• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.345-351
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• 2005

Physicochemical properties and functionalities of sodium caseinate, whey protein, skim milk, and whole milk with or without transglutaminase (TGase, 200 : 1) at $38^{\circ}C$ were determined. After crosslinking by TGase, whey protein was effective in improving heat stability compared to native protein at over $70^{\circ}C$. Whole milk was stable with lower turbidity compared to native solution. Whey protein showed low hydrolysis degree, fewer than sodium caseinate, during early activation time and increased slightly thereafter Emulsifying activities of sodium caseinate at pH 2 and 8, and whey protein at pH 7 and 8 improved. Emulsion stability of sodium caseinate improved at entire pH range studied. Foam expansion and foam stability of samples improved with TGase-treatment. Viscosities of TGase-treated samples were higher than those of untreated ones.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.359-363
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• 2015

This study was conducted to investigate the differences in the physicochemical properties of organic and conventional milk from Chungnam and Jeonbuk, Korea. The milk was collected from 10 organic and 10 conventional milk farms in February, March and August, and then analyzed for milk composition, minerals and fatty acids. Organic milk showed lower fat (p<0.01) and total solid (p<0.05), but higher phosphorous (p<0.01) content than conventional milk. However, there was no difference in the content of lactose or the somatic cell count. Organic milk showed lower (p<0.01) stearic acid and total saturated fatty acid content, but higher (p<0.01) total, mono-, and poly-unsaturated fatty acid content. These results showed that organic and conventional milks differ mainly in their fat and unsaturated fatty acid content. Due to increasing consumer interest in food safety and health, organic milk, which contains more beneficial fatty acids, might be preferred over conventional milk.

• Korean journal of food and cookery science
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• v.22 no.2 s.92
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• pp.204-212
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• 2006

The physicochemical and sensory characteristics of milk bread substituted with a high wont of $\beta$-glucan were investigated. As $\beta$-glucan content increased up to 20%, the loaf volume and bread height were increased. There were no significant differences in Hunter color $L^*,\;a^*\;and\;b^*$ values of both crust and c겨mb of milk bread with $\beta$-glucan added up to 20%. The moisture content and water holding capacity of bread with 30% $\beta$-glucan were the highest among the treatments. Textural properties by TPA showed that hardness was not changed by the addition of $\beta$-glucan right after baking. Sensory evaluation results showed tt the scores of color, flavor, taste and over-all acceptability of the bread with $\beta$-glucan were not significantly different among the treated groups, except for milk bread with 30% $\beta$-glucan. Based on our results, $\beta$-glucan addition up to 20% enhanced baking quality of milk bread.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.6
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• pp.889-893
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• 2016

This study was carried out to investigate the physicochemical and fermentation properties of yogurt made from high pressure processing (HPP) treated milk. Raw milk and commercial yogurt starter were used to make yogurt. Raw milk was HPP treated at 350 or 450 MPa (HPP 350 or 450) for 15 min or heat treated at $80^{\circ}C$ for 10 min. The numbers of lactic acid bacteria of the HPP treated group (HPP yogurt) rapidly increased during 2~4 h, whereas there was not significant difference from control (P<0.05). Titratable acidity of all samples increased, and pH decreased during storage from 0.99 to 1.24%, as well as from 4.59 to 4.20, respectively. It is confirmed that these values are in general ranges for yogurt. Control showed higher viscosity than HPP 350. Syneresis was significantly lower than that of the control (P<0.05). Based on the data obtained from the present study, HPP treatment was effective to enhance the quality of yogurt.

• Food Science and Preservation
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• v.24 no.5
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• pp.576-584
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• 2017

With the goal of developing a new functional fermentation milk using green tea powder (GP), milk was fermented with direct vat set (DVS) starter culture containing Streptococcus salivarius subsp. thermophilus, Lactobacillus paracasei and L. delbrueckii subsp. bulgaricus. We investigated fermentation characteristics and antioxidative activities of fermented milk supplemented with different concentrations (0.5, 1, 2, 3%) of GP. All samples were evaluated for pH, total acidity, viable cell count, and sugar contents. The pH of all samples decreased during fermentation, and the final pH ranged from 4.35 to 4.51. The acidity increased during fermentation, after the fermentation was completed, the titratable acidity was 0.8 to 1.1%. And viable cell count of all samples increased during fermentation, and the final viable cell count was 8.57 to 8.89 log CFU/mL. The sugar content decreased as the fermentation proceeded and finally reached 12 to $13^{\circ}Brix$. And increasing GP, decreased brightness and increased yellowness. Increasing GP concentration added to milk, improved DPPH free radical scavenging activity and ferric ion reducing activity of fermentation milk. The fermentation milk kept their pH, total acidity and viable cell counts standard of fermentation milk during the storage period at $4^{\circ}C$. These findings confirmed the possibility of development of the novel functional fermentation milk through the investigation of the quality characteristics of the fermentation milk added with GP.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.220-231
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• 2023

