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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 28, Issue 6 - Dec 1996
Volume 28, Issue 5 - Oct 1996
Volume 28, Issue 4 - Aug 1996
Volume 28, Issue 3 - Jun 1996
Volume 28, Issue 2 - Apr 1996
Volume 28, Issue 1 - Feb 1996
Selecting the target year
Preparation of Calcium-fortified Soymilk and in Vitro Digestion Properties of Its Protein and Calcium
Pyun, Jin-Won ; Hwang, In-Kyeong ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 995~1000
The present study was attempted to preprare calcium-fortified soymilk using proteases to improve calcium intolerance of soymilk protein and to evaluate its nutritional properties. The protease from Bacillus polymyxa was chosen as an enzyme source because it produced the least bitter taste and calcium-aggregation of soymilk among various enzymes. The optimum treatment time was 10 minutes at
for the best result. In vitro protein digestibility of calcium-fortified soymilks was comparable with that of control soymilk. Calcium in the digested soymilks was mostly in the ionic form and the amount of ionic calcium increased in accordance with the amount of fortified calcium in soymilk. This suggests that fortified calcium in the soymilk is bioavailable.
Rapid Detection of Enterotoxigenic Staphylococcus aureus by Polymerase Chain Reaction
Kim, Eun-Seon ; Jhon, Deok-Young ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1001~1008
Staphylococcal food poisoning is the major cause of bacterial food poisoning occurring in this country. Therefore government regulates commercial foods through Official Dictionary of Food that there should be free of enterotoxigenic Staphylococcus aureus in Korean rice cakes, bread, and a box lunch. Since at least 5 days are required to identify the S. aureus by the official method in the Dictionary it is difficult to prevent the food poisoning and the investigation of the outbreaks. In this report an improved determination method of the S. aureus has been developed using polymerase chain reaction (PCR) technique. Sense and antisense primers for specific amplification of genes encoding staphylococcal enterotoxins were designed and synthesized for the PCR. Rapid chromosomal DNA isolation method was also developed from S. aureus using lysostaphin. The PCR condition was developed as follows. Reaction solution
consisted of target DNA
(about 20ng), 10X buffer
, primer 100pmole, dNTP (10 mM)
and Taq DNA polymerase 2.5 unit in a thin-wall tube. Operation condition of the PCR was 5 min pre-denaturation at
, 15 sec denaturation at
, 15 sec annealing at
, 20 sec extension at
, and 5 min post-extension at
, and 30 cycles of denaturation-annealing- extension. Using the PCR with Perkin Elmer GeneAmp PCR system 2400, types of enterotoxigenic S. aureus could be identified from Ddok or bread in a day.
The Effect of Molecular Size and Degree of Phosphorylation on the Emulsion Stability of Microcrystalline Chitin
Lee, Young-Chun ; Im, Ji-Soon ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1009~1013
This study was carried to investigate the emulsion stability of microcrystalline chitins (MCC) prepared from chitins of different molecular sizes and different degrees of phosphorylation in a model fatty food system. Chitins of low, medium and high molecular size prepared from crabshells were phosphorylated to 30-50% to make MCC. MCC prepared from chitin of medium molecular size revealed a high emulsion stability. The best emulsion stability was observed in MCC prepared from medium size chitin with 40% phosphorylation (M-40-MCC). The fat binding capacity of MCC was not significantly different among the samples. MCC with 50% phosphorylation had more fat binding capacity, ranging from 650-690%. When 2.46% of M-40-MCC was applied to a coconutoil-water system as an emulsifier, emulsion separation was observed from 10 min after emulsification, indicating that it could not be used as a sole emulsifier. When 50% of emulsifier (Span-60 &Tween-60) in a liquid coffee creamer, selected as a model fatty foods, was replaced by M-40-MCC, emulsion stability was as good as control. Consistency of liquid creamer was decreased and L value increased as the amount of MCC repacement increased. A liquid creamer with 50% emulsifier replaced by MCC had sensory characteristics equivalent to control.
