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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Journal of Food Science and Technology
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Journal DOI :
Korean Society of Food Science and Technology
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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
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Comparative Studies on the Lipid Content and Neutral Lipid Composition in Japonica and Indica Rice Bran Oils
Kwon, Kyoung-Soohn ; Kim, Hyun-Ku ; Ahn, Myung-Soo ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 207~211
This study was carried out to determine the lipid content and neutral lipid compositions of Japonica and indica rice bran oils. The average content ratio of neutral lipids, g]ycolipids and phospholipids were 89.5 : 4.0 : 6.5 in japonica rice bran oil and 93.7 : 2.6 : 3.7 in Indica rice bran oils, respectively. It was seen that the neutral lipid content was significantly higher in JAponica rice bran oil, while the contents of glycolopods and phospholipids were significantly higher in japonica rice bran oils. The neutral lipids consisted of esterified sterol, triglyceride, free fatty acid, free sterol, diglyceride and monoglyceride. Triglyceride was the highest (48.7-49.7%) among the neutral lipids. Major fatty acids of rice bran oils were oleic (39.65-43.68f)), linoleic (32.62-39.42%) and palmitic acid (16.54-18.83%). The linoleic acid content was higher in Japonica rice bran oils than in indica rice bran oils.
Monitoring of Dynamic Changes in Maillard Reaction Substrates by Response Surface Methodology
Lee, Gee-Dong ; Kim, Jeong-Sook ; Kwon, Joong-Ho ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 212~219
Four-dimensional response surface methodology was used for monitoring dynamic changes in substrates during Maillard reaction. The coefficients of determination (
) of response surface regression equations for the changes in amino acids during Maillard reaction were 0.9478 for total amino acids and above 0.90 for each amino acid.
of regression equations for the changes in sugars during Maillard reaction were 0.9250 for glucose and 0.6490 for fructose. The contents of total amino acids gradually decreased with increasing reaction temperature and pH of the solvent. Browning color intensity increased with rising reaction temperature, showing maximum color intensity at around
. Each amino acid showed a decreasing tendency in its contents, which was similarly found in total amino acids. Four-dimensional response surface methodology indicated that the increased temperature during Maillard reaction was the most influential factor in decreasing substrates, such as aspartic acid, threonine and glucose. While the reaction time and pH of solvent little affected the changes in the above-mentioned substrates during Maillard reaction.
Quality Attributes of Quarri Green Peppers at Different Storage Temperatures
Kim, Hyun-Ku ; Kim, Hee-Seung ; Lee, Gee-Dong ; Lee, Boo-Young ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 220~225
Quarri green peppers were stored at
, and capsaicin, ascorbic acid, chlorophyll, free sugars and surface color of the peppers were measured for 35 days of storage. Capsaicin and dihydrocapsaicin of quarri green peppers decreased during storage. The changes were bigger at
storage than at
. Weight loss and decaying rate of the peppers were affected most by the increasing storage period and temperature. Ascorbic acid diminished remarkably at the beginning of storage period. Free sugars and chlorophyll decreased gradually during storage. Browning of quarri green peppers progressed slowly during storage not in pericarps but in seeds.
Volatile Flavor Components in Concentrated Peach Pulp
Lee, Kyoung-Hae ; Lee, Young-Chun ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 226~231
A serum-pulp method was applied to concentrate peach pulp with aroma recovery. The serum portion was concentrated to five-fold at
mmHg with aroma recovery. The concentrated serum, insoluble pulp and aroma fraction were recombined to make a two-fold concentrated peach pulp. The results of GC and GC/MS analysis for volatile compounds and sensory evaluation of concentrated peach pulp indicated that flavor quality was significantly improved by addition of aroma fractions. A 10% aroma recovery appeared to be appropriate for peach pulp.
