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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Journal of Food Science and Technology
Journal Basic Information
Journal DOI :
Korean Society of Food Science and Technology
Editor in Chief :
Volume & Issues
Volume 29, Issue 6 - Dec 1997
Volume 29, Issue 5 - Oct 1997
Volume 29, Issue 4 - Aug 1997
Volume 29, Issue 3 - Jun 1997
Volume 29, Issue 2 - Apr 1997
Volume 29, Issue 1 - Feb 1997
Selecting the target year
Development of Meat-like Flavor by Maillard Reaction of Model System with Amino acids and Sugars
Ko, Soon-Nam ; Yoon, Suk-Hwan ; Yoon, Suk-Kwon ; Kim, Woo-Jung ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 827~838
Optimal substrates and reaction conditions were studied to develop boiled or roasted meat flavor by Maillard reaction under a model system. Sugars for the reactions were xylose, ribose, glucose, lactose, maltose, and sucrose. Amino acids were cystine, cysteine, methionine, lysine, and glycine as the reaction substrates. The reacted solutions were measured their absorbances at 278 nm and 420 nm and were evaluated their sensory properties. Except cysteine, the pentose mixtures with all of the four amino acids showed a faster reaction rate than those mixtures with hexose or disaccharides. pH was decreased rapidly until 8 hours and then changed a little thereafter. Sensory evaluation showed that cystine-lactose or cystine-xylose from single substrate and cystine-lactose-maltose, and cystine-lactose-xylose from mixed substrates reacted at
for 16 or 20 hours were found to be close to boiled or roasted meat flavor. The volatile compounds from the four selected sugar-amino acid solutions by GC/MS were 8 hydrocarbons, 10 aldehydes, 6 ketones, 7 alcohols, 2 aromatics (benzene), 1 ester, 4 furans, 1 base and 5 sulfur compounds.
Development of Meat-like Flavor by Maillard Reaction with Addition of Natural Flavoring Materials
Ko, Soon-Nam ; Nam, Hee-Sop ; Kim, Woo-Jung ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 839~846
Addition of three natural flavoring materials, hydrolyzed vegetable protein (HVP), hydrolyzed animal protein (HAP) and yeast extract (YE), into 0.2 M cystine-0.1 M lactose-0.1 M maltose solution (control) was studied for development of meat-like flavor by Maillard reaction. The HVP, HAP and YE were added individually at various concentrations and were mixed at selected concentration in order to compare their effects. The absorbance, color, sensory characteristics and volatile compounds of the solutions after the reaction at
for 8 hr were measured. The results showed that the absorbances of reaction solution at 420 nm and 278 nm were increased as reaction time and the concentration of the natural flavoring material increased. Also ‘L’ values of reaction solutions added with HVP, HAP or YE decreased while the ‘b’ value increased slightly. From the results of sensory evaluation 1.16% HVP, 0.94% HAP, 1.48% YE or 1.16% HVP + 0.94% HAP were selected as the appropriate substrates for the meat-like flavor development. The volatile compounds identified by GC/MS for the control and those added with 1.16% HVP or 1.16% HVP+0.94% HAP were 1 hydrocarbons, 9 aldehydes, 5 ketones, 1 ester, 5 alcohols, 2 aromatics(benzene), 2 furans, 1 sulfur compound.
Compositions of Opuntia ficus-indica
Lee, Young-Chul ; Hwang, Keum-Hee ; Han, Dong-Hyu ; Kim, Sung-Dae ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 847~853
Attempts were made to determine the compositions of Opuntia ficus-indica var. saboten for the utilization as food materials. The major components of Opuntia ficus-indica and aloe in proximate compositions were nitrogen free extract. Total mineral contents of stem, fruit and seed of Opuntia ficus-indica were 9400.8, 6151.2 and 1096.8 mg%, respectively, and their major minerals were Ca, P and Mg. The major free amino acids of fruit were tyrosine, proline and arginine, those of stem were glycine and arginine and that of seed was glutamic acid. The major amino acid of fruit was glutamic acid, those of stem were glycine and arginine and those of seed were glutmic acid and arginine. Vitamin C contents of fruit and stem were 163.8 and 71.2 mg% but not presented in seed. Vitamin A was also not presented in fruit, stem and seed. Contents of total polyphenols and flavonoids were changed by extraction solvent and temperature. Total polyphenols of fruit were higher than those of stem and seed. Total flavonoids of fruit were similar to those of stem.
Physicochemical Properties of Aqueous Extracts in Small Red Bean, Mung Bean and Black Soybean
Koh, Kwang-Jin ; Shin, Dong-Bin ; Lee, Young-Chun ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 854~859
In order to compare physicochemical properties of aqueous extract in 3 beans (small red bean, mung bean, black soybean), proximate composition, free sugars, free amino acids, minerals, absorbance and surface refractance color were investigated. Regardless of raw materials composition, the 3 beans extracts had similar proximate compositions. Free sugar analysis showed that fructose, glucose, sucrose, maltose, raffinose and stachyose were varied among the extracts. Raffinose and stachyose were the major sugar and fructose was measured only in black soybean and glucose was merely found in small red bean. Seventeen free amino acids in beans extract were analysed in the extracts. Among the free amino acids, arginine, aspartic acid, glutamic acid and serine were the main amino acids. Black soybean extract had maximum absorbance at 460 nm and 540 nm. L value of black soybean extract was lower than those of small red bean and mung bean.
