• Title/Summary/Keyword: rheological evaluation

검색결과 208건 처리시간 0.034초

MCT 대체지방의 산화안정성 및 조리 적합성에 관한 연구 (A Study on the Oxidative Stability and Cooking Scientific Characteristics of Fat Substitute MCT)

  • 안명수;우나리야
    • 한국식생활문화학회지
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    • 제18권2호
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    • pp.181-191
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    • 2003
  • This study was carried on the oxidative stability and the real practice possibilities in cooking of fat replacer MCT. Nowadays, it was known that fats and oils had become causes for cardiac disease, obesity and cancer, so the new materials were needed for fat substitute that has less fat contents and low calories. The food industry concerned about fats and oils had been researched and developed new and various kinds of substitute fats. MCT(medium chain triglycerides) is one of the fat based fat substitutes used as fat replacers. The POV of com germ oil(CO), soybean oil(SO), shortening(ST), butter(BT), their blended oil with MCT 10-50%(w/w), and MCT were determined and oxidative stability by POV was compared MCT with those of them. MCT has shown higher oxidative stability than CO, SO, ST, BT, so oxidative stabilities in all kinds of blended oils become higher and higher by the increased substitution ratios. In case of bread, the volume of bread prepared with MCT(MCT bread) substituted for ST at 10-40% level(w/w) were increased a little comparing to that made of shortening(ST bread). But degree of gelatinization of MCT bread were a little lower than ST bread, at the substitute ratio above 40%, the degree of gelatinization were reduced greatly. These phenomena were sustained in 9 stored days. While baking losses of MCT breads were almost same as ST bread until 30% substitute ratio, and the appearances of MCT breads were similar to ST bread until 40% substitute ratio. Also rheological properties and color(Lab) of MCT breads had shown no different significantly from ST bread until 20% substitute ratio, but by the results of sensory evaluation, overall acceptance including appearance, color, flavor, taste, texture of MCT breads were recognized almost same as ST bread by panel until 40% substitute ratio. Depends on the above results, we can suggest that 30-40% of MCT will substitute for shortening in making bread in order to reduce fat and calories intake amounts.

어묵에 처리한 grapefruit 종자추출물의 보장효과 (Preservative Effect of Grapefruit Seed Extract on Fish Meat Product)

  • 조성환;주인생;서일원;김재욱
    • 한국식품위생안전성학회지
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    • 제6권1호
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    • pp.67-72
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    • 1991
  • 어묵에 grapefruit 종자 추출물의 농도별로, 침지 처리한 후 저장기간에 따른 물리, 화학적 변화를 검토하여 다음과 같은 결과를 얻었다. 1. 저장 기간 중 어묵의 조단백함량 변화는 대조구에 비하여 GFSE 의 처리 농도가 높을수록 더 작았다. 2. Texture 는 저장기간이 경과함에 따라 감소하는 경향을 나타내었으나 GFSE 용액 처리구에서는 감소율이 낮았다. 3 어묵 단백질의 SDS-PAGE pattern 변화는 저장기간이 경과함에 따라 분자량, 30,000-32,000의 protein은 점차 가수분해되어 소멸되는 현상을 보였으며 특히 대조군의 경우 2일 경과 후부터 급격한 분해라 이루어져 단백질 major band의 손실율이 크게 증가한 것으로 나타난 반면, GFSE처리 시험구의 경우 4일 경과시에야 비로소 뚜렷한 손실반응을 보여 GFSE처리에 의하여 어묵단백질의 변패 발생 시기를 상당 기간 연장함을 확인할 수 있다.

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폴리덱스트로스의 첨가량에 따른 저 열량 레이어 케이크의 특성 (Characteristics of low calorie layer cake by adding different levels of polydextrose)