Although omega-3 fatty acids including docosahexaenoic acid (DHA) contain various health-promoting effects, their poor aqueous solubility and stability make them difficult to be induced in dairy foods. The aims of this research were to manufacture casein derivative-based delivery system using acid-induced gelation method with glucono-σ-lactone and to investigate the effects of production variables, such as pH and charged amount of linoleic acid, on the physicochemical properties of delivery systems and oxidative stability of DHA during storage in model milk. Covalent modification with linoleic acid resulted in the production of casein derivatives with varying degrees of modification. As pH was reduced from 5.0 to 4.8 and the charged amount of linoleic acid was increased from 0% to 30%, an increase in particle size of casein derivative-based delivery systems was observed. The encapsulation efficiency of DHA was increased with decreased pH and increased charged amount of linoleic acid. The use of delivery system for DHA resulted in a decrease in the development of primary and secondary oxidation products. An increase in the degree of modification of casein derivatives with linoleic acid resulted in a decrease in the formation of primary and secondary oxidation products than of free DHA indicating that delivery systems could enhance the oxidative stability of DHA during storage in model milk. In conclusions, casein derivatives can be an effective delivery system for DHA and charged amount of linoleic acid played a key role determining the physicochemical characteristics of delivery system and oxidative stability of DHA.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1307-1313
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• 2011

This study was conducted to evaluate the effects of irradiation temperature on the physicochemical and sensory properties of Tarakjuk, milk porridge. Tarakjuk was gamma-irradiated at different temperatures of $25^{\circ}C$ (in room), $4^{\circ}C$ (in ice), and $-20^{\circ}C$ (in dry ice) at a dose of 10 kGy, and then autoclaved at $120^{\circ}C$ for 15 min for comparison. pH and Hunter's color value of Tarakjuk were not changed by irradiation regardless of the temperature. However, the TBA (2-thiobarbituric acid) value decreased as irradiation temperature was decreased. The viscosity of Tarakjuk irradiated in dry ice was significantly higher than that irradiated at room temperature and in ice (p<0.05). For the sensory evaluation, there were no significant differences in overall acceptability between non-treated Tarakjuk and that irradiated in dry ice. Flavor pattern analysis using an electronic nose with a SAW (surface acoustic wave) sensor determined that the main peaks at retention times 3.88 and 7.34 sec were related with off-flavor induced by irradiation and unique flavor of Tarakjuk, respectively. These results indicated that irradiation at freezing temperature improved quality deterioration of Tarakjuk by gamma irradiation. However, sensory quality of Tarakjuk irradiated at freezing temperature was still lower than that of non-irradiated Tarakjuk. Therefore, further research is needed to improve the quality of Tarakjuk using combined treatment such as addition of antioxidants and vacuum packaging method.

• Journal of Dairy Science and Biotechnology
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• v.37 no.3
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• pp.196-205
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• 2019