Effects of Oil Unsaponifiables and Plant Extracts on the Thermal Oxidation of Oils at
Jung, Mun-Yhung ; Yoon, Suk-Hoo ; Kim, Seong-Yeol ; Lee, Jee-Hyeun ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 860~868
The effects of oil unsaponifiables (8 species) and methanolic plant extracts (53 species) on the thermal oxidation of oils during 14 or 16 hour heating at
were studied by analyzing the fatty acid composition of soybean oil or cottonseed oil. All the unsaponifiables tested did not show any antioxidative activities on the thermal oxidation of soybean oil. However, among the 53 species of methanolic plant extracts, some species (Rheum undulatum L., Chelidonium majus L. var. asiaticum and Eugennia caryopyllata T.) showed very strong antioxidative activities on the thermal oxidation of cottonseed oil. The antioxidative activities of methanolic extracts of these 3 species on thermal oxidation of cottonseed oil during an extended heating period were also studied by heating cottonseed oils for 7 hours a day for 8 days at
. The methanolic extracts of Chelidonium majus L. v. asiaticum and Eugennia caryopyllata T. greatly reduced both polymer formation and linoleic acid decomposition after the 8 day heating at
. However, the methanolic extracts of Rheum undulatum L. was effective for the reduction of polymer formation, but not for the reduction of linoleic acid decomposition.
Components Analysis of Korean Pollens and Pollen Extracts
Lee, Boo-Yong ; Choi, Hee-Don ; Hwang, Jin-Bong ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 869~875
The chemical components of Korean pollens and pollen extracts were analysed to provide fundamental data for pollen processing and products development. The contents of crude protein, crude lipid, crude ash, crude fiber and carbohydrate of pollens were
respectively, showing the specially high crude fiber content (37.5%) in Pine pollen. Almost all the carbohydrate, lipid, protein and ash components except fiber were extracted by water and n-hexane. Free sugars identified in water extracts
of pollens were fructose and glucose as major component and maltose as minor component. The proportions of three free sugars to total soluble solid content of Mixed, Acorn, and Pine water extracts were 73.6%, 85.4% and 47.7% respectively. Potassium and phosphorus content in pollens and pollen water extracts were high, but Ca, Na, Mg, Fe and Zn were not major mineral components. The essential amino acids such as leucine, phenylalanine, methionine, lysine, valine, isoleucine and threonine were contained richly in pollens and those were almost completely extracted by water. Vitamin
and C were not detected, but only small amount of vitamin
was detected in the pollens and pollen extracts tested. The essential fatty acids such as linoleic acid and linolenic acid were contained richly in pollens. The proportion of unsaturated fatty acids to total fatty acid content in Mixed, Acorn and Darae pollen except Pine was higher than 50%.
Relationship between Molecular Structure of Acid-Hydrolyzed Rich Starch and Retrogradation
Kang, Kil-Jin ; Kim, Kwan ; Lee, Sang-Kyu ; Kim, Sung-Kon ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 876~881
The relationship between the molecular structure of acid-hydrolyzed rice starch and the retrogradation rate of starch gel was investigated. The molecular structure of starch was modified by acid hydrolysis with 1 N HCl at
. The molecular weight of starch decreased as acid hydrolysis time was increased. At the early stage of hydrolysis up to 3 hr, the branching point of amylopectin was degraded and thereafter both
linkages were hydrolyzed. The starch gel (50%) stored at
revealed that the rapid retrogradation occurred during 4 hr of storage which was more pronounced as the hydrolysis time increased. The degree of retrogradation of starch gels after 4 hr storage showed a linear relationship with the yield of hydrolyzate. These results suggested that the retrogradation of starch gel was accelerated by degradation of
linkages with acid.
Determination of sulforaphane in cruciferous vegetables by SIM
Kim, Mee-Ree ; Lee, Kun-Jong ; Kim, Jin-Hee ; Sok, Dai-Eun ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 882~887
Quantitative determination of sulforaphane, S-methylsulfinylbutyl isothiocyanate in 20 cruciferous vegetables of Korean origin was performed. Homogenate of vegetable was extracted with dichloromethane, and the extract, after drying, was subjected to GC/MS analysis, which was based on single ion monitoring (SIM) at m/z 72, 160, 55, 114 and 177. The content of sulforaphane was found to be the highest in the extract of broccoli
followed by turnip
, red cabbage
and kale (8 ppm). Among various cultivars of broccoli, broccoli '1243' and broccoli 'Pilgrim' showed higher content of sulforaphane than others. Especially, in the stem of broccoli '1243' and the floret of broccoli 'Pilgrim' the amount of sulforaphane was the highest (>700 ppm). Thus, the content of sulforaphane differed according to the cultivars and the portion of the vegetables.