  • 송은승;김상진;강명화
    • 한국식품조리과학회지
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    • 제17권4호
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    • pp.367-372
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    • 2001
  • 본 연구에서는 옐로우 레이어 케이크 제조시 쇼트닝 대신 탄수화물계 지방 대체물인 폴리덱스트로스가 사용될 수 있는지 그 가능성을 조사하고 폴리덱스트로스를 여러 가지 비율로 대체하여 제조한 저열량 레이어 케이크의 특성을 평가하였다. 케이크 반죽의 비중과 점도는 지방 대체율이 증가할수록 비중은 증가하지만 점도는 낮아졌다. 주사전자 현미경 측정 결과 지방 대체물이 증가함에 따라 air cell과 함께 지방구의 수와 크기는 감소하였고 점도는 높을수록 치밀한 구조를 보였다. 물성은 대체율이 높을수록 hardness, gumminess, cohessiveness 및 chewiness는 감소하였고 springiness는 증가하였으며 resilience는 차이를 나타내지 않았다 관능적 평가에서 폴리덱스트로스 첨가 25%에서 대조군과 비슷한 선호도를 나타내었고 지방 대체율이 크게 증가할수록 관능적으로는 낮게 평가되었다. 본 실험 결과 지방 대체물인 폴리덱스트로스는 저열량 레이어 케이크 제조시 쇼트닝 대신 25% 첨가시 대조군과 유사한 특성을 나타내어 지방 대체 소재로 사용될 수 있을 것으로 생각되었다.

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Rheology of Concentrated Xanthan Gum Solutions : Steady Shear Flow Behavior

  • Song Ki-Won;Kim Yong-Seok;Chang Gap-Shik
    • Fibers and Polymers
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    • 제7권2호
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    • pp.129-138
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    • 2006
  • Using a strain-controlled rheometer, the steady shear flow properties of aqueous xanthan gum solutions of different concentrations were measured over a wide range of shear rates. In this article, both the shear rate and concentration dependencies of steady shear flow behavior are reported from the experimentally obtained data. The viscous behavior is quantitatively discussed using a well-known power law type flow equation with a special emphasis on its importance in industrial processing and actual usage. In addition, several inelastic-viscoplastic flow models including a yield stress parameter are employed to make a quantitative evaluation of the steady shear flow behavior, and then the applicability of these models is also examined in detail. Finally, the elastic nature is explained with a brief comment on its practical significance. Main results obtained from this study can be summarized as follows: (1) Concentrated xanthan gum solutions exhibit a finite magnitude of yield stress. This may come from the fact that a large number of hydrogen bonds in the helix structure result in a stable configuration that can show a resistance to flow. (2) Concentrated xanthan gum solutions show a marked non-Newtonian shear-thinning behavior which is well described by a power law flow equation and may be interpreted in terms of the conformational status of the polymer molecules under the influence of shear flow. This rheological feature enhances sensory qualities in food, pharmaceutical, and cosmetic products and guarantees a high degree of mix ability, pumpability, and pourability during their processing and/or actual use. (3) The Herschel-Bulkley, Mizrahi-Berk, and Heinz-Casson models are all applicable and have equivalent ability to describe the steady shear flow behavior of concentrated xanthan gum solutions, whereas both the Bingham and Casson models do not give a good applicability. (4) Concentrated xanthan gum solutions exhibit a quite important elastic flow behavior which acts as a significant factor for many industrial applications such as food, pharmaceutical, and cosmetic manufacturing processes.

$\beta-Glucan$ 첨가 Pound Cake의 이화학적$\cdot$관능적 특성 (Physicochemical Characteristics of Pound Cake Added with $\beta-Glucan$)

  • 신유미;김미경;조한영;김미리
    • 동아시아식생활학회지
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    • 제15권6호
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    • pp.728-737
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    • 2005
  • This study was conducted to evaluate the physicochemical characteristics of pound cake made of substituted flour with different amount of $\beta-glucan$ i.e. 3, 6 and $9\%$ respectively. $\beta-glucan$ is a functional food material produced from Agrobacterium sup. R259 KCTC 10197BP. The specific gravity and pH of dough were found to be increased according to $\beta-glucan$ content Rheological property such as adhesiveness of dough has no difference between control and $\beta-glucan$ added groups. The pH of baked pound cake was not significantly different between control and $\beta-glucan$ groups. The volume of baked pound cake wag not significantly different between control and the ones with up to $6\%$ $\beta-glucan$, Lightness (L), redness (a) and yellowness (b) value of Hunter color system of cake crumb were not significantly different among teated groups, except a value of crust in $9\%$ $\beta-glucan$ group. the moisture content of cake increased according to $\beta-glucan$ content. Hardness by texture analyser was decreased with increasing $\beta-glucan$ content although cohesiveness wag not changed in β$\beta-glucan$ groups, compared with the control. Sensory evaluation results showed that the mean scores of over·all acceptability in 3 and $6\%$ $\beta-glucan$ were higher than that of control. Based on these results, the addition of $\beta-glucan$ to pound cake up to $6\%$ was considered to be desirable especially in terms of texture.

