• Food Science and Preservation
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• v.23 no.6
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• pp.848-858
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• 2016

This study was conducted to determine the $F_0$-values of a retort machine at different locations and to evaluate the effects of these $F_0$-values on various quality characteristics of retorted Samgyetang samples. Samples were divided into three groups based on $F_0$-values-T1, 10~20; T2, 20~30; T3, >30. Mineral content in Samgyetang broth and breast meat mostly increased with increasing $F_0$-values. In general, the free amino acid values, hardness, and springiness, except for bone springiness, of Samgyetang decreased significantly at higher $F_0$-values. Protein content of meat and broth of the treated samples were significantly lower than that of the control. An increase in the digestion rate of meat and porridge, as well as the turbidity of the broth was observed in most of the treated samples with increasing $F_0$-values. With increasing $F_0$-values, the $L^*$ and $b^*$ values of meat and the $b^*$ values of broth tended to increase, while the $a^*$ value of broth increased significantly. Electronic nose analysis revealed different flavor patterns for samples treated at different $F_0$-values. For sensory traits, samples treated with higher $F_0$-values tended to receive lower evaluations. Particularly, the color and texture of T3 samples were lower than those of T1 and T2 samples. In conclusion, to improve the quality of Samgyetang, the efficiency and optimization of retort machines as well as the standardization of sterilization techniques are needed.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.728-736
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• 2001

Effects of packaging material and oxygen absorbant on physical and chemical properties of Yukwu were studied during storage to develop packaging conditions. The packaging materials used were PET/EVOH $(16\;{\mu}m)/PL$ : P1 and PET/EVOH $(24\;{\mu}m)/PL$ : P2 with or without oxygen absorbent (E1A : P1 and E2A : P2 for w/ $O_2$, absorbent, E1EA : P1 and E2EA : P2 for w/o $O_2$, absorbent). Color values for Yukwu indicated that L values of E1A, E1EA, E2A and E2EA were decreased during storage while those b values were increased. Hardness and chewiness of Yukwa were generally decreased, however those of E1A and E1EA were rather increased after 6 weeks of storage. Acid value of E2A had maintained less than 2.0 during 12 weeks of storage. E1A, E2A had the below of 20 in peroxide during 12 weeks. Aroma data by using electronic nose showed that there was no difference after 6 week storage time in different packaging materials. Sensory evaluation (Yukwa odor and rancid odor) showed very similar results with electronic nose one. E2A had the highest value of overall acceptability for sensory evaluation. Hardness and cheweness in physical measurement results had the highest correlation with hardness, crispness, overall-acceptability in sensory evaluation results.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.201-208
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• 2007

Functional oils (FOs) were produced from commercial diacylglycerol oil and red yeast rice extracts from 80% ethanol for 1 hr in a shaking water bath at $35^{\circ}C$ and 175 rpm. FOs contained (A) 600, (B) 1200, (C) 1800, and (D) 2280 ppm of red yeast-rice extracts, respectively. The Hunter a value and b value were risen whereas L value was reduced along with the increase of extract concentration. Content of monacolin K and total phenolic compounds in FOs significantly increased according to the increase of extract concentration. The oxidation stability of FOs was observed by Rancimat at $98^{\circ}C$. Induction time decreased according to the increase of extract concentration. The major volatile compounds of FOs were compared using the electronic nose (EN) system and solid phase microextraction (SPME) method combined with gas chromatograph/mass spectrometry (GC/MS). EN was composed of 12 different metal oxide sensors. Sensitivities (Rgas/Rair) of sensors from EN were analyzed by principal component analysis (PCA), whose proportion was 99.66%. For qualitative or quantitative analysis of volatile compounds by SPME-GC/MS, the divinylbenzene/carboxene/polydimethyl-siloxane fiber and sampling temperature of $50^{\circ}C$ were applied.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.20-29
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• 2014

Recently, LTE is preparing to make a new leap forward LTE-A all over the world. As LTE privides high speed service, the role of mobile phones seems to change from voice to data service. According to Cisco, global mobile data traffic will increase nearly 11-fold between 2013 and 2018. Mobile video traffic will reach 75% by 2018 from 66% in 2013 in Korea. However, voice service is still the most important role of mobile phones. Thus, controllability of throughput and low BLER is indispensable for high-quality VoIP service among various type of traffic. Although the maximum AMR-WB, 23.85 Kbps is sufficient to a VoIP call, it is difficult for the LTE which can provide tens to hundreds of MB/s may not keep the certain level VoIP QoS especially in the cell-edge area. This paper proposes a new scheduling algorithm in order to improve VoIP performance after analyzing various scheduling algorithms. The proposal is the technology which applies more priority processing for VoIP than other applications in cell-edge area based on two-tier scheduling algorithm. The simulation result shows the improvement of VoIP performance in the view point of throughput and BLER.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.190-194
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• 2008

Physicochemical properties of the green tea component enriched mushroom (Flammulina velutipes) were investigated. The yield of mushroom was highest with green tea powder untreated sample and the yield was decreased by the addition of green tea powder. However, hardness was increased by the addition of green tea powder. Analysis of catechins and caffeine in mushrooms showed that catechins were not transferred into mushrooms, whereas caffeine content was increased. The content of total polyphenol in mushroom was not affected by the addition of green tea powder and crude catechins. Analyses of aroma patterns using the electronic nose based on GC with SAW sensor showed that new peaks occurred from 3 to 6 sec in green tea added mushroom. This study showed that functional components and quality of mushroom were possibly improved by incorporating green tea powder in growth medium.