Enrichment from Pearled Barley and Milled Barley Fractions
Lee, Young-Tack ; Seog, Ho-Moon ; Cho, Mi-Kyung ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 888~894
Two hulled and two hull-less barley varieties were investigated for
enrichment. Hull-less barleys contained higher levels of total
than hulled barleys, and were thus suitable as starting materials for preparing
fractions. Particularly, a waxy type (Suweon-291) of hull-less barley was found to have high soluble dietary fiber content containing primarily
, compared to the other non-waxy barley varieties.
content of barley during pearling process was measured, and the highest value was observed at the pearling yield of approximately
. The pearled barley grains were ground and sieved to yield
enriched fractions containing up to 22%
. In the meanwhile, whole barley samples were directly milled by
mill to produce bran, shorts, break flour and reduction flour.
contents in the bran and shorts from the milled stream were relatively high, and further concentration of
could be accomplished by successive sieving of the bran and shorts fractions. Pearled barley and milled stream could be used to prepare barley fractions with
times those of the original barley grain. Water solubility of barley
from pearled barley and the milled stream was in the range of
Changes of Takju Qualities by Addition of Cyclodextrin during the Brewing and Aging
Song, Jae-Chul ; Park, Hyun-Jeong ; Shin, Wan-Chul ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 895~900
Cyclodextrin (CD), which is one of food additives, was applied to Takju in oder to suppress the production of a stinking odor which its brewing and storage. CD was added to Takju in two different manners: one right after its brewing dilution stage, the other during its second mashing stage. After equal intervals of time, each sample was tested for fermentation process, storage capability, and sensory characteristics. The amount of CD ranged from 0.1 to 0.3% (w/w). The effect of CD on alcohol concentration, pH, total acidity and sugar content of Takju was shown to be more greatly influenced in the second sample rather than the first. The qualities of Takju were not affected by the addition of CD in the first sample. The sensory evaluation showed that the sample of the brewing dilution stage proved to be more attractive in the level of acceptability. However, when CD was over-added to Takju, the degree of acceptability declined due to the fact that the over-addition of CD suppresses its unique taste and flavor.
Changes in Microflora and Enzymes Activities of Traditional Kochujang Prepared with Various Raw Materials
Shin, Dong-Hwa ; Kim, Dong-Han ; Choi, Ung ; Lim, Mi-Sun ; An, Eun-Young ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 901~906
In order to reproduce and improve quality of traditional kochujang, various raw materials were added to prepare kochujang by replacing part of the glutinous rice. Chemical composition, microbial characteristics and enzyme activities were investigated during fermentation. Crude protein and salt contents of kochujang did not change significantly during fermentation, but moisture contents increased linearly. The pH and titratable acidity of kochujang changed little in garlic added group. The viable cell counts of aerobic bacteria and yeasts in the kochujang increased until 60 days of fermentation and then decreased slowly except for the garlic added group in which they increased during the last period of fermentation. Aerobic bacterial count did not show any remarkable differences among the samples and slowly decreased after 60 days of fermentation. The activities of liquefying and saccharifying amylases decreased until 45 days, but increased at 60th day. Acidic protease activities of each group were strong during the initial period, but neutral protease showed the highest activity from the 30 to 45 days of fermentation. Protease activities increased by addition of soy sauce, Chinese matrimony vine and purple sweet potato.
Physicochemical Characteristics of Traditional Kochujang Prepared with Various Raw Materials
Shin, Dong-Hwa ; Kim, Dong-Han ; Choi, Ung ; Lim, Mi-Sun ; An, Eun-Young ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 907~912
Physicochemical characteristics of kochujang prepared with various raw materials, were investigated during 90 days of fermentation to obtain information for the industrial production of traditional kochujang. Reducing sugar contents of kochujang increased until 60 days but slightly decreased thereafter, showing highest value for malt added group. Ethanol contents increased after 45 days and were highest in Chinese matrimony vine group, followed by purple sweet potato and malt added groups. Amino nitrogen contents increased until the 45 to 60 days of fermentation, but ammonia nitrogen contents did not change significantly during fermentation. Amino and ammonia nitrogen contents were higher in soy sauce and Chinese matrimony vine added groups. Water activities decreased slightly during fermentation and purple sweet potato added group was lowest among the groups. Consistency of kochujang decreased until the middle of the aging but after that it increased. Consistency of purple sweet potato and Chinese matrimony vine added groups were remarkably higher than that of the others. The color values tended to decrease slightly during fermentation. Purple sweet potato kochujang was low in the lightness, redness and yellowness. Results of sensory evaluation showed garlic and malt added kochujang were more acceptable than purple sweet potato added kochujang due to more desirable taste and color.
Taste Components of Traditional Kochujang Prepared with Various Raw Materials
Shin, Dong-Hwa ; Kim, Dong-Han ; Choi, Ung ; Lim, Mi-Sun ; An, Eun-Young ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 913~918
Taste components of traditional kochujang prepared with various raw materials, were investigated during 90 days of fermentation. The major free sugars, maltose and glucose, were higher in malt added kochujang than others. The major organic acids of kochujang were succinic and citric acids, followed by formic acid. The contents of succinic acid in the kochujang decreased during fermentation, whereas that of citric acid increased. Purple sweet potato kochujang was highest in total free amino acids. The major free amino acids were glutamic acid, serine and aspartic acid. They remarkably increased during fermentation. Among the nucleotides and their related components in kochujang, cytidine-5-monophosphate was the most abundant component at the beginning of aging period, while hypoxanthine increased remarkably during fermentation. Kochujang prepared with purple sweet potato Chinese matrimony vine contained higher amounts of organic acids and nucleotides than the others.