Technical Development of Korean Type Hot sauce
Kwon, Dong-Jin ; Lee, Sung ; Yoon, Ki-Do ; Han, Nam-Su ; Yoo, Jin-Yong ; Jung, Kun-Sub ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1014~1020
To develope a manufacturing process of the Korean type hot sauce, ingredients and chemical components of the imported hot sauces were investigated. The major ingredients of the imported hot sauce were chili, vinegar and salt. Chemical analysis of the imported hot sauce showed: moisture; 44.73-95.66%, total nitrogen; 0.11-1.06%, reducing sugar; 0.03-3.18%, crude fiber; 0.42-2.51%, salt; 0.87-10.44%, pH; 3.22-4.05, titratable acidity; 1.18-3.62%, capsanthin; 0.44-1.06% and capsaicin; 2.40-4.28 mg%. With the red pepper powder and/or kochujang, 20 Korean type hot sauces were prepared. Chemical analysis of the Korean type hot sauce showed: moisture; 53.07-78.30%, total nitrogen; 0.34-0.68%, reducing sugar; 1.60-4.34%, curde fiber; 1.31-2.54%, salt; 4.07-5.56%, pH; 3.37-2.54, titratable acidity; 1.15-3.06%, capsanthin; 0.11-1.36% and capsaicin; 0.55-1.42 mg%. Chemical components except capsaicin of the Korean type hot sauce were similar to those of the imported one. As the results of sensory evaluation on the 20 Korean type hot sauces with red pepper powder and/or kochujang developed, three Korean type hot sauces were finally selected. As compared with Sriracha hot sauce, an imported hot sauce, the Korean type hot sauces were evaluated to be superior to the imported one.
Studies on the Frozen Storage of Ascidian, Halocynthia roretzi
Park, Choon-Kyu ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1021~1025
The experiments were carried out to find how the processing of ascidian (Halocynthia roretzi) was affected by the frozen storage. The quality of ascidian which takes the shell-on was changed quickly in the frozen storage. The causes of the change were as follows: 1. the damage caused by the ice crystal in the muscle, 2. a lot of drips after thawing, 3. the discoloration of the muscle after thawing. On the contrary, the quality of ascidian which takes the shell-off was even better in color, texture, yield and drips after 60 days of the frozen storage. But the muscle was blackened after that.
Physicochemical Properties of Rice Affected by Steeping Conditions
Kim, Sung-Kon ; Bang, Jung-Bum ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1026~1032
The effects of steeping temperature
and steeping time
on the physicochemical properties of milled rice (variety; Chucheongbyeo) were investigated. The pH of the steep water decreased as the steeping time increased, which was more pronounced at higher steeping temperature. The solid loss was about 4.0% during steeping. The contents of protein, fat and ash decreased during steeping, which was greater at elevated temperature. The lightness of rice was slightly increased, and the yellowness was decreased upon steeping. The water-binding capacity of rice was increased during steeping at above
. The slight increase of the swelling power of rice at
was observed upon steeping. The maximum wavelengh for the rice flour-iodine complex was moved to a higher wavelengh, but X-ray diffraction patterns remained constant regardless the steeping conditions. The pasting properties of rice flour (10%) by amylograph indicated that the peak viscosity increased as the steeping time was increased at all steeping temperatures. The steeping resulted in the greater breakdown and the 1ower setback. The log peak viscosity showed a linear relationship with the steeping time. The activation energy and
value for the visciosity increase rate was 2, 320 cal/mole and 1.14, respectively.
Analysis of Preservatives in Flavor-Containing Foods
Kim, Jin-Ho ; Kim, Hyeon-Wee ; Cha, Ik-Soo ; Lee, Yoon-Kyoung ; Park, Ki-Moon ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1033~1037
An attempt was made to analyze preservatives in flavor-containing curry and tomato ketchup without interference due to their of flavor components. Samples were steam-distillated and extracted with ether. Sorbic acid, benzoic acid, dehydroacetic acid and salicylic acid were analyzed by GC with capillary column. Benzoic acid and dehydroacetic acid in curry were interfered by flavor components, but there was no interference in case of tomato ketchup. Samples were pretreated with Sep-Pak
cartridge and analyzed with HPLC to avoid any interference due to flavor components. The recoveries by HPLC were higher than those by GC. Recoveries of sorbic acid, benzoic acid and salicylic acid from curry were 79.9%, 71.2% and 64.4%, respectively. Recoveries of sorbic acid, benzoic acid and salicylic acid from tomato ketchup were 83.4%, 87.8% and 77.7%, respectively.
Studies on the Processings of Sterilized Salt-Fermented Anchovy Sauces
Oh, Kwang-Soo ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1038~1044
The salt-fermented anchovy sauce (AS) was packed in round No. 307-1 can, and thermally processed at
to obtain Fo values of 3, 5 and 10. The changes of food components and qualifies by thermal processing of sterilized AS (RAS) were examined. The compositions of AS were as followed; pH 6.81, VBN 394.7 mg/100g, total nitrogen 2,195.5 mg%, amino-nitrogen 1,010.5 mg%, and acidity 10.5 ml. Viable cell counts of AS on 0%, 5%, 20% NaCl-medium were
and not detected, respectively. And viable cell counts of RAS were not detected. Acidity, total nitrogen and amino nitrogen contents of AS decreased slightly with the severeness of heat treatments, whereas pH and VBN content were increased. Total free amino acid contents of raw AS and RAS were 12,802.5 mg% and
, and major amino acids were alanine, glutamic acid, leucine, isoleucine, valine and lysine. Also contents of IMP, hypoxanthine, TMAO and TMA in AS and RAS were 42.1 mg% and
, 103.7 mg% and
, 78.8 mg% and
, 55.8 mg% and
respectively. And a little changes were observed in whole volatile components of AS with severeness of heat treatments by GC chromatogram patterns. Judging from the chemical and sensory evaluations, the Fo 3 heat treatment sample was not inferior to raw AS, and maintained good quality for 1 year storage.
