• Weed & Turfgrass Science
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• v.4 no.4
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• pp.308-314
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• 2015

This study was conducted to establish a fluorescence assay system for high efficient mass screening of the herbicides causing rapid membrane peroxidation, based on the fact that peroxide in cellular leakage could be fluorometrically determined through the fuorescent compounds formed after reacting with homovanillic acid (HVA) and peroxidase (HRP). The assay procesure established in this study was as follows. Only single disc (4 mm diameter) excised from cucumber cotyledon is placed on the well containing test solution ($200{\mu}L$) with 96-well microplate. The plate is shaking-incubated for 8 h under light condition. Then after removing the cucumber disc, HVA and HRP are supplied in the medium buffer and incubated for 5 min at room temperature. Fluorescence values are determined at Ex 320 nm/Ex 425 nm. The higher fluorescence values are obtained in the treatment of chemical having higher herbicidal activity. Using this assay with 96-well microplates, a large number of herbicides inducing rapid membrane peroxidation seemed to be screened more efficiently than spectrophotometric microtiter assay reported previously.

• Korean Journal of Food Science and Technology
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• v.10 no.3
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• pp.320-330
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• 1978

Riced dehydrated potato granules with a good reconstituton quality was made from Irish Cobber (IC) and Shimabara which are representative varieties in Korea. A part of IC potato granules was packed in small vinyl-bags while the rest, including some BHA (75ppm)-treated granules, was packed in $301{\times}407$ plain tin cans. These granules were stored in a room at room temperature, and their physico-chemical properties and lipid composition were studied. The color of the granules was measured with a Hunter-type Tristimules colorimeter. L, $a_L,$ and $b_L-values$ were respectively 83.8, -1.1 and 18.3. Variety and package-type did not affect the color. In general, it was darker than that of commercial wheat flour, but whiter than that of commercial defatted soy flour. At $100^{\circ}C$, the granules, irrespective of variety and package-type, absorbed water rapidly, and reached the maximum moisture content of $90{\sim}92%$ in 3 min., whereas they absorbed water more slowly at $8{\sim}14^{\circ}C$, and reached the maximum content of $72{\sim}74%$ in 5 minutes. Peroxide, TBA, carbonyl, acid, and iodine values of the granules after 3 months storage were respetively $150{\sim}460\;meq/kg,\;20{\sim}26,\;154{\sim}380$ micromole, $24{\sim}59,\;and\;70{\sim}78$. Except iodine values, all the chemical values were affected by variety and package-type. Ether and $CHCl_3-extracts$ of the granules from IC and Shimabara were subjected to GLC and TLC analyses. In case of IC, the major fatty acids were palmitic, stearic, and oleic (30.0, 18.8, 40.6), while in case of Shimabara they were palmitic, oleic, and linoleic acids (26.7, 39.6, 23.4%). The major lipid classes were, in both cases, triglycerides and phospholipids. Their contents were raspectively 19.1 and 43.1 (IC), and 30.1 and 37.4% (Shimabara).

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.435-441
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• 2017

The present study was carried out to evaluate the applicability of Tenebrio molitor larvae (mealworm) as a health functional food material in order to contribute to the development of the domestic insect industry and health functional food industry. Protein hydrolysates were prepared from mealworm powder by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain), and the hydrolysates were then tested for their antioxidant activities. Based on available amino group contents and sodium dodecyl sulphate-polyacrylamide gel electrophoresis analyses, mealworms treated with alcalase ($4,781.39{\mu}g/mL$), flavourzyme ($5,429.35{\mu}g/mL$), or neutrase ($3,155.55{\mu}g/mL$) for 24 h showed high degree of hydrolysis (HD) value, whereas HD values of bromelain ($1,800{\mu}g/mL$) and papain-treated ($1,782.61{\mu}g/mL$) mealworms were much lower. Protein hydrolysates showing high HD values were further separated into > 3 kDa and ${\leq}3kDa$ fractions by a centrifugal filter system and then lyophilized, and the production yields of the low molecular weight protein hydrolysates (${\leq}3kDa$) by alcalase, flavourzyme, and neutrase were 42.05%, 26.27%, and 30.01%, respectively. According to the RC_{50} values of the protein hydrolysates (${\leq}3kDa$) obtained from three different antioxidant analyses, all three hydrolysates showed similar antioxidant activities. Thus, alcalase hydrolysates showing the highest production yield of low molecular weight protein hydrolysates were further tested for their inhibitory effects on peroxidation of linoleic acid by measuring thiobarbituric acid values, and the results show that peroxidation of untreated linoleic acid increased dramatically during 6 days of incubation. However, pretreatment with the hydrolysates ($100{\sim}800{\mu}g/mL$) significantly inhibited linoleic acid peroxidation in a dose-dependent manner over 6 days.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.452-458
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• 2010

