• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.141-150
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• 2002

Owing to a need for simple extraction and purification for analysis of water soluble vitamins in food samples by RP-HPLC with UV-detector, the methods of bromelain and protease hydrolysis and $C_{18}$ Sep-Pak solid phase extraction were employed. The recoveries of standard water soluble vitamins by the bromelain and protease hydrolysis and $C_{18}$ Sep-Pak solid phase extraction were significantly high compared to AOAC methods in most of vitamins. The contents of pyridoxal determined with protest in the pork was similar, but in the bromelain hydrolysis and AOAC method, was high compared to the results of reference. The niacinamide, thiamin and riboflavin determined with bromelain and protease hydrolysis showed similar values to the results of references. In the potato, pyridoxamine was detected in the AOAC method, which was not detected in the bromelain and protease hydrolysis methods. Pyridoxal contents in the protease hydrolysis and AOAC methods were very similar to the results of references. The recoveries of fortified standard vitamins in food samples were significantly high and accurate compared to those of AOAC methods. The extraction and purification with $C_{18}$ Sep-Pak solid extractor might be considered superior method for the determination of water soluble vitamins in food samples.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.333-338
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• 2004

Antioxidant activities of water extracts of 20 medicinal plants (1 mg/mL) on peroxidation of linolic acid were evaluated by thiocyanate method, among which 11 showed strong antioxidant activity (> 70%). Higher hydroxy radical scavenging activity (> 60%) were shown in Corner officinalis, Acanthopanax sessiliflorus, and Epimedium koreanum than the other plants. Epimedium koreanum than the other plants extract showed highest superoxide radical scavenging activity (42%). Total polyphenol contents ranged from $2.6\;(Polygonatum\;odoratum){\sim}81.2(Epimedium\;koreanum)\;mg/g$. Direct correlation between the antioxidant activity and polyphenol content (r=0.8) was established through simple regression analysis. $IC_{50}$ for selected four plant extracts, showing highest polyphenol contents and antioxidant activities, were significantly higher than positive control. Total antioxidant activity of vitamin c was significantly lower than those of Acanthopanax sessiliflorus, Epimedium koreanum, and Erythrina variegata. Superoxide radical scavenging activity of Acanthopanax sessiliflorus was similar to BHA. Results suggest water extracts of some medicinal plants could be potential candidates for natural antioxidants.

• Journal of agriculture & life science
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• v.46 no.4
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• pp.129-139
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• 2012

This study was carried out to evaluate the chemical properties and functional characteristics, such as general composition and bioactivity compounds contents of fresh and blanched (at $95^{\circ}C$, for 5min) garlic shoot from Namhae. Also, evaluated antioxidant and antimicrobial activities of water and ethanol extract of fresh and blanched garlic shoot. The moisture content of fresh garlic steam was $ 85.14{\pm}0.35%$, crude protein and crude lipid were $0.79{\pm}0.26%$ and $2.96{\pm}0.03%$ respectively. Vitamin C content was higher in fresh garlic shoot ($7.07{\pm}0.84mg/100g$) than blanched. Total phenol and total chlorophyll contents were respectively $16.93{\pm}1.17mM/g$ and $6.70{\pm}0.46mg/g$ in fresh garlic shoot. Allicin content of blanched garlic shoot was $128.63{\pm}1.59mM/g$. This content was 1.82 times higher than the fresh garlic shoot. Total pyruvate content was higher in fresh garlic shoot ($24.63{\pm}1.59mM/g$), but thiosulfinate was higher in fresh garlic shoot. Total flavonoide was the highest in water extract of blanched garlic shoot ($3.67{\pm}0.00mM/g$). ABTS radical scavenging activity of water extract form blanched garlic shoot was $85.09{\pm}0.28%$, which was higher than the other extracts. NO radical scavenging activity of ethanol extract from blanched garlic shoot was significantly higher than the extracts from fresh garlic shoot. Antibacterial activity to S. aureus, S. enterica, B. cereus and E. coli was only indicated in water extract of fresh garlic shoot.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.454-462
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• 2019

