• Journal of the Korean Professional Engineers Association
• /
• v.34 no.5
• /
• pp.82-88
• /
• 2001

Mackerel(Scomber japonicus), pacific saury (Cololabis saira) and sardine(Sardinops melanosticta) is widely distributed in coastal seawater of Korea, these fishes are not effective utilization as processing material cause by rapid lipid oxidation and off flavour. This study was attempted to lipid distribution in body section, whole body, meat, viscera, skin and head, and fatty acid composition of the oils obtained from these body section. The content of total lipid of mackerel, pacific saury and sardine were 12.48%, 12.79% and 13.81% respectively, and lipid contents in different body section of mackerel was muscle 2.31%, viscera 3.54%, skin 1.43% and head 5.20%, while in cause of sardine was muscle 4.17%, viscera 3.15%, skin 1.72%, and head4.77%. The major saturated fatty acids of mackerel, pacific saury and sardine oil were C$\_$16:0/(palmitic acid), C$\_$18:0/(stearic acid), C$\_$14:0/(myristic acid), and monoenoic acids was C$\_$18:0/(oleic acid), C$\_$16:1/ (palmitolic acid), C$\_$22:0/(erucic acid) and C$\_$20:1/(gadoleic acid), in cause of polyenoic acid was C$\_$22:6/(DHA, docosahexaenoic acid), C$\_$20:0/(EPA, eicosapentaenoic acid), C$\_$22:4/(behenic acid), C$\_$18:2/(linoleic acid) high quantity in order. When fresh oil extracted from mackerel, pacific saury and sardine was stored for 20 days at 5$\^{C}$, carbonyl and acid value of oil increased with storage day, but peroxide value decreased after 15 days.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.4 no.1
• /
• pp.7-16
• /
• 1994

This study was designed to establish the relationship between airborne trichloroethylene concentrations and total trichloro-compounds and trichloroacetic acid in urine samples of the trichloroethylene exposed workers, to examine if the biological screening value for trichloroacetic acid in urine set by the Ministry of Labor is appropriate, and to suggest a suitable biological screening value for total trichloro-compounds in urine. Seventy male workers from the cleaning, the packing, and the inspcetion areas were selected as the study group and eighty male office workers were chosen as the control group. The results were as follows: 1. The mean values of total trichloro-compounds and trichloroacetic acid in the exposed group ($48.1{\pm}1.5mg/{\ell}$, $19.7{\pm}1.9mg/{\ell}$) were significantly higher than those in the control group($4.3{\pm}1.5mg/{\ell}$, $1.8{\pm}1.2mg/{\ell}$). 2. The airborne tichloroethylene concentrations were significantly related with the concentrations of total trichloro-compounds in urine(r=0.8212) and the concentrations of trichloroacetic acid in urine(r=0.7216). 3. The average trichloroethylene concentrations in the manual cleaning plants and that in the automatic cleaning plants were 40.1 ppm and 7.7 ppm, respectively. The difference between two groups was statistically significant. 4. The geometric mean of 49.6 ppm trichloroethylene concentration was resulted in the $185.4mg/{\ell}$ total trichloro-compounds in urine, and the 50 ppm trichloroethylene concentration was expected to produce $170.4{\pm}28.5mg/{\ell}$ total trichloro-compounds in urine. 5. With the geometric mean of 49.6 ppm trichloroethylene concentration, the corresponding geometric mean concentration of trichloroacetic acid in urine was $74.7mg/{\ell}$. In conclusion, the level of personal exposure to trichloroethylene concentration was significantly correlated with the concentrations of total trichloro-compounds and trichloroacetic acid in urine. Current biological screening value of $75mg/{\ell}$ for trichloroacetic acid in urine set by the Ministry of Labor was thought to be appropriate, and a biological screening value for total trichloro-compounds in urine should be set in the range of $170.4{\pm}28.5mg/{\ell}$ as a reference value for trichoroethylene exposure.

• Journal of Plant Biotechnology
• /
• v.48 no.2
• /
• pp.77-85
• /
• 2021

Hydroponic cultivation, in which crops are grown without soil and are unaffected by the weather, has many advantages over conventional soil cultivation. The crop's growth can be further accelerated by using nutrient solution in place of water. This study investigated the growth and physicochemical properties of hydroponic barley sprouts under various nutrient solution and artificial light treatments. The shoot, root, and total plant length increased over time, with the fastest growth occurring in the nutrient solution and light-emitting diode (LED) treatments. Fresh and dry plant weights were higher in the fluorescent lamp treatment than in the LED treatment. Barley sprout powder color differed slightly by treatment, with the Hunters L value ranging from 50.79 to 53.77; Hunters a value from -6.70 to -4.42; and Hunters b value from 13.35 to 14.76. The Hunters L and Hunters b values were highest in the LED treatment, whereas the Hunters a value was relatively highest in the fluorescent lamp treatment. The total phenol content was higher in the control than in the nutrient solution treatment; however, the total flavonoid content showed the opposite pattern to that of total phenol content, being highest in plants that were grown in nutrient solution. The Trolox equivalent antioxidant capacity (TEAC) was higher in the control group than in the nutrient solution group. The ferric ion reducing antioxidant power (FRAP) was higher in the fluorescent treatment group than in the LED treatment group. The total amino acid composition ranged from 106.82 to 122.63 mg/g dry powder, with the essential amino acid composition ranging from 47.01 to 56.19 mg/g, and non-essential amino acid composition from 67.86 to 77.66 mg/g. The most frequently detected compositional amino acid was aspartic acid, followed by glutamic acid, alanine, leucine, and valine.