Surface Sterilization Effect of Electrolyzed Acid-water on Vegetable
Jung, Sung-Won ; Park, Kee-Jai ; Park, Kyung-Jo ; Park, Byoung-In ; Kim, Young-Ho ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1045~1051
The influence of electrolyzed acid-water (oxidation-reduction potential (ORP): above 1,150 mV, pH : 2.5) on the survival of some microorganisms was investigated. It was observed that the ORP of electrolyzed acid-water was kept at the level of above 1,000 mV for 15 days at room temperature. Escherichia coli. Salmonella typhi, Staphylococcus aureus and Saccharomyces cerevisiae were not detected after 10 to 40 min in electrolyzed acid-water. However, Bacillus cereus showed higher tolerance to electrolyzed acid-water than other test microorganisms. After 60 min of inoculation, only 0.4% of initial population remained. The investigation of surface sterilization effect on some vegetables was carried out too. Total count of cabbage, Chinese cabbage and kale were reduced to below 3% of initial count, and no coliform was detected after 20 to 60 min of immersion in 5 volumes of electrolyzed acid-water. In the lettuce, total and coliform counts were reduced to 90% and 2% of initial population. This study shows that the electrolyzed acid-water has a potential for the sterilization of food products such as vegetables and fruits which cannot be thermally sterilized.
Retrogradation Behavior of Rice Starches Differing in Amylose Content and Gel Consistency
Kum, Jun-Seok ; Lee, Sang-Hyo ; Lee, Hyun-Yu ; Lee, Chan ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1052~1058
The effect of varietal differences of rice starches by amylose content and gel consistency on the retrogradation behavior was studied. Setback viscosity of rice flour measured in a Brabender amylograph was significantly affected by amylose content as well as gel consistency. Increase in the rigidity modulus (E) of rice starch gels during storage determined by using texture analyzer indicated that amylose content was an important factor in terms of hardness increase. Kinetics of retrogradation showed that time constant of rice starch gels was influenced by amylose content, but not by gel consistency.
In vitro Antimutagenic Activity of Chitosan and Its Bio-antimutagenic Characteristics
Chun, Hyang-Sook ; Chang, Hyun-Joo ; Lee, Jong-Mi ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1059~1064
The inhibitory effects of chitosan on mutagenicity induced by 3-amino-1-methyl-5H-pyrido [4,3-b] indole (Trp-P-2), sodium azide (SA), 2-nitrofluorene (2-NF), and 4-nitroquinoline oxide (4-NQO) were investigated using Salmonella typhimurium reversion assay and SOS Chromotest. In Salmonella typhimurium reversion assay. Chitosan showed 24-65% of inhibitory effect against the mutagenicity of an indirect-acting mutagen, Trp-P-2. On the other hand, no inhibitory effect was observed against the mutagenicity of direct-acting mutagens (2-NF, SA). In SOS chromotest. chitosan showed 46-49% effects on SOS function induced by 4-NQO. Chitosan inhibited the mutagenicity induced by Trp-P-2 with 9-39% of inhibition rate. It was also evaluated whether inhibitory effect of chitosan is due to its bio-antimutagenic or desmutagenic action. Chitosan at high concentrations showed a bio-antimutagenicity with dose-dependent manner, but it showed a desmutagenicity at low concentrations against the mutation induced by Trp-P-2.
Antimutagenic Activity in vitro of Chitosan Hydrolysates
Chang, Hyun-Joo ; Chun, Hyang-Sook ; Lee, Su-Rae ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1065~1070
Antimutagenic effect of chitosan hydrolysates was investigated using Salmonella typhimurium reversion assay and SOS chromotest against 3-amino-1-methyl-5H-pyrido[4,3-b]lindole(Trp-P-2), aflatoxin
, 2-nitrofluorene and 4-nitroquinoline oxide. After partial acid hydrolysis of chitosan, six fraction of different molecular size were obtained by ultrafiltration. Chitosan hydrolysates showed antimutagenic effect of
on 2-nitrofluorene in Salmonella typhimurium reversion assay. Inhibitory effect in Salmonella typhimurium reversion assay showed the highest at 5% concentration of fraction 6 in Trp-P-2, 10% concentration of fraction 5 in aflatoxin
and 5% concentration of fraction 6 on 2-nitrofluorene. In SOS chromotest, chitosan hydrolysates showed anitimutagenic effect of
on Trp-P-2 and
on 4-nitroquinoline oxide, These results suggest that high molecular weight fraction of chitosan hydrolysates (MW>30,000) in most effective to inhibit mutagenicity of tested mutagens.
