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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 17, Issue 6 - Dec 1985
Volume 17, Issue 5 - Oct 1985
Volume 17, Issue 4 - Aug 1985
Volume 17, Issue 3 - Jun 1985
Volume 17, Issue 2 - Apr 1985
Volume 17, Issue 1 - Feb 1985
Selecting the target year
The Antioxidant Activity of Gingerol
Lee, In-Kyung ; Ahn, Seung-Yo ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 55~59
Antioxidant activity of gingerol, a component of ginger, was studied in
acid-water emulsion system. Crude gingerol extracted from ginger was separated and purified by thin-layer chromatography (TLC) into two bands. The two bands were identified as 6- and 10-gingerol by color reactions on TLC plate, acid dehydration reaction, infrared and nuclear magnetic resonance spectrometry. The antioxidant activity of gingerols (mixture of 6- and 10-gingerol) separated from ginger was remarkable, but lower than that of BHA or BHT.
Studies on the Hydrolysis of Milk Fat by Microbial Lipases
Park, Jong-Hack ; Lee, Young-Chun ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 60~64
To utilize microbial lipases for hydrolysis of milk fat, optimum reaction conditions and characteristics of enzymatic reactions of lipases originated from Rhizopus delemar, Mucor sp., and Candida cylindracea were investigated. Optimum pH and temperature were pH 5.6 and
for Rhizopus delemar lipase, pH7.5 and
for Mucor sp. lipase, and pH7.5 and
for Candida cylindracea lipase. Optimum lipase concentration and optimum substrate concentration were
and 20% milk fat, regardless of their origin. Km values were 6.06% milk fat for Rhizopus delemar lipase, 7.69% for Mucor sp. lipase and 7.99% for Candida cylindracea lipase. Rate of lipid hydrolysis was Rhizopus delemar lipase>Mucor sp. lipase>Candida cylindracea lipase. As the reaction time was extended, liberation of short chain fatty acids was increased. After 8 hours reaction, capric acid content significantly increased with Candida cylindracea lipase, palmitic acid with Mucor sp. lipase and butyric acid with Rhizopus delemar lipase.
Factors Affecting the Extraction of Protein from Antarctic Krill
Lee, Sung-Ki ; Kim, Young-Myoung ; Min, Byong-Yong ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 65~70
To recover proteins from antarctic krill(Euphausia superba) for the use of food material, some factors affecting the extraction of protein were investigated. The protein solubility profile showed a minimum solubility level(33.2-38.8%) within the range of pH4.0-4.5 and very high solubility levels as 56.8% at pH2.0 and 80.7% at pH11.0. The extraction yield increased as the solvent-to-krill ratios increase in which a ratio of 5:1(volume of solvent/weight of krill) was found to be preferable from the point of handling convenience and extraction yield. The extraction temperatures did not seem to be important variables on extraction of protein. The extraction of krill protein occurred fairly rapidly with little further extraction of protein after 30 minutes. The extraction of protein was slightly decreased at both acidic(pH2.0) and alkaline(pH11.0) conditions with the increasing concentration of sodium chloride. The extractibility of krill protein at strong alkaline condition(pH11.0) was higher than at strong acidic condition(pH2.0) under the same concentration range as 1-6% of sodium chloride. In phosphate treatments, the extraction of protein was slightly influenced by presence of sodium chloride as the concentration range of 3-4% in the aqueous solvent by which maximize the extraction yield as over 80%.
A Mechanism for the Hydroperoxide Decomposition in a Soybean oil during Thermal Oxidation
Shin, Ae-Ja ; Kim, Dong-Hoon ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 71~74
In the present study, a tentative mechanism for the decomposition of the hydroperoxide formed during the thermal oxidation of an edible soybean oil was proposed. The soybean oil was thermally oxidized at
for 7 hrs with air injection at a rate of 120 ml/min. Through kinetic studies of the decomposition process based on the tentative mechanism and the actual experimental data obtained from the hydroperoxide decomposition at 100, 120, 150 and
, it was found that the reaction order of the hydroperoxide decomposition in these conditions was of first order. It was also estimated that the dissociation energy for the hydroperoxide in the same conditions was 15.876 kcal/g. mol.