• Journal of Nutrition and Health
• /
• v.11 no.3
• /
• pp.25-30
• /
• 1978

A study was planned to evaluate the influence of continual heating at $150{\pm}5^{\circ}C$ and $170{\pm}5^{\circ}C$ respectively upon edible oils for frying the several food. Two kinds of domestic edible oils (Sample A and B) were collected by random sampling from market and in order to estimate deterioration degrees at both temperatures previously mentioned, thiobarbituric acid (TBA) value, acid value (AV), peroxide value (POV) and carbonyl value (CV) were measured at intervals due to its optical density. Those values were examined and compared according to the temperatures and times, and it was concluded as follows: 1) TBA value was rapidly increased until 24 hours in both temperatures and after 1 day its value have shown a slower increase as compared with initial rapid reaction. 2) Acid value and peroxide value of both oils (A & B) used for frying were increased continuously during heating and the changes in these values were dependent on the thermal oxidation, and moreover at low temperature $(150{\pm}5^{\circ}C)$ these values were found to be increased more readily than at high temperature $(170{\pm}5^{\circ}C)$. 3) Carbonyl value of both sample A and B show almost the same increasing rate at either $150{\pm}5^{\circ}C$ or $170{\pm}5^{\circ}C$ in proportion to the heating time. 4) It was found that there were differences between the chemical changes caused by heating sample A and B at high and low temperature.

• Korean journal of food and cookery science
• /
• v.8 no.2
• /
• pp.147-154
• /
• 1992

This study was carried out to investigate the rancidity of deep frying foods (cuttlefish and swetpotato) in Incheon city. The samples were collected from 3 snack corners in market, and at 10, 14 and 18 o'clock. The Acid Value, Peroxide Value and TBA value of the fried products were determined and Sensory Evaluation was also performed. The results are as follows: 1. The range of Acid Value was 0.73~1.91 on cuttlefish and 0.33~1.03 on sweetpotato. There was no significant difference in all samples by times and places. 2. The range of Peroxide Value was 3.26~8.23 on cuttlefish and 3.45~11.63 on sweetptato. There was no significant difference in all samples by times and places. 3. the range of TBA Value was 50.03~132.27 on cuttlefish and 30.63~112.83 on sweetpotato. The TBA Value of the products in department store at 18 o'clock more less than mat at 10 o'clock. 4. The Acid Value and TBA Value of sweetpotato was more less than those of cuttlefish. 5. In sensory evaluation, mere was no significant difference by times but significant difference by places on all items. 1) In greasy taste, the first one among cuttlefish products was mat of department store and last one was market product which was much more greasy taste. Among sweetpotato products, the products of department store and near-college were more less greasy man market product. 2) In flavor and overall quality, the product of department store was better than near-college and market products on all samples, 3) In color, the products of department store and near-college were more light man market products on all samples. 4) There was correlation between color and flavor, and overall quality flavor. The flavor and color of products have the effect on the overall quality of products.

• Journal of the East Asian Society of Dietary Life
• /
• v.3 no.2
• /
• pp.147-153
• /
• 1993

Phenolics as antioxidant were added to linoleic acid to prevent lipid oxidation. Antioxidative effectiveness of them was measured by peroxie value at each 24hour interval in order to compare with 0.02% protocatechuic acid(PRL) and phloroglucinol(PHL) in linloleic acid, contrast tube at 37$^{\circ}C$for 96 hours blowing oxygen into specimen. Perocide values of oxidized linoleic acid, PRL, PHL for 96 hours were 78, 42, 30, From that the effect is more clearly demonstrated by NMR rather than UV and that the effect was dependent on the functional group and geometric molecular structure of phenolics.

