbage
Yoon, Hye-Hyun ; Jeon, Eun-Jae ; Sung, Soon-Jung ; Kim, Dong-Man ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 97~101
Major characteristics of waste brine from the repeated salting and rinsing processes of Chinese cabbage for Kimchi were investigated. Salt concentration of brine was increased with the number of successive salting steps from 12% after 1st salting step to 14% after 5th step. Total waste brine which is the representative of wastewater produced from salting process of cabbage showed 6-8% salt concentration. The pH values in all samples decreased with the number of reuse of brine and showed pH 5.9 and pH 5.2 for the mixture of brine for quarter-cut and small-cut cabbage, respectively, after 5th salting process. Soluble solid contents increased with repetition and resulted in 14-16
. Total brine showed increased COD values with the number of reuse of brine and 40-50 ppm of COD values for both quarter-cut and small-cut cabbages.
Changes in Quality of Garlic during Frozen Storage
Shin, Dong-Bin ; Lee, Young-Chun ; Kim, Ji-Hyun ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 102~110
Peeled garlic was stored at
, respectively and changes in main quality factors during storage were determined for
months. The puncture force measured by texturemeter was
G.S at the beginning of storage and did not change significantly after the 15 months storage. Drip losses of stored garlic were 0.4% and 0.7% at
, respectively. Major flavor compounds of garlic analyzed by GC and GC/MS, such as diallyl disulfide, 1,3-dithiane, diallyl sulfide, 2-butanal, were not changed in their quantity during the frozen storage. The contents of cysteine, valine and tyrosine increased slightly notwithstanding the storage temperature. Sucrose content slightly decreased, but glucose and fructose tended to increase in garlic stored at
. The content of pyruvic acid, degradation product of alliin, did not change during storage at both storage temperatures. These results indicated that peeled garlic could be stored at
for longer than 15 months without quality problems.
Changes in Quality of Low Salt Fermented Anchovy by High Hydrostatic Pressure Treatment
Lim, Sang-Bin ; Yang, Moon-Sik ; Kim, Soo-Hyun ; Mok, Chul-Kyoon ; Woo, Gun-Jo ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 111~116
Effects of ultra-high pressure treatment on viable cell count and quality characteristics of low salt fermented anchovy under different operating conditions such as pressure
and treatment time
were investigated. Viable cell count decreased gradually with the increase of pressure and suddenly at 400 MPa. It also decreased by seven folds at
and logarithmically with the increase of treatment time. Peroxide value increased with the increase of pressure, temperature and treatment time, and temperature played a major role. Thiobarbituric acid value was higher by two folds in samples treated than in the untreated regardless of any conditions investigated. Volatile basic nitrogen was almost the same in all samples except the one at
. The sample treated at greater than
under high hydrostatic pressure indicated higher value in amino nitrogen. Treatment at
MPa/15 min showed greater reductions in viable cell counts, remaining better quality of low salt fermented anchovy.
Optimization of Microwave-Assisted Extraction under Atmospheric Pressure Condition for Soluble Ginseng Components
Kwon, Joong-Ho ; Kim, Kyung-Eun ; Lee, Gee-Dong ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 117~124
Considering the thermal unstableness of ginseng components, microwave-assisted extraction(MAE) was performed under the atmospheric pressure condition. The monitoring of extraction characteristics and the optimization of extraction conditions were made by response surface methodology. The extraction efficiency of soluble ginseng components was high at lower ethanol concentration and at higher microwave power, while crude saponin content was easily extracted at higher ethanol concentration. Estimated conditions for the maximized extraction of soluble components including crude saponin, total phenolics and electron donating ability were
in ethanol concentration,
W in microwave power, and within 4 min in extraction time. Predicted values at the optimum condition(60% ethanol, 80 W microwave power and 4 min extraction time) were in good agreement with observed values.