Cooling Properties and Quality Changes during Storage of Citron (Citrus junos)
Jeong, Jin-Woong ; Lee, Young-Chul ; Kim, Jong-Hoon ; Kim, Oni-Woung ; Nahmgung, Bae ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1071~1077
Quality changes in citron (Citrus junos) during storage were studied to investigate the efficiency, cooling properties and the washing and storage effects of hydrocooling method. As a result of plotting the nondimensionalized citron temperature versus cooling time, its cooling rate coefficient was shown to be
at center, and to be
at surface. During storage, weight loss was more affected by storage temperature than by pretreatment condition and in reached
after 7 weeks at
after 8 weeks at
in all samples. However, changes in moisture contents of hydrocooled citron were shown to be about
after 7 weeks while that of non-treated citron was about 3% after 1 week of storage at
. And the change of pH, acidity and soluble solid content were not significantly different between each treatments during storage
. Changes in Hunter L, a, and b values of hydrocooled citron were lower than those of non-treated one as the storage time increased. The respiration rate of hydrocooled citron during storage at
, which is about 50% of that of non-treated citron.
Physicochemical Properties of Hull-less Barley Flours Prepared with Different Grinding Mills
Lee, Young-Tack ; Seog, Ho-Moon ; Cho, Mi-Kyung ; Kim, Sung-Soo ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1078~1083
During the pearling process of hull-less barley, protein, lipid, ash and insoluble dietary fiber (IDF) contents decreased, while soluble dietary fiber (SDF) and
contents slightly increased. Depending on milling methods and types of grinding mills used, there were differences in particle size distribution of barley flour. Flour particle size was smaller in the following order of Fitz mill, Ball mill, Pin mill, Cyclotec sample mill and Jet mill. Color (brightness) was closely related to the particle size of barley flour. Damaged starch (%) in pearled barley flour was the highest in Jet mill among different mills. Flours prepared with Cyclone mill and Pin mill had a reasonable amount of damaged starch. Flour produced by Fitz mill showed the lowest amount of damaged starch. Scanning electron microscopy (SEM) of the flour samples demonstrated different sizes and shapes of particles consisting of starch granules and cell wall materials. Damaged starch tended to increase water absorption index (WAI), water solubility index (WSI), and water retention capacity (WRC). Pasting viscosity determined by amylograph was relatively high in Pin-milled and Cyclone-milled flours. Viscosity was the lowest in coarsely ground flour by Fits mill.
Inhibitory Effect of Flavan-3-ols Isolated from Oolong Tea on Xanthine Oxidase
An, Bong-Jeun ; Bae, Man-Jong ; Choi, Chung ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1084~1088
As a series of study for an anti-gout agent, two flavan-3-ols have been isolated from Oolong tea. They showed positive reaction in
, which were able to be confirmed in TLC with dimeric flavan-3-ols. The components were identified as procyanidin B-2 and procyanidin B-2-O-3, 3'-di-gallate by spectroscopic analysis. Their inhibitory effect on xanthine oxidase was also investigated and procyanidin B-2-O-3, 3'-digallate showed 60.6% inhibition at
. The compound competitively inhibited the xantine oxidase and dimeric flavan-3-ols contanining gallate had higher inhibition activity.
Effect of Tyrosinase Inhibitors on the Melanogenesis of Gold Fish(Jet Black Color)
Han, Dae-Seok ; Jung, Sung-Won ; Kim, Seok-Joong ; Kim, Sang-Hee ; Ahn, Byung-Hak ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1089~1094
The in vivo effect of tyrosinase inhibitors in the melanogenesis of gold fish (jet black color) was evaluated by measuring surface color and observing melanin pigment. The fish was firstly cultivated in 0.9% NaCl solution for 1 week to induce melanogenesis, and then, it was transferred to each treatment group containing tyrosinase inhibitor. The fish was grouped into control. food additive group (addition of 5 mM glutathione, 5 mM cysteine, and 1 mM benzoic acid), microbial inhibitor group (addition of culture broth of Aspergillus oryzae in shiitake and glucose medium), and plant extract group (addition of the mixed extracts of green tea, beet, red chicory, and nameko). After 6 days, the fish was anesthetized by electric shock, and color of pectoral region, lateral region, and dorsal fin was measured. Hunter's L and b values of treated group were generally higher than those of control group, indicating that the tyrosinase inhibitors could inhibit the melanogenesis of the fish. Effect of plant extract was apparent, though relatively weak, not because it did not work in vivo, but because a sufficient amount of extract could not be added to fish globes. If a large amount of extract was added, fish gradually died due to a microbial contamination. Microscopic observation of melanin in lateral scale and dorsal fin showed that in the treated groups with tyrosinase inhibitors, the number of melanophore per unit area and the size of one melanophore decreased.
