• Food Science of Animal Resources
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• v.23 no.1
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• pp.63-69
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• 2003

This experiment was carried out to study changes in solubility and emulsifying properties of whey protein. Whey protein hydrolysates were obtained from tryptic hydrolysis of whey protein concentrate at pH 8.0 and 37$^{\circ}C$ for 6 hours. Emulsifying activity of whey protein hydrolysate was highest at 4 hours of hydroysis and at 5.50% of DH. During hydrolysis of whey protein concentrate with trypsin, ${\alpha}$-lactalbumin was not easily broken down. But ${\beta}$-lactoglobulin was hydrolysed rapidly from the early stage of hydrolysis, producing several low molecular weight peptides, which have to participate in increasing emusifying activity. The solulbility of hydyolysates tended to increase depending on hydrolysis time; however, there was a gradual decrease after 5 hours. The hydrolysate had a minimum solubility near the isoelectric point range (pH 4∼5). The more hydrolysed the whey protein concentrates, the more soluble they are near the pl. They aye also more soluble above pH 6. Emulsifying activity of hydrolysates showed similar results to solubility. Creaming stability gradually increased when hydrolysis increased, increasing rapidly above pH 8 after 4 hours of hydrolysis.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.155-167
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• 2016

Surface-active substances in defatted rapeseed cake were obtained using a supercritical fluid extraction method. Then, it was purified by removing sinapine in the extract through a series of steps using a mixed solvent: diethyl ether and ethyl acetate (1:1, v/v). Emulsifying properties of purified surface-active substances were investigated, including fat globule size, zeta potentials and creaming stability and its antioxidant activity in emulsion systems were also studied by peroxide value and $^1H$-NMR spectrum. It was found that fat globules in emulsions with purified surface-active substances were much smaller than ones with the unpurified. In addition, as pH of the emulsion lowered and with increasing NaCl concentration in the emulsion, they were observed to increase, which led to worse creaming stability. These properties were reflected in changes of zeta potentials of emulsions. The oxidative stability was better in emulsions with purified surface-active substances than ones with Tween 20 or commercial lecithin, possibly resulted from the existence of sinapic acid in the extract. It was concluded that purified surface-active substances from defatted rapeseed cake could be simultaneously used as emulsifier and antioxidant agent in emulsion system.

• Food Science and Preservation
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• v.17 no.4
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• pp.435-443
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• 2010

Physicochemical and functional properties of collage from skate skin (Raja Kenojei) are examined depending on pH and NaCl concentration in the medium. The solubility decreased as NaCl concentration increased but, turbidity increased as concentration of collagen increased. Oil-holding capacity and water-holding capacity were similar to other fish skin collagens. Emulsion activity, creaming stability, and viscosity were lowest at where pH levels were isoelectric point regions of collagens. However, the higher pH values at 7.0-9.0 caused increasing foam expansion, foam viscosity, and gel strength. These results indicated that collagen from skate skin could be used as a functional ingredient for food and industrial applications.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.999-1005
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• 2007

An oil-in-water (O/W) emulsion [20 wt% com oil, 0.5-6.0 wt% fish gelatin (FG), pH 3.0] was produced by high pressure homogenization, and the influence of pH, protein concentration, and homogenization condition on the formation of FG-stabilized emulsions was assessed by measuring particle size distribution, electrical charge, creaming stability, microstructure, and free FG concentration in the emulsions. Optical microscopy indicated that there were some large droplets ($d>10\;{\mu}m$) in all FG-emulsions, nevertheless, the amount of large droplets tended to decrease with increasing FG concentration. More than 90% of FG was present free in the continuous phase of the emulsions. To facilitate droplet disruption and prevent droplet coalescence within the homogenizer, homogenization time was adjusted in O/W emulsions stabilized by 2.0 or 4.0 wt% FG. However, the increase in the number of pass rather promoted droplet coalescence. This study has shown that the FG may have some limited use as a protein emulsifier in O/W emulsions.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.610-617
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• 2009

The stability of corn oil-in-water emulsions coated by milk proteins, sodium caseinate (CAS), or whey protein concentrate (WPC), was compared under the environmental stress of pH change. Emulsions were prepared at 0.1 of protein:oil because the majority of droplets were relatively small ($d_{32}=0.34$ and $0.35\;{\mu}m$, $d_{43}=0.65$ and $0.37\;{\mu}m$ for CAS- and WPC-emulsions, respectively) and there was no evidence of depletion flocculation. As the pH of the emulsions was gradually dropped from 7 to 3, there was no significant difference in the electrical charges of the emulsion droplets between the 2 types of emulsions. However, laser diffraction measurements, microscopy measurements, and creaming stability test indicated that WPC-emulsions were more stable to droplet aggregation than CAS-emulsions under the same circumstance of pH change. It implies that factors other than electrostatic repulsion should contribute to the different magnitude of response to pH change.