A conventional Korean meal typically includes various roasted, steamed, stir-fried, and braised foods. For this study, we investigated the contents of water soluble vitamins, $B_1$ (thiamin), $B_2$ (riboflavin) and $B_3$ (niacin) in various roasted, steamed, stir-fried, and braised foods. Method validation for analytical data in this study showed a high linearity ($r^2$>0.999), and the limit of detection and quantification were 0.001-0.067 and $0.002-0.203{\mu}g/mL$, respectively. For accuracy and precision, analytical values using standard reference materials were in the certified ranges. Roasted foods contained 0.039-1.057 mg/100 g of thiamin, 0.058-0.686 mg/100 g of riboflavin and 0.021-21.772 mg/100 g of niacin. Steamed foods contained 0.049-1.066 mg/100 g of thiamin, 0.025-0.548 mg/100 g of riboflavin and 0.134-21.509 mg/100 g of niacin. Stir-fried foods contained 0.114-0.388 mg/100 g of thiamin, 0.014-1.258 mg/100 g of riboflavin and 0.015-2.319 mg/100 g of niacin. Braised foods contained 0.112-1.656 mg/100 g of thiamin, 0.024-0.298 mg/100 g of riboflavin and 0.322-2.157 mg/100 g of niacin. The data on water-soluble vitamins in this study can be used for a nutritional database of conventional Korean meals.

• Korean Journal of Poultry Science
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• v.20 no.2
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• pp.93-105
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• 1993

This study was carried out to determine the concentrations of previtamin D$_3$(PreD$_3$), lumisterol$_3$(L3), tachystero1$_3$(73), vitamin D$_3$(VD$_3$) and provitamin D$_3$(ProD$_3$) in leg skins of broiler chicks exposed to UVB lights (maximum intensity at 297 nm) with dose of 0.204 or 0.409 mJ/$\textrm{cm}^2$(30 or 60 min irradiation) . The broiler Hubbard line day old chicks(2 dose $\times$9 elapsed time $\times$4 replica＋10 control＝82) were fed VD-deficient diet for 31 days in a windowless subdued light room. The skin was collected at 0, 6, 12, 18, 30, 42, 66, 90 or 138 hr after UVB irradiation. The skin lipid was extracted by 9％ ethyl acetate/n-hexane, and the fraction of VD$_3$ and its analogues was purified by Sep-Pak silica cartridge. The straight phase HPLC was utilized to analyze ProD$_3$ and its products. The mole ％(absolute level expressed in ng/$\textrm{cm}^2$) of PreD$_3$ in leg skin (epidermis＋dermis) was 4.67％(44 ng/$\textrm{cm}^2$) or 3.97％(37 ng/$\textrm{cm}^2$) right after UVB irradiation by 0.204 or 0.409 mJ/$\textrm{cm}^2$(30 or 60 min) at 15 cm distance, respectively. It content in leg skin at 0 hr after exposure was 7.24％(12 ng/$\textrm{cm}^2$) or 0.92％(9 ng/$\textrm{cm}^2$), respectively. The increase in irradiation dose did not affect proportionally the If synthesis.73 concentration in leg skin was 0.58％(S ng/$\textrm{cm}^2$) or 0.57％(6 ng/$\textrm{cm}^2$), respectively 0 hr after irradiation. The VD$_3$ in leg skin of birds exposed to UVB light with dose of 0.204 or 0.409 mJ/$\textrm{cm}^2$ was 2.13％ (21 ng/$\textrm{cm}^2$) or 0.97％ (16ng/$\textrm{cm}^2$), respectively at 0 hr after exposure, 2.72％(26ng/$\textrm{cm}^2$) or 3.84％(37ng/$\textrm{cm}^2$), respectively at 6 hr, and 4.30％ ((33ng/$\textrm{cm}^2$) or 6.40％(76ng/$\textrm{cm}^2$), respectively at 12 hr. The peak concentration of VD$_3$ was presented at 18 or 30 hr when 0.204 or 0.409 mJ/$\textrm{cm}^2$) was treated, respectively. It was shown that 18~30 hr were necessary for the thermal conversion of PreD$_3$ into VD$_3$ in the leg skin of broiler chicks. The ProD$_3$ contents in leg skins of negative control, 0.204 mJ/$\textrm{cm}^2$ and 0.409 mJ/$\textrm{cm}^2$ treated birds were 966, 948 and 815 ng/$\textrm{cm}^2$, respectively at right before and after UVB exposure. It was estimated that 18 or 151 ng/$\textrm{cm}^2$ of ProD$_3$ was isomerized to PreD$_3$, L$_3$, T$_3$ and VD$_3$ when exposed to 0.204 or 0.409 mJ/$\textrm{cm}^2$, respective)y. Consequently it was shown that when double dose of UVB light was applied to irradiate the chick body, more but not double synthesis of VD$_3$ and its analogues was occured in leg skin of brolier chicks.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.537-544
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• 2013