Changes of Free Sugar and Organic Acid in the Osmotic Dehydration Process of Apples
Youn, Kwang-Sup ; Lee, Jun-Ho ; Choi, Yong-Hee ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1095~1103
In order to minimize the deterioration of dried apple quality, changes of free sugar content, organic acid and ascorbic and during osmotic dehydration with sucrose at various temperature, concentration and immersion time were investigated in this study, total sugar increased as the temperature, concentration and immersion time were increased. Sucrose showed the largest change in content while fructose and glucose showed no and small changes, respectively. Large amounts of malic and fumaric acids, and small amounts of oxalic, citric, maleic and succinic acids were detected. Organic acids were high at low temperature treatment, and became higher with increasing concentration. Loss of ascorbic acid was small at the low temperature and high concentration. Effect of immersion time was negligible. Changes of free sugar, and organic and ascorbic acid followed the first-order and second-order reaction rate equations, respectively. Arrhenius equation was applied to determine the effect of temperature on reaction rate constants with high
. To predict the changes of quality, a model was established by using the optimum functions of temperature, concentration and immersion time. The model had high
value for the quality changes during drying.
Initial Control of Microorganism in Kimchi by the Modified Preparation Method of Seasoning Mixture and the Pretreatment of Electrolyzed Acid-Water
Park, Kee-Jai ; Jung, Sung-Won ; Park, Byoung-In ; Kim, Young-Ho ; Jeong, Jin-Woong ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1104~1110
To lessen the initial level of microorganism in kimchi, the preparation method of seasoning mixture was modified and electrolyzed acid-water was substitute for washing water and brine water. Changes in the microbial counts of the red pepper powder-garlic mixture prepared with red pepper powder, garlic and 4.8% (w/w) water (tap water and electrolyzed acid-water) of manufactured kimchi showed that coliform count and E. coli count were reduced to 93% and 98%, of the initial level in the tap water added red pepper powder-garlic mixture and 97% and 99% in the electrolzed acid-water added mixture after 6 hours of mix. After 24 hours of mix, no E. coli was recovered in borth mixtures. Microbial levels were revealed as
for total count,
for Lactobacillus count.
of coliform count and
of E. coli count in the seasoning mixture prepared by the general method, and
of total count,
of Lactobacillus count,
of coliorm count and
of E. coli count in the mixture propared by the modified method. During fermentation at
, the levels of total and Lactobacillus counts in kimchi prepared by the modified method were significantly lower than those of kimchi were recovered in kimchi prepared by the modified method, whereas there were at the level of
in kimchi prepared by the general method. The pH and acidity of kimchi prepared by the modified method were 4.66 and 0.54%, respectively, whereas those in kimchi prepared b the general method were 4.51 and 0.70%, respectively. But after 14 days of fermentation significant differences were not observed in the changes of microbial, pH and acidity for both kimchi.
Extractive Nitrogenous Constituents of Toha (Caridina denticulata denticulata, Freshwater Shrimp) and Jeotsaeu (Acetes japonicus , Seawater Shrimp)
Park, Choon-Kyu ; Park, Jung-Nim ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1111~1118
The extracts of toha, a kind of freshwater shrimp (Caridina denticulata denticulata) being cultivated in Naju district, Chonnam of Korea and jeotsaeu, a kind of seawater shrimp (Acetes japonicus) being caught in Shinan district, Chonnam of Korea, were analyzed for the taste constituents-extractive nitrogen, free amino acids, oligopeptides, nucleotides and related compounds, quaternary ammonium bases, and guanidino compounds-using specimens collected from December in 1994 to November in 1995. The content of extractive nitrogen. free amino acids, oligopeptides, nucleotides and related compounds in toha extract was higher than that in jeotsaeu extract. On the contrary, the amount of homarine, trimethylamine oxide and trimethlamine in toha extract was lower than that in jeotsaeu extract. But in case of creatine and creatine both species showed almost the same level. Arginine, lysine, glutamine, glutamic acid, phenylalanine, leucine, alanine, asparagine and glycine were the major amino acids in toha extract, while arginine, glutamic acid, proline, glutamine, lysine, leucine, glycine, alanine and taurine were the major amino acids in jeotsaeu extract. Methionine, glutamine, valine were almost the same level between the two species. As for nucleotides and related compound, AMP was the principal constituent in toha extract, and inosine was the principal constituent in jeotsaeu extract. In conclusion, the content of major nitrogenous constituents in toha extract was more abundant than that in jeotsaeu extract. So toha was more excellent raw material than jeotsaeu.