• KSBB Journal
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• v.7 no.2
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• pp.118-125
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• 1992

Most of cosmetics are emulsion-type products which contain the sources of nutrition, i.e., vegetable oil, mineral oil and carbohyrate etc.. These additives are usually very susceptible to the contamination by microorganisms. The purpose of this study is to obtain the data necessary not only to prevent dermalopathia occurred by microbials but also to maintain the quality. In this experiment we observed the growth of P.aeruginosa in the cosmetics with or without antiseptics so as to prevent contamination. During the contamination period, the phase became unstable and creaming phenomina was happened together with some discoloration and bad smell. The pH of cosmetic was decreased from 7.6 to 6.0 and the concentration was increased from 1.443 to 1.453 in terms of refractive index during 40 days incubation. By adding antiseptics to the cosmetics, the number of P. aeruginosa from the challenge test method were decreased from $10^8$ cell/ml to $5{\times}10^3$ cell/ml. For the antibacterial effect against P. aeruginosa, p-hydroxy benzoic acid propyl ester in phosphoric acid buffer solution showed the best result.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.473-479
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• 2008

The principal objective of this study was to evaluate the sensory properties and physical characteristics of muffins produced using different fats(butter, grape seed oil) and mixing methods(Creaming method, Foam method, Single-stage method). The muffins weighed between $63.25{\sim}64.50$ g and were $5.77{\sim}6.42$ cm in height. In a texture analyzer test, muffins prepared via the single-stage method with butter evidenced the highest hardness, gumminess, and chewiness values among the five kinds of muffin prepared in these experiments. The springiness value was highest in the muffin prepared via the foam method with grape seed oil. In the sensory evaluation, we detected no significant differences among the muffins in terms of flavor($4.76{\sim}5.24$), taste($4.65{\sim}5.29$), softness ($4.65{\sim}5.41$), and overall acceptability ($4.47{\sim}5.29$). In the chemical composition analysis, moisture and crude protein contents were found to be higher in the control group(p<0.05) than in the muffin prepared via the foam method with grape seed oil(p<0.01). We noted no significant differences among the muffins in terms of crude lipids or crude ash content.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.607-614
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• 1997

Flurbiprofen- and flurbiprofen axetil-loaded microemulsions composed of soybean oil, poloxamer 407, glycerine and water were prepared by generator-type homgenizer and ultrasoni c probe system. The particle size of microemulsions was measured by the dynamic light scattering method. The pharmacokinetics and organ distribution of flurbiprofen were investigated after intravenous injection of flurbiprofen solution, flurbiprofen-loaded microemulsion and flurbiprofen axetil-loaded microemulsions equivalent to 10mg/kg of flurbiprofen to rats. Blood samples were collected from the anterior ciliary artery of rats for 24hr, and flurbiprofen in plasma and organs was analyzed by HPLC. Stable microemulsions were prepared. Even though there is a little change in droplet size just after the preparation, no creaming and no separation were occured during the storage period for 6 months at 4, 21, 37 and 45$^{\circ}C$. Pharmacokinetic parameters and organ distribution of flurbiprofen after intravenous injection of flurbiprofen- and flurbiprofen axetil-loaded microemulsions emulsified with poloxamer 407 were not significantly different from those of commercial lipid microemulsion emulsified with lecithin. Therefore, it is concluded that flurbiprofen- and flurbiprofen axetil-loaded microemulsion prepared with poloxamer 407 could be used as a parenteral formulation.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.2
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• pp.159-165
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• 1997

The primary objective of this study was to learn the effect of various sugar particle size and level on cookie spread, The effect of sugar particle size and level on sugarsnap cookie spread was studied. Three different particle sized sugars; powered sugar, granulated sugar and sanding sugar, were used for the cookie test baking with five different sugar levels; 30, 45, 60, 75 and 90% based on the weight of flour. In mixing process, 5 minutes of creaming time was used for cream making and then the specific gravity of cream was measured on the basis of each different sugar particle size and level. In the result, the specific gravity of cream was influenced by sugar particle size and sugar level. However, the specific gravity of cream had no influence on cookie dough specific gravity. Cookie spread was influenced by sugar particle size and sugar level. Greater cookie spread was obtained by decreasing sugar particle size and increasing sugar level resulted in increased spread. Therefore, selection of suitable sugar particle size and its use level can be factors in controlling spread and imparting desired packaging characteristics.

• Journal of the Korean Society of Safety
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• v.7 no.3
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• pp.22-29
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• 1992

Emulsion-type cometics contain many kinds of carbon and energy source i.e., vegetable oil, mineral oil and carbohydrate etc., those can be used as nutrients and caused contamination by microbials. Thereby we have to keep cosmetics from the possibility of contamination by microbials. From this viewpoint, the purpose of this study is to get the data necessary not only to prevent dermatopathia occurred by microbials but also to sustain the quality. In this experiment, we observed how many Staphylococcus aureus were grown in the prepared cosmetics with or without antiseptics so as to prevent contamination. When the contamination proceed, the stability of phase was disturbed and creaming phenomina was happened with some discoloration and bad smell. About 40 days after, the pH was changed from 7.6 to 6.5 and the refractive index of cosmetic raw materials were changed from 1.4415 to 1.4490(water : oil=70:30). By adding antiseptics Into prepared cosmetics, the number of Staphylococcus aureus with challenge test method were decreased to 7$\times$103 cell/ml. For the antibacterial effect against Staphylococcus aureus, p-hydroxy benzoic acid propyl ester in phosphoric acid buffer solution was the best.