• Journal of Dairy Science and Biotechnology
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• 제40권3호
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• pp.134-142
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• 2022

Protein-enriched dairy powder is widely consumed to promote muscle synthesis. Recently, in Korea, elderly people have also begun consuming protein powder products to prevent muscle loss. However, these protein-enriched powders have poor flowability and hydration properties because of the fine particles of spray-dried milk protein powder. Therefore, in this study, the fluidized bed agglomeration process was used to solve these problems. The rheological and physical properties of milk protein isolate (MPI)/skim milk powder (SMP) mixtures were effectively improved via fluidized bed agglomeration. The particle size of the MPI/SMP mixtures significantly increased from 35.7-58 ㎛ to 118-136 ㎛, the flowability level improved from fair (21.4-26.3) to good (15.7-16.3), and the cohesiveness level changed from intermediate (1.27-1.36) to low (1.18-1.19) after fluidized bed agglomeration. In addition, the wetting time of the agglomerated MPI/SMP mixtures was effectively reduced to 4.67-58.3 s by fluidized bed agglomeration. These findings may be useful for manufacturing protein-enriched dairy powders with good instant properties.

• 한국수산과학회지
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• 제28권3호
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• pp.325-330
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• 1995

해조류 중 생산량이 많고 건강식품 소재로 가능성이 높은 미역과 다시마를 이용하여 두유와 분리대두 단백질이 첨가된 혼합묵의 제조조건을 규명하였다 두유혼합 미역묵의 제조는 두유의 비율을 증가시킴에 따라 겔강도는 감소되었고, 농축한 두유를 혼합할수록 겔강도는 증가하였다. 또한 조체용해액에 대한 두유의 비율을 7 : 1로 혼합하여 $65^{\circ}C$에서 겔화하는 것이 적절하였다. 조체용해액에 분리대두단백질을 $5\%$(w/w)를 혼합하여 $65^{\circ}C$에서 겔화할때 조체묵이나 두유혼합묵에 비해 높은 겔강도$(900g/cm^2)$을 가지는 분리대두단백질 혼합묵제조가 가능하였다

• 한국식품과학회지
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• 제24권3호
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• pp.294-299
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• 1992

본 연구에서는 분리대두단백질에 단백질 가수분해효소를 처리하여 대두단백질에 가수분해적 변성을 야기하여 그 기능성을 변화 고찰하고 실제 식품에의 이용방법으로 효소처리된 두유로 두부를 만들어 물성실험과 관능평가를 실시하였다. 장엽에서 SPI를 제조한 후 15분간 bromelain으로 처리하여 2.7% 가수분해된 MSPI를 만들어 기능특성을 측정 비교하였다. MSPI는 전 pH범위에서 용해도가 증가하였고, 특히 등전점에서 15% 정도 증가하였다. 유화형성력과 기포팽창력은 증가하였으나 이들의 안정성은 감소하였는데, 특히 기포안정성은 알칼리쪽에서 급격히 감소하였고, 등전점에서는 가장 큰 것으로 나타났다. 표준두유와 변형두유를 혼합하여 제조한 두부로 물성실험과 관능평가를 실시하였을 때 압착실험에서는 변형두부I이 연하고 탄력성 있는 두부를 형성하는 것으로 나타났다. 각 두부의 물성모형은 spring 한개와 Maxwell 모형 세개를 가진 7요소모형으로 동일한 물성모형을 나타내었다. 관능평가에서는 표준두유와 변형두유를 3 : 1의 비율로 혼합하여 제조한 두부의 품질이 가장 우수한 것으로 평가되었다.

