• Applied Biological Chemistry
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• 제12권
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• pp.7-11
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• 1969

Mucor-rennin, the crystalline milk-clotting enzyme, isolated from Mucor pusillus var. Lindt, has an acid protease activity. The optimum pH for the digestion of k-casein is 4.5, while that for hemoglobin digestion is 4.0. The skim milk solution was easily clotted acidic solution than alkalin solution, and the milk clotting activated by Ca ion. The enzyme was heat stable against heat from pH 4.0 to 6.0 but was more stable at pH 5.0. The activity of the enzyme at pH 5.0 did not decrease at 30 C for 15 days and the activity was not effected by sodium propionate and salicilic acid. Therefore, the enzyme of liguid type could store for a long time and could be transported from Erzyme production Co. to Manufacture of cheese Co. by adding the antiesptic and by adjusting pH to 5.0.

• Food Science and Biotechnology
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• 제18권1호
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• pp.36-42
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• 2009

This study was performed to develop low-fat/reduced-salt sausages (LFRSS; <3% fat and <1.5% salt) containing milk protein (whey protein concentrate, WPC, or sodium caseinate, SC) that showed the similar cooking yield and textural characteristics to those of regular-fat/salt sausage control (RFC; 20% fat and 1.5% salt) or low-fat sausage control (LFC; <3% fat and 1.5% salt). Low-fat sausages (LFS) were formulated with a 2.5% fat replacer (konjac flour:carrageenan:soy protein isolate=1:1:3) and various salt levels (0.75, 1.0, 1.25, and 1.5%). LFS had differences in color and expressible moisture (EM, %) values as compared to those of RFC. A minimum salt level of 1% and addition of nonmeat proteins were required to manufacture LFRSS that have similar characteristics to those of RFC. However, LFS with 2% milk proteins reduced the hardness and gumminess as compared to LFC. These results indicated that 1% milk protein in combined with 1% salt was a proper level for manufacturing of LFRSS.

• 한국식품저장유통학회지
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• 제20권6호
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• pp.810-817
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• 2013

본 연구는 백진주 쌀가루를 이용한 비유탕 쌀과자 제조조건의 최적화를 목적으로 두 가지 독립변수인 쌀 수침시간과 콩물 첨가량에 따라 9가지 조건의 비유탕 쌀과자 품질특성을 분석하였다. 무게는 쌀 수침시간이 길어짐에 따라 증가하다가 11.26일 이후에는 다시 감소하였으나 콩물 첨가량은 영향을 주지 않는 것으로 나타났다. 부피와 부피팽창율은 쌀 수침시간이 길어지고, 콩물 첨가량이 증가할수록 증가하는 것으로 나타났다. 밀도는 쌀 수침시간이 1.94일 이전이고, 콩물 첨가량이 32.23% 이상일 때 밀도가 가장 낮은 구간으로 나타났다. 색도에서 쌀 수침시간이 3.52일 이상이고 콩물 첨가량이 35.47%일 때 L값은 높은 구간으로 나타났고, a값은 유의성이 없는 것으로 나타났으며, b값은 쌀 수침시간이 길어지고 콩물 첨가량이 증가할수록 높게 나타났다. 경도는 쌀 수침시간이 5.28~8.53일이고, 콩물첨가량이 5.34~20.26%일 때 가장 높은 구간으로 나타났다. 색, 향미, 외형 및 전체적인 선호도는 쌀 수침시간이 짧고, 콩물 첨가량이 적을수록 선호도가 높은 것으로 나타났다. 최적 조건을 설정하기 위하여 독립변수인 쌀 수침시간과 콩물 첨가량을 범위 내에서 최소로 설정하고, 종속변수에서 밀도는 최소로 설정하고 다른 항목은 최대로 설정하였을 때 백진주 쌀가루를 이용한 비유탕 쌀과자의 최적 조건은 쌀 수침시간 0.69일이고 콩물 첨가량은 26.67%로 나타났다.