Studies on the Immobilization of Lipase by Adsorption Method
Park, Jong-Hack ; Lee, Young-Chun ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 75~80
To utilize lipase obtained from Candida cylindracea for lipid hydrolysis, methods to immobilize lipase by adsorption and reaction characteristics of the immobilized lipase by adsorption were investigated. Among the tested adsorbents, silica gel was selected as a suitable adsorbent. The optimum condition for adsorption of lipase was when 47.5 units of lipase were adsorbed to 1.6g of silica gel at pH7.0 and
for 100 min. Optimum pH and temperature for activity of the immobilized lipase were at
and pH7.0, which were same as the soluble lipase. Optimum enzyme concentration of the immobilized lipase were 30g for milk fat and 80g for olive oil, whereas those of the soluble lipase were 800 units for milk fat and 1200 units for olive oil. The optimum substrate concentrations of the immobilized and soluble lipases were 20% lipid, regardless of lipid types. Rapid hydrolysis of milk fat was observed with the soluble lipase for the initial 4 hours and with the immobilized lipase for the initial 8 hours. The immobilized lipase produced same amount of capric acid as the soluble lipase, but more myristic acid and less butyric acid than the soluble lipase.
Studies on the Production of Lipid by Microorganism
Kim, Il -Young ; Chung, Dong-Hyo ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 81~88
A potential lipid producing strain of Penicillium sp. was isolated from natural source. Penicillium sp. was cultivated in an appropriate medium containing 6% of glucose as a corbon source, ammonium nitrate as a nitrogen source, C:N ratio 200, pH 4.0 for a period of 17 days at
. Under the condition, the lipid content was 64.2% of dry cell weight. The total lipid produced was 13.7g/100g of glucose consumed. The proportion of nonpolar and polar lipid fractions was 92.2% and 7.8%, respectively. The nonpolar lipid compositions of lipid produced under optimum condition were 5.3% of free fatty acids, 6.8% of free sterols, 9.3% of partial glycerides and 72.0% of triglycerides. The major fatty acids of total lipid were 20.1% of palmitic acid, 21.6% of linoleic acid and 53.3% of oleic acid.
Causes of Can Swelling of Commercially Canned Fruits
Moon, Eun-Joo ; Kim, Hyeung-Yong ; Kyung, Kyu-Hang ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 89~94
Seventy nine swollen commercially canned grapes and peaches were collected from wholesale and retail outlets in Seoul area for the investigation of the causes of their swell. Hydrogen generation and microbial spoilage were the only two common causes of can swelling. Nevertheless, the spoilage profile of the two products was different. Seventeen out of twenty one canned peaches were spoiled by microorganisms, while the rest of five were swollen due to hydrogen generation. In contrast, fifty one out of fifty eight canned grapes were swollen due to hydrogen generation, while the rest of seven were spoiled by microorganisms. Seventeen yeast and five bacterial strains were isolated and only the yeasts were identified to their genera and species. Saccharomyces cerevisiae was the most frequently isolated spoilage yeast, closely followed by Torulopsis stellata. Candida parapsilosis, Pichia kluyveri, Pichia membranaefaciens, Torulopsis globosa and Torulopsis lactis-condensi were also isolated but with lower frequencies.
Effect of Number of Washings with Solvents on Quality of Dried Soymilk Residue
Kim, Woo-Jung ; Sohn, Jung-Woo ; Chung, Sung-Soo ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 95~100
Effects of number of washings with solvents on drying rates and physicochemical properties of dried soymilk residues(SMR) were investigated. The dried soymilk residue was prepared by washing the residue with acetone or ethanol, followed by drying at
. Increase of number of washings with a residue/solvent ratio of 1/1.5 resulted in an increase in drying rate and in protein content of the residue while the lipid content decreased. The brightness of the dried residue and the properties of water and oil absorption were also improved by washing with acetone which was advantageous to ethanol for all of the properties measured. Washings more than 3 times with acetone or 2 times with ethanol were found to be less effective in terms of quality improvement. The more addition of dried residue into the mixture of SMR-wheat flour resulted in a linear increase of water and oil absorption characteristics.
Equations for Water Sorption Isotherms of the Mixture of Dried Soymilk Residue and Wheat Flour
Sohn, Jung-Woo ; Kim, Woo-Jung ; Kim, Sang-Soon ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 101~106
Dried soymilk residue(SMR) which was prepared by washing with ethanol and acetone, followed by drying at
was investigated for its sorption characteristics and the relationship between moisture content and water activity when it was mixed with wheat flour. During storage at
and various RH, an excess sorption phenomena was observed for solvent treated and dried SMR before equilibrium reached. A simple equation of log(dw/dt)=b log t+log a, where t is storage time(hr) and w is %
was drived for sorption or desorption rate of dried SMR at RH range of 12%-92%. From sorption isothermifigure, the moisture content(Mi) could be calculated from water activity by the equation of Mi=b Aw+a. The proposed equation was proved to have better fitness than those of the Smith isotherm equation or Lang and Steinberg equation for the mixture of dried SMR and wheat flour.