Helianthus tuberosus is a perennial plant in the genus, Asteraceae. Pork potato has various pharmacological functions such as improving constipation, preventing bowel disease, inhibiting colon cancer, reducing serum cholesterol, lowering blood lipids, and enhancing blood sugar. This study investigated the physicochemical properties of fermented milk by adding Helianthus tuberosus powder. During the fermentation process, the pH of the fermented milk with added Helianthus tuberosus was higher after 16 hours of fermentation. At 48 hours of fermentation, the pH decreased to 3.70, 3.65, 3.63, and 3.59 with 0% (the control group), 1%, 3%, and 5% Helianthus tuberosus added, respectively. In the last 48 hours of fermentation, the acidity increased to 2.35%, 2.57%, and 3.17% with 0% (the control group), 1%, 3%, and 5% Helianthus tuberosus added, respectively. The number of lactic acid bacteria increased as the quantity of Helianthus tuberosus added increased. The highest number of lactic acid bacteria was 9.96 log CFU/g after 16 hours of fermentation with a 5% addition of Helianthus tuberosus . After 48 hours of fermentation, the amount of lactic acid bacteria decreased to 7.84 log CFU/g and 7.88 log CFU/g in the control group and the 1% added Helianthus tuberosus group, respectively. The addition of 3% and 5% Helianthus tuberosus increased the lactic acid bacteria count to 9.48 log CFU/ g and 9.81 log CFU/g, respectively. As the fermentation time increased, oxalic acid and tartaric acid decreased but lactic acid increased. Lactose degraded galactose and glucose over time. After 48 hours of fermentation, the viscosity in the control, 1%, 3%, 5% added Helianthus tuberosus groups increased to 1,006 cP, 1,026 cP, 1,040 cP, and 1,106 cP, respectively. The antioxidant effect was higher in the 5% added Helianthus tuberosus group (84.14%) than in the control group (80.39%) at 48 hours of fermentation. The concentration of polyphenol was 1.6 mg/g and antimicrobial activity was strong against E. coli and Staphylococcus aureus.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.795-799
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• 1989

This study was carried out to hydrolyze lactose in commercial milk by ${\beta}-galactosidase$ from Kluyveromyces fragilis and to compare some physicochemical properties of yoghurts made from control and lactase-treated commercial milks. Quantitative analysis of sugars was performed by gas liquid chromatograph (GLC) on trimethylsilyl (TMS) derivatives. In commercial milk, 94.6% of lactose was hydrolyzed after 2 hours incubation at $40^{\circ}C$ with 6.0 units/ml of ${\beta}-galactosidase$. pH, titratable acidity and viable cell number of yoghurt made from lactase-hydrolyzed (LH) commercial milk were 4.1, 1.04% and $6.5{\times}10^8/ml$ of Str. thermophilus, $8.9{\times}10^8/ml$ of L. bulgaricus after 8 hours incubation at $40^{\circ}C$, respectively, The total contents of amino acid were 2.63% in control and 2.19%. in LH yoghurt. The total contents of free amino acid were 26.95 mg% in control and 17.55mg% in LH yoghurt. Analysis of free fatty acids resulted in that the contents of short chain fatty acids in LH yoghurt were a little higher than those in control. Both in control and LH yoghurt, the palmitic acid content was highest and that was followed by oleic and myristic acid.

• Korean Journal of Human Ecology
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• v.5 no.1
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• pp.48-61
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• 2002

This study was carried out to investigate the effects of four kinds of leavening agents on Jeung-Pyun fermantation. Milk-wine(M), fresh yeast(F), dry yeast(D), instant yeast(I) were used in Jeung-Pyun ingredients. The physicochemical properties, sensory evaluation were examined. The results of this study are summarized as follows: 1. Basic recipes for Jeung-Pyun by preliminary test were developed. 2. Specific volumes and expansion ratio of Jeung-Pyun was higher in the fresh yeast-added sample. 3. The pH of Jeung-Pyun was decreased significantly as the fermentation progressed 4. In the result comparing Jeung-Pyun extracting after 1st fermentation with Jeung-Pyun extracting 2nd fermentation by SEM, the former was widely distributed in stability of bubble and pore than the latter. 5. Standard recipe by Q.D.A. test added four kinds of leavening agents were as follows: (1)Jeung-Pyun added milk wine was 240min for 1st fermentation time, 60min for 2nd fermentation time, 35$^{\circ}C$ for fermentation temperature, 80% for fermentation humidity respectively. (2) Jeung-Pyun added fresh yeast was 90min for 1st fermentation time, 40min for 2nd fermentation time, 35$^{\circ}C$ for fermentation temperature, 80% for fermentation humidity respectively. (3)Jeung-Pyun added dry yeast was 90min for 1st fermentation time, 60min for 2nd fermentation time, 35$^{\circ}C$ for fermentation temperature, 60% for fermentation humidity respectively. (4)Jeung-Pyun added instant yeast was 90min for 1st fermentation time, 40min for 2nd fermentation time, 30$^{\circ}C$ for fermentation temperature, 60% for fermentation humidity respectively. 6.Based on sensory evaluation, Jeung-Pyun added fresh yeast was significantry higher than others in color, sweetness, moistness, softness, and overall quality. There was negative significance between milk wine flavor and astrigentness, and yeast flavor.