This study was performed to establish method of simultaneous determination of fructose, glucose, and sucrose in honey and commercial vitamin drinks by GC and GC/MS. Optimum chromatographic separation of trimethylsilyl-oxime (TMSO) derivatives by GC was achieved on a DB-5 column. Calibration curves for fructose, glucose and sucrose TMSO derivatives by GC were linear in the range of 50-5000 ${\mu}g/mL$, and their $r^2$ values were 0.9999, The limit of detection and limit of quantification of fructose, glucose, and sucrose were 0.68, 0.47, and 0.53 ${\mu}g/mL$, respectively, and 2.27, 1.58, and 1.77 ${\mu}g/mL$, respectively. Average recoveries of fructose, glucose, and sucrose were 100.5, 101.0, and 99.7%, respectively. When the method was applied to 12 honey samples, the average concentrations of fructose, glucose and sucrose were $42.58{\pm}1.97%$, $27.74{\pm}1.16%$, and $0.79{\pm}0.52%$, respectively. The F/G ratio was $1.53{\pm}0.07$. For fructose and glucose contents, results from the GC analysis were similar to those from the HPLC analysis, but the sucrose content was different for each analysis method. We suggest that the GC method is more suitable than other official analytical methods for simultaneous determination of fructose, glucose, and sucrose in honey.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.272-279
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• 2018

The high pressure processing (HPP) is a technology which can preserve the quality of foods, such as the fresh taste, incense, texture, vitamin content, and so on, by minimizing the heating process. It does so by applying an instantaneous and uniform pressure that is the same as the water pressure that is 60 km deep in the sea. HPP is a technology that can inhibit food poisoning and spoilage caused by microorganisms and is currently an actively studied area. In this study, we investigated the effects of a high pressure treatment (0, 4, 6 min) on sliced ham, which is a typical meat product, at 600 MP a were tested for their effect on freshness. Moisture contents varied from 48 to 69%, salinity varied from 1.07 to 1.11%, and the pH decreased from 6.4~6.5 to 6.1~5.15. However, there was no difference between the control and treatment groups. General bacteria stored at $20^{\circ}C$ after hyper-pressure treatment were found to have no significant microorganisms in all groups until 4 weeks. but exceeded $10^5$ in control group and HPP 6 min treatment group from 5 weeks, At week 7, it was found to exceed $10^6$. The results indicate it was not possible to ingest food in the 4-and 6 minute treatment groups. Coliform was not observed in all groups despite observing for a total of 7 weeks at $20^{\circ}C$ weight test. VBN, a method used to determine the protein freshness of meat, showed a VBN value of less than 1 mg% until the fourth week and a value of 1 to 2 mg% after 5 weeks. The TBA was used as an index of the degree of fat acidosis in the meat tissues. The results showed it was below 0.18 mgMA / kg until the end of 7 weeks; this value was within the range for fresh meat, and there was no difference in treatment group. In this experiment, deformation of the packaging material did not occur and no swelling occurred due to the generation of gas. It is believed that the basic preservation effect was achieved only by blocking with the air due to the close contact of the packaging material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.569-576
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• 2016

