• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.465-472
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• 2017

In this study, tuna sawdust was added to extruded meat analog in order to develop a meat analog with high quality. Addition of tuna sawdust has merit for utilizing a byproduct from poultry processing. Physicochemical characteristics were examined through the extrusion cooking process. The basic mixture of sample mixed with 65% deffated soy flour 25% isolated soy protein, and 10% corn starch was setup as the raw material. Three kinds of samples were made in total by addition of 15% and 30% tuna sawdust to this mixture. The extrusion process had a screw speed of 250 rpm, die temperature of $140^{\circ}C$, and moisture content of 50%. As addition of tuna sawdust increased, breaking strength and density decreased, specific length increased, and integrity and water holding capacity decreased. Likewise, nitrogen solubility index and protein digestibility decreased as addition of tuna sawdust increased. DPPH radical scavenging activity increased as addition of tuna sawdust addition, whereas it decreased as storage period increased to 30 or 60 days. The value of rancidity decreased as addition of tuna sawdust increased. However, 60 days later, radical scavenging activity increased more or less, and a significant difference was detected 150 days later. In conclusion, addition of tuna sawdust increased soft texture, and nutrition of the basic mixture sample. The process promoting functionality such as improvement of antioxidant function was confirmed through this study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1327-1335
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• 2017

This study was carried out to determine the effect of cacao bean addition on the physicochemical properties of extruded rice flour. Rice-based cacao beans (0, 20, 40, 60%) were extruded at a die temperature of $130^{\circ}C$, screw speed of 200 rpm, and moisture content of 25%. As the content of cacao beans increased from 20% to 60%, expansion index decreased, while piece density and specific length increased. The water soluble index and water absorption index of the extrudate increased through extrusion cooking. Lightness decreased as cacao bean content increased while redness increased. As the content of cacao beans increased, paste viscosity decreased. Cold peak viscosity was observed in all extrudates of raw roasted cacao beans. ${\alpha},{\alpha}$-Diphenyl-${\beta}$-picrylhydrazyl (DPPH) radical-scavenging activity increased upon extrusion and cacao bean addition. As content of cacao beans increased, non-roasted cacao beans had higher total phenolic contents than roasted cacao beans. This study showed that addition of cacao beans to extruded rice snack improved antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1716-1723
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• 2014

This study was designed to examine the change in physical properties of extruded brown rice-vegetable mix at different pregelatinized brown rice contents and $CO_2$ gas injection. Moisture content, screw speed and die temperature were fixed to 30%, 100 rpm and 60, respectively. $CO_2$ gas injection was adjusted to 0, 300, 600, and 800 mL/min. The content of vegetables (carrot, pumpkin, kale and Angelica keiskei) mix was fixed 5%. Pregelatinized and raw brown rice powder were blended as the ratio of 0/95, 30/65 and 50/45. Specific mechanical energy input decreased as pregelatinized brown rice ratio increased. Expansion index increased and the size and number of pores increased but density decreased with the increasing in $CO_2$ gas injection. Gelatinization degree increased as $CO_2$ gas injection increased. In conclusion, cold extrusion with $CO_2$ gas injection at $60^{\circ}C$ die temperature could be applied for Saengsik (uncooked food) making.

• 기계와재료
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• v.23 no.3
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• pp.96-113
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• 2011