The Nitrite Scavenging and Electron Donating Ability of Phenolic Compounds
Kang, Yoon-Han ; Park, Yong-Kon ; Lee, Gee-Dong ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 232~239
Phenolic compounds are known to inhibit the nitrosation or oxidation reaction. In the present work, the effects of phenolic compounds including phenolic acids and flavonoids on the nitrite-scavenging and electron donating ability were tested as scavenger of nitrite which is believed to participate in the formation of N-nitroso compounds and investigated as electron donator. The nitrite scavenging ability appeared in all the phenolic acids and showed the highest value at PH 1.2. Among the Phenolic compounds, phenolic acids showed higher nitrite-scavenging action than some flavonoids. Futhermore, the nitrite scavenging action of phenolic compounds was pH dependent highest at pH 1.2 and lowest at pH 6.0. The electron donating ability (EDA) by reduction of
-picrylhydrazyl (DPPH) among hydroxybenzoic acids was in the decreasing order of gallic acid, gentisic acid, syringic acid, protocatechuic acid, salicylic acid, vanillic acid, benzoic acid and p-hydroxybenzoic acid. EDA of hydroxycinnamic acids was in the decreasing order of hydrocaffeic acid, caffeic acid, ferulic acid, p-coumaric acid and trans-cinnamic acid. EDA of flavonoids was in the decreasing order of (+)catechin, rutin, quercetin, naringin and hesperidin. Other phenolic compounds were significantly high in electron donating abilities.
Comparison of Growth Characteristics of Soybean Sprouts Cultivated by Three Methods
Shin, Dong-Hwa ; Choi, Ung ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 240~245
Soybean sprouts(Paektae chunjari variety) cultivated for 5 days at a high temperature and humidity condition placed in the position of either upside down (method 1) or up right (method 2) were compared with the sprouts grown for 9 days with the conventional method (method 3) with respect to appearance, yield, rotten rate and organoleptic quality. The method 1 sprouts cultivated at a high temperature and humidity by sprinkling underground water (controlled temperature
) 8 times a day were not significantly different in yield, rotten rate and moisture content from the method 2 sprouts except the lighter individual weights. The total weight yield of method 1 sprouts (
699±8.14%) was lower than that of the method 3 sprouts (
) but there was no significant difference in rotten rate (
). The organoleptic quality of the method 1 sprouts were superior in colour, flavor and overall taste than the method 3 sprouts.
Changes in the Physico-Chemical Properties of the Meals from the Defatted Sesame Seeds at Various Roasting Temperature and Time
Ha, Jae-Ho ; Kim, Dong-Hoon ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 246~252
Changes in physicochemical properties of the defatted sesame meals at various roasting temperature and time have been studied. The roasting temperatures were
whereas roasting times were 5, 10, 20 and 30 minutes, The protein content of defatted sesame meals decreased during roasting and the oil content of the meals roasted at
for 10 minutes was 8.4%. The yields of sesame mea]s and oil, when roasted at
for 10 minutes, were 50.1% and 46.9%, respectively. The amino acids in sesame meals gradually decreased as roasting conditions became severe. Sucrose (162.6 mg%), glucose (37.7 mg%) and fructose (18.7 mg%) were detected in the raw sesame meals. The color of roasted sesame seeds and oils extracted from them became darker as the roasting temperature and time increased and the change in lightness greatly affected the total color change. The browning pigment of the sesame meal roasted at
was separated into a fraction I, II and III. When roasted at
for longer than 10 minutes, the soluble browning pigment decreased.
Distribution and Physiological Characteristics of Yeasts in Traditional and Commercial Kochujang
Jung, Yoon-Chang ; Choi, Won-Jin ; Oh, Nam-Soon ; Han, Min-Su ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 253~259
To investigate the yeast florae in the traditional and commercial Kochujang, computer identification systems, Vitek, API kit and conventional identification methods were used. Yeast florae of each process were compared and their typical physiological characteristics were also tested. Various process intervals yielded 330 colonies, which resulted in 11 species 184 strains classified. They were identified into Candida glabrata C. guilliermondii. C. humicola. C. rugosa, C. zeylanoides, Cryptococcus uniguttulatus, Pichia farinosa, Rhodotorula glutinis, Saccharomyces cerevisiae and Zygosaccharomyces rouxii. The strains of Candida, Pichia, Saccharomyces and Zygosaccharomyces were existing in both processes. In case of commercial process, the maximum distribution of Z. rouxii and S. cerevisiae were 33% at 15 day fermentation and 13% at 21 day, respectively. The distribution of Candida spp. was gradually decreased throughtout the fermentation period from 40% to 10%. In the traditional process, the maximum distribution of Z. rouxii and S. cerevisiae were 53% after 3 months and 26% after 7 months, respectively, S. cerevisiae and Z. rouxii showed distintive growth pattern at the high concentration of glucose and sodium chloride and played important roles in both processes of fermentation. Physiological tests revealed that only two major yeasts. S. cerevisiae and Z. rouxii, showed vigorous carbon dioxide formation under the tested conditions.
