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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 40, Issue 6 - Dec 2008
Volume 40, Issue 5 - Oct 2008
Volume 40, Issue 4 - Aug 2008
Volume 40, Issue 3 - Jun 2008
Volume 40, Issue 2 - Apr 2008
Volume 40, Issue 1 - Feb 2008
Selecting the target year
Development of a Simultaneous Analysis Method for DDT (DDD & DDE) in Ginseng
Kim, Sung-Dan ; Cho, Tae-Hee ; Han, Eun-Jung ; Park, Seoung-Gyu ; Han, Chang-Ho ; Jo, Han-Bin ; Choi, Byung-Hyun ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 123~128
The MRLs (maximum residue limits) of DDT (DDD and DDE) in fresh ginseng, dried ginseng, and steamed red ginseng are set as low as 0.01 mg/kg, 0.05 mg/kg, and 0.05 mg/kg, respectively. Therefore, this study was undertaken to develop a simple and highly sensitive analysis method, as well as to reduce interfering ginseng matrix peaks, for the determination of DDT isomers (o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT, and p,p'-DDT) in fresh ginseng, dried ginseng, and steamed red ginseng at the 0.01 mg/kg level. The method used acetonitrile extraction according to simultaneous analysis, followed by normal-phase Florisil solid-phase extraction column clean-up. The purification method entailed the following steps: (1) dissolve the concentrated sample extract in 7 mL hexane; (2) add 3 mL of
; (3) vigorously shake on avortex mixer; (4) cetrifuge at 2000 rpm for 5 min; (5) transfer 3.5 mL of the supernatant to the Florisil-SPE (500 mg/6 mL);and (6) elute the SPE column with 1.5 mL of hexane and 10 mL of ether/hexane (6:94). The determination of DDT isomers was carried out by a gas chromatography-electron capture detector (GC-
ECD). The hexane and ether/hexane (6:94) eluate significantly removed chromatographic interferences, and the addition of 30%
to the acetonitrile extract effectively reduced many interfering ginseng matrix peaks, to allow for the determination of the DDT isomers at the 0.01 mg/kg level. The recoveries of the 6 fortified (most at 0.01 mg/kg) DDT isomers from fresh ginseng, dried ginseng, and steamed red ginseng ranged from 87.9 to 99.6%. The MDLs (method detection limits) ranged from 0.003 to 0.009 mg/kg. Finally, the application of this method for the determination of DDT isomers is sensitive, rapid, simple, and inexpensive.
Isolation and Identification of Low Molecular Phenolic Antioxidants from Ethylacetate Layer of Korean Black Raspberry (Rubus coreanus Miquel) Wine
Kim, Seong-Ja ; Lee, Hyoung-Jae ; Park, Keun-Hyung ; Rhee, Chong-Ouk ; Lim, Ik-Jae ; Chung, Hee-Jong ; Moon, Jae-Hak ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 129~134
Five antioxidative active substances were isolated from the EtOAc layer (20 g/56.2 g) of Korean black raspberry (Rubus coreanus Miquel) wine (11 L, black raspberry 15.7 kg fresh wt. eq.) by various column chromatography and high performance liquid chromatography (HPLC). Proton nuclear magnetic resonance (
-NMR) spectroscopy and gas chromatography Electro Ionization-Mass Spectrometry (GC-EI-MS) identified these as 4-hydroxybenzoic acid (1, 0.1 mg), 3,4-dihydroxybenzoic acid (2, 0.3 mg), 4-(2-hydroxyethyl)-phenol (3, 0.6 mg; tyrosol), pyrocatechol (4, 0.3 mg), 3,4,5-trihydroxybenzoic acid ethyl ester (5, 0.6 mg; ethyl gallate). The presence of 1 and 2 in Korean black raspberry has previously been reported. However, the presence of 3-5 in Korean black raspberry, and the identification of 1-5 from the Korean black raspberry wine have never before been reported.