녹색기술 및 친환경 공정의 필요성이 급증함에 따라 재료이용률 향상을 지향하는 차세대 압출공정의 대두가 필요하게 됨에 따라 유압 CNC(Servo) 제어를 이용한 가변단면 압출기술을 개발하게 되었다. 이러한 가변단면 압출(Varied section extrusion, VSE)기술은 공정 중에 압출구를 빠져 나가는 소재의 단면 형상을 변화시켜 재료이용률을 향상을 도모하였으며, 후가공 공정의 생략도 가능하여 국내 압출업체의 생산원가 절감 및 글로벌 기술경쟁력 확보에 큰 도움을 줄 수 있을 것이다. 아직은 소수의 선진국에서 시도한바 있으나 양산품 적용에는 생산원가 및 생산속도, 상품성 등에 문제가 있어 자동차 부품 적용에 한계를 보이고 있는 기술이다. 따라서 본 연구팀이 가변단면 압출용 금형을 포함한 최적의 압출공정 및 양산성 문제의 해결점을 거의 확보하고 있는 단계로 세계를 선도하는 리딩기술(Leading technology)을 보유하게 됨으로써 국가의 기술경쟁력 향상에 중요한 역할을 수행할 수 있을 것이다. 본 연구의 내용을 요약하여 정리해 보면 첫째로는 CNC 제어 가변단면 압출공정에 대하여 자세하게 소개하고 특징 및 장 단점을 설명하였으며, 자동차 부품군에로의 적용에 많은 이점들을 갖고 있음을 설명하였다. 두 번째로는 가변단면 압출을 위한 이동 금형(Moving die)부품을 갖는 구조의 압출금형에 관하여 기존의 압출금형과 비교하여 설명하였으며, 가변단면 압출용 금형의 구조 및 메커니즘의 최적화를 이루고자 하였다. 세 번째로는 가변단면 압출공정을 실현하기 위한 CNC 제어 압출시스템에 대하여 간략히 설명하였다. 네 번째로는 자동차 부품 적용을 위한 정밀 압출공정으로서 가변단면 압출공정에 대하여 유한요소해석을 통하여 가변단면 압출공정 변수 및 금형 변수 등에 대한 엄격한 검토를 선행적으로 수행하여 양산성 확보를 위한 정보들을 분석 정리하였다. 끝으로는 세 가지 단면형태를 갖는 가변단면 압출제 시제품에 대하여 CNC 제어 가변 단면 압출공정의 상용화 가능성을 확인 적용성 검토를 완료하였다. CNC 제어 가변단면 압출기술은 압출공정에 있어서 많은 경험과 기술적 검토가 선행되어져야 하는 고부가가치 성형공정으로써 재료 이용률을 획기적으로 향상시킬 수 있는 압출공법으로 향후 자동차 부품 뿐만아니라 다양한 알루미늄 제품군에 적용이 가능하다고 판단된다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2001.11a
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• pp.29-29
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• 2001

열전재료는 열전현상을 가지고 있어 열전발전과 열선냉각이 가능하기 때분에 해저용, 우주용, 군사용의 특수 전원으로 이미 실용화되어있고, 반도체, 레이저 다이오드, 적외선 검출소자 등의 냉각기로 쓰여지고 있어 많은 연구자들이 이들 재료에 대한 연구에 관을 갖고 열전특성을 향상시키기 위하여 많은 연구를 진행하고 있다 이들 열전재료는 사용 온도구역에 따라 3종류로 구분하고 있으며, 실온부근의 저온 영역(20$0^{\circ}C$)이하에서는 $Bi_2Te_3$계 재료, 중온영역(20$0^{\circ}C$~50$0^{\circ}C$)에서sms (Pb,Ge) Te계 재료, 고온영역(50$0^{\circ}C$~lOoo$^{\circ}C$)에서는 Si-Ge계 Fe Si계 재료가 이용되고 있다. 본 연구에서는 실온에서 성능지수가 높은 Bi_2(Te,Se)_3$에 대한 연구를 진행하였다. Bi_2(Te,Se)_3$계 열전재료는 기존의 공법인 Zone melting법을 이용하는 경우 성능지수가 높으나, 단위정이 Rhombohedral 구조파 기저면(basal plane)에 벽개성이 있는 관계로 재료의 적지 않은 손실과 가공상의 어려움이 있다. 또한 사료전체에 걸쳐 화학적으로 균질한 고용체를 얻는 것도 어려운 문제점으보 부각되고 있디 따라서 이와같은 문제점을 보완하기 위하여 용질원자의 편석감소, 고용도의 증가, 균일 고용체 형성, 결정립의 미세화등의 장점이 있는 급속응고법을 본 연구에 응용하였다. 본 연구에서는 위에서와 같은 급속응고의 장점과 대량 가공이 능늪한 연간압출공정을 이용하여 제조된 분말을 성형화 하였다. 특히 열간압출 가공에 있어서 압축다이 각 변화는 재료의 소성유동에 매우 중요한 역하을 하게되며, 이와 갇은 소성유동은 본 재료의 열전특성에 중요한 영향을 미치는 C 면 배양에 중요한 역할을 한 것으 로 기대된다. 이에 본 연구에서는 압출다이 각도 변화에 따른 미세조직변화와 이들 조직이 강도와 열전특성에 미치는 영향을 석하고자 한다. 압출재의 미세조직은 XRD(X Ray Diffraction), SEM(Scanning Electron Microscopy)으로 분석하였으며, 열전특성인 Seebeck계수($\alpha$)와 전기비저항( $\rho$ )은 열전측정장치로, 기계적 강도는 MTS장비를 이용하여 이루어졌다. 또한 압축다이각도 변화에 따른 결정방위 해석은 모노크로미터가 장착된 X RD장비감 이용하여 분석되었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.473-480
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• 2017

