• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.307-311
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• 2005

본 연구는 동결농축유의 미량성분을 분석하고 관능적 특성을 알아보기 위하여 실시하였다. 농축유의 수용성비타민은 동결농축유가 진공농축유보다 비타민의 감소율이 적었고, 같은 동결농축유의 경우에 17% 고형분인 농축유가 27% 고형분인 농축유보다 비타민의 감소율이 적었다. 지용성비타민도 동결농축유가 진공농축유보다 비타민 감소율이 적었으며, 수용성비타민 보다는 그 감소율이 크지 않았다. 유리아미노산은 진공농축유보다 동결농축유에서 많이 측정되었고 단쇄유리지방산은 진공농축유가 동결농축유보다 생성량이 많았으며 고형분이 많을수록 많이 측정되었다. 지방산화도는 단쇄유리지방산의 결과와 같이 동결농축유보다 진공농축유가 더 높게 측정되었다. 관능검사는 cooked flavor, oxidized flavor, cheesy flavor, fat-taste, oxidized taste, off-taste에서 동결농축유가 진공농축유보다 양호하게 평가되었다. 결과적으로 동결농축유가 진공농축유보다 미량성분의 손실이 적고 관능적으로 양호하게 평가되었기 때문에 영양학적, 관능적으로 우수하다고 사료된다.

• The Korean Journal of Food And Nutrition
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• v.30 no.1
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• pp.139-147
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• 2017

The objective of this study was to develop anti-browning agents for commercial ready-to-eat pear products, which are preferred not only to maintain the flavor, color and texture of pears, but also to increase consumers' preference. The sliced 'Shin-go (Niitaka)' pears were immersed in 5% and 10% oxidized starch, 1% citric acid, and 5% and 10% oxidized starch with addition of 0.1% sucralose for 3 minutes, and then they were packaged in vacuum sealed bags at $1^{\circ}C$ for 9 days. In order to evaluate the quality of packaged sliced pears, the quality index was determined in terms of color, firmness, soluble solids, and sensory quality. With the passage of storage time, no specific variation in firmness and soluble solids was observed. However, the ${\Delta}E$ value of the sliced pears treated with 5% oxidized starch solution was significantly lower than that of the other pears. Also, the Hunter L and b values of the sliced pears treated with 5% oxidized starch solution remained nearly constant from the beginning of storage. This observation shows that 5% oxidized starch solution was effective in reducing surface browning of sliced pears. Moreover, sliced pears treated with oxidized starch solution with addition of 0.1% sucralose were given an overall liking score which was slightly higher than that given to the other pears because of the sweetness of sucralose. In conclusion, 5% oxidized starch solution with addition of 0.1% sucralose was effective in reducing browning of sliced pears and in improving the taste of sliced pears.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.189-195
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• 2014

Headspace volatile compounds of cold-stored and freeze-dried Krill Eupausia superba were analyzed to investigate their flavor qualities using a system combining a dynamic headspace isolator, an automatic thermal desorber, and a gas chromatograph-mass-selective detector. Levels of oxidation products of polyunsaturated fatty acids such as aldehydes, alcohols, and ketones, which are known to give seafood a nasty smell because of their low flavor threshold values, increased during cold storage of krill. Notably, levels of 2-methylpropanal, 3-methylbutanal, 2-methylbutanal and 2-butanone increased during its storage. They can be considered index compounds of off-odor according to freshness degradation during storage. By contrast, in freeze-dried krill powder, levels of aldehydes, ketones, and aromatic compounds decreased rapidly. Only alcohols, which did not greatly affect the food flavor, were isolated in large amounts. It was confirmed that levels of oxidized compounds of krill increased during cold storage, but decreased in freeze-dried krill.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.359-365
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• 2003