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찹쌀가루 첨가량에 따른 콩설기의 질감 및 관능 특성 변화 (Changes on the Textural and Sensory Characteristics of Kongsulgidduk by the Added Amount of Glutinous Riceflour)

  • 김정미;권석임;김종군
    • 동아시아식생활학회지
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    • 제19권1호
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    • pp.89-95
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    • 2009
  • This study was conducted to evaluate the textural and sensory properties of Kong-sulgidduk prepared with two types of soyflour (yellow and black) according to the amount of added glutinous riceflour. The rheological properties of Kong-sulgidduk were changed by the amount of added glutinous riceflour. When the amount of added glutinous riceflour was increased from 10% to 40%, hardness, gumminess, and brittleness were significantly increased in the sulgidduk prepared with yellow soyflour. In the case of black soyflour, the addition of 10% glutinous riceflour began to increase in the gumminess and brittleness. The addition of 30% glutinous riceflour effected a significant increase in hardness. The addition of yellow soyflour resulted in higher cohesiveness, gumminess and brittleness scores than those of black soyflour. The results of color assessments demonstrated that the more glutinous riceflour was added to the sulgidduk, the lower were the L-values; however, as the b- and a-values of the sulgidduk prepared with yellow soyflour increased. The addition of the same quantity of glutinous riceflour to the sulgidduk prepared with black soyflour resulted in a reduction in a- and b-values as compared to the sulgidduk prepared with yellow soyflour. In our sensory evaluation, with to the increasing quantities of added glutinous riceflour, the moisture and chewiness values clearly increased. However, the addition of 10% glutinous rice flour resulted in the highest overall quality. Also, the addition of 20% and 30% black soyflour resulted in better scores than the yellow soyflour samples in terms of color, moisture, and overall acceptability. These results demonstrated that the addition of glutinous riceflour to Kong-sulgidduk improves the textual and sensory properties.

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산처리 공정에 따라 추출한 돈피 젤라틴의 이화학적 특성에 관한 연구 (Effect of Acid Treatment Process on the Physicochemical Properties of Gelatin Extracted from Pork Skin)

  • 염건웅;;민상기
    • 한국축산식품학회지
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    • 제24권3호
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    • pp.266-272
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    • 2004
  • 본 연구는 gelatin의 생산공정에서 각종 산 처리가 최종 gelatin의 품질에 어떤 영향을 주는지를 평가함으로써 양질의 gelatin을 생산하는데 기초를 제공하고자 하였다. Gelatin gel의 물성은 lactic acid로 처리한 gelatin이 높은 hardness, cohesiveness, brittleness를 나타내었고 다음으로는 citric acid, acetic acid 순으로 나타났다. Gelatin의 색도는 citric acid, 처리한 gelatin이 acetic acid나 lactic acid로 산침한 젤라틴 보다 높은 명도를 나타냈다. a-value는 acetic acid로 산침한 gelatin이 가장 높게 나타났으며 황색도를 나타내는 b-value는 lactic > acetic acid > citric acid 순으로 높게 나타났다. Gelatin의 점도를 측정한 결과 전단속도(shear rate)에 대한 전단응력(shear stress)의 관계는 모두 전단속도가 증가함에 따라 전단응력이 증가하는Newton성 유체로 판단되었다. 그 기울기는 acetic acid로 산침한 것이 가장 높게 나타났으며 lactic acid, citric acid 순으로 높게 나타났다. Gelatin내의 hydroxyproline 함량을 살펴보면 acetic acid(0.186 g/100 g sample)로 가장 높은 수치를 나타나며 다음으로 lactic acid, citric acid 순으로 나타났다. 그러나, sample중 crude protein 함량을 비교하면 acetic acid(68.74%), lactic acid(80.08%), citric acid(85.47%)로 나타났다. 이것은 gelatin의 열수 추출시 가장 작게 용출된 acetic acid가 가장 높은 collagenous connective tissue 함량(1.35 g/100g)을 나타내었다.