Occurrence and Repression of Off-Odor in Cooked Rice during Storage under Low Temperature Warming Condition of Electric Rice Cooker
Park, Seok-Kyu ; Ko, Yong-Duck ; Cho, Young-Sook ; Shon, Mi-Yae ; Seo, Kwon-Il ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 919~924
The changes in physicochemical properties of cooked rice stored in an electric rice cooker at different temperature (63, 66, 69 and
) were investigated. The growth of thermophilic bacteria was gradually increased in all samples with storage time up to 6 hours and increased rapidly afterward. The bacterial growth rate was higher during storage at low temperature than at high temperature, and the bacterial number generally reached the maximum at 18 hours of the storage. The number of bacteria in sample stored at
was increased to
CFU/g after storage for 6 hours. The heat treatment at 6 hours of storage decreased the bacterial number to
CFU/g at 8 hours of storage. Bacterial number was gradually increased with storage time after the first heat treatment. When the sample was reheated after 8 hours of storage, the bacterial number was reduced to the level at which off-odor was not detected after storage for 24 hours. During the storage, moisture content of heat-treated sample was lower than that of sample stored at
but higher than that of sample stored at
. The L value of heat-treated sample was higher than that of the sample stored at
, but lower than that of the sample stored at
. The b value showed an opposite trend to the L value with regard to the storage temperature. Changes in texture were not remarkable during the storage for the sample heat-treated and stored at low temperature. The occurrence of off-odor and browning was depressed in the heat-treated sample, and the texture and overall eating quality were more acceptable than the samples stored at low temperature.
Preparation of Seasoned and Semi-dried Horse Mackerel by Cold Air Drying and Quality of Its Product during Partially Frozen Storage
Yang, Seung-Taek ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 925~931
An attempt was made in this study to investigate the possibility of processing seasoned and semi-dried horse mackerel (Tracharus japonnicus) and to examine its keeping quality, by analyzing the factors such as water content, pH, volatile basic nitrogen, viable cell count, peroxide value, color value and sensory evaluation. For processing of the seasoned and semi-dried product, optimum conditions of drying temperature and drying time were
and 4 hr, respectively, under
of relative humidity and 2 m/sec of air blast speed. The shelf-life of the products, vacuum-packaging method in nylon/polyethylene/linear low density polyethylene
film bag, was 42 days during storage at
, while that of unpackaged one was only 28 days.
Viscosity and Dynamic Rheological Properties of Job's-tears as a Function of Moisture Content
Yoon, Won-Byung ; Kim, Byung-Yong ; Shin, Dong-Hoon ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 932~938
Changes in viscosity and dynamic theological properties of Job's-tears were measured by Bohlin dynamic tester as a function of moisture, and measurement was performed within a linear viscoelastic range. The result of the shear stress vs shear rate of Job's-tears at different moisture contents
was applied to mathematical models and Herschel-Bulkley model showed the highest correlation coefficient. Lower moisture content (55%) produced higher yield stress and consistency index, but lower flow behavior index, whereas higher moisture content showed reverse effects. Job's-tears with
moisture contents showed a higher storage modulus (G') than loss modulus (G') at all frequencies, showing a higher concentrated polymer characteristics. However, higher moisture content (>75%) showed crossover point between G' and G', and frequency dependency. As the moisture content was increased, the amount of viscoelastic properties such as G', G', complex viscosity decreased during heating, and initial temperature and miximum value of viscoelastic properties shifted to higher temperatures, representing the moisture-dependence of Job's-tears upon theological properties.
Effects of Moisture Content on Recrystallization of Rice Starch Gels
Baik, Moo-Yeol ; Kim, Kwang-Joong ; Cheon, Ki-Cheol ; Ha, Yeon-Chul ; Kim, Wang-Soo ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 939~946
Effects of moisture content on the gelatinization and recrystallization of non-waxy and waxy rice starch gels were investigated by differential scanning calorimetry (DSC). The recrystallization rates of the starch gels containing various moisture contents
were analyzed by Avrami equation. The waxy rice starch had higher gelatinization temperature and enthalpy than non-waxy one. The highest degrees of recrystallization in both rice starch gels stored at
were shown at 40%, and recrystallizations above 80% moisture content were not found. The degree of recrystallization of waxy one was higher than that of non-waxy one in the range of 40 to 60% moisture content. The Avrami exponents (n) of both rice starch gels were near to 1.0 and the time constant (1/k) was increased with increasing moisture content in the range of 40 to 70% moisture content. The recrystallization rate of waxy rice starch gel was slower than that of non-waxy one. The recrystallization of rice starch gels could be explained by the change of ice melting enthalpy during storage. The Wg's, represented the maximum practical amount of plasticizing water, were about 29.9% and 28.2% for non-waxy and waxy rice starch gels, respectively.
Analysis of Physical Properties and Mechanical Energy Input of Cornmeal Extrudates Fortified with Dairy Products by Carbon Dioxide Injection
Ryu, Gi-Hyung ; Mulvaney, S.J. ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 947~954
Selected physical properties of cornmeal extrudates fortified with dairy products and extrusion process by
gas injection were analysed. Dairy products including whole milk powder, whey protein concentrate non-fat dry milk, and sodium caseinate were tested at the addition of 10% and 20%, based on cornmeal weight.
gas was injected to the barrel at the pressure of 0.7 and 1.4 MPa. Specific mechanical energy (SME) input was decreased by the addition of dairy products. Sodium caseinate had a little effect on decreasing the SME input, however whole milk powder tremendously reduced SME input when the concentration increased. An increase in milk product content resulted in increasing the piece density at the injection pressure of 0.7 MPa. At both 10% and 20% milk product content, the piece density was lowest at the injection pressure of 0.7 MPa. The sectional expansion index was highest at the injection pressure of 0.7 MPa. However, the specific length was constantly increased with the increase in
injection pressure. Water absorption index was decreased and water solubility index was increased by the addition of milk products. The injection pressure of
was optimum at 0.7 MPa. The addition of whole milk powder limited to puff the melt, but the other milk products tested resulted in puffing with
injection to 1.4 MPa.