Quality Characteristics of the Kochujang Prepared with Mixture of Meju and Koji during Fermentation
Choi, Jin-Young ; Lee, Taik-Soo ; Noh, Bong-Soo ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 125~131
Quality characteristics of kochujang prepared with meju, koji and mixture of the two(meju+koji) were investigated during fermentation to improve quality of kochujang. During fermentation of kochujang, moisture content was in the range of
, salt was
, crude protein was
and pH of kochujang was
. Amino-nitrogen content increased during fermentation and the levels were
after 150 days of fermentation. The highest amino-nitrogen content was found in mixed kochujang at the beginning stage of fermentation, but in koji kochujang after 30 days of fermentation. Maximum reducing sugar content was
at 60th day of fermentation. The highest amino acid content of kochujang protein was found in meju kochujang followed by koji kochujang at the first stage of fermentation. The content of glutamic acid, a major amino acid was
of total amino acid content. High levels of aspartic acid, leucine, arginine, alanine and phenylalanine were found in the kochujangs. Mixed kochujang showed the highest L value among the samples until 30 days of fermentation. After that, the highest L value was found in meju kochujang. The highest degree of redness was observed in meju kochujang until 60 days of fermentation and in koji kochujang during
days of fermentation.
Optimization of Emulsification and Spray Drying Process for the Microencapsulation of Flavor Compounds
Cho, Young-Hee ; Shin, Dong-Suck ; Park, Ji-Yong ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 132~139
This study was conducted to optimize the emulsion process and the spray drying process for the microencapsulation of flavor compounds. Using the wall system selected, emulsion process for microencapsulation was optimized on the change of the pressure of piston-type homogenizer. Emulsification pressure of 34.5 MPa was found to be the most suitable for preparing flavor emulsion. Effects of drying temperature and atomizer speed of the spray drier on total oil, surface oil, and flavor release of the flavor powder were investigated using response surface methodology. The optimum spray drying conditions for minimal surface oil and flavor release and maximum total oil were
inlet temperature and 15,000 rpm atomizer speed. The spray-dried powder processed with the highest drying temperature showed spherically-shaped particles with smooth surface.
Studies on the Physico-chemical Properties of the Pine Nut's Gruel During Storage
Lee, Seog-Won ; Bae, Se-Kyung ; Rhee, Chul ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 140~146
The physicochemical properties, such as retrogradation, fat acidity and viscosity, on the pine nut's gruel at various contents of pine nut (0, 1, 3 and 5%) during storage at 4, 25 and
were investigated. The degree of retrogradation was increased rapidly at the initial storage stage. The lowest value (about 10%) of the degree of retrogradation was observed in the gruel sample containing 3% of pine nut. Also, the rate constant of retrogradation was showed the lowest value (0.0422) in the gruel containing 3% of pine nut regardless of storage temperatures. The fat acidity was showed the lower value than 30 mg KOH in all samples. The viscosity increasing velocity(RVU/min) between holding strength and final viscosity was decreased as the pine nut's content was increased. However, it was not affected by the storage temperatures.
Optimization of Conditions for the Production of Algin-like Polysaccharide by Polyglucuronic Acid C5-Epimerase
Cho, Gye-Bong ; Chang, Pahn-Shick ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 147~153
We could produce algin-like biomaterial of polyiduronan using polyglucuronic acid C5-epimerase with polyglucuronic acid prepared by specific oxidation of primary alcohol groups of four kinds of polysaccharides(corn starch, rice starch, sweet potato starch, and cellulose). The enzyme activity was determined by the modified Dische carbazole methodology with the isolated crude enzyme from the supernatant centrifuged at
for 1 hr after grinding fresh bovine liver. And then, the optimal substrate, pH, and temperature for the enzyme reaction of polyglucuronic acid C5-epimerase were determined as the oxidized sweet potato starch, 7.0, and
, respectively. Conclusively, it could be possible to epimerize polyglucuronic acid in the oxidized sweet potato starch to polyiduronic acid. Therefore, we could obtain algin-like polysaccharide using the oxidized sweet potato starch and polyglucuronic acid C5-epimerase isolated from bovine liver.
Characteristics of Protease Produced by Bacillus subtilis PCA 20-3 isolated from Korean Traditional Meju
Lim, Seong-Il ; Kim, Hyun-Kyu ; Yoo, Jin-Young ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 154~160
Protease production and its characteristics were investigated with Bacillus subtilis PCA20-3 which was isolated from Korean traditional meju. The optimum culture conditions of Bacillus subtilis PCA20-3 for the production of the protease were as follow: 0.2% soytone, 2% starch, 0.1%
and 20 hrs. The optimum pH and temperature for enzyme activity of protease producing Bacillus subtilis PCA20-3 were pH 8.0-10.0 and
, respectively. The enzyme was relatively stable at pH
and at temperature below
. The activity of the enzyme was inhibited by
. 2 mM phenymethanesulfonyl fluoride inhibited 89.2% of enzyme activity. This indicates that the enzyme is serine protease. The
. This enzyme hydrolyzed casein more rapidly than bovine serum albumin.
