• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.295-304
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• 2011

This study was carried out to investigate the effect of harvest stage of Sorghum ${\times}$ Sorghum Hybrid (SSH) and manufacture methods of SSH silage on nutritive values and quality of SSH silage manufactured with SSH grown in paddy land of Department of Animal Resources Development, National Institute of Animal Science, RDA. SSH "SS405" was harvested at two different growth stages (heading and ripen stage) and ensiled at each harvest stages. The content of crude protein in both square baled SSH silage (SBSS) and bag silage (BS) increased with delayed harvest maturity, but the contents of ADF (acid detergent fiber), NDF (neutral detergent fiber) decreased. The contents of ADF and NDF was not influenced by the inoculation of lactic bacteria. The contents of TDN (total digestible nutrient) in both stage and in vitro dry matter digestibility (IVDMD) in heading stage was not influenced by the harvest stage of SSH. The pH in all SSH silage ranged from 3.8 to 4.4 at two different harvest stages, and pH in heading stage was higher than that of ripen stage (P<0.05). The content of lactic acid of all SSH silage increased with delayed harvest maturity (P<0.05), but the content of acetic acid decreased (P<0.05). The contents of lactic acid and acetic acid in ripen stage were not influenced by manufacture method of silage. The content of lactic acid in both SBSS was higher than that of both BS and RBSS in heading and ripen stage (P<0.05), but the content of acetic acid decreased (P<0.05). The contents of lactic acid and acetic acid in BS were similar as compared to that of RBSS. Therefore, we suggest that the quality of SSH silage in both heading and ripen stage can be improved by manufacture methods of SBSS and BS.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.25-33
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• 2013

Clenbuterol and ractopamine, which are ${\beta}$-agonists, have been misused as a growth promoting agent in meat producing animals. Clenbuterol was banned for veterinary drug in Korea because of its problems regarding safety. Due to their adverse effects, such as cardiovascular and central nervous diseases on human health proper control and monitoring should be conducted. The existing analytical method of clenbuterol and ractopamine in the Food code was improved through our present study. The bovine muscle samples were subjected to enzymatic hydrolysis, extracted with ethyl acetate and defatted by hexane-methanol partitioning. A molecular imprinted polymer (MIP) solid phase extraction cartridge was used for clean-up and LC-MS/MS was operated in positive multiple reaction monitoring (MRM). Clenbuterol-$d_9$ and ractopamine-$d_3$ were used as an internal standard. The renewed method was validated according to the CODEX guideline. The limits of quantitation for clenbuterol and ractopamine were 0.2 and 0.5 ${\mu}g/kg$, respectively. The mean recoveries ranged in 104.2-113.5% for clenbuterol and in 107.6-118.1% for ractopamine. The improved method was able to save both time and expenses.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.493-498
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• 2008

The aim of this work was to analyze the effects of salt and $NaNO_2$ on weight loss, proximate compositions. chemical parameters and texture characteristics of dry-cured ham processed using Korean methods. Four different treatments were considered: The HS group of 3 hams (11.30 kg) was salted with 9.2 g/kg salt (w/w) (high salt batch), the HS+$NaNO_2$ group of 3 hams (10.65 kg) was salted same as HS group and added 100 ppm $NaNO_2$. The LS group of 3 hams (11.42 kg) was salted with 6.2 g/kg salt (w/w) (Low salt batch), the LS+$NaNO_2$ group of 3 hams (10.62 kg) was salted same as LS group and added 100 ppm $NaNO_2$. The highest weight losses took place at the drying stage (27.46, 28.25, 26.99, and 28.42%). However, there were no significant differences in the weight losses between treatments (p>0.05). The moisture content was significantly affected with addition of $NaNO_2$ (p<0.05), the LS hams had significantly higher moisture content than HS+$NaNO_2$ and LS+$NaNO_2$ (p<0.05). The level of salt and $NaNO_2$ did not affect the fat, protein and ash contents. The hardness and chewiness in biceps femoris muscle from LS hams were significantly lower than in the muscles from HS+$NaNO_2$ hams (p<0.05). The $NaNO_2$ did not affect the texture characteristics of dry-cured hams. The processing conditions significantly affected the chemical parameters of biceps femoris muscle (p<0.05). The water activity in biceps femoris muscle from LS hams was significantly higher than in muscles from HS and HS+$NaNO_2$ hams (p<0.05). The salt content in biceps femoris muscles from LS+$NaNO_2$ hams was significantly lower than in the muscles from HS and HS+$NaNO_2$ hams (p<0.05). The $NaNO_2$ treatment did not affect the $NaNO_2$ content in biceps femoris muscles (p>0.05). The processing conditions did not significantly affect the lightness (L), redness (a), and $h^{\circ}$ of biceps femoris muscles (p>0.05). The yellowness (b) and chroma in biceps femoris muscle from HS+$NaNO_2$ hams were significantly higher than in the muscles from HS and LS hams.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1048-1056
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• 2002

