• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.131-135
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• 1985

The rheological studies on dilute and concentrate solutions of naked and covered barley starches were carried out with various viscosimeters. The rheology of dilute solutions (0.05-0.3%) were characterized by intrinsic viscosity and related parameter according to Huggins equation. Also, the rheology of the solutions of higher concentrations (1-5%) were characterized by time dependent characteristics and pseudoplastic behaviors. The values of consistency index according to the power equation were exponen tially dependent upon concentration and temperature. The results showed that the rheological properties could differ greatly due to difference in varieties. The naked barley starch exhibited higher intrinsic viscosity, more thixotropic behavior and more dependence of consistency index on concentration and temperature than the covered barley starch.

• Journal of Pharmaceutical Investigation
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• v.26 no.3
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• pp.221-232
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• 1996

An abrasive, calcium hydrogen phosphate dihydrate (DCPD), was synthesized in a Box-wilson experimental design by reactions between phosphoric acid and milk of lime, and calcium chloride and sodium phosphate solutions, and stabilized with TSPP and TMP. The optimum conditions for preparation of DCPD from phosphoric acid with milk of lime were such as; reaction temp.; $51.9^{\circ}C$, conc. of lime; 25.9%, conc. of phosphoric acd; 77.9%, drying temp.; $60.2^{\circ}C$ and final pH; 6.46. The physico-chemical and pharmaceutical properties of DCPD were showed as follows: glycerin absorption value(68 ml/100g), whiteness(99.5%), particle size(10.9 nm), pH(7.8), and set test(pass). XRD and SEM of DCPD indicated a monoclinic system crystallographically. $N_2$ adsorption isotherm curve by BET showed non porous type II form. The micromeritic parameters of DCPD showed that surface area was $3.27{\sim}4.6\;cm^{2}/g$ and pore volume, pore area and pore radius were negligible. The rheogram of the toothpaste containing DCPD showed pseudoplastic flow with yield value of 321, and thixotropic behavior forming hysteresis loop. These results meet the requirements as abrasive standard, and sythesized DCPD is expected as a good dental abrasive such as a high quality grade in practice.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.839-844
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• 1995

Appropriate types and concentrations of starch-based fat replacers which are low-pH stable, shear resistant and heat stable were selected to develop reduced-fat mayonnaise without affecting taste, texture and emulsion stability. Four kinds of commercial fat replacers [Neutral DR (DR), Stellar 100X (SX), Sta Slim 150 (SS) and N-Lite L (NL)] were thermally activated after appropriately hydrated and applied to mayonnaise formulation. For each fat replacer, eight recipes having various ratios of soybean oil/fat replacer(95/5 to 60/40) were formulated and compared with standard formulation(100% soybean oil) using rheological and sensory evaluations. All tested starch pastes showed pseudoplastic behavior, time-dependent thixotropic gel characteristics. The increasing order of pseudoplasticity and yield stress was RM, NL, SS and ST. The hardness and adhesiveness of each fat replacer-added mayonnaise was increased in the same order as above. Formulated mayonnaise which contained higher ratio of fat replacer showed lower values in hardness and adhesiveness. ST at up to 25% oil replacement exhibited the highest oil replacing ability among four replacers. ST-added mayonnaise also exhibited the highest sensory score and emulsion stability among all products including standard formula. The high sensory score in spreadability of RM-added mayonnaise well reflected the consistent index of RM paste. Use of fat replacers reduced oily odor and greasy aftertaste of mayonnaise.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.1
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• pp.47-54
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• 2013

Aloe gel microcapsule was prepared by dehydrating dispersed aloe gel droplets in the form of W/O emulsion using a vacuum evaporator. The microcapsules remained in stable suspensions after washing with mineral oil and had a homogeneous spherical structure with diameter less than 6.4 ${\mu}m$. The microcapsule suspension in mineral oil (> 41%) exhibited a step increase in viscosity and shear-thinning but not showed thixotropic behavior with a yield stress higher than 300 Pa. The dense suspension appeared to be semi-solid as the microcapsule fraction increases and to be stable after heat treatment at $105^{\circ}C$ for 15 min. In conclusion, the dense suspension composed of gel microcapsules is expected to provide a basic cosmetic formulation that can be applied to develop various types of aloe gel cosmetic products.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.415-420
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• 2019