Purification and Characterization of Protease Produced by Aspergillus wentti Isolated from Korean Traditional Meju
Lim, Seong-Il ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 161~167
The protease produced by a newly isolated Aspergillus wentti from Korean traditional Meju was purified and characterized. The optimal medium composition and culture conditions for maximum protease production were ; bran :1% glucose solution =1 : 1, pH 9.0,
, and 4 days of fermentation. Protease was purified by QAE-Sephadex, SP-Sephadex ion exchange chromatography and Sephadex G-100 chromatography. The specific activity and the purification fold of the purified enzyme were 213 unit/mg protein and 27.3, respectively. The molecular weight of purified protease was found to be 32 kDa by SDS-PAGE. Km and Vmax value's for hammastein milk casein were
, respectively. Kinetic parameters showed that the enzyme has higher affinity to casein than isolated soybean protein, hemoglobin and bovine serum albumin. Optimal pH and temperature for reaction of the purified enzyme were 9.0 and
, respectively. The enzyme was stable at pH 4.0-11.0, below
, and the activity was not stimulated by metal ions. 1mM phenylmethylsulfonyl fluoride inhibited the enzyme activity by 98.5%. It means that the enzyme is one of serine protease.
Anticariogenic Effects of Unripe Apple Extract
Yoon, Suck-Young ; Kim, Sung-Hoon ; Chung, Hae-Lim ; Lee, Jeong-Jun ; Huh, Chul-Sung ; Baek, Young-Jin ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 168~173
Anticariogenic activity of the unripe apple extract was studied by observing the inhibitory effects on GTase(glucosyltransferase) activity, cell adherence and acid production of Streptococcus mutans. Among the four S. mutans strains, S. mutans MT 8148 had the highest water-insoluble glucan forming activity. (+)-Catechin and tannic acid, the major components of the unripe apple polyphenols inhibited GTase activity by 60% at 1 mg/ml and 90% at 5 mg/ml. Tannic acid and unripe apple extract inhibited adherence ability of S. mutans by 50% and 30%, respectively. But the acid production of S. mutans was not influenced by the polyphenols. Disc diffusion test showed that the polyphenols have no antimicrobial activity against S. mutans, which indicates that the inhibition of GTase activity and cell adherence were not resulted from the cell growth inhibition. Our results convinced the possible application of the unripe apple extract as the anticariogenic food additives.
Effects of Mashing Proportion of Soybean to Salt Brine on Kanjang(soy sauce) Quality
Choi, Kwang-Soo ; Choi, Jong-Dong ; Chung, Hyun-Chae ; Kwon, Kwang-Il ; Im, Moo-Hyeog ; Kim, Young-Ho ; Kim, Woo-Seong ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 174~180
This work was carried out to investigate the effects of mashing proportion of meju(as wet weight basis of raw soybean) to 20% salt brine on the chemical compositions and sensory characteristics of kanjang. By increasing the salt brine proportion in the kanjang mash, total nitrogen, TCA soluble nitrogen and total free amino acid content in kanjang were decreased accordingly, but although pH values and organic acids content were not different noticeably, the major organic acids in kanjang, lactic acid, pyroglutamic acid and acetic acid were increased up to the mashing proportion of 1:2 from 1:1 and pH values decreased up to that of 1:2.5. Residual sugar content in 1:1 kanjang was exceptionally high. The major free amino acids in kanjang were glutamic acid, lysine, alanine and leucine. The acceptability scores of kanjang tested by sensory evaluation were decreased in inverse proportion to the salt brine proportion of kanjang mash, but those of kanjang samples with
mashing proportions were not significantly different but that of 1:3 different from 1:1 statistically at 5% level. The major chemical compositions, significantly effective to the acceptability of kanjang, were found to be glutamic acid and free amino acid by statistical analysis.
Changes in Aflatoxin and Flavor Components of Traditional Sigumjang
Son, Dong-Hwa ; Choi, Ung-Kyu ; Kwon, O-Jun ; Im, Moo-Hyeog ; Dahn, Kyeong-Nyeo ; Cha, Won-Seup ; Cho, Young-Je ; Chung, Yung-Gun ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 181~186
This study was conducted to investigate various components and aflatoxin of sigumjang during fermentation time. The contents of moisture were decreased during fermentation time. The contents of protein, fat and ash were
, respectively. The pH was gradually acidized. The result of measurement of surface color showed: L-value,
. Aflatoxin was not detected during fermentation. Among 81 kinds of flavor components identified in sigumjang, esters was most in number followed by acids, aldehydes, alcohols and phenols.