Quality of fresh ginger deteriorates rapidly during low temperature storage, and its storage life is short due to sprouting and microbial spoilage. The objectives of this research were to develop, using additives, a minced ginger product, which could maintain acceptable quality for over 30 days, and to investigate its quality changes during the cold storage. Storage stability of minced ginger product was investigated from the standpoint of the inhibition of brown discoloration, gas formation and liquid-solid separation. Fresh ginger was peeled and ground to produce minced ginger (control). Sodium bisulfite, L-cysteine, NaCl, sodium benzoate, modified starch, and/or xanthan gum were added to the control to minimize quality loss during storage, and to develop an optimum formula (A) of minced ginger. Samples were packed in Nylon/PE films, stored at $5^{\circ}C$, sampled at a 30-day interval, and subjected to quality evaluations. Changes in pH, surface color, gas formation, liquid-solid separation, contents of free amino acids, free sugars, organic acids, and fatty acids were determined. Gas formation was effectively inhibited in samples with sodium benzoate and/or NaCl. Samples with xanthan gum did not result in liquid-solid separation. L-Cysteine and sodium bisulfite were effective in controlling discoloration. pH decreased during storage in all samples, except sample A. Organic acid contents of all samples increased during storage, with lactic acid content showing the highest increase. Free amino acid content decreased with increasing storage time. Free sugar content of all samples decreased during storage. Sensory results showed sample A maintained acceptable quality until 90 days of storage. These results suggest that quality of minced ginger could be successfully maintained with the additions of selected additives for up to 90 days.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.333-339
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• 2009

This study was done to determine if there is any difference in microleakage between experimental composite resins, in which various proportions of three component photoinitiators (Camphoroquinone, OPPI, Amine) were included. Four kinds of experimental composite resin were made by mixing 3.2% silanated barium glass (78 wt.%, average size; 1 ${\mu}m$) with each monomer system including variously proportioned photoinitiator systems used for photoinitiating BisGMA/BisEMA/TEGDMA monomer blend (37.5:37.5:25 wt.%). The weight percentage of each component were as follows (in sequence Camphoroquinone, OPPI, Amine): Group A - 0.5%, 0%, 1% / Group B - 2%, 0.2%, 2% / Group C - 0.2%, 1%, 0.2% / Group D - 1%, 1%, 2%. Each composite resin was used as a filling material for round class V cavities (diameter: 2/3 of mesiodistal width; depth: 1.5 mm) made on extracted human premolars and they were polymerized using curing light unit (XL 2500, 3M ESPE) for 40 s with an intensity of 600 mW/$cm^2$. Teeth were thermocycled fivehundred times between $50^{\circ}C$and $550^{\circ}C$for 30s at each temperature. Electrical conductivity (${\mu}A$) was recorded two times (just after thermocycling and after three-month storage in saline solution) by electrochemical method. Microleakage scores of each group according to evaluation time were as follows [Group: at first record / at second record; unit (${\mu}A$)]: A: 3.80 (0.69) / 13.22 (4.48), B: 3.42 (1.33) / 18.84 (5.53), C: 4.18 (2.55) / 28.08 (7.75), D: 4.12 (1.86) / 7.41 (3.41). Just after thermocycling, there was no difference in microleakage between groups, however, group C showed the largest score after three-month storage. Although there seems to be no difference in microleakage between groups just after thermocycling, composite resin with highly concentrated initiation system or classical design (Camphoroquinone and Amine system) would be more desirable for minimizing microleakage after three-month storage.

• Resources Recycling
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• v.17 no.1
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• pp.80-87
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• 2008

Cementation and solvent extraction processes were studied to separate nickel and iron ions from the $H_2SO_4$ leaching solution with 47 g/L $Fe(Fe^{2+}/Fe^{3+}=1.03),$, 23.5 g/L Ni and 0.90M $H_2SO_4$ which leached from Fe-Ni alloy. Iron powder was used as a reducing agent for the cementation of Ni ion from the leaching solution. The reduction percentage of Ni ion was $17{\sim}20%$ by adding 4 times stoichiometric amount of iron powder at $60{\sim}80$. This may result from the fact that the cementation of Ni ion occurred after the reduction of $Fe^{3+}$ to $Fe^{2+}$ and the neutralization of $H_2SO_4$ with iron powder. The cementation process was proved to be unfeasible for the separation/recovery of Ni ion from the leaching solution including $Fe^{3+}$ as a major component. $Fe^{2+}$ present in the leaching solution was converted to $Fe^{3+}$ for solvent extraction of Fe ion using D2EHPA in kerosene as a extractant. The oxidation of $Fe^{2+}$ to $Fe^{3+}$ was completed by the addition of 1.2 times stoichiometric amount of 35% $H_2SO_4$. 99.6% $Fe^{3+}$ was extracted from the leaching solution (23.5 g/L $Fe^{3+}$) by 4 stages cross-current extraction using 20 vol.% D2EHPA in kerosene. $NiSO_4$ solution with 98.5% purity was recovered from the $H_2SO_4$ leaching solution of scrapped Fe-Ni alloy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.913-920
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• 2001