Headspace solid-phase microextraction(HS-SPME) was used to isolate the off-flavor volatile compounds, which are formed during the oxidation of porcine liver and unsaturated fatty acids in porcine liver induced by iron. Three fibers for HS-SPME method development were tested, and the polydimethylsiloxane/divinylbenzene(PDMS/DVB) fiber was selected as providing the best detection of analyzed compounds. In the oxidized arachidonic acid, the major compounds identified were hexanal, 1-octen-3-one(metallic), (Z)-4-heptenal, (E)-2-octenal, 1-octen-3-ol(mushroom), (Z)-2-nonenal (cardboard-like), and (E,E)-2,4-decadienal(fatty, oily). In the oxidized linolenic acid, the major ones were (E,E)-2,4-heptadienal(fishy), (E,E)-3,5-octadien-2-one and (E,Z)-2,6-nonadienal. Moreover, those of th oxidized porcine liver with iron were hexanal, 1-octen-3-one, (Z)-4-heptenal, (E,Z)-2,4-decadienal and (E,E)-2,4-decadienal. These results showed that the fishy and metallic off-flavor in porcine liver were due to the oxidation of unsaturated fatty acids in porcine liver.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.407-415
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• 1993

Sesame seeds were roasted for 30, 60, 90, and 120 min at different temperatures (100, 200, and $300^{\circ}C$) and extracted to investigate an adequate condition for producing the high quality sesame oil. Sesame seeds roasted at $200^{\circ}C$ for 90 min gave the high yield of oil. The oil contained the low content of brownish-black precipitates and exhibited an excellent organoleptic quality when judged by descriptive sensory analysis. Thirty one volatile flavor compounds, which are the largest number of volatiles among the oil samples prepared, were identified from the oil sample. The oil contained relatively high concentrations of furfurals (sweet candy-like flavor) and pyrazines (roasted-like flavor), that are considered as good contributors to sesame seed oil flavor, and low concentations of aldehydes $(C5{\sim}C10)$ and ketones, which are considerd as bad contributors (oxidized fat-like and painty-like flavors). These results suggest that the roasting condition of $200^{\circ}C$ for 90 min was the best for the oil production in terms of the overall aroma and taste quality under the test conditions (Received July 13, 1993; accepted November 4, 1993).

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.731-737
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• 1992

The specific attributes of aroma quality of canned tuna meat were investigated before and during refrigerated storage. Fresh, cooked tuna, beefy and meaty flavor notes of canned tuna meat were changed to card-boardy(1 week storage), oxidized fat-like(2 weeks storage), fatty acid-like and heavy oxidized fat-like(3 weeks storage), and then moldy and painty(4 weeks storage) flavor notes during storage in refrigerator at $4^{\circ}C.$ More than 126 peaks of volatile compounds collected from canned tuna meat were separated on Carbowax 20M capillary column of gas chromatographic analysis. Of the peaks, 54 compounds were identified by mass spectral data, matching $I_E$ values, and sniffing the effluent of each peak from GC detector. The contents of many low molecular weight compounds eluted with early retention times were decreased, whereas some other new compounds eluted with longer retention time were formed during storage. The compounds increased up to 3 weeks of storage and then decreased at extended storage time(4 weeks) were 1-penten-3-ol, 3-penten-2-ol, heptanal, limonene, 1-pentanol, octanal, 1-hexanol, nonanal, 2-octanone, 2-nonanone, 1-heptanol, benzaldehytde and some methyl substituted benzenes. p-Thiocresol, 2-chlorophenol, and 2-heptylthiophene were formed after 4 weeks of storage, but not detected in fresh canned tuna. Therefore, these compounds could be used as indicators for the quality changes during refrigerated storage.

• Journal of Food Hygiene and Safety
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• v.18 no.4
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• pp.218-223
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• 2003

This study was to carried out to estimate the relationship between acceleration storage and room temperature storage of gangjung (control unit) and dried insam gangjung (experiment unit), by acid value and peroxide value. The result were summarized as follows. : 1. Test for acid value of control unit, every 1 hour after acceleration storage is similar to each 7 days after room temperature storage is imilar to each 7.5 days after room temeprature storage. 2. Test for peroxide value of control unit, evry 1 hour after acceleration storage is similar to each 7.5 days after room temperature storage but to test peroxide value of experiment unit, every 1 hour after acceleration storage is imilar to each 7.7 days after room temperature storage. 3. In case of the oxidized flavor, control unit is not detected during storage stability but the experiment unit is detected unit is detected 1 hour ahead of acceleration storage than room temperature storage.