Discrimination of Geographical Origin for Herbal Medicine by Mineral Content Analysis with Energy Dispersive X-Ray Fluorescence Spectrometer
Jeong, Myeong-Sil ; Lee, Soo-Bok ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 135~140
In this study, the macromineral content ratios of four herbal medicine samples(Saposhnikoviae Radix, Bupleuri Radix, Cnidii Rhizoma, and Astragali Radix) were analyzed to discriminate their geographical origins using an energydispersive x-ray fluorescence (EDXRF) technique. EDXRF is a rapid, non-destructive, and multi-elemental analysis technique. Initially, samples of both domestic and imported herbal medicines were pulverized, and then their macromineral contents, including P, S, K, and Ca, were analyzed using EDXRF. For the discrimination of their geographical origins, canonical discriminant analysis was carried out based on the estimated macromineral relative content ratios of the samples. According to the results, the discrimination accuracies were as follows: 93.3% for Saposhnikoviae Radix, 95.7% for Bupleuri Radix, 98.8% for Cnidii Rhizoma, and 87.5% for Astragali Radix. Overall, the results imply that this technique could be used as a standard method, to discriminate their geographical origins between domestic and imported herbal medicines.
Oxidative Stability of Sesame Oil Prepared from Black Sesame Flour
Nam, Mi-Jin ; Chung, Ha-Yull ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 141~145
Oxidative stabilities of sesame oil prepared from black sesame flour and white sesame flour, and commercial sesame oil prepared from whole white sesame were compared by measuring oxidation induction periods, peroxide values and electron donating abilities of each oil. Oxidation induction period (12.25 hr) of sesame oil prepared from black sesame flour was longer than those (4.37 and 9.1 hr, respectively) of sesame oil from white sesame flour and commercial sesame oil. Peroxide values of sesame oil prepared from black sesame flour, sesame oil prepared from white sesame flour and commercial sesame oil were 1.3, 18.2 and 1.7 meq/kg oil, respectively. We ascertained that the oxidative stability of sesame oil prepared from black sesame flour was superior than sesame oil from white sesame flour as well as ommercial sesame oil. This was based on the fact that electron donating ability of sesame oil prepared from black sesame flour was 9% higher than that of sesame oil prepared from white sesame flour at the same concentration. The superior oxidative stability of sesame oil prepared from black sesame flour was expected, not only because only it had lignans such as sesamol and sesamolin, but also because of its brownish coloring compounds such as tannin which were not contained in white sesame flour.
-1,3-Glucan Functionality by Batch and Semi-continuous Typed Specific Carboxylation
Jeong, Suk-Yun ; Kim, Sang-Woo ; Lee, Yong-Hwan ; Lee, Jae-Hwan ; Chang, Pahn-Shick ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 146~151
In this study, batch or semi-continuous reactions, introducing site-specific carboxylic acids in
-1,3-glucan structures, were performed to increase water solubility and gel forming ability, using TEMPO/hypobromite with or without NaBr as catalysts. Regio-selective carboxylic acid formations were determined with infrared (IR) and
nuclear magnetic resonance (NMR) spectroscopic analyses. The regio-selective reactions with and without NaBr gave oxidation yields of 92.5 and 85.6%, respectively, in the batch type, and yields of 93.9 and 86.4%, respectively, in the semi-continuous type. The reaction times in the batch and semi-continuous reactions without NaBr were delayed by 100 and 150%, respectively, as compared to those with NaBr. A combination of IR and
NMR analyses were used to confirm the formation of carboxylic acids in
-1,3-glucan. From the batch reactions with and without NaBr, the water solubilities of oxidized products were 50.0 and 55.6%, respectively, and in the semi-continuous reactions they were 52.6 and 53.5%, respectively; while the water solubility of the native
-1,3-glucan was less than 1.0%. Finally, as compared to the native
-1,3-glucan, the gel forming ability of the reaction products was greatly increased irrespective of the presence of NaBr or the reaction type.