Food Constituents of Edible Ascidians Halocynthia roretzi and Pyura michaelseni
Oh, Kwang-Soo ; Kim, Jin-Soo ; Heu, Min-Soo ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 955~962
The food components of three kinds of edible ascidians being cultivated and caught in Tongyeong and Jisepo districts, Kyongnam of Korea were investigated. Wild Halocynthia roretzi (WM) and Pyura michaelseni (DM) were higher in contents of moisture and crude protein than cultured Halocynthia roretzi (CM). Total combined amino acid contents of CM, WM and DM muscles were 11,425.4 mg%, 11,595.4 mg% and 12,152.7 mg%, respectively, and major amino acids were Asp, Glu and Lys. The major fatty acids were 14:0, 16:0, 16:1n7, 18:1n7, 18:4n3, 20:5n3 and 22:6n3, and composition ratio of n3 polyunsaturated fatty acids of CM, WM and DM were 39.1%, 47.0% and 46.5%, respectively. In extracts components, total free amino acid contents of CM, WM and DM were 1,071.3 mg%, 1,278.7 mg% and 1,133.2 mg%, respectively, and the major amino acids were Tau, Glu, Pro, Asn, Gly, and Ala, while Arg was contained little quantities. As for nucleotides and related compounds, AMP was the principal component and IMP was detected though very small amounts in ascidian samples. Also contents of TMAO, total creatinine, betaine and peptide-N were
respectively. In inorganic ions of ascidian samples, the major components were
Quality Characteristics of Reconstituted Multi-Grain by Extrusion Process
Lee, Young-Tack ; Seog, Ho-Moon ; Kim, Sung-Soo ; Kim, Kyung-Tack ; Hong, Hee-Do ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 963~968
Cereals and legumes were ground, blended and extruded with a twin-screw extruder to form a reconstituted grain. The basic formula was as follows: brown rice 30%, barley 30%, wheat 20%, millet 5%, sorghum 5%, soybean 7%, and red bean 3%. Extrusion conditions were properly set for feed moisture content of
, barrel temperature of
, and screw speed at 250 rpm. The extruded grain was air-dried and evaluated for quality characteristics, compared with milled rice. Size and shape of the reconstituted grain were similar to short-grain milled rice. Stacking volume of the reconstituted grain was a little higher than that of milled rice, and its water absorption was more rapid. From the texture measurements, hardness of cooked reconstituted grain was slightly lower and adhesiveness was appeared to be higher.
Continuous Production of Transglucosylated Steviosides Using Immobilized Cyclodextrin Glucanotransferase
In, Man-Jin ; Chae, Hee-Jeong ; Kim, Min-Hong ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 969~973
In order to produce transglucosylated steviosides continuously, some types of bioreactors were investigated with cyclodextrin glucanotransferase immobilized on a high porous anion exchange resin, Diaion HPA75. Among the bioreactors, the packed-bed reactor (PBR) showed the highest specific productivity. The effect of linear velocity in a PBR on the stevioside conversion was not significant in the range of
at the same space velocity of
. When the space velocity of bioreactor was varied from 0.2 to
, the optimal velocity of substrate solution was determined as
. The stevioside conversion of more than 70% was maintained during 20 days in the continuous operation, if about 20% of immobilized enzyme was replaced in the top of reactor after two weeks operation as the one of the control methods in bioreactor. The specific production, which refers to as the amount of commercially valuable transglucosylated steviosides produced by a unit amount of immobilized cyclodextrin glucanotransferase, was found to be ca. 150g product/g immobilized enzyme.
Effect of a Combined Treatment of High Hydrostatic Pressure and Carbonation on the Quality Characteristics of Valencia Orange Juice
Yun, Hye-Suk ; Park, Seok-Jun ; Park, Ji-Yong ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 974~981
A combined treatment of high hydrostatic pressure and carbonation was used to inactivate pectinesterase (PE) and sterilize microorganisms in Valencia orange juice without major changes in its nutritive components. Quality characteristics of Valencia orange juice, such as microorganisms, PE activity, vitamin C content and color, were evaluated after it was treated with pressure, carbonation-and-pressure, and heat. Quality changes during storage at
after the treatments were also investigated. Pressurized orange juice (pressurized at 600 MPa for 10 min at
) showed 7.0% residual PE activity, while the carbonated-and-pressurized orange juice (207
gas pressure, pressurized at 600 MPa for 10 min at
) showed 0%. Pressurization at 400 MPa or higher decreased the population of microorganisms in the orange juice to less than 10 CFU/mL. Carbonated-and-pressurized orange juice showed slight decrease in vitamin C content when stored at both
. While heat-treated (
for 60 sec) orange juice showed 75% decrease in vitamin C content when stored at
. L value (lightness) and b value (yellowness) of carbonated-and-pressurized orange juice were higher than those of heat-treated orange juice when they were stored at
for 30 days.