The aim of this study was to investigate the effects of gluten and moisture contents on the physical properties of extruded soy protein isolate. Extrusion conditions included various moisture (45, 50, and 55%) and gluten contents (20, 40, and 60%) at a fixed screw speed and die temperature of 250 rpm and $140^{\circ}C$, respectively. Specific mechanical energy input decreased as gluten content increased from 20 to 60%. Hydration ratio was highest ($293.23{\pm}13.68%$) at gluten and moisture contents of 20 and 55%, respectively. Lightness and yellowness increased as gluten content increased from 20 to 60% while redness decreased as gluten content increased. Color difference was the highest at low gluten and moisture contents. Integrity index was the highest ($71.15{\pm}0.93%$) at gluten and moisture contents of 60 and 45%, respectively. Nitrogen solubility index was not significantly affected by moisture content and was lowest ($22.46{\pm}1.11%$) at gluten and moisture contents of 60 and 55%, respectively. In conclusion, higher gluten and lower moisture contents were effective for texturization of soy protein isolate.

• Food Engineering Progress
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• v.23 no.4
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• pp.283-289
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• 2019

This study was performed to determine the effect of psyllium husk addition on the physical properties of rice extrudates. Rice-based formulations mixed with psyllium husk (0, 7, 14 and 21%) were extruded at a die temperature of 140℃, screw speed of 200 rpm, and moisture content of 20%. As the content of psyllium husk increased, expansion ratio decreased, while piece density and specific length increased. Apparent elastic modulus, breaking strength, adhesiveness, and hardness augmented with an elevation in psyllium husk content. Lightness declined as psyllium husk content furthered, while redness, yellowness, and color difference intensified. Water soluble index and water absorption index increased with an increased amount of psyllium husk. In conclusion, the addition of psyllium affected the expansion of extruded rice snack possessing hard texture, small cells, and sticky texture due to higher water absorption during hydration.

• Food Science and Preservation
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• v.30 no.5
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• pp.875-884
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• 2023

In this study, the quality characteristics of texturized vegetable proteins (TVP) produced from defatted soy flour (DSF) were analytically compared with those of texturized vegetable proteins produced with isolated soy protein (ISP) and non-defatted soy flour (SF). The base raw material formulation consisted of 50% soy proteins, 30% gluten, and 20% corn starch. A cooling die-equipped extruder was used with a barrel temperature set at 190℃ and screw rotation speed of 250 rpm. With respect to the hardness of isolate soy proteins, that of soy flour and defatted soy flour was 22.4% and 68.8%, respectively, and gumminess was 17.6% and 44.3%, respectively. Defatting increased chewiness, shear strength, and springiness. Moisture content was higher in soy flour than in defatted soy flour, while there were no significant differences in terms of water absorption and turbidity. The pH was higher with soy flour than with defatted soy flour. Concerning color, the L and b values were higher with soy flour, while the a value was higher with defatted soy flour. These results suggest that defatting soybeans can improve the quality of plant-based proteins. Further research is needed to address the quality differences from those of isolated soy proteins.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.442-447
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• 1994

Effect of different mixing ratio of non-glutinous and glutinous rice on physical and rheological properties of extrudate prepared in a single screw extruder were examined. The extrusion conditions in term of screw speeds, moisture content and die temperature were 258 rpm, 18% and $120^{\circ}C$, respectively. The resisdence time distribution of the most of materials were within 30 second and small portion of them went up to 80 second. The expansion ratio was the highest value (2.93) for 70% of glutinous rice in the mixture, while the lowest value for 100% of non-glutinous rice. Breaking strength was in the range between 1,051g and 1,117g for $10{\sim}20%$ of glutinous rice in the mixture, while the lowest value (737g) for 80%r of glutinous rice. As the amount of glutinous rice increased, L and a values were increased and b value was decreased. The uncooked cold paste viscosity had 400 B.U. for 100% non-glutinous rice , while no peak for the 100% glutinous rice. As the amount of glutinous rice increased up to 100%, the water absorption index (WAI) was decreased, while water solubility index (WSI) was increased. The rheological properties of extrudate were accounted by the law of Oswald. The flow behavior index of extrudate was less than 1.0, which showed pseudoplastic behavior. Yield stress was the highest value for 20% of glutinous rice in the mixture and the lowest value for $80{\sim}100%$ of glutinous; rice. Number of air cell was between 128 and 159 for $80{\sim}100%$ of glutinous rice in the mixture, while $81{\sim}84%$ for $0{\sim}20%$ of glutinous rice. The degree of shapefact was increased more when the mixtures of glutinous and non-glutinous rice was used than when glutinous or non-glutinous rice was only used.