A Comparative Study on Quantifying Uncertainty of Vitamin A Determination in Infant Formula by HPLC
Lee, Hong-Min ; Kwak, Byung-Man ; Ahn, Jang-Hyuk ; Jeon, Tae-Hong ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 152~159
The purpose of this study was to determine the accurate quantification of vitamin A in infant formula by comparing two different standard stock solutions as well as various sample weights using high performance liquid chromatography. The sources of uncertainty in measurement, such as sample weight, final smaple vloume, and the instrumental results, were identified and used as parameters to determine the combined standard uncertainty based on GUM(guide to the expression of uncertainty in measurement) and the Draft EURACHEM/CITAC Guide. The uncertainty components in measuring were identified as standard weight, purity, molecular weight, dilution of the standard solution, calibration curve, recovery, reproducibility, sample weight, and final sample volume. Each uncertainty component was evaluated for type A and type B and included to calculate the combined uncertainty. The analytical results and combined standard uncertainties of vitamin A according to the two different methods of stock solution preparation were 627
g R.E./100 g for 1,000 mg/L of stock solution, and 627
g R.E./100 g for 100 mg/L of stock solution. The analytical results and combined standard uncertainties of vitamin A according to the various sample weighs were 622
g R.E./100 g, 627
g R.E./100 g, and 491
g R.E./100 g for 1 g, 2 g, and 5 g of sampling, respectively. These data indicate that the preparation method of standard stock solution and the smaple amount were main sources of uncertainty in the analysis results for vitamin A. Preparing 1,000 mg/L of stock solution for standard material sampling rather than 100 mg, and sampling not more than 2 g of infant formula, would be effective for reducing differences in the results as well as uncertainty.
Sensory Characteristics and Consumer Liking of Commercial Sojues Marketed in Korea
Jee, Joo-Hee ; Lee, Hye-Seong ; Lee, Jin-Won ; Suh, Dong-Soon ; Kim, Hee-Sub ; Kim, Kwang-Ok ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 160~165
This study was conducted to analyze sensory profiles of commercial sojues using a standardized sensory evaluation procedure, and to investigate the effects of sensory characteristics and brands on consumer liking for soju. Descriptive analysis and consumer taste testing were conducted for seven commercial sojues. For the descriptive analysis, eight panelists generated and evaluated 12 flavor and one pain-sensation attributes for the soju, and there were significant differences among the soju samples for all the 13 sensory attributes. For the descriptive data, principal component analysis was performed to summarize the sensory characteristics of the sojues. For the consumer testing, 224 soju drinkers (20-29 year-olds) were recruited and randomly divided into two groups; a blind group and a group with the knowledge of brand. While the hedonic ratings obtained from the blind group didn't indicate significant differences among the sojues, the ratings obtained from the brand-informed group showed significant differences. Finally, the individual preferences of the 112 consumers in each group were investigated by preference mapping techniques.
Effects of Heat Treatments on the Antioxidant Activities of Fruits and Vegetables
Kim, Hyun-Young ; Woo, Koan-Sik ; Hwang, In-Guk ; Lee, Youn-Ri ; Jeong, Heon-Sang ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 166~170
The effects of heat treatments on the antioxidant activities of selected fruits and vegetables were investigated by heating at various temperatures (110, 120, 130, 140, and 150
) for 2 hr. The examined fruits and vegetables included tomatoes (Lycopersicon esculentum), oriental melon (Cucumis melon var. makuwa), apples (Malus pumila Miller var. domestica Schneider), melon (Cucumis melon), watermelon (Citrullus vulgaris), and banana (Musa sapientum). The total polyphenol and total flavonoid contents of the juices from heated samples were quantified spectrophotometrically, and their antioxidant activities were determined using DPPH and ABTS radicals. As the heating temperature increased, antioxidant activity also increased. The highest total polyphenol content (2.80 mg/g) occurred in the oriental melon with heating at 150
, and this value was 7 times higher than that of the untreated oriental melon (0.40 mg/g). The highest total flavonoid content (148.80
g/g) occurred in the melon heat treated at 150
, and this value was 37 times higher than that of the untreated melon (4.54
g/g). DPPH radical-scavenging activity was the highest in the watermelon treated at 150
(84.37%, 0.50 mg/g), and this value was 40 times higher than that of the untreated watermelon. Finally, the highest ascorbic acid (AA) equivalent antioxidant capacity (AEAC) value (239.50 mg AA eq/g) was obtained in the watermelon heat treated at 150
for 2 hr (control = 18.35 mg AA eq/g).
Effects of Washing-water Temperature and Packaging Type on the Quality of Fresh-cut Crown Daisies
Chang, Min-Sun ; Kim, Byeong-Sam ; Kim, Gun-Hee ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 171~177
The effects of hydrocooling and packaging type on the quality attributes of fresh-cut crown daisies (Chrysanthemum coronarium var. spatiosum) were investigated by examining weight loss, respiration, vitamin C content, total chlorophyll content, microbial load, and sensory properties during storage at 4 and 10
. Fresh crown daisies were trimmed and washed with cold water (1 and 5
) as well as tap water (10
) 3 times each for 30 sec. They were then packaged in PP (polypropylene) film bags or PETE (polyethylene terephthalate) trays, and stored for 9 days at 4 and 10
, respectively. In general, weight loss was reduced as a result of the washing and packaging. The respiration rate increased slowly during storage at 4
, and the vitamin C and total chlorophyll contents of the crown daisies packaged in PETE trays decreased gradually during storage. Finally, the treatments consisting of hydrocooling and then packaging in PETE trays resulted in approximately 1-2 log CFU/g reductions in microbial load.