Effect of Propolis Addition on the Shelf-Life and Staling of White Bread
Kim, Chong-Tai ; Lee, Soo-Jeong ; Hwang, Jae-Kwan ; Kim, Chul-Jin ; Ahn, Byung-Hak ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 982~986
Propolis extract was added to white bread(P1-1.48%, P2-0.74%, P3-0.37%), prepared in the straight-dough method, and its effects on shelf-life, antimicrobial activity, staling and sensory evaluation of white bread were investigated. In all P1, P2 samples, added propolis inhibited the growth of fungi, and the more propolis extract was added, the higher degree of inhibition of fungal growth was observed. The staling rates of white breads with P1, P2 and P3 were retarded by 22.5%, 19.2% and 6.4% respectively compared to that of control, and the Avrami exponent was similar in all samples. As a result of sensory evaluation, flavor, off-flavor, texture and overall acceptability of P2 and P3 were not significantly different from that of control.
Effect of Morphology and Granule Size of Crystalline D-Sorbitol on Texture of Sugar-Free Chewing Gum
Kim, Sang-Yong ; Oh, Deok-Kun ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 987~991
Effect of morphology and granule size of crystalline D-sorbitol on texture of sugar-free chewing gum was investigated with different morphology of sorbitol such as a compact shaped P-type and a loose shaped S-type, and with different granule size such as 50 mesh, 80 mesh, and 100 mesh. The chewing gum including S-type sorbitol exhibited an increased flexibility and a decreased hardness as compared with that including P-type sorbitol. S-type sorbitol was chosen as a solid phase of sugar-free chewing gum because the consumer preferred a chewing gum with high flexibility and low hardness. The flexibility and hardness of chewing gum including S-type sorbitol were determined to be optimum at 80 mesh of the sorbitol size. The flexibility of the chewing gum including 80 mesh S-type sorbitol increased but the hardness decreased with increasing temperature.
Chemical Changes During Desalting of Fish Sauces Using Electrodialyzer
Oh, Se-Wook ; Nam, Eun-Jung ; Jo, Jin-Ho ; Kim, Eun-Mi ; Kim, Young-Myoung ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 992~998
For the development of kimchi seasoning, fish sauces were desalted using electrodialyzer and some chemical components were analyzed. The salt content of fish sauce was adjusted to 20%, 15%, 10%, 5%, 2% and pH, total nitrogen (TN) content, amino nitrogen (AN) content and
content was determined. During desalting process pH was increased and TN, AN content also increased. But
content was decreased. It was surposed that
was eliminated with
because similar charge characteristic. In conclusion, using electrodialyzer fish sauce could be desalted to less than 2% and salt and moisture was co-eliminated.
Presence and Control of Coliform Bacteria in Kimchi
Chung, Chang-Ho ; Kim, Youn-Soon ; Yoo, Yang-Ja ; Kyung, Kyu-Hang ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 999~1005
The consistant appearance of coliforms in fermenting kimchi was examined and measures of removing coliforms early in the fermentation were investigated. Allyl isothiocyanate
, horseradish powder
, and garlic juice
were effective in removal of coliforms early in kimchi fermentation. However, mustard powder and methyl methanethiosulfonate were not effective. Nisin, known as a promising agent for the prevention of kimchi over-acidification, allowed coliforms to survive in kimchi longer with only marginal extention of edible period. Individual kimchi ingredients such as Chinese cabbage, garlic, red pepper powder, ginger and green onion were all found to contain coliforms. Coliforms were not detected from garlics sold unpeeled and commercially prepared red pepper powder.
Fermentation Characteristics of Whole Soybean Meju Model System Inoculated with 4 Bacillus Strains
Kim, Dong-Ho ; Lim, Dae-Won ; Bai, Suk ; Chun, Soon-Bai ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1006~1015
Whole soybean meju was fermented with four Bacillus strains for 45 hr in its model system. The pH range of the product was
, the contents of amino nitrogen and ammoniacal nitrogen were
, respectively and that of reducing sugar ranged
. During fermentation, the enzyme activities increased up to
of fermentation and slightly decreased after 45 hr. Stachyose was special sugar components for B. licheniformis and raffinose was for B. natto. The components of the organic acid showed distinctive patterns among four products and the patterns of amino acids and fatty acids were almost similar to those of other reports. The main and common odor concentrates of meju were pyrazine components, 3-methyl-1-butanol, acetic acid and ethanol. Chunggukjang, mixed with B. natto and B. licheniformis showed more acceptabilities than other combinations. Soybean paste, mixed with B. megaterium and B. subtilis, soysauce, mixed with B. megaterium and A. oryzae showed excellent acceptability, respectively.
Effects of Gamma-Ray and Heat Treatment on Sterilization of Escherichia coli O157:H7
Kwon, Oh-Jin ; Yook, Hong-Sun ; Kim, Seong-Ai ; Byun, Myung-Woo ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1016~1020
Treatments of irradiation alone and/or in combination with heat were investigated for the sterilization of Escherichia coli O157: H7. D values of the strain were 129.2 min at
, 27.1 min at
, and 2.4 min at
. The survival effect of E. coli O157:H7 during heating at various media was investigated. On heating at temperature of
for 10 min, the strain was generally more resistant in the media containg such chemical substrates such as 0.03 M cysteine, 1% sodium citrate or 5% sucrose, whereas this strain was appeared weaker in the chemical substrates added group such as 1% meat extract, 1% casein or 1% casamino acid. In the case of irradiation alone,
value of E. coli O157:H7 was 0.116 kGy, and inactivation factors were
at doses of 2 to 3 kGy. Pre-and post-irradiation heating showed the same
value about 0.07 kGy. And Inactivation factors were
at doses of 2 to 3 kGy. Therefore, combination treatment with heat and irradiation significantly increased in inactivation rate by increasing radiation sensitivity of E. coli O157:H7.