Bacterial Distribution of Kochujang
Lee, Jeong-Mi ; Jang, Jae-Hee ; Oh, Nam-Soon ; Han, Min-Su ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 260~266
This study was carried out to investigate the bacterial microflora of commercial and traditional Kochujang. Computer aided idetification systems were used to identify the bacteria in Kochujang. Seven genera such as Bacillus, Corynebacterium, Enterococcus, pasteurella, Pseudomonas, Staphylococcus and Streptococcus in commercial process and 10 genera such as Bacillus, Corynebacterium, Enterococcus, Flavimonas, Flavobacterium, Gemella, Pasteurella, Pseudomonas, Staphylococcus and Streptococcus in traditional process were identified. Distribution of genus Bacillus was
during fermentation in the commercial process and
in the traditional process. B. lichenoformis strains identified in this study were classified into three types by their physiological characteristics.
Improvement on Textural Properties of Soybean Curd by Freeze Denaturation of Soybeans
Baik, Sang-Ho ; Kim, Myung-Kon ; Yun, Sei-Eok ; Joo, Hyun-Kyu ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 267~272
Effect of freezing of soybeans on instrumental and sensory textures of soybean curd was investigated. The hardness, gumminess and chewiness of soybean curd prepared with frozen soybeans were about three times as high as those prepared with unfrozen soybeans, while cohesiveness and elasticity were affected little by freezing. Sensory evaluation showed that freezing improved the quality of soybean curd. Instrumental and sensory textures of soybean curd prepared with frozen soybeans were excellent and almost same regardless of the boiling time when the soy slurry was boiled for 2.5 min or 5 min. However, the textures of soybean curd prepared with unfrozen soybeans were deteriorated by reducing the boiling time to 2.5 min. It was postulated that freezing facilitate the heat-denaturation of soyprotein to enhance aggregation of soy proteins and formation of cross-linkage between aggregate and
. Frozen soybeans resulted in soybean curd which lower fat content, while protein content of soybean curd was almost he same. Frozen soybeans gave a lower yield of soybean curd, which is supposed to be caused by the more fat loss during whey-off.
Reaction Mode of Transglucosidase from Aspergillus niger for Production of Isomaltooligosaccharides
Ahn, Jang-Woo ; Hong, Seung-Shu ; Park, Kwan-Wha ; Seo, Jin-Ho ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 273~278
The research was undertaken to characterize the reaction mode of transglucosidase (TG) from Aspergillus niger for the production of isomaltooligosaccharides such as isomaltose, panose and isomaltotriose. TG hydrolyzed maltose to glucose units and produced panose and glucose by transglucosylation. TG hydrolyzed panose to maltose and glucose when panose was used as an initial substrate. The reaction patterns of products when isomaltose, isomaltotriose or isomaltotetraose were used as substrates were different from the case when maltose was used as a substrate. Maltotriose and maltose showed the same formation pattern of products. TG also produced isomaltooligosaccharides from maltooligosaccharides. The production of panote by TG from maltose was mathematically described by Michaelis-Menten kinetics. The kinetic constants,
(the maximum velocity) and
(Michaelis constant), were estimated by Lineweaver-Burk plot to be 400 M/min and 21.4 mM, respectively.