Viscometric Properties of Waxy Rice Starches
Song, Bum-Ho ; Kim, Sung-Kon ; Lee, Kyu-Han ; Pyun, Yu-Ryang ; Lee, Shin-Young ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 107~112
Viscometric properties of japonica(Olchal) and japonica
indica(Hankang and Suwon 317) waxy rice starches were investigated. Light transmittance of starch suspension increased from
and remained constant after
. Swelling power was in the order of Hankang, Suwon 317 and Olchal. Amylograph data revealed that Hankang had the highest viscosity at all reference points. The apparent viscosity of 5% starch suspension indicated that the j
indica starches were completely gelatinized after 30 min cooking at
whereas japonica starch at
. The apparent viscosity of gelatinized starch at
(15 psig) was higher compared to that of gelatinized one at
. Hankang was the most susceptable to alkali gelatinization followed by Suwon 317 and Olchal.
Effects of Frying Oils and Storage Conditions on the Rancidity of Yackwa
Min, Byung-Aye ; Lee, Jin-Hwa ; Lee, Su-Rae ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 114~120
This study was carried out to investigate the storage stability of Yackwa (a Korean fried cake made from wheat flour, honey and 20% oil), with the variation in frying oils (soybean oil of fresh or heat-treated corn oil and rapeseed oil) and storage conditions (temperature, humidity and in dark or under fluorescent light) for 20 weeks period. In
storage, acid and peroxide values increased slowly, showing the peroxide value of 20 meq/kg after 13 weeks. In
storage, acid and peroxide values increased remarkably. The product became harder at storage humidity of 25% and softer by moistening at storage humidity of 80%. Acid and peroxide values of Yackwa from corn, rapeseed and soybean oils increased with storage period, to a different extent. The values of fluorescent groups, especially rapeseed oil group, were higher than those of control groups and the heat-treated oil groups were higher than those of fresh oil groups. Sensory scores for rancid flavor were gradually increased with the storage period in all groups. There was no significant difference with the kinds of frying oils, storage conditions and heat treatment. Correlation of sensory scores with acid values was positive throughout whole storage period, with low
. Its correlation with peroxide values was positive up to 6th week but negative at 9th week of storage.
Similarities of Scaritoxin to Ciguatoxin on the Chromatographic Behaviours
Joh, Yong-Goe ; Scheuer, Paul J. ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 121~127
In studying the structural work on ciguatoxin, parrot fish collected were identified as Scarus sordidus, S. frenatus, S. scaber and S. pectarlis, in which only S. sordidus contained toxic materials. Crude toxins obtained by silicic acid column chromatography, could be separated on a DEAE-cellulose column into two fractions, ST-1(less polar) and ST-2(polar) eluted with chloroform and chloroform-methanol(1:1). Furthermore ST-1 could be changed into ST-2 by repeated chromatography on DEAE-cellulose. Rf values of ST-1 and ST-2 were 0.60-0.75 and 0.30-0.54 on TLC coated with silica gel 60F-254 developed by chloroform-methanol-water-acetic acid (90:9.5:0.2:0.3) mixture. The peaks of ST-1 and ST-2 were not observed on each HPLC chromatogram at low sensitivity(2X), but by bioassay they were detected in the fraction of 24-27ml(less polar toxin, 120ng) and 22-27 ml (polar toxin, 150 ng). Less polar ciguatoxin from morey eel viscera also showed its peak in the same elution volume(25ml). Being subjected to chromatography on basic aluminum oxide (activity grade I) or to alkaline treatment, followed by basic aluminum oxide (activity grade I) chromatography ST-1 toxin was remarkably converted into the polar toxic component supposed to be polar ciguatoxin in both cases. In the latter case, approximately 74% of the residual toxicity was changed into the polar component, accompanied by about 50% loss of the initial toxicity. More than 26% of ST-2 toxicity was transformed into the less polar toxic component supposed to be less polar ciguatoxin on a deactivated aluminum oxide (activity grade V) column.
Effect of Oxalic and Phosphoric acid on Degumming of Rice Bran Oil
Kim, Sun-Ki ; Yoon, Suk-Hoo ; Kim, Chul-Jin ; Cheigh, Hong-Sik ;
Korean Journal of Food Science and Technology, volume 17, issue 2, 1985, Pages 128~130
Solutions of 4.8 and 12% oxalic and 85% phosphoric acid were used for degumming of crude rice bran oil. 96.6% of total phosphatides was removed by degumming with either 2ml of 85% phosphoric acid or 20ml of 4% oxalic acid when added to 1kg of crude rice bran oil. Yields after degumming with oxalic and phosphoric acids were 63.6% and 61.0%, respectively.