• 한국축산식품학회지
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• 제34권2호
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• pp.207-213
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• 2014

This study investigated the effects of microbial transglutaminase (MTGase) and pH-shift processing on the functional properties of porcine myofibrillar proteins (MP). The pH-shift processing was carried out by decreasing the pH of MP suspension to 3.0, followed by re-adjustment to pH 6.2. The native (CM) and pH-shifted MP (PM) was reacted with and without MTGase, and the gelling and emulsion characteristics were compared. To compare the pH-shifted MTGase-treated MP (PT), deamidation (DM) was conducted by reacting MTGase with MP at pH 3.0. Rigid thermal gel was produced by MTGase-treated native MP (CT) and PT. PM and DM showed the lowest storage modulus (G') at the end of thermal scanning. Both MTGase and pH-shifting produced harder MP gel, and the highest gel strength was obtained in PT. All treatments yielded lower than CM, and CT showed significantly higher yield than PM and DM treatments. For emulsion characteristics, pH-shifting improved the emulsifying ability of MP-stabilized emulsion, while the treatments had lower emulsion stability. PM-stabilized emulsion exhibited the lowest creaming stability among all treatments. The emulsion stability could be improved by the usage of MTGase. The results indicated that pH-shifting combined with MTGase had a potential application to modify or improve functional properties of MP in manufacturing of meat products.

• 한국응용과학기술학회지
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• 제29권1호
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• pp.19-32
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• 2012

가교에 관한 리뷰논문으로 특허의 다수는 의료용이다. 조직공학용 지지체나 약물전달용 매체로 쓰이는 고분자의 가교는 세포 무독성, 제 자리 겔 형성성이 있는 가교반응을 중시하고 있다. 가교를 탄성률, 내약품성, 내열성의 증대 목적 외에 가교부위에 금속 흡착성, 방오성, 항균성, 이온교환성 등의 기능을 부여하고 있다. 환경의 자극에 응답하는 스마트 가교, 환경을 고려한 광 가교, 물리적 가교, 효소가교, 천연물 가교, 수성가교가 연구되고 있다. 120세 수명을 목표로 의용재료의 발전에 고분자 소재의 개발도 필수적이다. 가교를 통한 고분자의 기능성 부여 및 물성 강화도 더욱 섬세하게 될 것이다. 고분자 가교물 중의 중요한 분야를 점하는 히드로젤은 주사용 제자리 겔 형성성의 개선 방향으로 전개될 것이다. 코팅용 고분자 가교제는 작업자, 작업환경을 고려하여 저독성-무독성의 가교제, 낮은 에너지에서 가교되는 에너지 절약형 가교제가 개발될 것이다.

• Applied Biological Chemistry
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• 제38권2호
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• pp.147-150
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• 1995

에탄올처리 찰가자미껍질 젤라틴의 젤라틴농도, pH, 정치온도 및 시간과 같은 겔화조건에 대한 물리적 특성 및 색조의 변화를 측정하였다. 젤라틴의 농도가 증가할수록 겔강도, 녹는점과 같은 물리적 특성은 증가하였고, 일정농도에서의 이러한 값들은 에탄올처리한 젤라틴이 무처리한 젤라틴에 비하여 컸다. 젤라틴 졸의 pH가 에탄올처리한 젤라틴의 경우 6.0일 때, 무처리한 젤라틴의 경우 5.0일 때, 겔강도, 졸화온도 및 겔화온도가 가장 높았고, 이를 벗어난 $pH\;5.0{\sim}7.0$의 범위에서는 서서히 감소하였으며, pH 5.0이하 및 pH 9.0이상에서는 급격히 감소하였다. 젤라틴 졸을 겔화시키기 위하여 정치시키는 온도의 경우 낮을수록, 정치시키는 시간의 경우 길어질수록 겔강도 및 졸화온도는 높았다. 겔화조건을 동일하게 하였을 때 에탄올처리한 젤라틴이 무처리한 젤라틴보다 물리적 특성값이 높게 나타났다.