A New Selective Medium for the Isolation and the Detection of Leuconostocs in Foodstuffs
Choi, Hak-Jong ; Shin, Young-Jae ; Yu, Ju-Hyun ; Yoon, Sung-Sik ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 279~284
To develop a selective medium for the isolation and the detection of leuconostocs from the various samples including fermented vegetables, ten strains of leuconostocs and seven strains of lactobacilli were tested for their sensitivity to various antibiotics. The basal-medium containing 5
of novobiocin inhibited the growth of lactobacilli completely, but not that of leuconostocs. On the basis of this result, a new selective medium was developed and to be named NLS medium. This medium contains 1% Tryptone (Difco), 0.1% Yeast Extract (Difco), 2% sucrose, 0.1% Beef Extract (BBL), 0.5% sodium acetate, 0.2% ammonium sulfate, 0.01% magnesium sulfate, 0.2% dipotassium phosphate, 0.05% sorbic acid, 75 ppm sodium azide (Sigma), 0.1% (vol/vol) Tween 80, 30
of Vancomycin (Sigma), 5
of Novobiocin (Sigma), 0.5
of cysteine HCI, and 1.5% Agar (Difco). All of the eighty six isolates obtained from some foodstuffs were identified as members of the genus Leuconostoc. Comparative counts with the MRS, PES, LUSM, and NLS medium indicated that the recovery percent was lower than other selective media. Therefore, this result suggested that NLS medium was suitable for the isolation of leuconostocs, but not for counting or enumerating.
Packaging Techniques to Prevent Winter Kimchi from Inflation
Hong, Seok-In ; Park, Noh-Hyun ; Park, Wan-Soo ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 285~291
The effect of various packaging methods on Kimchi quality was investigated in order to develop the packaging techniques for preventing commercial Kimchi Products from ination and explosion due to fermentative gas evolved during storage and distribution. Kimchi was packaged in different methods; atmospheric (AP), check-valved (CV), double (DP) and vacuum (VP) packaging. The quality of Kimchi during storage at
was evaluated ill terms of gas composition, free volume, pH, titratable acidity, color index, lactic acid bacteria and sensory properties.
concentration decreased to about 1% at
days of optimal ripening time in all packages except DP, in which it remained around 20%.
days in AP, CV and DP, while it stayed around 10% in DP. The free volume in AP had typical sigmoidal curve similar to
concentration changes. It remained almost constant in CV and DP, but started to increase at the late stage of storage In VP. There was no significant influence of packaging methods on the other quality attributes such as pH, titratable acidity, color index (L.b/a), lactic acid bacteria count and sensory evaluation score. As results, it could be proposed to employ CV and DP method as the effective packaging techniques for preventing commercial Kimchi products from inflation.
Biochemical Changes in Muscle Protein of Squid Sikhae during Fermentation -Effects of Temperature and Moisture Content-
Lee, Nam-Hyouck ; Oh, Se-Wook ; Kim, Young-Myoung ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 292~297
In this study, biochemical changes of muscle protein in squid Sikhae prepared at various temperatures and moisture content were investigated. The pH values in squid Sikhae decreased rapidly with increase in titratable acidity during fermentation at high temperature and moisture content. Growth rate of lactic acid bacteria increased rapidly during fermentation at high temperature and moisture content. Changes in muscle protein subunit were analyzed by SDS-PAGE; myosin heavy chain component disappeared completely during preparation of squid Sikhae and actin component decreased slowly during fermentation. Therefore, it was suggested that myosin heavy chain component in squid muscle protein was autolyzed at the incipient for-mentation time and actin component was degraded by acidic protease in muscle and protease produced from microorganisms during fermentation.
Sensory Characterization of Roasted Sesame Seed Oils Using Gas Chromatographic Data
Yoon, Hee-Nam ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 298~304
Thirty-nine samples of roasted sesame seed oils were sensorially evaluated in terms of nutty odor, burnt odor and overall desirability, and their volatile compounds quantitatively analysed using direct sampling capillary GLC. Five volatile compounds were appeared to be significant for the sensory Properties of sesame oils through the multivariate analytical techniques such as stepwise discriminant analysis. canonical discriminant analysis, discriminant analysis and principal component analysis. The most important compounds were 2,5-dimethylpyrazine and 2-methylpyrazine which could be effectively used as chemical indicators related to nutty and burnt odor of sesame oils, respectively. The sesame oils which have represented a good grade of overall desirability have been always kept
ppm of 2,5-dimethylpyrazine and also
ppm of 2-methylpyrazine.