Application of Heat/Moisture-Treated Rices for Sikhe Preparation
Yook, Cheol ; Cho, Seok-Cheol ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1119~1125
Physically modified rices were prepared by heat/moisture-treatment and its application for sikhe preparation was examined. The modified rice starch showed decreases in swelling, viscosity and enthalpies of gelatinization. But gelatinization temperature was increased by the treatment. The rate of saccharification for sikhe with the heat/moisture-treated rice autoclaved at 15 psi,
for 1 hr was twice higher than the untreated rice. Brix in sikhe of the untreated rice saccharified for 2 hrs was 8.2, whereas sikhe made with rice autoclaved for 1 hr was 8.7 only after 1 hour of saccharification. However. there was no difference in sugar composition analyzed by HPLC between both of them.
Drying Characteristics of Osmotically Pre-treated Carrots
Youn, Kwang-Sup ; Choi, Yong-Hee ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1126~1134
The physical characteristics changes of carrots during drying were studied to minimize the quality degradation by applying improved drying process and pretreatment method. Physico-chemical properties of the product were analyzed, and then, drying mechanisms were explained by diffusion coefficients and drying models. In hot air drying process, the drying and rehydration efficiencies were high at low relative humidity and high temperature. Browning degree and specific volume also showed similar trend to drying efficiency. Diffusion coefficient, which describes moisture transfer, was also high at low relative humidity and at high temperature. It was verified using. Arrhenius equation that drying process was influenced by temperature. It was also observed during experiment that temperature changes were more effective in drying than relative humidity changes. Quadratic model was the most fittable in explaining the process. As a result of analyzing the experimental data with respect to the drying time, the contents of carotene and moisture could be modeled as a polynomial. As the air velocity increased, drying performance and rehydration efficiency increased.
Extractive Nitrogenous Constituents in Commercial Saeujeot, a Salted and Fermented Shrimp (Acetes japonicus)
Park, Choon-Kyu ; Kim, Woo-Jun ; Kim, Kui-Shik ; Park, Jung-Nim ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1135~1141
In order to investigate the composition and the actual status of extractive nitrogenous compounds in saeujeot, a salted and fermented seawater shrimp(Acetes japonicus), the extract was analyzed separately into extractive nitrogen, free amino acids, oligpopeptides, nucleotides and related compounds, quaternary ammonium bases, and guanidino compounds, using specimens collected at fish markets from July in 1994 November in 1995. The extractive nitrogen of saeujeot was ranging from 430 mg to 528 mg, and the total of free amino acids in it was ranging from 1,509 mg to 2,131 mg, The extract was rich in free amino acids especially in lysine, glutamic acid, leucine, arginine, glycine, histidine, and glutamine, However, the content of most free amino acids was fluctuated from collection to collection. The total of nucleotides and related compounds in the extract was ranging from
, and the rage of fluctuation was essential identical with those of the extractive nitrogen and free amino acids. Homarine, trigonelline,
, and glycinebetaine were found in the saeujeot extract. Among them, homarine was the most abundant, ranging from 97 mg to 224 mg, but trigonelline,
, and glycinebetaine were very low. TMAO and TMA in the saeujeot extract were
, respectively. A small amount of creatine (less than 6 mg) and creatinine (less than 1 mg) was detected in all samples.
Collection and Identification of Molds from Citrus Oranges during Post-Harvest Storage
Ko, Young-Hwan ; Kim, Se-Jae ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1142~1145
Long term-storage of citrus oranges after harvest has been hindered mainly by molds The goal of this research was to collect and identify those molds, which would help find a way to extend shelf-life after harvest. During the period of 1994 to 1995, fourteen different strains were isolated and purified from putrefied fruit (Citrus unshiu var.) that was stored at room temperature under open air. The storage disease was caused by the following molds: Penicillium italicum, 25.8%, Monilia candida, 19.8%; Alternaria citri, 18.1%; Mucor hiemalis, 11.0%; Phomopsis citri, 6.6%; Botrytis cinerea. 5.5%; Phoma citricarpa, 3.8%; Glomerella cingulata, 3.8%; P. digitatum, 1.1%; other molds, 4.5%; Most of the strains showed pectinolytic activity and putrefaction. These citrus fruit-putrefying molds will be used as target strains for the control of microorganisms during post-harvest storage.