Effect of Osmotic Dehydration and Vacuum Impregnation on the Quality of Dried Apple
Choi, Hee-Don ; Lee, Hae-Chang ; Kim, Yun-Sook ; Choi, In-Wook ; Park, Yong-Kon ; Seog, Ho-Moon ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 178~183
This study investigated the effects of osmotic dehydration (OD) and vacuum impregnation (VI) on the quality of dried apple products. Weight reduction and water loss increased during OD, but these decreased in the apples during VI. In particular, VI's effect on increasing solid gain was superb. For apples in 40% sucrose solution, OD and VI were followed by hot-air drying at 50
. The experimental data were fitted successfully using the modified Page model. OD and VI increased drying time and decreased the drying rate constant of these apples as compared to the control. Shrinkage and rehydration capacity greatly decreased in the apples dried by OD and increased in the apples dried by VI as compared to the control. OD also decreased titratable acidity and ascorbic acid content considerably. Sensory evaluations of the products indicated that the apples prepared by OD had higher palatability in their rehydrated form in yoghurt, and the apple products prepared by VI had higher palatability in their dried form.
Rheological Properties of Sweet Potato Starch-sucrose Composite
Cho, Sun-A ; Yoo, Byoung-Seung ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 184~189
Effects of sucrose at different concentrations (0, 10, 20, and 30%, w/w) on steady and dynamic shear rheological properties of sweet potato starch (SPS) paste (5%, w/w) were investigated. The steady shear rheological properties of SPS-sucrose composites were determined from rheological parameters based on power law and Casson flow models. At 25
all the samples showed pseudoplastic and thixoropic behavior with high yield stress. Consistence index (K), apparent viscosity (
), and yield stress (
) values of SPS-sucrose composites decreased with increasing sucrose concentration from 10% to 30%. The decrease of swelling power was observed at higher sucrose concentration (>20%) and the low swelling power yielded a lower K,
values. In temperature range of 25-70
, Arrhenius equation adequately assessed variation with temperature. Oscillatory test data showed weak gel-like behavior. Magnitudes of storage (G') and loss (G") moduli increased with an increase in sucrose concentration and frequency. The SPS-sucrose composite at 30% concentration closely followed the Cox-Merz superposition rule.
Optimization of Enzymatic Hydrolysis for the Production of Antitoxic Bovine Hepatic Extract
Kim, Hyun-Jung ; Kwon, Do-Hyeong ; Shon, Dong-Haw ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 190~193
Bovine hepatic extract is recognized as possessing detoxifying activity against various liver diseases. In orderto develop a process for its mass production, various enzymatic hydrolysis conditions were tested, and bovine hepatic extracts were prepared. These extracts were then examined for composition, microorganism levels, and vitamin
content. Among the enzymes tested, papain was selected based on yields for dry residue and amino nitrogen. The other enzymes tested included bromelain, ficin, pancreatin, and protease NP. The optimal hydrolysis conditions were established at 65
for 24 hr, with an addition of 1%(w/w) papain to the beef liver. The prepared spray-dried bovine hepatic extract showed an 11% recovery yield on a raw beef liver basis, with 95% dry residue and 11.8% total nitrogen content. Microorganisms were not detected in the dried extract, and its vitamin
content was 4.1
g/g. In summary, the conditions established in this study could be applied for the high yield mass production of bovine hepatic extract.