• Journal of Biosystems Engineering
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• v.41 no.2
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• pp.85-92
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• 2016

Background: The same plant, Camellia sinensis, is used to produce all types of tea, and the differences among the various types arise from the different processing steps that are used. Based on the degree of fermentation, tea can be classified as black, green, white, or oolong tea. Of these, black tea is the most or fully fermented tea. The oxidized polyphenolic compounds such as theaflavins (TF) and thearubigins (TR) formed during fermentation are responsible for the color, taste, flavor, and aroma of black tea. Results: Research indicates that an optimum ratio of TF and TR (1:10) is required to ensure a quality cup of tea. The concentrations of TF and TR as well as desirable quality characteristics increase as fermentation time increases, reaching optimum levels and then degrading if the fermentation time is prolonged. It is also necessary to control the environment for oxidation. There are no established environment conditions that must be maintained during the fermentation of the ruptured tea leaves. However, in most cases, the process is performed at a temperature of $24-29^{\circ}C$ for 2-4 h or 55-110 min for orthodox tea or crush, tear, and curl (CTC) black tea, respectively, under a high relative humidity of 95-98% with an adequate amount of oxygen. Conclusion: The polyphenolic compounds in black tea such as TF and TR as well as un-oxidized catechins are responsible for the health benefits of tea consumption. Tea is rich in natural antioxidant activities and is reported to have great potential for the management of various types of cancers, oral health problems, heart disease and stroke, and diabetes and to have other health benefits such as the ability to detoxify, improve urine and blood flow, stimulate, and improve the immune system.

• Journal of Applied Biological Chemistry
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• v.42 no.4
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• pp.175-179
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• 1999

Grape seed oil was extracted using different preparatory treatments as follows: (1) grinding, (2) grinding and roasting, (3) grinding and wet- roasting, (4) grinding, roasting, and wet-roasting, and (5) grinding, wet-roasting, and wet-roasting. The highest antioxidant activity was obtained from the sample with the method (2). Initial states of oxidation were similar except method (1) that showed more oxidized state, being P.O.V.8. Acid values were observed in the range from 1.42 to 1.89. The lowest acid value was found as 1.42 in method (1) and those of others were somewhat higher, indicating that heating process of roasting produced some free fatty acids. From the results of sensory evaluation, the best odor and taste were obtained from the methods (2) and (3). Repetitive procedure of wet-roasting, like method 5, caused some loss of flavor components and decrease in the sensory evaluation score. Addition of grape seed oil (method 2) to soybean and perilla oil at the level of 20% retained considerable antioxidant activities as much as 4.3 and 5 times, respectively, than 100% soybean or perilla oil stored for 12 weeks. When soybean or perilla oil was mixed with 20% grape seed oils, P.O.V. decreased to half of that of unmixed oils.

• Korean journal of food and cookery science
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• v.27 no.4
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• pp.27-34
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• 2011

The function of mulberry leaves and the quality of muffins including mulberry leaves were examined. The electron donating ability of both a water and ethanol extract was 40% for both at 100 ppm, 62 and 72% at 500 ppm, and 77 and 83% at 1,000 ppm respectively. These experiments showed good oxidized substance activity. The SOD-like ability of the water and ethanol extracts at 1,000, 500, and 300 ppm was 49% and 55%, 33% and 39%, and 28% and 33% respectively. These results show that the ethanol extract had higher SOD-like ability than that of the water extract. The nitrite scavenging abilities of 1,000 ppm of the mulberry leaf water extract and ethanol extract at pHs of 1.2 and 3.0 were 40.5 and 47%, and 20 and 22% respectively. The Hunter lightness value tended to be lower as the amount of added mulberry leaves increased compared to the contrast set, so the lightness level with a 7% addition was the lowest. The contrast set was the highest for redness and added mulberry leaves tended to decrease redness at 3% but tended to increase it again with additions >3%. The b-value (yellowness) showed a similar tendency as redness. Adding Mulberry leaves tended to decrease the contrast set to the lowest level, then values increased slowly to a peak at 5% added mulberry leaf and then decreased thereafter. Strength and hardness were less after increasing added mulberry leaf. Cohesiveness, springiness, gumminess and brittleness, decreased at up to 5% added mulberry leaves but the 7% addition showed the same level as the contrast set. The mulberry leaves muffins were less preferred to the contrast set in appearance and color. However, the mulberry leaf muffins were preferred to the contrast set in taste and flavor but the result was not significant. Overall the quality of the muffins with 3% added mulberry leaves was preferred over the 1% added mulberry leaf muffins.