• Title, Summary, Keyword: Emulsion stability

Search Result 517, Processing Time 0.042 seconds

Orthokinetic Stability of $\beta$-Lactoglubulin-Stabilized Emulsions : Effects of Protein Heat Treatment and Surfactant Addition

  • Hong, Soon-Taek
    • Preventive Nutrition and Food Science
    • /
    • v.3 no.2
    • /
    • pp.133-142
    • /
    • 1998
  • Effects of protein heat treatment and surfactant additionoo the orthokindetic stability of $\beta$-lactoglobulin-stabilized emulsions have been investigated under turbulent flow conditions. In studies on protein-stabilized emulsions, samples which had been subjected to heat treatment(i.e. the protein solution orthe emulsion) have been found to be more prone to orthokinetic coalescene than the untreated ones. The emulsions stabilized with protein heated above the denaturation temperature(i.e. 7$0^{\circ}C$) showed the bigger initial average droplet size, which resulted in an increased orthokinetic coalescenece rate. The storage of the protein-stabilized emulsion at high temperature prior to the shearing experiment also made the emulsion less stable in the shear field. Interestingly. the addition of DATEM has been found to produce a substantial increase in orthokinetic stability of the heat-denatured protein-stabilized emulsion system, although Tween 20 is the opposite case.

  • PDF

The Formulation of Semi-Transparent Gel Emulsion by the Liquid Crystal Emulsification Method

  • Kim, Jungil;Lee, Youngkeun;Kim, Yongmin;Yun, Seiyoung
    • Journal of the Korean Applied Science and Technology
    • /
    • v.35 no.4
    • /
    • pp.1478-1486
    • /
    • 2018
  • Liquid crystals offer plenty of useful activities as improving the stability of emulsion, increasing moisturizing power, drug release, improving skin feeling and visual effect for cosmetics fields. In order to prepare stable semi-transparent gel emulsion, liquid crystal emulsification method was used. The emulsion stabilities of systems containing glycerin, fatty alcohols, surfactants, water and oil were investigated at various temperatures as time passed. The stabilities of all emulsions were evaluated by means of a polarizing microscope, SEM, rheometer, colorimeter and DSC. Even though the samples stored at $50^{\circ}C$ thermostatic chamber were occurred the reduction of hardness, turbidity and ${\Delta}H$ and the peak shift, the semi-transparent gel emulsion was very stable without separation between water and oils phase in emulsion.

Production and Heat-Stable Characteristics of Emulsion Made from Buckwheat Sprout Extracts (메밀 싹 추출물 에멀젼의 제조 및 에멀젼의 열 안정 특성)

  • Cha, Bo-Sook
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.43 no.10
    • /
    • pp.1549-1554
    • /
    • 2014
  • This study analyzed the production and heat stability of an emulsion made from buckwheat sprout extracts with high rutin content. To obtain high rutin contents, buckwheat was sprouted and the polyphenols and rutin were extracted from buckwheat sprouts. Concentrated extracts were made into an emulsion using a homo mixer and hydraulic homogenizer, after which heat stability was analyzed. The polyphenol contents were highest in ground sprouts grown for 8 days (10.66 mg/g), which was 10 times higher than those of buckwheat seeds. Extraction with 50% ethanol after blanching was the most effective method for obtaining extracts with higher polyphenol content and rutin content. Extracts were concentrated up to 60% soluble solid content and then emulsified using a homo mixer and hydraulic homogenizer. Heat stability of the emulsion passed through the hydraulic homogenizer was slightly higher than that made using the homo mixer. The heat stability of the emulsion was more strongly affected by heating time than temperature. In conclusion, the buckwheat concentrate emulsion passed through the hydraulic homogenizer was more heat stable than buckwheat extract alone.