• Korean journal of food and cookery science
• /
• v.11 no.1
• /
• pp.37-43
• /
• 1995

Effect of the pretreatment with acetic acid(0.01%, 0.05%, 0.1%) on the fermentation of Chinese cabbage Kimchi, and differences in the degree of maturity between Chinese cabbage blades and midribs were observed. To estimate the degree of maturity, correlation analysis was used with several variables such as pH, titratable acidity, volatile acidity, ascorbic acid content, resazurin test value and pH/acidity ratio. Based on the pH and titratable acidity, the degree of maturity of Chinese cabbage midribs fermented at 10$^{\circ}C$ until the optimum stage of fermentation increased more rapidly than those of the blades. The stage of maturity of Kimchi pretreated with 0.01% acetic acid were slightly prolonged, compared to those pretreated with acetic acid at the higher levels. The pH of Chinese cabbage midribs and blades pretreated with acetic acid was lower than those of control between 2nd and l0th day of fermentation. The volatile acidity of Chinese cabbage midribs and blades increased proportionally with the concentration of acetic acid. The ascorbic acid contents of Chinese cabbage midribs showed higher than those of Chinese cabbage blades. During the fermentation, the higher concentration of acetic acid was used, the less ascorbic acid content was remained. The pH/acidity ratio, volatile acidity, ascorbic acid content and resazurin test value of Chinese cabbage midribs and blades during Kimchi fermentation at 10$^{\circ}C$ showed good correlations with the pH and titratable acidity.

• Journal of Life Science
• /
• v.16 no.3 s.76
• /
• pp.427-432
• /
• 2006

The possibility of citron seed oil for use as food resources of fats was tested by analyzing the composition of fatty acid and oxidative stability. Oil yield from citron seed was 55.4% in without roasting and 56.8% with roasting. Total mineral content in citron seed without and with roasting were 2,820.33 mg/kg, 1,702.55 mg/kg, respectively. For all citron seed oils tested, the potassium content was found to be the highest among four kinds of minerals detected in this study. Further, major fatty acids detected in the citron seed oils were linoleic acid, oleic acid and palmitic acid. Their relative contents with respect to total fatty acid contents were 77.12% in without roasting and 67.67% in with roasting. This result indicated that roasting the citron seed decreased the acid contents. However, POV (peroxide value) and acid value of citron seed oils were in,.eased significantly with increasing the storage days and heating time. In details, POV was $84.17{\pm}1.68meq/kg$ in without roasting and $76.46{\pm}1.19meq/kg$ with roasting, after 28 days. Acid value was $9.52{\pm}0.27mg\;KOH/g,\;8.35{\pm}0.09mg\;KOH/g$, respectively, After the 48 hours heating at $180^{\circ}C$, POV of citron seed oils was increased by 3.8 times, irrespective of roasting. Yet, acid value increased dramatically 8.3 in without and 6.4 times with roasting, exhibiting its dependence on roasting. During storage time, oxidative stability of citron seed oils was higher than heating.

• Preventive Nutrition and Food Science
• /
• v.14 no.4
• /
• pp.354-357
• /
• 2009

Three compounds, vanillic acid, p-hydroxylcinnamic acid, p-hydroxybenzaldehyde have been isolated from the ethylacetate extract of Sparganium stoloniferum Buch.-Ham roots using silica gel open column chromatography, preparative thin-layer chromatography (pTLC) and reverse phase high performance liquid chromatography. The structures of the compounds were established on the basis of IR, extensive 1D NMR, and MS analyses. The ethylacetate (EtOAc) extract, vanillic acid, and p-hydroxybenzaldehyde showed $\alpha$-glucosidase inhibition activity of 72.71%, 20.13%, and 30.42%, at the concentration of 10 ${\mu}g/mL$, respectively. The EtOAc extract exhibited strong antioxidant activity with an $IC_50$ value of 24.37 ${\mu}g/mL$ against DPPH radical scavenging activity, the vanillic acid, p-hydroxylcinnamic acid, and p-hydroxybenzaldehyde with an $IC_50$ value of 2.10 ${\mu}M$, 1.59 ${\mu}M$, and 2.72 ${\mu}M$ against DPPH, respectively.

• Korean Journal of Agricultural Science
• /
• v.45 no.3
• /
• pp.379-384
• /
• 2018

In this study, we analyzed the amino acid contents of corn to provide basic data for promoting the use of proteins in livestock. The present study was done to examine the amino acid contents of the corn 'Gwangpyungok' grown in a natural field at the National Institute of Animal Science, Cheonan province, Korea, in 2016. Gwangpyungok, which is Korean corn cultivar, was used as the sample to provide basic data for promoting the use of proteins in livestock by analyzing the amino acid contents of each part of corn as a breed that is adaptable to the environment of Korea. The asparagine acid content was the highest in the leaf blade among the parts of corn, and the glutamic acid content was the highest in the corn ear, stem, leaf sheath, corn bract and inflorescence. The essential amino acids in the corn ear, leaf blade and inflorescence revealed that their contents were in the following order: leucine > phenylalanine > valine > threonine > lysine > isoleucine, and in the inflorescences and stem, leaf sheath and corn bract, their contents were in following order: leucine > valine > phenylalanine > threonine > lysine > isoleucine. Therefore, further research on the nutritional aspects of forage must be performed because livestock growth is influenced by the nutritive value of the various parts of forage.