This study aimed at improving the packaging technology of Yukwa to improve the quality and extend the shelflife using secondary packaging. After packaging the Yukwa using an OPP film, P2, P3, and P4 packaging materials were applied secondarily. Various films including (1) P1: OPP (oriented polypropylene), (2) P2: P1+OPP/LLDPE (linear low density polyethylene), (3) P3: P1+PET (polyethylene terephthalate)/NY (nylon)/CPP (cast polypropylene) and (4) P4: P1+PET/AL (aluminum)/NY/CPP (P4) were used for packaging Yukwa. The experiment was conducted at $25^{\circ}C$ for 12 weeks. P1 showed the highest acid value score (1.26 mg KOH/g), and P3 had the highest peroxide value score (32.91 meq/kg) among all packaging groups. Nevertheless, these values did not exceed the guideline values of 2.0 g KOH/g and 40 meq/kg specified in the Korean food code. The overall color difference showed a tendency for decreasing Hunter 'L' values and increasing 'a' and 'b' values; however, no noticeable difference in the outer appearance was observed in any of the packaging treatments except in the P1 for greater than 10 weeks of storage. Some texture defects were observed in the Yukwa when the moisture contents dropped below 5%. The P4 packaging treatment had the lowest moisture permeability and showed the least rheological deterioration change, followed by P3 and P2. In conclusion, the use of a secondary packaging with less gas and moisture permeability was more effective for maintaining the quality and extending the shelf-life of Yukwa than other types of packaging material.

• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.379-390
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• 1997

Background : It has long been suggested that neutrophils and their products are implicated as the central mediators of the acute lung injuries. Contrary to the dominant role of neutrophils in ARDS, many cases of ARDS has occurred in the setting of severe neutropenia without pulmonary neutrophil infiltration. Therefore it is certain that effector cell(s) other than neutrophil play an important role in the pathogenesis of ARDS. This experiment was performed to define the mechanism of ARDS in the setting of neutropenia, 1) by comparing the severity of endotoxin-induced lung injury, 2) by measurement of hydrogen peroxide production and cytokine concentration in the bronchoalveolar lavage cells and fluids obtained from different rats with and without cyclophosphamide-pretreatment. Method : The male Sprague-Dawleys were divided into the normal control (NC)-, endotoxin (ETX)-, and cyclophosphamide (CPA)-group in which neutropenia was induced by injecting cyclophosphamide intraperitoneally. Acute lung injury was evoked by injecting lipopolysaccharide (LPS) into a tail vein. The bronchoalveolar lavage (BAL) was performed at 3 and 6 hour after administration of LPS to measure the change of cell counts and concentrations of protein and cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Hydrogen peroxide (HPO) production from BAL cells was measured at 6 hour after LPS administration by phenol red microassay with and without zymosan stimulation. Results : The results were as follows. A change of leukocyte counts in the peripheral blood after treatment with CPA : More than 95% of total leukocytes and neutrophils were reduced after CPA administration, resulting in severe neutropenia. A change of BAL cells : In the ETX-group, the number of total cells (p < 0.01) and of macrophage and neutrophil (p < 0.05) were increased at 3 and 6 hour after LPS administration compared to those of NC-group. In the CPA-group, the number of total leukocyte and macrophage were not changed after LPS administration, but neutrophil counts were significantly reduced and it took part in less than 0.1% of total BAL cells (p < 0.01 vs NC-group). BAL cells in this group were almost all macrophages (99.7%). A change of protein concentration in the BALF : In the ETX-group, protein concentration was increased at 3 hour and was more increased at 6 hour after LPS administration (p < 0.05 and < 0.01 vs NC-group, respectively). In the CPA-group, it was also significantly elevated at 3 hour after LPS administration (p < 0.05 vs NC-group), but the value was statistically not different from that of ETX-group. The value measured at 6 hour after LPS administration in the CPA-group became lower than that of ETX-group (p < 0.05), but showed still a higher value compared to that of NC-group (p < 0.05). A change of cytokine concentration in the BALF : TNF -alpha and IL-6 were elevated in the ETX - and CPA-group compared to those of NC-group at both time intervals. There was no statistical difference in the values of both cytokines between the ETX- and CPA-groups. Measurement of hydrogen peroxide production from BAL cells : There was no intergroup difference of HPO production from resting cells. HPO production after incubation with opsonized zymosan was significantly elevated in all groups. The percent increment of HPO production was highest in the ETX-group (89.0%, p < 0.0008 vs NC-group), and was 42.85 in the CPA-group (p = 0.003 vs NC-group ). Conclusion : Acute lung injury in the setting of neutropenia might be caused by functional activation of resident alveolar macrophages.