The Study on Emulsifying and Foaming Properties of Buckwheat Protein Isolate (분리 메밀 단백질의 유화 및 기포특성에 관한 연구)

  • 손경희;최희선
    • Korean journal of food and cookery science
    • /
    • v.9 no.1
    • /
    • pp.43-51
    • /
    • 1993
  • Buckwheat protein isolate was tested for the effects of pH, addition of sodium chloride and heat treatment on solubility, emulsion capacities, emulsion stability, surface hydrophobicity, foam capacities and foam stability. The solubility of buckwheat protein isolate was affected by pH and showed the lowest value at pH 4.5, the isoelectric point of buckwheat protein isolate. The solubility significantly as the pH value reached closer to either ends of the pH, i.e., pH 1.0 and 11.0. The effects of NaCl concentration on solubility were as follows; at pH 2.0, the solubility significantly decreased when NaCl was added; at pH 4.5, it increased above 0.6 M; at pH 7.0 it increased; and at pH 9.0 it decreased. The solubility increased above $80^{\circ}C$, at all pH ranges. The emulsion capacity was the lowest at pH 4.5. It significantly increased as the pH approached higher acidic or alkalic regions. At pH 2.0, when NaCl was added, the emulsion capacity decreased, but it increased at pH 4.5 and showed the maximum value at pH 7.0 and 9.0 with 0.6 M and 0.8 M NaCl concentrations. Upon heating, the emulsion capacity decreased at acidic pH's but was maximised at pH 7.0 and 9.0 on $60^{\circ}C$ heat treatment. The emulsion stability was the lowest at pH 4.5 but increased with heat treatment. At acidic pH, the emulsion stability increased with the increase in NaCl concentration but decreased at pH 7.0 and 9.0. Generally, at other pH ranges, the emulsion stability was decreased with increased heating temperature. The surface hydrophobicity showed the highest value at pH 2.0 and the lowest value at pH 11.0. As NaCl concentrationed, the surface hydrophobicity decreased at acidic pH. The NaCl concentration had no significant effects on surface hydrophobicity at pH 7.0, 9.0 except for the highest value observed at 0.8 M and 0.4 M. At all pH ranges, the surface hydrophobicity was increased, when the temperature increased. The foam capacity decreased, with increased in pH value. At acidic pH, the foam capacity was decreased with the increased in NaCl concentration. The highest value was observed upon adding 0.2 M or 0.4 M NaCl at pH 7.0 and 9.0. Heat treatments of $60^{\circ}C$ and $40^{\circ}C$ showed the highest foam capacity values at pH 2.0 and 4.5, respectively. At pH 7.0 and 9.0, the foam capacity decreased with the increased in temperature. The foam stability was not significantly related to different pH values. The addition of 0.4 M NaCl at pH 2.0, 7.0 and 9.0 showed the highest stability and the addition of 1.0 M at pH 4.5 showed the lowest. The higher the heating temperature, the lower the foam stability at pH 2.0 and 9.0. However, the foam stability increased at pH 4.5 and 7.0 before reaching $80^{\circ}C$.

  • PDF

Performance Evaluation of 100 % RAP Asphalt Mixtures using different types of Rapid-Setting Polymer-Modified Asphalt Emulsion for Spray Injection Application (속경성 바인더 유형에 따른 긴급보수용 스프레이 패칭 상온 재활용 아스팔트 혼합물(RAP)의 성능 평가)

  • Kim, Doo Yeol;Jeon, Ji Seong;Lee, Sang Yum;Rhee, Suk Keun;Kwon, Bong Ju
    • International Journal of Highway Engineering
    • /
    • v.19 no.2
    • /
    • pp.75-85
    • /
    • 2017
  • PURPOSES : The purpose of this study was to determine the optimum mix design of the content of 100 % reclaimed asphalt pavement (RAP) for spray injection application with different binder types. METHODS : Literature review revealed that spray injection method is the one of the efficient and economical methods for repairing a small defective area on an asphalt pavement. The Rapid-Setting Polymer modified asphalt mixtures using two types of rapid setting polymers-asphalt emulsion and a quick setting polymer asphalt emulsion-were subjected to the following tests to determine optimum mix designs and for performance comparison: 1) Marshall stability test, 2) Retained stability test, 3) Wet track abrasion test, and 4) Dynamic stability test. RESULTS and CONCLUSIONS : Type A, B, and C emulsions were tested with different mix designs using RAP aggregates, to compare the performances and determine the optimum mix design. Performance of mixtures with Type A emulsion exceeded that of mixtures with Type B and C emulsion in all aspects. In particular, Type A binder demonstrated the highest performance for WTAT at low temperature. It demonstrated the practicality of using Type A mixture during the cold season. Furthers studies are to be performed to verify the optimum mix design for machine application. Differences in optimum mix designs for machine application and lab application will be corrected through field tests.