This study researched the effects of cooking methods on phytochemical-enriched thin rice porridge (RP) of three colors (red, yellow, and green). Each of the RPs was prepared by three cooking methods and retorted through two-steps (step 1, at $80^{\circ}C$ for 15 min; step 2, at $82^{\circ}C$ for 25 min) for pasteurization. Cooking method (CM) 1 involved heating a mixture of all ingredients while CM 2 involved addition of apple/beet (AB, red), sweet-pumpkin/cabbage (PC, yellow) or vitamin/pear (green) while heating rice flour and glutinous rice flour. CM 3 involved mixing pre-cooked fruits and vegetables with cooked thin RP. The viscosity of RP prepared by CM 1 was lower than those of other RPs (P<0.05). The result of colorimetric a value show that red and green color of AB and VP prepared by CM 2 and CM 3 were most vivid. Contents of phytochemicals and antioxidants were higher when RP was prepared by CM 2 and CM 3 compared to CM 1. ${\Delta}E$ values of PC showed no significant difference before and after pasteurization, whereas AB and VP were significantly different (P<0.05). Antioxidant activity after retorting was not significantly different from those of un-retorted RPs. The results of color, phytochemical content, and antioxidant activity show that CM 2 or CM 3 were considerably better than CM 1, whereas cooking method had no effect after two-step retorting. Therefore, uncomplicated cooking method such as CM 1 or CM 2 are suited for commercial production of RPs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.537-543
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• 2014

Three different granule powders of Citrus Hallabong were prepared with different ratios of fresh juice and citric acid (J10C3=10.0:3.08, J08C4=8.75:4.33, J07C5=7.5:5.58) at fixed quantities of juice powder (70%), pressed cake powder (10%), and additives (6.92%), and their physicochemical properties were measured and compared with targeted commercial product (CP). The moisture content of Hallabong granules (HG) was 5.08~5.44% (w/w), which was two times higher than that of CP. Titratable acidities increased with higher citric acid content and were 1.7~2.3 times lower in HG compared to that of CP. Soluble solids of HG increased with higher citrus juice content ($90{\sim}98^{\circ}Brix$) and were slightly lower than that of CP. Vitamin C contents of HG increased with higher citrus juice content and were 5.8~7.6 times lower than that of CP. In terms of color difference, L and b values of HG were higher while a value was lower than those of CP. Bulk and compaction densities of HG were 0.541~0.660 g/mL and 0.561~0.689 g/mL, respectively and were similar to those of CP. Water solubility and swelling capacity were 66.6~72.0% and 3.84~6.40 g/g, respectively, and were similar to those of CP. Hygroscopicity of HG after an hour of elapsed time was 1.6~1.8 times higher than that of CP. Sensory evaluation test showed that color, sweetness, and overall acceptance of HG were not significantly different from those of CP, whereas flavor and bitterness of HG were lower than those of CP. In conclusion, convenient food granules could be made with Citrus Hallabong juice and pressed cake, which is similar to the commercial product.

• Korean journal of food and cookery science
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• v.26 no.1
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• pp.88-94
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• 2010

This study was carried out to investigate the total polyphenol and flavonoid contents and antioxidative activities of the methanol extracts of Citrus sunki, C. unshiu and C. natsudaidai peels before and after drying. Total polyphenolic content was high in the citrus peels before drying compared to the dried peels, and highest in the order of C. sunki, C. natsudaidai and C. unchiu. On the other hand, flavonoid content was high in the dried citrus peels than in the citrus peels before drying, and was highest in the order of C. unshiu, C. natsudaidai, C. sunki, but in dried peels it was highest in the order of C. natsudaidai, C. unshiu, C. sunki. DPPH radical scavenging activity was highest in the order of C. natsudaidai, C. unchiu, C. sunki, and that in the citrus peels before drying was higher than in the dried peels. Inparticular, C. natsudaidai peels before drying showed higher activity than vitamin C in 0.5 or 1.0 mg/100 g. Hydrogen peroxide scavenging activity was highest in the order of C. unshiu, C. natsudaidai, and C. sunki in the citrus peels before drying. The dried peels were highest in the order of C. unshiu, C. natsudaidai, C. sunki at 0.5 mg/100 g, but high in order of C. natsudaidai, C. unshiu and C. sunki at more than 1.0 mg/100 g. Inparticular, all C. natsudaidai peels displayed high activity more than 87% at 2.0 mg/100 g. Clear patterns in alkyl radical scavenging activity could not be confirmed in Citrus species whether before or after drying of peels. Hydroxyl radical scavenging activity was highest in the order of C. natsudaidai, C. unshiu and C. sunki but was relatively low compared to the scavenging activity of other activated oxygen species.