• Journal of the Korean Home Economics Association
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• v.29 no.4
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• pp.25-35
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• 1991

This study was carried out to determine the proximate composition, amino acids and fatty acids contents and changes of physicochemical characteristics of each oil extracted from Spanish and Virginia type peanuts grown in Korea roasted at 110, 120, 130 and 14$0^{\circ}C$ for 2 minutes. 1. The moisture contents of raw Spanish and Virginia type peanuts were 6.5~6.8% respectively. The crude ash and reduced sugar contents of raw Spanish and Virginia type peanuts were 2.3% and 16.5% and the crude protein content was 27.0% in Spanish type peanuts and was aproximately 1% higher than in Virginia type peanut. The protein content was 25.7%~26.7% in Virginia type peanut roasted at 110, 120, 130 and 14$0^{\circ}C$. The crude fat content of Virginia type peanut was 46.0% which was aproximately 1% higher than that of Spanish type. But four kinds of oils content were 51.3%~51.8% in Spanish type peanut roasted at 110, 120, 130 and 14$0^{\circ}C$, which was about 2% higher than those of Virginia type. 2. Amino acids existed in peanut were glutamie acid, arginine, aspartic acid, leucine, glycine, phenylalanine, proline-lysine, tyrosine, valine and isoleucine, etc mainly. But methionine and threonine contents were very low. The content of glutamic acid was the highest in 71.6-81.7mg among amino acids. Glutamic acid content of Virginia type peanut was about 12% higher than that of Spanish type peanut. Total amino acid content was 441.8mg/g in Virginia type peanut and that was 16% higher than that of Spanish type peanut. The lysine content of Spanish and Virginia type peanuts roasted at 14$0^{\circ}C$ were 24% and 13%, these were lower than those of peanuts roasted at 11$0^{\circ}C$. 3. Main fatty acids of raw Spanish and Virginia type peanut oils were oleic(40.99-46.58%), linoleic(33.21-38.82%) and palmitic acid(9.72-11.58). Linoleic acid content of raw Virginia type peanuts was 5.6% higher than that of raw Spanish type peanut. And the oleic acid content of Spanish and Virginia type peanuts roasted at 11$0^{\circ}C$, 12$0^{\circ}C$, 13$0^{\circ}C$ and 14$0^{\circ}C$ was 50-53% and 41-43% respectively. Linoleic acid content of Spanish and Virginia type peanuts roasted at same temperatures as the former was about 28-31% and 37-38% respectively. That linoleic acid content of roasted peanuts was lower than that of raw peanuts. Linoleic acid content of raw and roasted Virginia type peanut, were higher than that of Spanish type peanuts. 4. Acid value and peroxide value of oils extracted from roasted Spanish and Virginia type peanuts were much higher than those of oils extracted from raw peanuts. The maximum AVs of oils extracted from Spanish and Virginia type roasted peanuts were samples roasted at 12$0^{\circ}C$and those AVs were 0.50 and 0.63 respectively. And the maximum POVs of oils extracted from Spanish and Virginia type roasted peanuts were samples roasted at 12$0^{\circ}C$ also and those POVs were 26.8 and 32.8 meq/kg. oil respectively. Acid value and peroxide value of oils extracted from roasted peanuts were increased with increasing the roasting temperatures from 11$0^{\circ}C$ to 12$0^{\circ}C$, then decreased, while TBA values were increased continuously with increasing the roasting temperatures.

• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.43-50
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• 1975

The antioxidant effects of the alcohol extracts obtained from a Maillard-type and a caramelization-type browning reaction mixtures were determined and compared. The Maillard-type reaction mixtrue contained 0. 2 M glucose and 0. 2 M glycine while the caramelization-type reaction mixture contained only 0. 2 M glucose and both were heated at $100^{\circ}C$. The results obtained are as follows. 1. The color intensity of the Maillard-type reaction mixture appeared to increase in proportion to the length of reaction time. However, the antioxidant activity of the extracts did not seem to increase in proportion to the length of reaction time. The antioxidant activity of the extracts from the reaction mixture heated for 16 hours was not much greater than that of the extracts from reaction mixture heated for 2 hours. 2. The color intensity of the caramelization-type browning reaction appeared to increase in proportion to the length of reaction time. The antioxdant activity of the extracts did not seem to increase in proportion to the length of reaction time. 3. It appeared that the antioxdant effects of the alcohol extracts from the Maillard-type browning reaction mixture were far greater than those from the caramelization-type browning reaction mixture, compared on the basis of the same length of reaction time. Substrates, containing the alcohol extracts of the caramelization reaction mixture taken after 4 and 120 hours, developed peroxide values of 88. 9 and 33. 0 after a 20 day storage period (control, 135. 0) whereas substrates, containing the alcohol extracts of the Maillard-type reaction mixture taken after 1 and 16 hours, developed peroxide value of 9. 5 and 7. 5 after the same storage period.