Moisture Sorption Characteristics of Model Food Powders
Kim, Dong-Woo ; Chang, Kyu-Seob ; Kim, Suk-Shin ; Lee, Un-Hyun ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1146~1150
The purpose of this research was to provide fundamental data required for the process design of conveying, storage and processing of food powders. Potato starch, corn starch, wheat protein, soybean protein, and model food powders prepared by mixing potato starch and wheat protein were selected and their sorption characteristics such as equilibrium moisture content, monolayer moisture content, and sorption enthalpy were determined. Equilibrium moisture content and monolayer moisture content of high starch powders were higher than those of high protein powders, and the equilibrium moisture content decreased with temperature. The determination coefficients of the regression equations to predict the equilibrium moisture content of food powders were from 0.997 to 0.999. Sorption enthalpy experiments indicated that powder of high moisture content showed lower sorption than that of low· moisture content, and the high protein powder showed lower sorption than high starch powder.
Effect of Xylose and Glucose on Xylitol Production by Candida parapsilosis
Oh, Deok-Kun ; Kim, Sang-Yong ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1151~1156
Effects of xylose and glucose on the xylitol production were investigated with Candida parapsilosis KFCC 10875. With increasing the ratio of glucose to xylose, xylitol production decreased but ethanol and glycerol production increased. The maximum concentrations of ethanol and glycerol were 21.5 g/l and 3.6 g/l, respectively, in a medium consisting of 10 g/l xylose and 40 g/l glucose. No xylitol was formed in the glucose medium without xylose since xylitol could not be produced from glucose alone. The inhibitory effect of ethanol, a major by-product, on xylitol production was also studied. As the added ethanol concentration was increased, xylitol production decreased. When cells were inoculated in a xylose medium after removing the by-product (ethanol), xylitol production was not inhibited. The concentrated cells grown on xylose or glucose were inoculated in a fermentor containing the xylose medium. The total activities
of xylose reductase and xylitol dehydrogenase in concentrated cells grown on glucose were the same as those in a normal fermentation; the specific activities of the above enzymes in the cells grown on xylose were the same as those in a normal fermentation. It indicates that the xylitol productivity of concentrated cells grown on xylose could be increased with increasing the cell concentration. By using concentrated cells of 20 g/l grown on xylose, the final xylitol concentration of 40 g/l was obtained for 18 h fermentation from 50 g/l xylose.
Antioxidative Activity of Extract from Bangah Herb
Jhee, Ok-Hwa ; Yang, Cha-Bum ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1157~1163
Bangah, one of the herbs grown in Korea, was investigated for its antioxidant activity. The ether extracts of bangah herb was separated into neutral, phenolic, acidic and basic fractions and further separated into subfractions. Antioxidative activities were measured by hydrogen donating activity (HDA), peroxide value (POV), thiobarbituric acid (TBA) value and inhibition activity against lipid peroxidation of rat liver microsomes, The subfraction components were identified by GC/MS and NMR. Phenolic, though being very small in quantity, showed higher antioxidant activity at all assay system by hydrogen donating activity. POV, TBA value and inhibition activity against lipid peroxidation of rat liver microsomes. Five subfractions(P-1, P-2, P-3, P-4 and P-5) were fractionated from phenolic fraction of bangah herbs, and subfraction P-2 among them showed strong antioxidant activity on a level with BHT or gallic acid at each assay system. Four compounds (peak I, peak II, peak III and peak IV) were isolated by gas chromatogram of TMS derivatives of subfraction P-2 and thes compounds were confirmed to be phenolic substance having -OH and COOH group. There subfractions (N-1, N-2 and N-3) were fractionated from neutral fraction of bangah herbs, and subfraction N-2 among them showed highest antioxidant activity and inhibition activity against lipid peroxidation of rat liver microsomes. Subfraction N-2 was indentified to be estragole by H-NMR spectroscopy.