• Food Science and Preservation
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• v.19 no.3
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• pp.328-336
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• 2012

The objective of this study was to investigate the storage effects of the packaging method of blanched namul(Gosari, Torandae, Chwinamul and Siraegi). The samples were packaged with three packaging types (Vinyl packaging, sealing packaging and vacuum packaging) and were stored for 10 days at $10^{\circ}C$. The quality characteristics were evaluated via a microbiological test, hardness, pH and flavor patterns analysis. The pH values of the samples were not affected by packaging method. The total aerobic and coliform plate counts were high, in the order of vacuum packaging < sealing packaging < vinyl packaging. Vacuum packaging resulted in the highest hardness value. The flavor patterns of blanched namul by packaging type were analysed with electronic nose system equipped with 12 metal-oxide sensors, and the storage shelf life of namul was evaluated by measuring the change in volatile production. As a result, it was shown that namul in vacuum packaging had few volatile production changes with higher storage time.

• Food Science and Preservation
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• v.22 no.5
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• pp.690-698
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• 2015

Effects of roasting on physical (weight, volume, density and color) and chemical properties (total phenol, caffeine, chlorogenic acid and antioxidant properties) of three Arabica coffee beans (Brazil Bourbon, Indonesia Mandheling and Kenya Tatu) were investigated. A steady weight loss, volume increase, and bean density decrease were observed during the roasting process. The $L^*$, $a^*$, and $b^*$ values tended to decrease as the roasting temperature and time increased. Caffeine level was approximately 0.73% in green beans, and increased to 40-67% for darker roasts. Green beans contained the highest chlorogenic acid content, which decreased as the roasting temperature and time increased. The light- and medium-roasted coffee showed the highest total phenolol contents. The antioxidant activities were measured using DPPH and ABTS. The light-roasted coffee beans showed the highest antioxidant activities, and an approximately 36-51% loss in antioxidant activity was observed after further roasting. The flavor patterns of roasted coffee beans were analyzed using an electronic nose system based on gas chromatography. This analysis demonstrated that an electronic nose system can be applied to identify the green bean variety and the degree of roasting.

• Food Science and Preservation
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• v.23 no.7
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• pp.1042-1049
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• 2016

This study was conducted to investigate and compare the characteristics of acetic acid fermentation in detoxified Rhus verniciflua vinegar (DRV) produced by different yeast strains. The DRVs were prepared by static acetic acid fermentation using six different yeast strains (Saccharomyces cerevisiae Fermivin, Pichia kudriavzerii N77-4, Hanseniaspora pountiae HP1-2, Candida tropicalis Y447, Wickerhamomyces anomalus N43-8, and Pichia kluyveri Frootzen). Alcohol content of the S. cerevisiae Fermivin fermented DRV was highest 16.07%. Among the yeast strain DRVs, there were significant differences in alcohol content, but all alcohol levels were 11%. Moreover, there were differences in pH and titratable acidity of the DRVs. The organic acid content of the DRVs ranged from 35.88 to 55.49 mg/mL and there were significant differences among the yeast strain DRVs. Essential free amino acids, particularly glutamic acid, alanine, leucine and valine, were detected in each of the 6 DRVs. Electronic nose analysis revealed that three different volatile chemical patterns were present in the 6 DRVs. The results indicate that yeast strains with different characteristics can produce vinegars with different characteristics.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1549-1556
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• 1999

This study was conducted to investigate the effects of pre-treated sub-ingredients and deodorization materials on the smell intensity of Kimchi during fermentation.Among the various sub-ingredients of Kimchi, garlic, ginger and green onion have comparatively strong smell. The smell intensities of the sub-ingredients, which were pre-treated with various patented methods were examined using the sensory evaluation method and AromaScan. The results showed that the good methods to reduce the smell of sub-ingredients were hot air drying and soaking with heating treatment. The pH, titratable acidity and the number of microorganism of Kimchi prepared with pre-treated sub-ingredients were not different among samples during fermentation. The smell intensity of the Kimchi with pre-treated sub-ingredients was weaker than that of control until ten fermentation days, but the smell intensity after 10 days of fermentation was not different among samples. The addition of ${\alpha}-cyclodextrin\;and\;{\beta}-cyclodextrin$, which are known to have deodorization effect, at a level of 0.1% respectively, to Kimchi resulted in no difference in the pH, titratable acidity and smell intensity during fermentation at $10^{\circ}C$ compared to those of control Kimchi. However, the addition of deodorizer reduced sulfide classes such as methyl allyl sulfide, dimethyl disulfide, allyl sulfide, methyl propyl disulfide up to 50%.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.467-475
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• 2012

This study was carried out to investigate the effect of the addition level (0 ppm, 400 ppm, 800 ppm, and 1,200 ppm) of green tea extract on the lactic acid bacteria, oxidative stability, and aroma in kimchi-fermented sausage. The sample sausages were fermented at $24^{\circ}C/RH$ 89% until attained to a pH value of 4.9 (for 17 h), and then dried at $10^{\circ}C/RH$ 75-80% for 6 d. The lactic acid bacteria count and pH value were 7.5-7.7 Log CFU/g sausage and 4.30-4.33, respectively, at 6 d of ripening. The results of those did not show significant differences among all treatments. The formation of TBARS (2-thiobarbituric acid reactive substances) was significantly lowered by increasing the addition level of green tea extract. During ripening periods, the CIE $L^*$ and $a^*$ values decreased; however, the $b^*$ value increased due to the addition of green tea extract. Utilizing an electric nose, the aroma pattern was clearly discriminated between green tea extract treatments and the control. Therefore, in kimchi-fermented sausages, the high addition level of green tea extract improved the lipid oxidation stability. In addition, regardless of the addition level, green tea extract changed the aroma while reducing the color stability. Moreover, it did not have any effect on the growth of lactic acid bacteria.