Retrogradation of Sucrose Fatty Acid Ester and Soybean Oil Added Rice Flour Gels
Mun, Sae-Hun ; Kim, Jeong-Ok ; Lee, Shin-Kyung ; Shin, Mal-Shick ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 305~310
The degrees of retrogradation (DR) for 50% rice flour gels kept at
for the 6-day storage period at 0.5, 1.0 and 2.0% (w/w, on dry weight basis) levels of lipid additives (sucrose fatty acid ester, SE1670; soybean oil) were measured by
-amylase-iodine method, differential scanning calorimetry (DSC) and X-ray diffractometry. The DRs were higher in rice flour gels stored at
than those stored at
. The sucrose fatty acid ester and soybean oil reduced the retrogradation of rice flour gels, but the effect was higher in samples stored for 1 day. The DR decreased more effectively in the addition of SE1670 than that of soybean oil In case of SE1670, the change of enthalpy by DSC showed similar patterns with the degree of retrogradation by
-amylase method; however, it was not the case for soybean oil. The intensity of peak at
in X-ray diffraction pattern was reduced with lipid additives but it was not clear.
Effect of Temperature and pH on Thermal Stability of Aspartame
Kim, Woo-Jung ; Chung, Nam-Yong ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 311~315
Thermal stability of aspartame was investigated as affected by the temperature and pH during heating. The thermal stability study of aspartame heated at
showed that aspartame was degraded more rapidly as the heating temperature increased. Activation energy for thermal degradation was 20.77 kcal/mol. The thermal degradation products, a diketopiperazine (DKP) and
-AP), were rapidly increased while the aspartame concentration decreased. The pH change of aspartame solution was rapidly decreased during initial three hours of heating and more significant at high temperature. In the pH range ()』 3-7, aspartame was the most unstable at pH 7 and stable at pH 4. The thermal degradation rate contants were 0.827 at pH 7, 0.286 at pH 6, 0.072 at pH 5 and 0.045 at pH 4 during initial heating at
Flavor Components in Mash of Takju Prepared by Different Raw Materials
Lee, Joo-Sun ; Lee, Taik-Soo ; Park, Sung-Oh ; Noh, Bong-Soo ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 316~323
Flavor components in mash of Takju prepared by different raw materials such as nonglutinous rice, glutinous rice, barley and wheat flour were detected by GC and GC-MS method using non-polar column. Seven alcohols, 15 esters, 10 organic acids, 1 aldehyde, 4 benzenes, 3 phenols, 8 alkans, 2 ketones and 5 others were found in takju after 16 day of fermentation. takju by wheat flour had the most various components of volatile flavor. Treatment with addition starter had less flavor component than that without addition starter in takju by nonglutinous rice. Nine kinds of flavor components including acetic acid ethyl ester, 3- methyl-1-butanol, acetic acid, ethyl benzene, acetic acid 3-methyl butyl ester, 2-phenylethanol, 2,6-di-tert-butyl-4-methyl phenol. plumbagic acid and 1,2-benzenedicarboxylic acid dibutyl ester were commonly detected in all the treatments. Especially, 2,4,0-trimethyl-1,3-benzenediamine was isolated in takju that was made of nonglutinous rice without addition starter. Diethyl sulfide, 4-methoxy benzaldehyde, docosane and 2-methyl propyl octadecanoic acid were isolated from takju by nonglutinous rice with addition starter. Propionic acid ethyl ester, acetic acid butyl ester, 2-methyl butane and 3-methyl pentane were isolated from takju glutinous rice. 2-Hydroxy-4-methyl pentanoic acid and 2-methyl tridecane were isolated from akju by barley 3-(Methylthio)-1-propanol. hexanoic acid ethyl ester, butanoic acid monomethyl ester, tridecanoic acid, ethyl tetramethyl cyclopentadiene and 1,5-diaza-2,9-diketocyclotetradecane were isolated from takju by wheat flour. Major volatile flavor components were acetic acid ethyl ester, 3-methyl-1-butanol, acetic acid and 2-phenylethanol.
Dewatering of Soybean Milk Residue by Hydraulic Press with Ohmic Heating
Cho, Won-Il ; Pyun, Yu-Ryang ; Lee, Youn-Soo ; Kwon, Ik-Boo ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 324~329
In order to develop a novel dewatering process for soybean milk residue, hydraulic press with ohmic heating was built and its expression conditions were examined. The electric conductivity of raw soybean milk residue was 0.128 S/m and increased linearly with increasing temperature. Water content of the residue could be reduced to 74% with the conventional hydraulic press, but to less than 70% by applying ohmic heating to the hydraulic press. The most effective dewatering was achieved by applying alternative current with 5 kHz frequency at 60 V during expression. The solid content of the expressed liauid was markedly reduced from 10% to 3.3% by ohmic heating during expression. Temperature of the cake rose to above
during the dewatering due to ohmic heating.