Changes of Constituent Components in Chestnut during Storage
Nha, Young-Ah ; Yang, Cha-Bum ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1164~1170
Studies were carried out to investigate the changes of constituent components in chestnuts (Castanea crenata Sieb. et Zucc) during storage at
for 9 weeks and
for 15 weeks. Ascorbic acid content of chestnut was 4.08 mg% in oxidized form and 17.7 mg% in reduced form which was 81.3% of total ascorbic acid. The reduced form gradually decreased during storage, while the oxidized forms increased during 5 weeks at
and 7 weeks at
. The major organic acids in chestnut were malic acid, citric acid and quinic acid. Citric acid significantly decreased during storage, while malic acid increased during storage at
and decreased at
. Free sugars in chestnuts were identified as glucose, fructose, sucrose and maltose. Glucose and fructose decreased after 5 weeks storage at
followed by an increase thereafter. Sucrose and maltose also increased. The major free amino acids in the chestnut were glutamic acid, aspartic acid, arginine, alanine, proline and serine. Glutamic acid, arginine, alanine, threonine, phenylalanine, valine and lysine increased during storage at
, while proline, serine, isoleucine. leucine and
Analysis of Volatile Components of a Chicken Model Food System in Retortable Pouches Using Multivariate Method
Choi, Jun-Bong ; Kim, Jung-Hwan ; Moon, Tae-Wha ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1171~1176
The changes in volatiles of the model system were analyzed by GC and GC-MS before and after retorting. The GC data were analyzed statistically by applying the analysis of variance, and 42 peaks were selected at 5% significance level. Multivariate statistical analysis was performed with these 42 peaks as independent variables. Through the stepwise discriminant analysis, 8 peaks, which corresponded to the compounds such as 2-heptanone, cis-3-hexenal, 2-pentyl-furan, 1-methyl-trans-1,2-cyclohexanediol, 2-hexanone, 3-octanone, trans, trans-nona-2,4-dienal and 1-octen-3-ol, were obtained in sequence to distinguish the samples with and without retorting. The principal component analysis of a set of 8 independent variables resulted in 3 principal components which accounted for 96.1% of the variance, while the first principal component (PC 1) explained 76.5% of the total variance. In addition, through the factor analysis of the principal components, the peaks 11, 20 and 21 could be grouped togather in accordance with the direction and the size while the peaks 9, 33 and 39 constituted the second group in the direction.
Quantitative Determination of Solvents in Food Packaging Film Using Headspace Gas Chromatography
Kim, Hyeon-Wee ; Cha, Ik-Soo ; Kim, Jin-Ho ; Park, Ki-Moon ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1177~1179
A static headspace gas chromatographic (HSGC) technique was used to quantify toluene and other solvents (methanol, isopropyl alcohol, methyl ethyl ketone and ethyl acetate) in food packaging films. Comparison of retention times and coefficient variations for standard solvents showed consistent retention time and good reproducibility. Therefore, this method using static HSGC proved to be superior in rapidity and reproducibility, and is thought to be adaptable to analysis of a large number of samples. The methanol content was
, melthyl ethyl ketone
, total solvent content was
Growth Characteristics and Changes of Pigment Content of Purple Sweet Potato during Growth
Kim, Seon-Jae ; Rhim, Jong-Whan ; Lee, Lan-Sook ; Lee, Joon-Seol ; Jeong, Byeong-Choon ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1180~1183
Growth characteristics and changes of pigment content of purple sweet potato (PSP) during growth were investigated. Vine length of PSP was increased to the maximum length of 130 cm after 100 days of growth. Numbers of branches and nodes were increased to the maximum of 21and 550, respectively, after 120 days of growth. Vine weight was also increased to the maximum of 4,384 kg/10a after 120 days of growth, while the weight of marketable root was increased continuously to the end of the growth period of 150 days to reach the production of 1,875 kg/10a. Uniquely considerable amount of anthocyanin pigment has been developed in both skin and flesh of young roots harvested after 40 days of growth. The pigment content was increased slowly until 140 days of growth then decreased. This fact indicates that the best time for harvesting of PSP is 140 days after planting.
An Enzyme-Linked Immunosorbent Assay for
in Cow's Milk without a Cleanup Procedure
Shon, Dong-Hwa ; Lim, Sun-Hee ; Lee, Yin-Won ;
Korean Journal of Food Science and Technology, volume 28, issue 6, 1996, Pages 1184~1187
A simple and rapid detection system for
in cow's milk by an enzyme-linked immunosorbent assay (ELISA) was developed. Specific antibodies against
, conjugated to bovine serum albumin
were raised in rabbits and purified. The cross-reactivities of the antibodies against aflatoxin analogs were less than 29.9%. When a competitive direct ELISA (cdELISA) for
, established by use of the antibodies was applied to the spike test of
onto uncontaminated cow's milk, the assay recovery was unstable unless cow's milk was diluted to 40% (2:3) with phosphate buffered saline (PBS). In that condition of sample dilution, the mean ELISA recovery of
, from the cow's milk was 113% (coefficient of variation (CV) of each recovery percentage, 8.2%) in the range of
. These results showed that the ELISA system could be a convenient tool to monitor the contamination of AFM1 more than 0.5 ppb in cow's milk (FDA allowance limit) easily.