• 한국추진공학회지
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• 제16권6호
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• pp.23-31
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• 2012

본 연구에서는 $SiO_2$ 계열 젤화제로 알려진 Aerosil(R) R972, Silica 230, Silica 530을 사용하여 케로신 기반 젤 연료를 제작하였다. 케로신 계열 연료로는 Jet A-1을 사용하였으며 젤화(gelification) 여부를 확인하기 위한 전단박화(shear thinning) 현상은 멱법칙(power-law) 모델을 이용하여 검증하였고 제작된 모든 젤 연료는 전단박화 효과와 함께 $SiO_2$ 젤화제의 함유량이 증가할수록 젤의 점도가 높게 형성됨을 확인하였다. 본 연구에서 사용된 젤화제 중 Aerosil(R) R972를 첨가한 젤 연료의 점성계수가 전단률 전 영역에 걸쳐 멱법칙 모델을 따르는 것이 확인되었으며 상대적으로 Silica 230과 Silica 530을 첨가한 젤 연료는 전단률 150 [1/s] 근방 이하에서 멱법칙이 유효하지 않음을 알 수 있었다. 또한, 젤화제 함유량이 증가할수록 vortex 혼합법과 수동 혼합법 간의 유변학적 특성이 크게 차이 나는 것이 관찰되었다.

• 한국축산식품학회지
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• 제33권2호
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• pp.221-228
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• 2013

This study was performed to evaluate the effects of various levels of mungbean flour (MF) (0-2.4%) on the quality characteristics of pork model sausages (PMS) in experiment 1 and also select the optimum level of MF to enhance the water retention and gelling properties of low-salt PMS (LSPMS) with or without microbial transglutaminase (MTGase) in experiment 2. In experiment 1, the addition of MF did not affect pH, chemical compositions (fat and moisture contents), color values, and functional properties (expressible moisture, EM (%) and cooking yield, CY (%)) of PMS. However, the addition of MF increased the chewiness of PMS and hardness if the mungbean flour at the level of more than 1.2% was incorporated. Since the interaction between the microbial transglutaminase (MTGase) treatment and MF level was not significant (p>0.05), data were pooled by different factors (MTGase treatment and MF level) in experiment 2. MF improved the water binding ability and textural springiness of LSPMS. On the other hand, MTGase treatment decreased the pH and cooking yield (%) of LSPMS, but increased most textural properties. In conclusion, the addition of MF could enhance the water retention and textural properties of PMS and LSPMS, regardless of MTGase, when it was added to over 1.2%. Based on these results, mungbean protein may interact with MTGase on the low-salt comminuted meat systems. Therefore, further study might be needed to understand the mechanisms of interaction between MTGase and functional components induced from MF.

• Fisheries and Aquatic Sciences
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• 제13권1호
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• pp.1-11
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• 2010

The study was performed to optimize the processing conditions (alkali concentration, extraction time, and temperature) for rockfish skin gelatin based on yield using response surface methodology and comparison of the physicochemical properties with those of rockfish skin gelatin pretreated and extracted under ordinary conditions (alkali treatment concentration: 1.0 M; extraction time: 2 hr; extraction temperature: $60^{\circ}C$). Predicted maximum gelatin yield of 19.1% and gelatin content of 87.8% were obtained by extraction at $106.6^{\circ}C$ for 69.0 min after pretreatment with 1.1 M calcium hydroxide. Yield of gelatin extracted under high temperature/high pressure (G-HT/HP) was 54% higher than that extracted under ordinary temperature/time (G-OT/T). However, G-HT/HP was inferior in gel strength and gelling point to (G-OT/T), but comparable in transmission. Based on the physicochemical properties, G-HT/HP was unsuitable for use in products requiring higher physical properties, but could be useful for health-functional foods.

• 한국식품영양과학회지
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• 제32권1호
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• pp.75-81
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• 2003

전지활성 생대두미세분말(micronized full-fat soyflour, MFS)로부터 제조된 두유는 의가소성 의 비뉴턴성 유체로서, 고형분 증가와 응고제의 첨가 및 가열에 따라 점도가 증가하였다. MFS용액은 열처리에 따른 점도가 급격하게 증가되는 시점의 온도는 응고제의 첨가 및 단백질의 함량이 증가함에따라 낮아졌다 충진형 전두부제조에 적합한 응고제는 가열된 MFS용액에 응고제 첨가 후 MFS용액의 점도를 완만하게 변화시키는 GDL, MgSO$_4$가 적 합한 것으로 나타났으며 전두부용 응고제는 0.1% salt, 0.1% GDL, 0.2% MgSO$_4$ㆍ7$H_2O$로 조제되었다. 고형분과 물의 비율이 1 : 6.0인 MFS60용액을 121$^{\circ}C$에서 3분간 가열하여 응고제를 첨가하여 제조된 전두부는 견고성과 깨짐성이 양호한 조직감을 나타내었으며, 여기에 SPI를 첨가하여 총단백질이 7.1%인 MFSS60용액으로 제조된 전두부의 경도와 깨짐성(brittleness)은 각각 120 g, 176 g으로 조직감이 개선되었다.