The effect of kimchi pill supplementation on plasma lipid concentration of middle aged healthy people were studied. Freeze-dried mustard leaf added (30%) Korean cabbage kimchi and powdered glutinous parch were used to prepare kimchi and placebo pill, respectively. Experimental group if six participants took 3 g of freeze-dried kimchi as a pill daily for 6 weeks which is equivalent to 30 g of fresh kimchi and control group of six people took same amount of placebo. The diet intakes for the kimchi and placebo group fairly remained unchanged during 6 weeks of trial. When the effect of kimchi pill supplementation was expressed as average percentage changes based on each individual changes, the plasma triglyceride concentration of kimchi pill group was sig-nificantly decreased by 16.8% during trial (p<0.05)while that of placebo group increased by 9.8%, But no changes in plasma and LDL cholesterol concentrations of both groups were observed. HDL cholesterol of kimchi pill group significantly increased by 11.7%(p<0.05), therefore the ratio LDL/HDL cholesterol was significantly decreased by 6.7%(p<0.05) while that for the placebo group increased. The atherogenic index at the kimchi group was also significantly decreased by 10.8%(p<0.05). Kimchi supplementation seemed to have beneficial effects on controlling plasma triglyceride and HDL cholesterol in middle aged men.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1245-1250
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• 2006

This study was carried out to develop the method of preparing lecithin-fortified ginseng extract. Firstly, soybean lecithin was mixed with soybean oil (LCS) in varying ratio (2.5%, 5%, 10% and 20%). Then, one part volume of LCS was mixed with three parts volume of ginseng extract with 10% solid matter content and the mixture was vortexed vigorously. Finally, the mixture was spinned at the speed of 3,000 rpm for 30 minutes to separate oil and aqueous ginseng extract layer (AG). AG was then subjected to qualitative and quantitative analysis of phospholipids and ginsenosides. Fatty acid composition and crude fat content before and after LCS was determined. Stability of lecithin in ginseng extract was determined by analyzing phospholipid content in the one third upper and lower layer of the concentrated AG in Falcon tubes while storing the LCS treated concentrated AG in 4, 25 and 40oC for 6 months. Ratio of lecithin transferred to AG increased with the increase in lecithin content of soybean oil. There was no significant change in fatty acid composition and crude fat content, and ginsenoside content in the ginseng extract before and after LCS treatment. TLC and HPLC pattern of saponin fraction before and after treating the ginseng extract with LCS demonstrated no observable difference. There was no change in lecithin content in the upper and lower one third layer of ginseng extract in the tubes after storing the concentrated AG in 4, 25 and $40^{\circ}C$ for 6 months. Ginsenosides HPLC pattern was not changed when stored the LCS-treated ginseng extract in those conditions for six months, indicating satisfiable stability of the LCS-treated concentrated ginseng extract. From these results, it can be concluded that treatment of the ginseng extract with lecithin containing soybean oil is a labor effective method with satisfiable stability to fortify lecithins to ginseng extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.85-88
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• 2015

This study attempted to establish an HPLC analysis method for determination of marker compounds as a part of material standardization for the development of health functional food materials from Perilla frutescens Britton var. acuta Kudo. The quantitative determination method of rosmarinic acid as a marker compound of P. frutescens Britton var. acuta Kudo extract (PFE) was optimized by HPLC analysis using a C18 column ($4.6{\times}150mm$, $5{\mu}m$) with 0.1% acetic acid as the elution gradient and methanol as the mobile phase at a flow rate of 1 mL/min and detection wavelength of 280 nm. The HPLC/UV method was applied successfully to quantification of the marker compound in PFE after validation of the method with linearity, accuracy, and precision. The method showed high linearity in the calibration curve at a coefficient of correlation ($R^2$) of 0.9995, and the limit of detection and limit of quantitation were $0.36{\mu}g/mL$ and $1.2{\mu}g/mL$, respectively. Relative standard deviation (RSD) values of data from intra- and inter-day precision were less than 3.21% and 1.43%, respectively. Recovery rate test at rosmarinic acid concentrations of 12.5, 25 and $50{\mu}g/mL$ scored between 97.04~98.98% with RSD values from 0.25~1.97%. These results indicate that the established HPLC method is very useful for the determination of marker compound in PFE to develop a health functional material.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.480-485
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• 2019

The present study was conducted to compare antioxidant capacities of protein hydrolysates from four different edible insects (Protaetia brevitarsis larvae, Allomyrina dichotoma larvae, Gryllus bimaculatus imago, and Tenebrio molitor larvae) which have recently been registered as food varieties in Korea. Protein hydrolysates were prepared from each insect using enzymatic hydrolysis using alcalase, and were then separated into a fraction containing ${\leq}3kDa$. According to $RC_{50}$ values and trolox equivalent antioxidant capacity results obtained from five different antioxidant analyses, the Gryllus bimaculatus (GB) hydrolysate showed relatively high levels of antioxidant capacity and, in particular, the GB hydrolysate showed considerably strong antioxidant activities in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and in ferric reducing antioxidant power (FRAP) assays. The GB hydrolysate also showed the strongest inhibitory effect on peroxidation of linoleic acid, and its rate of inhibition at $100{\mu}g/mL$ on day 3 of treatment was 60.26%. These results suggest that protein hydrolysates from edible insects including GB represent potential sources of natural antioxidants.