Effect of Glycyrrhiza uralensis on Shelf-life and Quality of Takju
Kim, Ah-Ram ; Lee, So-Young ; Kim, Koth-Bong-Woo-Ri ; Song, Eu-Jin ; Kim, Jin-Hee ; Kim, Mi-Jung ; Ji, Kyong-Won ; Ahn, Im-Sook ; Ahn, Dong-Hyun ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 194~200
This study was performed to examine the properties of takju containing added Glycyrrhiza uralensis ethanol extract (GUEE) at 10
for 12 days. Change in TBARS values was lower in the takju with GUEE as compared to control. The total viable cell count and yeasts cell count of all samples remained constant over the storage period. The brix of the takju treated with 0.5% GUEE (3.8-4.3) was higher than that of the control (3.8-4.0). Suspension stability and yellowness increased as the added concentration of GUEE increased. After 12 days of the storage, the pH level of the 0.5% GUEE takju was 3.9, which was 0.2 higher than that of control. In terms of acidity, the 0.5% GUEE takju ranged from 0.269 to 0.282, whereas the acidity of the control ranged from 0.294 to 0.302. In treated Takju with GUEE represented at treated takju with GUEE had the positive effects toward improving its preservation and quality.
Changes of Physicochemical, Sensory and Antioxidant Activity Characteristics in Rice Wine, Yakju Added with Different Ratios of Codonopsis lanceolata
Jin, Tie-Yan ; Lee, Wan-Gyu ; Lee, In-Sook ; Wang, Myeong-Hyeon ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 201~206
The physicochemical, sensory and antioxidant activity characteristics of rice wine, yakju added with different ratios of Codonopsis lanceolata (0, 10, 20, and 30%) were investigated. The pH of the rice wine decreased and the total acidity increased with greater additions of C. lanceolata. Furthermore, the total sugar content increased, while the alcohol content decreased with increasing amounts of C. lanceolata. The color L-value had no change, but the color a- and bvalues increased with increasing amounts of C. lanceolata. The DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical scavenging activity increased with the addition of C. lanceolata. The highest overall acceptability values in the sensory test for color, flavor, taste, and overall favorite were 5.53, 5.50, 5.63, and 5.65, respectively, with the addition of 20% C. lanceolata.
Effect of the Hexane Extract of Saussurea lappa on the Growth of HT-29 Human Colon Cancer Cells
Kim, Eun-Ji ; Park, Hee-Sook ; Lim, Soon-Sung ; Kim, Jong-Sang ; Shin, Hyun-Kyung ; Yoon, Jung-Han ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 207~214
In Asia Saussurea lappa (SL) has been used as a traditional herbal medicine to treat abdominal pain and tenesmus. Recently, in vitro cell culture studies have shown that SL has anti-ulcer, anti-inflammatory, and anti-tumor properties. To explore its potential chemopreventive and chemotherapeutic effects in colon cancer, we examined whether the hexane extract of SL (HESL) could inhibit the growth of HT-29 human colon cancer cells, and investigated the mechanisms for this effect. The cells were cultured with various concentrations (0-5
) of HESL. The results indicated that HESL markedly decreased the numbers of viable HT-29 cells; whereas at the concentration of 5
, HESL slightly decreased the viable cell numbers of CCD 1108Sk human skin normal fibroblasts at 72 hr. HESL substantially increased the numbers of cells in the sub G1 phase, and dose-dependently increased apoptotic cell numbers. Western blot analysis of the total cell lysates revealed that HESL increased Bax protein levels, but did not affect Bcl-2 levels. HESL induced the cleavage of poly (ADP-ribose) polymerase and caspases 8, 9, 7, and 3. This study demonstrated that HESL inhibits cell growth and induces apoptosis in HT-29 cells, which may be mediated by its ability to increase Bax levels and activate the caspase pathway. These findings may lead to the development of new therapeutic strategies for colon cancer treatment.
Effects of Complex Food Ingredient Composed of Garlic and Fermented Soybean Hypocotyl on the Serum Lipid Profiles of the Rats Fed High-Fat Diet
Choi, Hyung-Taek ; Kim, Eui-Su ; Ham, Seung-Shi ; Park, Seung-Yong ; Chung, Ha-Yull ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 215~219
Garlic that has been reacted with fermented soybean hypocotyl, termed Bio-Garlic, contains 6 times more allithiamine than garlic alone, and it was prepared as a complex food ingredient. To examine the effects of Bio-Garlic on obesity and hyperlipidemia, rats were fed a high-fat diet for 8 weeks. Bio-Garlic arrested increases in body weight without affecting feed intake in the rats. The Bio-Garlic also lowered serum levels of total cholesterol and triglycerides, while increased serum HDL-cholesterol levels. The atherogenic index of the Bio-Garlic treated group decreased, suggesting that Bio-Garlic has the potential to be marketed as a functional health food ingredient with beneficial effects on the circulatory system.