Yeast Cell Wall Lytic Enzyme Produced by Dicyma sp. YCH-37 II. Effect of Culture Conditions and Pretreatment of Yeast on the Enzyme Activity
Chung, Hee-Chul ; Hahm, Byoung-Kwon ; Yu, Ju-Hyun ; Bai, Dong-Hoon ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1021~1027
We examined some properties of yeast cell wall lytic enzyme produced by Dicyma sp. YCH-37. Several metal ions, reducing reagents, and chemical modifiers have little effects on the lytic activity, except guanidine-HCl. Yeast cells of early log phase were more susceptible to the enzyme than those of stationary phase, and heat-treated cells were more easily lysed than intact living ones. Yeast cells pretreated with organic solvents such as butanol and acetone were more susceptible to the enzyme than intact living ones. Yeast cells cultured in Yeast extract-Malt extract medium containing 0.5 M ammonium sulfate were easily lysed by the lytic enzyme, and yeast cells cultured without shaking were more easily lysed by the enzyme than those with shaking. When SDS,
, Triton X-100, sodium sulfite, and KCl were added to enzyme reaction mixture each, lysis of yeast cells was more effective.
Isolation and Identification of Cellulase-producing Microorganism, and Determination of Optimal Culture Condition
Hahm, Byoung-Kwon ; Kim, Yoon-Keun ; Yu, Ju-Hyun ; Bai, Dong-Hoon ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1028~1032
The strain No. 33, which produces cellulose-degrading enzyme, was isolated from soil. Yellow halo was identified when the culture supernatant of the strain was loaded onto agar plate containing 2.0% CMC using paper disc method. From scanning electron microscopic observation, the morphology of the stain was rod-shaped. For identification, several biochemical characteristics were tested, and this strain was identified to Bacillus sp. So, we named this strain as Bacillus sp. No. 33. The maximal growth was observed when the stain was cultured in the medium containing 1.0% glucose, 3.0% yeast extract, 0.5%
, pH 7.0 at
for 39 hours with shaking. The maximal enzyme production was accomplished using the medium containing 4.0% CMC, 2.0% yeast extract, 0.5%
, pH 7.0 at
for 42 hours with shaking.
Occurrence of Mold Growth due to Moisture Migration in a Composite Chocolate Product
Kim, Sang-Yong ; Noh, Bong-Soo ; Oh, Deok-Kun ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1033~1037
The occurrence of mold growth due to moisture migration in a composite chocolate product filled with marshmallow during storage was investigated. The correlation between water activities and water contents of dark chocolate coating and filling marshmallow at
was well applied to Kuhn's equation. The marshmallow was found to be more hydrogroscopic than the chocolate. Since the moisture transferred from marshmallow to chocolate, the water activity of marshmallow decreased from 0.88 to 0.80 and that of chocolate increased from 0.22 to 0.76 at
for 30 days. This water activity, 0.76, can allow mold growth. A mold was isolated on the surface of a composite chocolate product at
after 3 months and then was identified as Aspergillus repens. Growth experiments at varied water activities with A. repens were performed. When the water activity in a chocolate solid medium increased from 0.73 to 0.93, the occurrence time of mold growth decreased from 62 to 15 days. These results suggested that the occurrence of mold growth was due to the increased water activity of the chocolate resulting from the moisture transfer from filling marshmallow dark to chocolate coating.
The Study on Antibacterial Activity of Adipic Acid and Medium Chain Monoglycerides
Jang, Jae-Kweon ; Shin, Woong-Kyu ; Lee, Sang-Ho ; Han, En-Sang ; Lee, Young-Chun ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1038~1044
The mode of the combined effect of adipic acid and medium chain monoglycerides was investigated by using nine strain. Though monoglycerides alone had little antibacterial activity against gram negative strains, the combined use with adipic acid showed much higher activity against others of gram positive strains as well as gram negative strains. But exceptionally, it seemed difficult practically to prevent the growth of lactic acid bacteria completely by the combined use of adipic acid and monoglyceride. For yeast and mold, monoglycerides alone had a high activity but adipic acid had a little activity. In antibacterial mechanism, we thought that adipic acid acted on the cell envelope and then monoglyceride acted on the altered cell.