Changes in Physicochemical Properties of Salted and Fermented Shrimp at Different Salt Levels
Mok, Chul-Kyoon ; Lee, Ju-Yeon ; Song, Ki-Tae ; Kim, Sun-Young ; Lim, Sang-Bin ; Woo, Gun-Jo ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 187~191
This study was performed to examine the effects of salt addition level on the changes in physicochemical properties of the salted and fermented shrimp during fermentation. Amino nitrogen content increased with the fermentation time, and was higher at low salt addition level. Volatile basic nitrogen content in the fermented shrimp with 3 and 8% salt increased rapidly at initial fermentation period, but decreased at 6 week fermentation and remained constant afterward, while that with 18 and 30% salt maintained its initial level through 22 week fermentation. Thiobarbituric acid(TBA) value decreased rapidly in the early stage of the fermentation, but slightly increased after 4-6 week fermentation. The TBA value was higher at lower salt level after 6 week fermentation. Peroxide value of the fermented shrimp with salt content higher than 8% increased rapidly at 2-4 week fermentation and decreased sharply at 6 week, while that with 3% salt showed the maximum value at 10 week fermentation.
Effects of Freeze Drying Protectant Added to Lactic Acid Bacteria Fermented Food Prepared from Milk or Egg White Powder on Growth and Organoleptic Properties
Ko, Young-Tae ; Kang, Jung-Hwa ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 192~199
Lactic acid bacteria (LAB) fermented food was prepared from milk or egg white powder (EWP) and added with five kinds of freeze drying protectant (FDP). Effects of FDP on growth and acid production of LAB were investigated. Effects of FDP on organoleptic properties of LAB fermented food were also studied. (1) Some of FDPs showed protective effect against damage to Lactobacillus acidophilus in LAB fermented food during freeze drying, while FDP did not show any protective effect against damage to L. acidophilus during freezing. This protective effect differed with substrate and concentration of FDP (2) Optimum concentration of Tween 80 and ascorbate added to milk sample was 0.2 % (W/V) and 1 %(W/V), respectively. Optimum concentration of raffinose and ascorbate added to EWP sample was 3 %(W/V) and 1 %(W/V), respectively (3) Among FDPs added to L. casei fermented food, raffinose and ascorbate added to EWP sample showed FDP effect. Among FDPs added to L. delbrueckii fermented food, raffinose added to EWP sample showed FDP effect. (4) Samples added with MSG showed MSG taste. Milk sample added with ascorbate showed slightly more acid taste than reference sample, while taste of EWP sample added with ascobate did not differ with reference sample. Tween 80 added to milk sample or EWP sample improved texture of LAB fermented food.
Plasma Cholesterol-Lowering Effects of Alpiniae katsumadaii Extract as an Inhibiter of Pancreatic Cholesterol Esterase Activity
Kim, Hee-Sook ; Kim, Ji-Young ; Choi, Jong-Won ; Huh, Young-Mi ; Suh, Pann-Ghill ; Ryu, Sung-Ho ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 200~205
Ethanol extract of Alpiniae Katsumadaii semen inhibited potently cholesterol esterase activity in vitro. Chloroform fraction of ethanol extract showed the stronger inhibitory effect than other solvent fractions-ethylacetate fraction, butanol fraction, and aqueous fraction. The chloroform frac ion of Alpiniae katsumadaii semen were studied as a candidator of plasma cholesterol lowering material in high cholesterol-fed rats. In high cholesterol-fed rats, the diet with chloroform fraction of 100 mg/kg and 150 mg/kg lowered not only plasma neutral lipids contents 25.9% and 26.5% but also plasma total cholesterol level 11.8% and 20.8%, respectively. Plasma HDL-cholesterol level and Atherogenic Index(AI) in Alpiniae chloroform fraction-fed rats were recovered as those level of normal rats.