Emulsion stability of cosmetic creams based on water-in-oil high internal phase emulsions

  • Park, Chan-Ik;Cho, Wan-Gu;Lee, Seong-Jae
    • Korea-Australia Rheology Journal
    • /
    • v.15 no.3
    • /
    • pp.125-130
    • /
    • 2003
  • The emulsion stability of cosmetic creams based on the water-in-oil (W/O) high internal phase emulsions (HIPEs) containing water, squalane oil and cetyl dimethicone copolyol was investigated with various compositional changes, such as electrolyte concentration, oil polarity and water phase volume fraction. The rheological consistency was mainly destroyed by the coalescence of the deformed water droplets. The slope change of complex modulus versus water phase volume fraction monitored in the linear viscoelastic region could be explained with the resistance to coalescence of the deformed interfacial film of water droplets in concentrated W/O emulsions: the greater the increase of complex modulus was, the more the coalescence occurred and the less consistent the emulsions were. Emulsion stability was dependent on the addition of electrolyte to the water phase. Increasing the electrolyte concentration increased the refractive index of the water phase, and thus decreased the refractive index difference between oil and water phases. This decreased the attractive force between water droplets, which resulted in reducing the coalescence of droplets and increasing the stability of emulsions. Increasing the oil polarity tended to increase emulsion consistency, but did not show clear difference in cream hardness among the emulsions.

Determination of Emulsion Stability Index in W/O Emulsion (유중수적형 유화계내에서의 유화안정지수 산출법의 확립)

  • Chang, Pahn Shick
    • Analytical Science and Technology
    • /
    • v.7 no.2
    • /
    • pp.233-236
    • /
    • 1994
  • To evaluate the emulsion stability indices of W/O emulsion system, we developed the simple and sensitive "VOLUMETRIC METHOD". This technique involved the first step of homogenizing the milk fat-water system with Ultra-turrax T25, then the volume of the added water phase was measured immediately. After quiescent incubation in test tubes at room temperature for a desired storage time, the bottom volume of the separated water layer was measured. And then "emulsion stability index(ESI)" was calculated by the following equation : $ESI=(1-V_s/V_a){\times}100$, where $V_a$ means the volume of the added water in the W/O emulsion and $V_s$ represents the volume of the separated water in the W/O emulsion for a desired storage time. The emulsion stability indices of W/O emulsion system at sorbitan trioleate, span 60, and tween 20 were $95.4{\pm}1.8$, $56.1{\pm}2.8$, and $41.6{\pm}2.2$ respectively. Furthermore, the differences between "VOLUMETRIC METHOD" and "Titus et al method" were less than 5.0 of ESI Value.

  • PDF

Stability of Oil-in-Water Emulsions with Different Saturation Degrees from Beef Tallow Alcoholysis Products (우지 Alcoholysis 반응물을 이용한 Oil-in-Water Emulsion의 포화도에 따른 산화특성 및 안정성 연구)