• Bulletin of the Korean Chemical Society
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• 제30권6호
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• pp.1360-1364
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• 2009

The bacterium Sphingomonas chungbukensis DJ77 produces the extracellular polysaccharide gellan in high yield. Gellan produced by this bacterium is widely used as a gelling agent, and the enzyme UDP-glucose pyrophosphorylase (UGP) is thought to play a key role in the gellan biosynthetic pathway. The UGP gene has been successfully cloned and over-expressed in E. coli. The expressed enzyme was purified with a molecular weight of approximately 32 kDa, as determined by a SDS-polyacrylamide gel, but the enzyme appears as ca. 63 kDa on a native gel, suggesting that the enzyme is present in a homodimer. Kinetic analysis of UDP-glucose for UGP indicates $K_m$ = 1.14 mM and $V_{max}$ = 10.09 mM/min/mg at pH 8.0, which was determined to be the optimal pH for UGP catalytic activity. Amino acid sequence alignment against other bacteria suggests that the UGP contains two conserved domains: An activator binding site and a glucose-1-phosphate binding site. Site-directed mutagenesis of Lys194, located within the glucose-1-phosphate binding site, indicates that substitution of the charge-reversible residue Asp for Lys194 dramatically impairs the UGP activity, supporting the hypothesis that Lys194 plays a critical role in the catalysis.

• 대한가정학회지
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• 제42권9호
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• pp.1-18
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• 2004

Most of the Korean diaspora who lived in Yunhaeju moved to Central Asia in 1937 following the policy of deportation of Russia. Uzbekistan is the representative place for Korean diaspora to have settled down in Central Asia at that time and mort Korean diaspora in Central Asia are living in Uzbekistan now. Korean diaspora have maintained a traditional way of living for 140 years without a deep relationship with Korea. This study examined the dwellings of the Korean diaspora of Uzbekistan in Central Asia by visiting their houses and conducting interviews. Results of the research were as following: 1) The houses of the Korean diaspora in Uzbekistan in early times consisted of 2-3 bedrooms with Gudle. Gudle is the most traditional element of the Korean diaspora's house and it has been used as a place for gathering family members. 2) Korean diaspora's houses in Uzbekistan were built according to Russian and Uzbek style but most of the Korean diaspora's have a mixed style with traditional Korean elements of living.3) The changing process of planning and building codes of apartments in Uzbekistan is similar to that in other CIS nations and all of Russia. 4) Korean's food style is a mixture of Korean, Russian and Central Asian foods. Kimchi and Jang (bean paste) are essential for most Koreans and most Koreans are making these at home. 5) Most Koreans have maintained a good relationship with the Uzbek people and Koreans are very active in gelling along well with all. This enables them to exchange their culture eventually in various parts. This study could be the first step to supply basic information for the study of the Korean diaspora in Uzbekistan. Deeper research over a wider range is needed in Russia.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1547-1552
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• 2009

Sphingomonas chungbukensis DJ77 has the ability to produce large quantities of an extracellular polysaccharide that can be used as a gelling agent in the food and pharmaceutical industries. We identified, cloned and expressed the UDP-glucose dehydrogenase gene of S. chungbukensis DJ77, and characterized the resulting protein. The purified UDP-glucose dehydrogenase (UGDH), which catalyzes the reversible conversion of UDP-glucose to UDPglucuronic acid, formed a homodimer and the mass of the monomer was estimated to be 46 kDa. Kinetic analysis at the optimal pH of 8.5 indicated that the $K_m\;and\;V_{max}$ for UDP-glucose were 0.18 mM and 1.59 mM/min/mg, respectively. Inhibition assays showed that UDP-glucuronic acid strongly inhibits UGDH. Site-directed mutagenesis was performed on Gly9, Gly12 Thr127, Cys264, and Lys267. Substitutions of Cys264 with Ala and of Lys267 with Asp resulted in complete loss of enzymatic activity, suggesting that Cys264 and Lys267 are essential for the catalytic activity of UGDH.