Quality Characteristics of Mash of Takju Prepared by Different Raw Materials
Lee, Joo-Sun ; Lee, Taik-Soo ; Noh, Bong-Soo ; Park, Sung-Oh ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 330~336
Quality characteristics of mash of takju prepared by different raw materials such at nonglutinous rice. glutinous rice, barley and wheat flour were investigated during fermentation. At the beginning stage of fermentation, ethanol content was in the range of
but it was increased to
after 16 day of fermentation. takju that was made of nonglutious rice with starter showed higher ethanol content than any other treatment. At the first stage, pH of takju that was made of nonglutinous rice without starter was 6.57 while other sample showed pH
There was no significant difference in pH value between treatments after 2 day of fermentation. Total acid was increased rapidly at the first stage of fermentation, and increased slowly after 2 day of fermentation. Takju that was made of nonglutious rice without of fermentation, and increased slowly after 2 day of fermentation. Takju that was made of nonglutious rice without addition starer showed higher total acid content than the other teratments. Total sugar contents were
at the beginning of fermentation, and decreased to
after 2-4 days of fermentation. Takju that was made of wheat flour showed higher value of total sugar during the fermentation. Reducing sugar contents of takju decreased with fermentation progressing to
after 16 day if fermentation. L value decreased during the fermentation. period and that of takju that was made of barley had lowest L value among the treatment. Alcohols, such as n-propanol (
), iso-butanol (0.02), iso-amyl alcohol (
), n-hexanol (
), n-heptanol (
), and phenylethanol (
) were detected. There were no alcohols detected at the beginning of fermentation, but their contents were increased during fermentation.
The Preparation of Yogurt from Egg White Powder and Casein
Ko, Young-Tae ; Lee, Eun-Ju ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 337~344
Gel-type yogurt was prepared from egg white powder (EWP), casein and glucose. The effects of EWP on acid production and growth of Lactobacillus were studied. The effect of EWP on sensory properties and volatile aroma compounds were also studied. Acid production by Lactobacillus in EWP (1-3%, W/V) was significantly lower than that by Lactobacillus in milk (control). However, the increase of EWP content from 1 to 3% increased acid production significantly, Number of viable cells of L. acidophilus at 24 hrs in milk and EWP containing samples (1-3%) was
respectively Sample containing lower amount of EWP generally showed lower number of viable cells. Sensory property of EWP samples (1-3%) was showed lower than that of milk yogurt (reference). However, sensory property of samples containing EWP 2% or 3% was significantly better than that of sample containing EWP 1%. Though the composition of volatile aroma compounds was slightly different from sample to sample, gas chromatographic analysis detected acetone, ethanol, diacetyl and acetoin in samples fermented by L. acidophilus.
Extraction and Characteristics of Purple Sweet Potato Pigment
Kim, Seon-Jae ; Rhim, Jong-Whan ; Lee, Lan-Sook ; Lee, Joon-Seol ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 345~351
Studies on extraction and color characteristics of purple sweet potato (PSP) pigment were performed to provide the basic information for the utilization of PSP as a new source of natural food colorant. PSP pigment was extracted well with the polar solvents such as distilled water, ethanol, and methanol. but hardly extracted with the non-polar solvents. Among the tested solvents, 20% ethanol solution containing 0.1% citric acid was found to be the most efficient for extraction of the pigment from PSP. PSP contained high amount of pigment not only in the epidermis but also in the flesh of the potato. The PSP pigment was heat stable even under pretreatments such as autoclaving and blanching of the potato before extraction. The optimum temperature of the extraction for the PSP Pigment was decided to be
by considering the stability and the rate of extraction. The pigment was markedly influenced by the change of pH. The color of the pigment solution was red at the pH range of
, became blue at
, then turned green at
. A characteristic batho-chromic shift of the pigment solution was observed as the pH of the solution increased.