• 한국식생활문화학회지
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• 제24권5호
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• pp.561-569
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• 2009

The effects of substituting whey protein isolate (WPI) powder for rice flour during the preparation of paeksulgi (Korean rice cake) were evaluated by objective and subjective tests. Milk whey is drained from milk curd as a by-product of the cheese manufacturing process. Whey protein is known as a good nutritional source and a functional material for many processed foods. WPI contains more than 90% whey protein. The moisture content decreased gradually during storage and the decrease was less in control than WPI powder-substituted groups. The color lightness (L) decreased significantly with increasing WPI powder, wherease the redness (a) and yellowness (b) both increased. Texture analyses revealed that the hardness, chewiness, gumminess, adhesiveness and fracturability of paeksulgitended to increase in proportion to the amount of WPI powder added. Evaluation of the gelatinization of paeksulgi by amylographing revealed that the initial pasting temperature, peak viscosity, hot pasting viscosity and breakdown was lower in samples that contained WPI powder. However, the lowest setback value was observed in the control. The results of the sensory evaluation indicated that paeksulgi prepared with 2% WPI powder had the highest overall acceptability. Taken together, these results suggest that WPI paeksulgi containing 2% WPI powder has the best quality.

• 한국식품과학회지
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• 제38권2호
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• pp.304-308
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• 2006

본 연구에서는 시판되고 있는 카제인 나트륨, 유청 단백질 분리물, 탈지분유 및 전지분유에 TGase를 첨가하여 단백질 이동특성 및 pepsin에 의한 가수분해 정도를 조사하였다. 우유 단백질과 분말 제품들을 TGase로 2시간 동안 반응시킨 후 전기영동을 실시한 결과 모든 시료에서 고분자량의 중합체를 형성하였으며 가교결합 정도는 카제인 나트륨 >탈지분유 >전지분유 >유청 단백질 분리물 순으로 감소하는 양상을 보였다. 인체 내 소화효소인 pepsin에 의하여 가수분해된 카제인 나트륨은 10kDa 이하의 펩타이드로 분해됐고, 유청 단백질은 분해 전, 후 양상이 유사하였다. 유청 단백질 중 ${\beta}-Lg$는 pepsin에 의해 거의 분해되지 않고 저항성을 보였다. 탈지분유, 전지분유 역시 더 낮은 분자량의 펩타이드가 관찰되었는 바, in vitro 상에서의 TGase작용으로 인한 교차결합은 소화효소에 의한 가수분해가 용이함을 확인하였다. 이 결과는 TGase를 첨가하여 새로운 유제품을 개발, 이용하는데 인체내에서의 소화에 거의 문제가 없을 것임을 시사하는 것으로 보인다.

• 한국축산식품학회지
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• 제42권5호
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• pp.889-902
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• 2022

With increasing consumer demand for "clean label" products, the use of natural ingredients is required in the food industry. Protein/polysaccharide complexes are considered good alternatives to synthetic emulsifiers and stabilizers for formulating stable emulsion-based foods. Milk protein and carrageenan are widely used to improve the physical properties and stability of dairy food products. In a previous study, milk protein isolate (MPI) was conjugated with 𝛋-carrageenan (𝛋-Car) in a wet-heating system through the Maillard reaction, and the Maillard conjugates (MC) derived from MPI and 𝛋-Car effectively improved the stability of oil-in-water emulsions. Therefore, MPI/𝛋-Car conjugates were used in whipping cream as natural emulsifiers in this study, and the physical and rheological properties of whipping creams stabilized using MPI/𝛋-Car MC and MPI/𝛋-Car electrostatic complexes (EC) were investigated. The whipping creams stabilized with MPI/𝛋-Car MC have lower rheological parameters (η_a,50, K, G', and G'') than those of whipping creams stabilized with MPI/𝛋-Car EC. Although the overrun value was slightly reduced owing to the addition of MPI/𝛋-Car MC, the stability of the whipped creams with MC was effectively improved due to enhanced water-holding ability by conjugation.