To investigate the effect of nonionic surfactant and emulsion stabilizer on O/W emulsions, various emulsion formulations with different types of nonionic surfactants and emulsion stabilizers were prepared and their rheological properties were compared. In this study, polysorbate 60 (Tween 60), PEG-60 hydrogenated castor oil (HCO 60), octyldodeceth-16 (OD 16), and ceteareth-6 olivate (Olivem 800) were used as hydrophilic nonionic surfactants, whereas cetyl alcohol, glyceryl monostearate, and stearic acid as emulsion stabilizers. Phase separation occurred only in the emulsion formulation with octyldodeceth-16 and all other emulsion formulations maintained a stable phase. The viscosity, hardness, and creaminess of emulsion formulation using a mixture of ceteareth-6 olivate and cetyl alcohol were the highest, and the emulsified droplet size was also the largest. These results are due to the formation of a network structure texture with the development of a large amount of liquid crystal in the O/W emulsion. In this formulation, the value of elastic modulus was large and the thixotropic behavior, in which the viscosity varies with the history of external force, was observed.

• Food Science and Preservation
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• v.30 no.3
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• pp.405-418
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• 2023

The aim of this research was to study the feasibility of the defatted wheat germ flour (DWGF) alone or in combination with xanthan gum (XG) as egg yolk substitutes in mayonnaise formulation. In this research, DWGF was used at different levels (0, 25, 75 and 100%) alone or in combination with the XG (0.2%) as egg substitutes. The effects of these substitutions on the stability, textural and rheological characteristics of mayonnaise were investigated. According to the results, DWGF can be used as an egg yolk substitute in mayonnaise. Combining DWGF and XG as egg yolk substitute, improved the stability, textural and rheological properties. Mayonnaise with 100% egg yolk replacement showed the hardest structure, while the lowest firmness value was obtained in the control containing 100% egg yolk. Also, the highest adhesiveness value occurred in the sample with 100% DWGF. The thixotropic behavior was observed for all investigated mayonnaise samples over the all ranges of the studied shear rate (0.05-450/sec). Furthermore, the highest content of consistency coefficient value was observed in the sample with 100% DWGF and 0.2% XG. Therefore, it can be concluded that low-cholesterol mayonnaise with proper stability, textural and rheological characteristics are achievable by applying of the desirable combination of DWGF and XG.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.2
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• pp.119-127
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• 1986

The rheological properties of mayonnaise were studied with cylindrindrical viscometer. It was observed that mayonnaise showed pseudoplastic behavior, yield stress and time dependent characteristics. In the initial period of shear time, the decay of viscosity of mayonnaise was followed by a second-order kinetic equation. The influence of temperature on viscosity could be described by Arrhenius equation. The apparent viscosity of mayonnaise markedly increased with an rise in the concentration of egg yolk; and the emulsion was most stable at the concentration of 12%. At the concentration of $65{\sim}75%$ oil, the apparent viscosity was increased; the maximum value was reached at 75% oil, and above 75% oil, the remarkable decreased was observed. The size of oil drops was decreased with an increase in oil concentration of 75% oil. The apparent viscosity of mayonnaise was increased with an rise in water contents, while being decreased with one in the concentration of vinegar.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.184-189
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• 2008

Effects of sucrose at different concentrations (0, 10, 20, and 30%, w/w) on steady and dynamic shear rheological properties of sweet potato starch (SPS) paste (5%, w/w) were investigated. The steady shear rheological properties of SPS-sucrose composites were determined from rheological parameters based on power law and Casson flow models. At 25$^{\circ}C$ all the samples showed pseudoplastic and thixoropic behavior with high yield stress. Consistence index (K), apparent viscosity (${\eta}_{a,100}$), and yield stress (${\sigma}_{oc}$) values of SPS-sucrose composites decreased with increasing sucrose concentration from 10% to 30%. The decrease of swelling power was observed at higher sucrose concentration (>20%) and the low swelling power yielded a lower K, ${\eta}_{a,100}$, and ${\sigma}_{oc}$ values. In temperature range of 25-70$^{\circ}C$, Arrhenius equation adequately assessed variation with temperature. Oscillatory test data showed weak gel-like behavior. Magnitudes of storage (G') and loss (G") moduli increased with an increase in sucrose concentration and frequency. The SPS-sucrose composite at 30% concentration closely followed the Cox-Merz superposition rule.