Study on the Stability of Anthocyanin Pigment Extracted from Purple Sweet Potato
Lee, Lan-Sook ; Rhim, Jong-Whan ; Kim, Seon-Jae ; Chung, Byeong-Chun ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 352~359
Stabilities of purple sweet potato (PSP) anthocyanin pigment on pH, sugars, organic acids, metal ions, ascorbic acid and light were investigated to provide the basic information for utilization of PSP as a potential source of anthocyanin pigment. pH has a marked influences on the color of the PSP anthocyanin solution; i.e., at low pH the color of PSP was more intense and stable. It showed characteristic bathochromic shift as the pH of the solution increased. Among the sugars tested, glucose showed a protective effect on the color of PSP pigment to raise the color intensity and stability, while sucrose and fructose showed an adverse effect. Addition of organic acids greatly increased the stability of PSP anthocyanin pigment. Citric acid was found to be the most effective followed by malic. tartaric, and succinic acids. Most metal ions except
were found to be detrimental effect on the stability of PSP pigment. Ascorbic acid degraded PSP pigment considerably, and had a synergistic effect with oxygen on the pigment degradation. The effect of light on PSP pigment was found to be very deleterious. The pigment degradation can be minimized by shielding the light from the pigment solution.
Brassinosteroids in Rice Bran and Polished Rice
Park, Kyoung-Won ; Park, Jong-Dae ; Park, Keun-Hyung ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 360~365
To investigate the presence of brassinosteroids in rice bran and pㅐlished rice, they were extracted with MeOH. The extracts were purified through sequential procedure of solvent fractionation, silica gel adsorption chromatography, Sephadex LH-20 column chromatography and charcoal adsorption chromatography. The activity of brassinosteroids was monitored by the rice inclination test and its presence was confirmed in each purification step. The purified active components were further separated by TLC and HPLC. Brassinosteroids in active fractions of rice bran were identified as castasterone and teasterone by HPLC. We acknowledge that our work is probably the first report of brassinosteroids in mature seeds of rice The more amount of brassinosteroids was confirmed in rice bran than polished rice. The contents of castasterone and teasterone which were identified in rice bran were 0.15 ng/g and 0.37 ng/g, respectively.
Elimination of Microorganisms Contaminated in Red Ginseng Powder by Irradiation Processing
Yook, Hong-Sun ; Kim, Seong-Ai ; Byun, Myung-Woo ; Kwon, Joong-Ho ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 366~370
Gamma irradiation was applied to red ginseng powder for improving its hygienic quality 7.5 kGy of gamma irradiation completely eliminated the microorganisms contaminated in red ginseng powder. And there was no growth of microorganisms after six months of storage at room temperature. The molds isolated from red ginseng powder were identified as Pen. commune, Asp. niger, Asp. versicolor and Asp. Unguis, the conidia of which showed the decimal reduction dose (
value) of 0.37-0.50 kGy, 0.24-0.31 kGy, 0.25-0.36 kGy and 0.28-0.41 kGy and inactivation factor of 5.0-6.5, 7.4-9.3, 6.5-9.1 and 6.1-8.4, respectively The radiosensitivity of identified molds' conidia decreased in medium containing red ginseng extract.
Identification and Determination of Dietary Fibers and Flavonoids in Pulp and Peel of Korean Tangerine (Citrus aurantium var.)
Eun, Jong-Bang ; Jung, Young-Min ; Woo, Gun-Jo ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 371~377
Potential health promoting effects such as antiallergic, anti-inflammatory, antiviral, anticancer and anticarcinogenic properties have been ascribed to citrus flavonoids. Dietary fibers have also been used as functional food components due to the various beneficial physiological activities. Two kinds of flavonoids, naringin and hesperidin, were identified both in the pulp and in the peel of Korean tangerine. The contents of naringin and hesperidin in the pulp were 2.95 mg/100 g and 0.53 mg/100 g, respectively. However, the contents of naringin and hesperidin in the peel were much higher (10.77 mg/100 g and 38.90 mg/100 g) thanthose of two identified flavonoids in the pulp. The content of soluble dietary fiber (SDF) in the pulp of tangerine was 1.90%, insoluble dietary fiber (IDF) 0.37%, and total dietary fiber (TDF) 2.27% based on wet matter, respectively. The content of SDF was 1.09%, IDF 4.77% and TDF 1.86% in the peel of tangerine. The total pectin content was 1.53% in the pulp and 0.94% in the peel of tangerine. The peel of Korean tangerine, a by product in tangerine processing, would be a good source for the production of naringin, hesperidin and pectin.