• Korean Journal of Food Science and Technology
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• v.3 no.3
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• pp.178-184
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• 1971

Samples of refined soybean oil were irradiated with lights from a 20-watt incandescent tungsten lamp, a 20-watt fluorescent daylight type lamp, a 20-watt low-pressure mercury vapor germicidal lamp, and direct sunlight for an experimental period of 147 days. Some samples were stored in a dark room throughout the period as a control. The peroxide values of all samples were measured every week. The induction period of the samples was arbitrarily taken as the time required for the samples to reach a peroxide value of 15. The induction period of the control was estimated at 198 days. Those of the samples irradiated with the incandescent light, the fluorescent light, the ultraviolet light, and the sunlight were estimated at 196, 119, 52 and 6 days, respectively. The sunlight showed by far the strongest prooxidant activity whereas the incandescent light showed the weakest but distinct prooxidant activity. The small temperature differences observed among the various samples throughout the experimental period did not seem to affect the oxidation rates of the irradiated samples in any significant way.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.5
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• pp.812-824
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• 2020

Objective: The aim of this work was to assess the effect of fermented blueberry (FB; 2%, 4%, and 6%) on the oxidative stability and volatile molecule profiles of emulsion-type sausage stored at 4℃ for 28 days. Methods: The antioxidant activity of FB was determined through radical-scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. Four formulations of sausage treatments with different FB levels (0%, 2%, 4%, 6%) were prepared, then peroxide value (POVs), thiobarbituric acid-reactive substances (TBARS) values, protein carbonyls and thiol groups were measured. The aroma profiles of sausages for each treatment was also determined. Results: The half maximal inhibitory concentration indicated that FB had greater scavenging ability than ascorbic acid against DPPH and hydroxyl radicals. Sausages with FB significantly retarded increases in POVs and TBARS, as well as in the content of protein carbonyls during all storage days (p<0.05). Particularly, 4% and 6% FB-treated sausages had better oxidation inhibition effects. However, FB accelerated the reduction in thiol groups (p<0.05). Additionally, FB inhibits the excessive formation of aldehyde compounds; for example, hexanal, which may cause rancid flavors, decreased from 58.25% to 19.41%. FB also created 6 alcohols (i.e., 2-methyl-1-propanol, 3-methyl-1-butanol, and phenylethyl alcohol), 5 ester compounds (i.e., ethyl acetate, ethyl lactate, and ethyl hexanoate) and 3-hydroxy-2-butanone in the sausages that contribute to sausage flavors. The principal component analysis showed that the aroma profiles of sausages with and without FB are easily identified. Conclusion: The addition of FB could significantly reduce the lipid and protein oxidation and improve oxidative stability for storage. Also, adding FB could inhibit rancid flavors and contribute to sausage flavors.

• Journal of Nutrition and Health
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• v.39 no.2
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• pp.91-99
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• 2006

This study was conducted to investigate the effects of mulberry fruit, mulberry leaves and silkworm powder with different mixing ratios on hepatic antioxidative system and lipid metabolism in streptozotocin-induced diabetic rats. Sprague-Dawley male rats weighing $100{\pm}10g$ were induced diabetic by 50 mg/kg bw streptozotocin and randomly assigned to following experimental groups; normal diet group (DM), 0.3% and 0.6% mulberry fruit diet groups (F and 2F), 0.3% mulberry leaves diet group (M), 0.3% silkworm powder diet group (S), 0.15% mulberry fruit+0.15% mulberry leaves diet group (FM), 0.15% mulberry fruit+0.15% silkworm powder diet group (FS), 0.1 % mulberry fruit+0.1 % mulberry leaves+0.1% silkworm powder diet group (FMS). The experimental diets were fed for 4 weeks. Hepatic SOD activity was not changed significantly by any of single or combined supplementations of mulberry fruit, leaves and silkworm powder but GSH-px and catalase activities were increased by the groups supplemented with two or three of the test ingredients (FM, FS, FMS) as compared with the DM group. Hepatic TBARS value was not reduced significantly by any of the supplementations but lipofuscin contents were significantly reduced in the FM, FS and FMS groups as compared with the DM group. Hepatic mitochondria and microsomal carbonyl values were reduced by the single and combined supplementations of the test ingredients. Hepatic HMG-CoA reductase activities were increased in the all supplementation groups as compared with the DM group. Hepatic total lipid and triglyceride contents were increased but cholesterol contents reduced in the supplemented groups. The effects on the enzyme activities, peroxide or its products and lipid contents were most remarkable in the FMS group. In conclusion, mulberry fruit, mulberry leaves and silkworm powder have the favorable effects on antioxidative system and lipid metabolism in the diabetic liver and the mulberry fruit, leaves and silkworm powder with equal ratio exert the synergistic effect expectedly to prevent diabetic complications.