• 한국축산식품학회지
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• 제42권6호
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• pp.915-927
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• 2022

Recently, protein-fortified milk powders are being widely consumed in Korea to prevent sarcopenia, and the demand for high-protein food powders is continuously increasing in the Korean market. However, spray-dried milk proteins have poor flowability and wettability owing to their fine particle sizes and high inter-particle cohesive forces. Fluidized bed agglomeration is widely used to improve the instant properties of food powders. This study investigated the effect of fluidized bed agglomeration on whey protein isolate (WPI)-fortified skim milk powder (SMP) at different SMP/WPI ratios. The fluidized bed process increased the particle size distribution, and agglomerated particles with grape-like structures were observed in the SEM images. As the size increased, the Carr index (CI) and Hausner ratio (HR) values of the agglomerated WPI-fortified SMP particles exhibited excellent flowability (CI: <15) and low cohesiveness (HR: <1.2). In addition, agglomerated WPI-fortified SMP particles exhibited the faster wetting time than the instant criterion (<20 s). As a result, the rheological and physical properties of the WPI-fortified SMP particles were effectively improved by fluidized bed agglomeration. However, the fluidized bed agglomeration process led to a slight change in the color properties. The CIE L^* decreased, and the CIE b^* increased because of the Maillard reaction. The apparent viscosity (η_a,10) and consistency index (K) values of the rehydrated solutions (60 g/180 mL water) increased with the increasing WPI ratio. These results may be useful for formulating protein-fortified milk powder with better instant properties.

• 한국식품조리과학회지
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• 제23권1호통권97호
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• pp.41-49
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• 2007

The substitution effects of whey protein isolate(WPI) for egg in the preparation of sponge cake were determined by objective and subjective tests. Milk whey is drained from milk curd as a by-product of cheese manufacture. Whey protein is known as a good nutritional source and a functional material for many processed foods, especially baked goods. WPI contains above 90% whey protein. The specific gravity and viscosity of sponge cakes tend to be affected by WPI substitution. The cooking loss of sponge cakes with WPI substituted for egg(abbreviated as WPI cake) during oven baking was smaller than that made with egg(abbreviated as egg cake) and the specific loaf volume of WPI cake was larger than that of egg cake. The number of pores was highly increased and the size of pores was more uniformly and finely distributed in the cross section of WPI cake than those of egg cake, as observed by scanning electron microscopy(SEM). The hardness, gumminess and chewiness of WPI cake made with 10-20% WPI substitution were the lowest among all the tested cakes, including egg cake, thereby confirming the considerable improvement in their cake qualities. By the results of sensory evaluation, appearance, pore uniformity, softness, chewiness, moistness, flavor, mouth feeling, and overall acceptability of 10-20% WPI substitute cakes were evaluated as being significantly superior to those of all other cakes(p<0.05). These results support the better physicochemical characteristics and sensory evaluations of sponge cake prepared with 10-20% of WPI substitution for egg.

• 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.

• 한국식품과학회지
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• 제32권3호
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• pp.564-569
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• 2000

가공식품중의 우유단백질 분석을 위하여 효소면역측정법, ELISA를 개발하였다. 특이 항체를 생산하기 위해 열에 안정하고 우유의 주요한 단백질인 ${\alpha}_{s1}-CN$을 토끼에 면역하였다. 항${\alpha}_{s1}-CN$ 항체를 이용하여 간접경합 ELISA를 실시한 결과 검출한계는 $0.1\;{\mu}g/mL$ 이었고 ${\alpha}_{s1}-CN$, skim milk, ${\beta}-CN$과 whey protein isolate에 대한 특이항체의 반응성은 각각 100%, 37%, 0.14%과 0.04% 이었다. 그러나 다른 우유단백질인, ${\beta}-lactoglobulin,\;{\alpha}-lactalbumin$, bovine serum albumin 과 대두단백질인 isolated soy protein 에 대해서는 거의 반응성을 보이지 않았다. 샌드위치 ELISA 결과는 검출한계가 $0.01\;{\mu}g/mL$로 간접경합 ELISA 에 비하여 10배 정도 민감해져 따라서 이를 시료 분석에 이용하였다. 시유에 1-10%의 whole CN을 첨가한 spike test 결과 whole CN의 평균 회수율이 94.8%(CV, 8.2%)으로 나타났다. 식품재료와 유가공 제품에 대한 whole CN의 정량분석을 실시한 결과 탈지유는 29%, WPI는 0.03%, 농후 요구르트는 0.25%였으며 가공치즈는 6.9%로 나타났다.