Optimization of Membrane Separation Process for the Production of Dietary Fibers from Tangerine Peels
Woo, Gun-Jo ; Nam, Jin ; Eun, Jong-Bang ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 378~383
Dietary fibers (DF) have been used as functional food components due to the various health promoting activities. Dietary fibers have been separated from the peels of Korean tangerine by employing ultrafiltration (UF) membranes. Optimum conditions in a batch type ultrafiltration unit using YM100 (molecular weight cut-off, MWCO=100,000), YM 10 (MWCO=10,000) and YM1 (MWCO=1,000) membranes were : transmembrane pressure 7.5 psi, temperature of the peel extracts
, and pH of the peel extract 3.0, respectively. The flux in YM 10 membrane unit was higher than that in YM 10 or YM 1 membrane unit. However, YM 100 membrane was superior to YM 10 or YM 1 membrane with respect to the recovery of the retentate and the contents of DF The contents of DF in the tangerine peel extract, in the 170 mesh retentate, and in the YM 100 retentate were shown to be 33.4%, 18.5% and 8.4% based on dry matter, respectively. Most dietary fibers were recovered at the separation stages of 170 mesh and YM 100.
Effect of Viscous Materials Removal from Sea Tangle Extracts on Volatile Flavor Constituents
Lee, Jung-Kun ; Yoon, Suk-Kwon ; Kim, Woo-Jung ; Choi, Hee-Sook ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 384~388
Volatile flavor compounds of a sea tangle powder and two kinds of extract were analyzed by GC/MS. Extract I was prepared by boiling for 2 hours and centrifugation, while extract II by a sequential procedure of enzymatic hydrolysis, boiling in 1.5% NaCl solution. centrifugation and ultrafiltration to remove viscous materials. Fifty six volatile compounds from the dried sea tangle powder and the extracts were identified. The GC profiles of the extract II were different from those of the dried powder and the extract 1, indicating most volatile compounds were lost during removing viscous materials. Particularly those compounds in the initial and later parts of the GC profiles were significantly decreased and some of the compounds such as fatty acids. 3,5-nonadien-2-ol and 1-penton-3-ol were not detected.
The Physicochemical Properties of Crude Polysaccharide Fraction Isolated from Korean Ginseng (Panax ginseng C.A. Meyer)
Kwak, Yi-Seong ; Kim, Eun-Mi ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 389~392
Crude polysaccharide fractions were isolated from white ginseng and red ginseng (Panax ginseng). The amount of crude polysaccharide fraction in red ginseng was higher than that of white ginseng. The glucose contents of crude polysaccharide fraction isolated from white ginseng and red ginseng were determined as 95.1% and 89.9% by HPLC, respectively. Method of carbazole-sulfuric acid was applied to determine the amount of acidic polysaccharide in white ginseng and red ginseng. The amount of acidic polysaccharide in red ginseng was higher than that of white ginseng. Whereas, contents of minerals (Cu, Zn, Fe, Mg) in crude polysaccharide fraction from white ginseng were higher than those of crude Polysaccharide fraction from red ginseng.
Infusion of Pectinesterase for Preventing Softening of Kimchi Tissue
Lui, Yih-Cherng ; Kwon, Ki-Sung ; Park, Kwan-Hwa ;
Korean Journal of Food Science and Technology, volume 28, issue 2, 1996, Pages 393~395
This study was conducted to investigate the effect of infusion of pectinesterase (PE) along with preheating treatment in
solution on softening Kimchi tissue. Preheating treatment showed preventive effect on softening of Kimchi tissue. Especially, the preheating in the presence of P was more effective in preserving firmness of both stem and leaf. As for of effect of PE infusion by vacuum treatment, a maximum crispness was obtained from the vacuum-treated stems in 0.05 M
solution containing PE. The crispness of all the samples decreased during fermentation and the PE-infused samples by vacuum treatment showed higher crispness than the control until the fourth day of fermentation.