Effects of Germinated-Buckwheat on Blood Pressure , Plasma Glucose and Lipid levels of Spontaneously Hypertensive Rats
Lee, Jung-Sun ; Park, Sung-Jin ; Sung, Ki-Seung ; Han, Chan-Kyu ; Lee, Myung-Heon ; Jung, Chul-Won ; Kwon, Tae-Bong ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 206~211
The purpose of this study was to investigate the effect of germinated buckwheat on blood pressure, plasma glucose and lipid levels of spontaneously hypertensive rats(SHR). The male and female SHR were divided into two groups. After feeding the germinated buckwheat diet(50%, w/w) ad libitum for 6 weeks, the weight gain of the germinated buckwheat group in male rats was higher than those of control group. Systolic blood pressure of the germinated buckwheat group in male rats was significantly decreased at 6 weeks by 3%. The fasting glucose levels of the germinated buckwheat group had a tendency to be lower compared with those of the control group. Total cholesterol, HDL-cholesterol and HTR of female SHR fed the germinated buckwheat diet were significantly increased compared to the control diet. Atherogenic index of the germinated buckwheat group was decreased in males(ns) and females(p<0.05) than those of the control group. From these results the germinated buckwheat might be useful for anti-hypertensive and anti-hyperlipidemic agents.
Physiological Characteristics of Tannins isolated from Astringent Persimmon Fruits
Seo, Ji-Hyung ; Jeong, Yong-Jin ; Kim, Kwang-Soo ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 212~217
This study was determined protein reaction, antioxidative activity, nitrite scavening ability and antimicrobial activity of tannins isolated from astringent persimmon fruits. Tannins extracted from green persimmon fruits reacted highly with BSA(bovine serum albumin). Reactions between tannins and BSA were more active when contents of tannin were higher than that of BSA. Antioxidative abilities of green persimmon tannin were comparable to that of BHT(butylated hydroxytoluene). Green persimmon tannins exhibited remarkable nitrite-scavenging activity. Different antimicrobial activities of persimmon tannins were observed depending on the maturity. The growth of V. parahaemolyticus and E coil were highly inhibited by the addition of persimmon tannins. Tannins from soft persimmon did not have antimicrobial activities against B. subtilis and S. typhimurium.
Antimicrobial Effects of Chitosans on Escherichia coli 0157 : H7, Staphyloccus aureus and Candida of albicans
Oh, Se-Wook ; Hong, Sang-Pill ; Kim, Hyun-Jung ; Choi, Yong-Jin ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 218~224
The antimicrobial activities of chitosan oligosaccharide(chitohexaose) and two types of chitosans M.W.(10,000 and M.W. 100,000) were examined against Escherichia coli O157 : H7(ATCC 43894), Staphylococcus aureus(ATCC 144458) and Candida albicans(KFRI 432). Chitosan with molecular weight of 10,000 showed the strongest antimicrobial activities to E. coil O157 : H7 and S. aureus, whereas chitohexaose acted most strongly against C. albicans. The most effective concentration of chitosan was measured to be 0.1 mg/mL for E. coil O157 : H7 and S. aureus, and that of chitohexaose to be 1 mg/mL for C. albicans. Antimicrobial activities of chitosans and chitohexaose were maintained for 60 min after their treatment. They were found to induce leakage of intracellular proteins and nucleic acids from treated microorganisms. The efflux determined by assaying the
leaked from the lactose-induced E. coli O157 : H7 cells was observed to reach the highest level within 60 min after treatment with the antimicrobial agents and chitosan with 10,000 molecular weight gave the highest
activity. Therefore, it is supposed that the antimicrobial activity of chitosan with its unique polycationic nature might be caused by its binding to anionic component(s) of the cell envelope and thereby inhibiting the membrane metabolism and/or leaking intracellular materials.
Effect of Compression Test Conditions on Texture Profile Analysis of Surimi-based Products
Lee, Young-Seung ; Yoo, Byoung-Seung ;
Korean Journal of Food Science and Technology, volume 32, issue 1, 2000, Pages 225~230
The texture profile analysis (TPA) parameters of commercial surimi-based products were evaluated at various compression test conditions. Cylindrical specimens of diameter to length (D/L) ratio of 1.0, 1.5, B.() cm/min were compressed to 50, 65 and 80% using crosshead speeds of 1.7, 3.3, 6.7 cm/min. TPA parameters of three surimi-based products (hardness-1, hardness-2, cohesiveness, springiness, chewiness and gumminess) were analyzed statistically. The TPA parameters were modified by dividing with cross section area and strain. The TPA parameters were affected by D/L and compression ratio except for crosshead speed for all three surimi-based products. The ecommended test conditions for TPA of surimi-based products seem to be D/L of 1.5, compression ratio of 80%, and crosshead speed of 1.7 to 6.7 cm/min.