Antioxidative Effect and Characteristics of Different Model Melanoidins with Same Color Intensity
Lim, Won-Yong ; Kim, Jong-Sang ; Moon, Gap-Soon ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1045~1051
Three kinds of model melanoidins adjusted to have the same brown color intensity were made from glucose-glycine, glucose-lysine, xylose-arginine and their antioxidative properties were determined. The antioxidative activities of these model melanoidins in linoleic acid emulsion system were determined by ferric thiocyanate method, conjugated diene contents, peroxide value and electron donating ability by DPPH. Xylose-arginine melanoidin showed the strongest antioxidative activity and electron donating ability. The antioxidative effect of melanoidin could be reliably predicted by determining peroxide value and DPPH method. Each melanoidin was separated on Sephadex G-50 column, and brown color intensity, reducing power, ninhydrin positive reaction and antioxidative activity of each fraction were determined. The antioxidative activities of melanoidin fractions showed strong correlation with their brown color intensity and especially to their reducing power. In spite of same brown color intensity, there is no big differences between these model melanoidins, thus xylose-arginine showing strongest antioxidative activity followed by glucose-lysine and glucose-glycine melanoidin. Xylose-arginine melanoidin also showed the strongest electron donating activity and broad range of reducing power when fractionated on Sephadex G-50, which was different tendency from the other model melanoidin.
A Study on Iron Binding Peptides from Casein Hydrolysates
Choi, In-Wook ; Kim, Ki-Sung ; Lim, Sang-Dong ; Kim, Hee-Soo ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1052~1056
When casein was hydrolyzed by trypsin, alcalase, neutrase, protamax, and S. aureus type V8, peptides
which were produced by trypsin and alcalase solubilized
of added irons at pH 6, respectively, while peptides which were produced by other proteases solubilized less than
. Peptides produced by trypsin and alcalase were fractionated to 10 fractions on a reverse phase column and each fraction was tested for its iron solubilizing ability at pH 6. Among peptides produced by trypsin, fraction 5 showed the highest iron solubilizing ability
. In the case of alcalase, fraction 7 showed the highest iron solubilizing ability
. To isolate iron binding peptides from peptides produced by trypsin and alcalase, immobilized iron affinity chromatography which irons were chelated to imino diacetic acids in chelating sepharose fast flow were utilized. Our results showed that immobilized iron affinity chromatography was an effective method to isolate iron binding peptides produced by either trypsin or alcalase from milk casein.
Inhibition of Topoisomerase-mediated DNA Cleavage by Lycoperdon perlatum
Park, Mi-Jung ; Cho, Kang-Jin ; Kim, Jung-Bong ; Kim, Dong-Hern ; Kim, Yang-Sub ; Seok, Soon-Ja ; Kim, Sun-Yeou ; Hwang, Young-Soo ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1057~1062
In the course of searching for anticancer agents from 32 mushrooms, it was found that methanol extract of Lycoperdon perlatum showed inhibitory effect on topoisomerase II-mediated DNA cleavage. This active methanol extract was sequentially fractionated with hexane, chloroform, n-buthanol and water. Among the solvent-fractionated extracts,
hexane fraction of L. perlatum inhibited on topoisomerase II-mediated DNA cleavage. The effect of hexane fraction of L. perlatum was dose- and reaction time-dependent. The hexane fraction of L. perlatum was found to have inhibitory activity on relaxation assay of DNA topoisomerase I. The hexane fraction of cultured L. perlatum, however, had no inhibitory effect on either type of topoisomerase.
Studies on the Genetic Diversity using RAPD in Leuconostoc sp. Isolated from Kimchi
Kim, Eun-Kyung ; Ryu, Chun-Sun ; So, Myung-Hwan ; Kim, Young-Bae ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1063~1066
Thirty four Leuconostoc strains originated from kimchi were subjected to analyse their genetical similarity by using RAPD-PCR. At the 0.5 level of similarity, L. mesenteroides subsp. mesenteroides and L. mesenteroides subsp. dextranicum. formed 3 and 2 clusters, and each L. lactis and L. paramesenteroides strain was clustered in one, respectively. Every type strain tested as a control, belongs to the cluster or one of the clusters of the corresponding species or subspecies as the isolates from kimchi, respectively. However the similarity between a and b cluster was less than 0.2 and c cluster is even less similar to both of them (a and b). L. mesenteroides subsp. mesenteroides strains from kimchi have shown a varaiety of RAPD patterns in spite of morphological and physiological similarities.
An Effective Method of Isolating Immunoglobulins from Bovine Plasma Proteins
Choi, In-Wook ; Lee, Hyun-Jung ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1067~1070
Imunoglobulins from bovine plasma proteins were isolated by IMAC which
was chelated on a chelating sepharose fast flow gel. Most plasma proteins were eluted by 1st (0.01 M
, 0.5 M NaCl, pH 4.0) and 2nd elution buffers (0.01 M imidazol). According to the reverse phase HPLC analysis, it was found that proteins which were eluted by 1st elution buffer were mainly composed of serum albumin, while most IgG and transferrin were eluted by 2nd elution buffer. When protein fractions obtained by 2nd elution buffer was applied to ultra filtration system (molecular weight cut off: 100 kD), IgG was further purified. These results indicate that IMAC is an excellent tool for isolating imunoglobulins from plasma proteins.
Effect of Calcium, Potassium and Magnesium Ion on Salting of Radish
Han, Kee-Young ; Park, Sung-Oh ; Noh, Bong-Soo ;
Korean Journal of Food Science and Technology, volume 29, issue 5, 1997, Pages 1071~1074
The Effect of
on salting of radish was investigated. Up to 0.2 M of
, sodium chloride content of radish increased respectively, comparing with no addition of these ions. The salting effect of radish incereased in proportion to the concentration (
in the salting solution up to 0.2 M, while there was no influence of
were added to brine solution,
influenced the salting effect of radish and