Characterization of Immuno-stimulating Polysaccharides Isolated from Korean Persimmon Vinegar
Hwang, Yong-Chul ; Shin, Kwang-Soon ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 220~227
In this study, polysaccharides were isolated from Korean persimmon vinegar to characterize the polysaccharides existing as soluble forms within traditional Korean fermented beverages, and their immuno-stimulating activities were examined. Three successive chromatographies were used to purify the main polysaccharide in the persimmon vinegar, PV-1b-I, to homogeneity from the crude polysaccharide (PV-0). The molecular mass of PV-1b-I was estimated as 110 kDa and it contained significant proportions of mannose (46.8%), galactose (28.5%) and arabinose (19.1%). PV-1b-I strongly reacted with
-glucosyl Yariv reagent, suggesting the presence of an arabino-3,6-galactan moiety. PV-1b-I also induced high levels of macrophage activation and mitogenicity on murine splenocytes in vitro. The intravenous administration of PV-1b-I significantly augmented NK cytotoxicity against YAC-1 tumor cells. PV-1b-I also showed potent anticomplementary activity in a dose-dependent manner. Finally, C3 activation products were identified by crossed immunoelectrophoresis using anti-human C3 and the anti-complementary activity of PV-1b-I under
-free conditions, suggesting that this PV-1b-I causes complementary activations via both alternative and classical pathways. From these results, one can conclude that Korean persimmon vinegar contains select polysaccharides in addition to healthy components, and these polysaccharides appear to provide immuno-stimulating activities beneficial to human health.
Distribution of Ultraviolet Intensity and UV Leaking of Commercial UV Sterilizers Used in Restaurants
Mok, Chul-Kyoon ; Lee, Nam-Hoon ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 228~233
Ultraviolet sterilizers (UVS) are widely used in restaurants, cafeterias and catering businesses in Korea. The proper application of UVS, however, is still questionable since no studies have clearly identified their efficacy and safety, while regulations and regulatory management systems are yet to be established. In the present study, the efficacy of UVS were investigated by measuring spatial UV intensity inside five commercially operated UVS. The operating safety parameters were also checked by measuring leaked UV intensity. The UV intensities were inversely proportional to distance from the UV lamp within 25 cm, and to the square of the distance exceeding 25 cm. The UV intensities in commercial UVS varied with the distance from UV lamp and the incident angle, highlighting efficacy and stability concerns. Notable leakage was detected through the door gaps of a studied UVS, which also brought about safety concerns. Allowable working distances for the UV leaking UVS were suggested based on international standards.
Effect of Black Rice Flour on the Quality of Sugar-snap Cookie
Park, Young-Seo ; Chang, Hak-Gil ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 234~237
The quality of sugar-snap cookie prepared with wheat flour supplemented with black rice flour was investigated. The pH of cookie batter decreased as the amount of black rice flour increased. Increasing proportions of black rice flour resulted in increase of width and spread factor of cookie, whereas thickness and fracturability decreased. L, a, and b values decreased as the amount of black rice flour increased. Sensory evaluation showed that supplements of 20, 25, and 20% black rice flour had the best overall preference in strong, medium, and weak flours, respectively.
Effects of Yeast Strains and Fermentation Temperatures in Production of Hydrogen Sulfide During Beer Fermentation
Kim, Young-Ran ; Moon, Seung-Tae ; Park, Seung-Kook ;
Korean Journal of Food Science and Technology, volume 40, issue 2, 2008, Pages 238~242
In this study, hydrogen sulfide (
) production was examined during beer fermentation using two ale and two lager yeast strains. In the lager yeast fermentation, a large amount of
was produced in the early fermentation stages when the yeast were actively fermenting wort, indicating a positive relationship between the level of H2S production and the yeast growth rate during fermentation. The ale yeasts produced much lower levels of H2S than the lager yeasts. In the lager fermentation, a higher fermentation temperature shortened the fermentation period, but much higher levels of
were produced at higher temperatures. American pilsner lager yeast fermenting at
produced a relatively high level of
at the end of fermentation, which would require a longer aging time to remove this malodorous volatile sulfur compound. Not including the English ale strain, which produced a higher level of H2S at lower temperatures, the ale yeast produced lower levels of
at lower temperatures, suggesting that each strain has an optimum fermentation temperature for H2S production.