• Journal of Dairy Science and Biotechnology
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• 제29권2호
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• pp.37-42
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• 2011

본 연구는 실시간으로 변동하는 유통조건하에서 온도데이터를 이용하여 우유의 품질을 예측하고 모니터링할 수 있는 적정 품질지표를 규명하고자 실시하였다. LTLT 살균우유와 UHT 살균우유를 0, 10, 20, 30 및 $40^{\circ}C$에서 저장하면서 pH, 산도, 색도, 미생물 및 관능특성 변화를 조사한 후 각 품질특성과 관능적 기호도와의 상관관계를 분석하였다. 우유의 저장온도에 따른 pH, 산도와 기호도와의 상관관계를 분석한 결과, 10, 20, 30 및 $40^{\circ}C$에서 유의적인 상관관계를 나타내었으며, 온도가 높을수록 높은 상관계수를 나타내었다(p<0.01). 미생물변화에서 일반세균수와 기호도와의 상관관계는 저온살균우유의 경우 0, 10, 20, 30 및 $40^{\circ}C$에서 각각 R=-0.81, R=-0.91, R=-0.96, R=-0.90 및 R=-0.99로 모든 온도조건에서 높은 상관계수를 보였으며, 초고온 살균우유에서도 $0^{\circ}C$를 제외한 모든 온도에서 유의적인 상관관계를 나타내었다(p<0.01). 색도는 고온저장에서만 유의성이 인정되었고, 그 외 온도에서는 기호도와 낮은 상관계수를 보이며 상관관계의 유의성이 인정되지 않았다. 따라서 모든 저장온도에서 관능적 기호도와 높은 상관관계를 나타낸 일반세균수의 변화를 우유의 유통 중 품질예측에 적용되는 품질지표로 선정하여 적용 하는 것이 적절한 것으로 판단되었다.

• 한국축산식품학회지
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• 제37권6호
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• pp.940-947
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• 2017

Goat milk has a protein composition similar to that of breast milk and contains abundant nutrients, but its use in functional foods is rather limited in comparison to milk from other sources. The aim of this study was to prepare a goat A2 ${\beta}$-casein fraction with improved digestibility and hypoallergenic properties. We investigated the optimal conditions for the separation of A2 ${\beta}$-casein fraction from goat milk by pH adjustment to pH 4.4 and treating the casein suspension with calcium chloride (0.05 M for 1 h at $25^{\circ}C$). Selective reduction of ${\beta}$- lactoglobulin and ${\alpha}_s$-casein was confirmed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography. The hypoallergenic property of A2 ${\beta}$-casein fraction was examined by measuring the release of histamine and tumor necrosis factor alpha from HMC-1 human mast cells exposed to different proteins, including A2 ${\beta}$-casein fraction. There was no significant difference in levels of both indicators between A2 ${\beta}$-casein treatment and the control (no protein treatment). The A2 ${\beta}$-casein fraction is abundant in essential amino acids, especially, branched-chain amino acids (leucine, valine, and isoleucine). The physicochemical properties of A2 ${\beta}$-casein fraction, including protein solubility and viscosity, are similar to those of bovine whole casein which is widely used as a protein source in various foods. Therefore, the goat A2 ${\beta}$-casein fraction may be useful as a food material with good digestibility and hypoallergenic properties for infants, the elderly, and people with metabolic disorders.

• Journal of Dairy Science and Biotechnology
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• 제34권4호
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• pp.217-229
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• 2016

Goat milk production and processing is a dynamic and growing industry that is fundamental to the health of hundreds of millions of people worldwide and is recognized as an important contributor to many national economies. Goat milk has contributed significantly to the economic and nutritional quality of life in developing countries, particularly in the Mediterranean, the Middle East, Eastern Europe, and Latin America. Goat milk has played an important role in the health and nutrition of infants and the elderly, and is also known to be beneficial and therapeutic for people with milk allergies. The potential and value of the nutritional, health, and therapeutic effects of goat milk and specialized goat milk products are now attracting attention. Various products can be made from goat milk based on its chemical properties. In addition, special products such as hair, skin care, products, and cosmetics produced using goat milk have garnered more attention in recent years. Nevertheless, high quality products can only be made from good quality goat milk. Advanced technical treatments are necessary to produce high quality goat milk that meets consumer expectation of nutritional, hygienic, and good sensory products. Good taste has been a critical criterion when deciding to buy and consume goat milk and associated products. However, it may be possible to produce more value-added products that cater to the new trends in consumer needs and thus maintain economic sustainability of goat milk industry.