식초기반 샐러드 드레싱용 다시마 식초 제조 및 이화학적 특성 (Preparation and Physicochemical Characterization of Sea Tangle Vinegar for Utilization as Vinegar-Based Salad Dressing)

  • 한아름;서정희
    • 한국식품조리과학회지
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    • 제33권3호
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    • pp.300-306
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    • 2017
  • Purpose: This study aimed to prepare sea tangle vinegar and test its applicability as a vinegar-based functional salad dressing in terms of physicochemical properties. Methods: Sea tangle vinegar was prepared by mixing sea tangle with sugar and vinegar and fermenting the mixture at room temperature for 3 months. The resulting sea tangle vinegar was examined for its physicochemical properties and antioxidant activity with brewed vinegar and persimmon vinegar as controls. Results: The sea tangle vinegar showed significantly higher viscosity than control vinegars, and shear thinning behavior that is typical for salad dressing containing polymers. In addition, storage modulus (G′) of sea tangle vinegar was relatively high in dynamic viscosity measurement while that of control vinegars remained negligible. Together with the high soluble solids content of sea tangle vinegar, rheological behavior indicates that sea tangle vinegar had soluble polysaccharides extracted from sea tangle, consequently leading to an increase in viscosity. Titratable acidity (TA) and pH were 2.52% and 3.58, respectively, which satisfies the TA and pH requirements for microbiological safety of a salad dressing. Absorbance at 285 nm and Folin Ciocalteu's reagent method revealed that sea tangle vinegar contained antioxidative phenolic compounds. Conclusion: This study demonstrates that sea tangle vinegar could be potentially developed as a vinegar-based functional salad dressing when combined with sensory evaluation in the future.

GDL 두부의 품질 평가 (Nutritive Quality Evaluation of GDL Soybean Curds)

  • 김상애
    • 한국식품영양과학회지
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    • 제13권1호
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    • pp.9-14
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    • 1984
  • 본 실험은 국내산대두와 수입대두를 GDL로 응고 시킨 두부의 화학성분, 무기성분, 구성아미노산, 객관적 평가 및 관능검사를 실시하여 두부제품의 영양적인 면과 기호면을 분석 평가하여 단백질 급원식품으로서 그 이용도를 높이고자 한 것이다. 실험결과는 다음과 같다. 1. 두부의 수율은 D-GDL두부가 I-GDL 두부보다 높아 대두품종에 따른 차가 있었다. 2. 단백질함량은 D-GDL 두부가, 회분함량은 I-GDL 두부가 더 높았다. 3. 구성아미노산 함량은 보통두부의 아미노산 함량보다 높았으며 D-GDL 두부는 I-GDL 두부보다 높았다. 4. Hardness, toughness, springiness, chewiness는 D-GDL 두부가 I-GDL 두부에 비하여 그 값이 높았으며 elasticity, cohesiveness는 거의 차가 없었다. 5. 색상은 D-GDL두부가 I-GDL 두부보다 더 희었으며 a, b값은 거의 차가 없었다. 6. 기호면에서 볼 때 GDL 두부는 우리의 식성에 맞지 않았다.

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유변학을 이용한 콘크리트 크리프 거동 예측 (A Rheological Approach on the Predicting of Concrete Creep)

  • 권기연;민경환;김율희;윤영수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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    • pp.697-700
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    • 2008
  • 본 논문은 유변학을 이용한 합리적인 크리프 예측 모델의 개발을 목표로 한다. 유변학은 응력에 의해 물질에 변형이 유발되었을 때, 변형과 응력 사이의 관계를 규명하는 학문으로 콘크리트와 같은 다공성의 점탄성 구조체의 변형 규명에 효과적이다. 본 논문에서 제안된 모델은 시간 의존성 여부와 발생 메커니즘에 따라 탄성거동, 장기크리프, 시간 의존적 단기크리프 그리고 시간 독립적 단기크리프로 나뉘며, 이와 같은 현상의 분류는 실제 실험값의 시간 경과에 따른 변형 양상을 근거로 한 것이다. 각 부분의 계수 추정 과정에서는 이론(미세프리스트레스 고체화 이론, Microprestress-solidification theory) 및 설계기준(CEB-FIP MC R99)을 최대한 활용하여 모델의 합리성의 높일 수 있도록 하였으며, 부득이하게 이론적 접근이 어려운 경우에는 제한적으로 수치적 접근을 시도하였다. 끝으로 수립된 모델을 실제 실험 데이터에 적용한 결과를 기존의 기준식 및 이론식의 적용 결과와 비교 평가 하였다.

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