  • Zhang, Hua;Lee, Young-Hwa;Shin, Jung-Ah;Lee, Ki-Teak;Hong, Soon-Teak
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.42 no.6
    • /
    • pp.933-940
    • /
    • 2013
  • In this study, methyl esters with different saturated fatty acids (SFA) were prepared by urea fractionation to make an oil-in-water emulsion. Emulsion characteristics (emulsion stability and oxidative stability) of the methyl ester emulsion were then studied at different percentages of methyl ester saturation (5, 28, 39, 50, and 72%, termed ${\Sigma}$SFA5, ${\Sigma}$SFA28, ${\Sigma}$SFA39, ${\Sigma}$SFA50, and ${\Sigma}$SFA72, respectively). The stability of emulsions (ES) with different SFA content was 46.0 (${\Sigma}$SFA5), 39.5 (${\Sigma}$SFA28), 32.7 (${\Sigma}$SFA39), 32.6 (${\Sigma}$SFA50), and 27.3 (${\Sigma}$SFA72). Results from Turbiscan showed that creaming or clarification, based on the backscattering intensity, was more pronounced with increases in the saturation degree of the emulsion. These results implied that the emulsions with lower saturation were more stable. During 30 days of storage, the lipid peroxide value increased for all emulsions, with the increase less pronounced with the increasing saturation of the emulsion; 1.880 (${\Sigma}$ SFA5), 1.267 (${\Sigma}$SFA28), 1.062 (${\Sigma}$SFA39), 0.342 (${\Sigma}$SFA50) and 0.153 (${\Sigma}$SFA72) mg $H_2O_2/mL$ emulsion. In addition, thiobarbituric acid reactive substances (TBARS) values were significantly lower in emulsions with high saturation (4.419 mg for ${\Sigma}$SFA50 and 4.226 mg for ${\Sigma}$SFA72) than emulsions with low saturation (6.229 mg for ${\Sigma}$SFA5, 6.801 mg for ${\Sigma}$SFA28 and 6.246 mg for ${\Sigma}$SFA39). In conclusion, the emulsions with a higher saturation degree of methyl esters showed lower emulsion stability but better oxidation stability.

Studies on the Development of a Microbial Cryoprotectant Formulation Using a W/O/W Multiple Emulsion System

  • Bae, Eun-Kyung;Cho, Young-Hee;Park, Ji-Yong
    • Journal of Microbiology and Biotechnology
    • /
    • v.14 no.4
    • /
    • pp.673-679
    • /
    • 2004
  • A microbial cryoprotectant formulation using a W/O/W multiple emulsion system was developed. The psychrotolerant microorganism, B4, isolated from soil in South Korea, was observed by the drop freezing method, in which the microorganism sample inhibited ice nucleation activity. The antifreeze activity was eliminated when the microorganism sample was treated with protease, indicating that the antifreeze activity was due to the presence of antifreeze protein. The result of the l6S rDNA sequencing indicated the B4 strain was most closely related to a species of the genus Bacillus. Culture broth of B4 strain (Bacillus sp.) and rapeseed oil containing 1 % polyglycerine polyricinolate (PGPR) were used as core and wall material, respectively. The most stable W/O emulsion was prepared at a core/oil ratio of 1:2. The highest W/O/W emulsion stability was achieved when the primary emulsion to external aqueous phase containing 0.5% caster oil polyoxyethylene ether $(COG25^{TM})$ ratio was 1:1. Microcrystalline cellulose showed better W/O/W emulsion stability than other polymer types. The viability of cells in a W/O/W emulsion was higher than free cells during storage at $37^\circ{C}$. An acidic pH and UV exposure decreased the viability of free cells, but cells in W/O/W emulsion were more stable under these conditions.

Emulsion Stability of Soymilk Produced by the Varied Homogenizing Pressure (균질기 압력을 변화시켜 제조한 두유의 유화안정성)

  • Lee, Kyung-Seok;Kim, Kyung-Tae;Jung, Yong-Myun;Lee, Ki-Young
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.35 no.10
    • /
    • pp.1434-1438
    • /
    • 2006
  • The purpose of this study was to make soy milk without using any food additives. First, it was attempted to find the effects of homogenizing pressure on the emulsion stability of soy milk without addition of monoglyceride. The soy milk was made with the ratio of bean and water as 1:8, and the yields of soy milk was measured to be 5.87 fold of the beans used. lifter making soy milk by differentiated pressure of the homogenizer at $50kg/cm^2,\;100kg/cm^2,\;150kg/cm^2\;and\;200kg/cm^2$, general composition of the center part of soy milk was analysed. The analysis results indicated that the lipid content increased by the increase of the emulsion pressure. Moreover, the suspension stability, emulsion stability and viscosity also increased by the increase of the emulsion pressure. Therefore, we thought that the production of soy milk without adding any emulsifier was possible only by homogenizing at higher pressure over $150kg/cm^2$.