• 한국축산식품학회지
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• 제29권5호
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• pp.545-549
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• 2009

The functional properties of cheese, such as texture and melt, are known to be controlled by several important parameters. Recently, the characteristics of Ca in cheeses, especially the form of Ca (insoluble (INSOL) or soluble) and the shift in Ca equilibrium (i.e., from INSOL to soluble Ca), during aging has received a lot of attention. The INSOL form of Ca, which is present as a structural form in casein, plays a critical role in determining the functional properties of cheese during the early period of ripening (~1 mon). It seems that there is always a reduction of INSOL Ca content in cheese during ripening and there are also factors that can affect the shift in Ca equilibrium. These factors may include the composition of cheese milk, cheese manufacturing pH, acid development during aging, adopting curd-washing in various methods, pre-acidification of milk, etc. There have been many studies showing that the rheological and melting properties of cheese during ripening were significantly (p<0.05) affected by the shift in Ca equilibrium. Therefore, for cheese makers, it is now possible to predict/manage the functional properties of cheese by monitoring and controlling Ca equilibrium in cheese during aging.

• 한국축산식품학회지
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• 제34권6호
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• pp.757-762
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• 2014

The object of this study was to investigate the difference in physical and sensory properties of various premium ice creams. The physical properties of the various ice creams were compared by manufacturing brand. The water contents of the samples differed, with BR having the highest value at 60.5%, followed by NT and CS at 57.8% and 56.9%, respectively. The higher the water content, the lower Brix and milk fat contents in all samples. The density of the samples showed almost similar values in all samples (p>0.05). The viscosity of each ice cream had no effect on the water content in any of the brands. Before melting of the ice cream, the total color difference was dependent on the lightness, especially in the vanilla ice cream, owing to the reflection of light on the surface of the ice crystals. The CS product melted the fastest. In the sensory test, CS obtained a significantly higher sweetness intensity score but a lower score for color intensity, probably due to the smaller difference in total color, by which consumers might consider the color of CS as less intense. From this study, the cold chain system for ice cream distribution might be important to decide the physical properties although the concentration of milk fat is key factor in premium ice cream.

• 한국축산식품학회지
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• 제18권1호
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• pp.35-41
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• 1998

The objective of this study was to examine the changes of physical properties by additions of different kinds of stabilizers milk proteins concentration, when stored at 4$^{\circ}C$ or 20$^{\circ}C$ for yoghurt. the results were summarized as follows: 1. Addition of 2% carboxyl methyl cellulose and carrageenan, gelation 0.4%, pectin and starch 0.6%, and carrageenan & pectin 0.8% in the manufacture of yoghurt increased the viscosity, water-holding capacity and protein hydration of yoghurt. 2. Addition of 3% skim milk powder, Ca-caseinate or Na-caseinate 0.6% increased the viscosity, water-holding capacity and protein hydration of yoghurt. 3. Twenty five percent of evaporation of milk promoted to build up the optimal structure of the micelles of yoghurt and improved viscosity, water-holding capacity and protein hydration of yoghurt. 4. Addition of stabilizers to yoghurt showed an increase of viscosity, water-holding capacity and protein hydration when compared with non-addition of stabilizers to yoghurt at 4$^{\circ}C$, 20$^{\circ}C$ storage for 12hrs, 96hrs followed by the decrease of it.

• 한국지역사회생활과학회지
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• 제14권2호
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• pp.63-70
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• 2003

In this experiment, the curd was made from soybean and cow's milk in the ratio of 7 to 3, and coagulated with Glucono-delta-lacton(GDL) and $CaSO_4&.$2H_{2}O& in the 1:1 ratio. During the procedure, the mulberry leaf powder was added. The amount of the added powder varied from 0.1 % to 0.5 %. This experiment aimed to show the change of yield, general components, minerals, amino acid, changes of pH, sensory properties of these products. As mulberry leaf powder addition increased, crude protein, crude fat, crude ash content, minerals and amino acids increased. Whereas moisture content decreased, and in particular,$Ca^{++}$, $K^+$ and $Na^+$ increased. On the other hand, in the sensory properties, the levels of satisfaction about the color, appearance, flavor, texture and savory were lower in mulberry leaf powder added than under control.