• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.213-218
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• 1985

As a way of improving the texture and flavor of soybean cheese, whey-say cheeses were made by coprecipitation of various mixtures of whey, whey powder, soy milk and soy protein powder, and mixed culture of str. lactis, str. cremoris and rennet were added, then the cheeses were cured at $15^{\circ}C$ for up to 10 weeks. Physicochemical characteristics of the cheese were investigated by analyzing pH, titratable acidity(TA), water soluble nitrogen, 10% TCA soluble nitrogen, amino acid composition, beany flavor, color and hardness. The pH of whey-soy cheeses during ripening changed from 5.3 to 4.2 after 5 or 6 weeks and maintained that value while that of soybean cheese maintained a higher pH value. TA of whey-soy milk cheeses was gradually increased to the value of 0.4-0.45 after 8 weeks, but that of soybean cheese reached only 0.2 after the same period. Water soluble and 10% TCA soluble-nitrogen increased steadily during ripening. Hardness of the whey-soy milk cheeses reached maximum after three weeks of ripening and greatest at those made from 3 : 1 mixture of whey and soy milk and that from soymilk. Color of the whey-soy milk chesses was lighter than that of soybean cheese. The bean flavor of soybean cheese was strong and persistent for the whole ripening period. Acid flavor was dominant in the whey-so milk cheese and masked the beany flavor partially.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.205-210
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• 1983

To investigate the characteristics of amino acid fortified tofu manufactured by coprecipition of cheese whey and soybean proteins, experimental tofus were made from various mixtures of whey, whey powder, and soy milk, and general and amino acid compositions and physical properties were analyzed. Physical characteristics such as elasticity, hardness, and brittleness of the whey-soybean tofu were very similar to those of traditional tofu but color of the whey-soybean tofu was lighter than that of soybean tofu. The contents of total solids and protein of traditional tofu were about 19% and 13%, respectively, while those of the whey-soy bean tofus were 17.3%$\sim$18.1% and 10.9$\sim$11.3%, respectively. The 5$\sim$15% of lactose in whey-soymilk mixture was transferred into the tofus. The Content of sulfur-bearing amino acids in the fortified tofu from 3 : 1 mixture of whey and soymilk was 3.8g/100g protein which indicated about 50% fortification of the amino acids as compared to the traditional tofu which contained 2. 54g/100g protein of the sulfur-bearing amino acids.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.99-104
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• 1996

Carbohydrate-free caseinomacropeptide (CMP) was isolated from the sweet whey powder by a precipitation method using 12% trichloroacetic acid. The yield of carbohydrate-free CMP was 2.7 g from 100 g sweet whey powder. The electrophoretic pattern and the amino acid analysis of CMP showed that isolated CMP was quite pure, indicating the precipitation with 12% trichloroacetic acid was very effective for isolating carbohydrate-free CMP from the sweet whey powder. Trypsin, covalently immobilized on pore glass beads by carbodiimide (EDC) method, was 20mg per 1g glass beads. CMP was almost completely hydrolyzed by soluble trypsin in 24hr, but not by immobilized trypsin. The tryptic hydrolysates were fractionated on a Bio-Gel P 4 column $(1.5{\times}120\;cm)$and separated peptides were tested for their capacities to inhibit platelet aggregation using a aggregometer. The hydrolysate obtained from CMP after 24hr digestion by immobilized trypsin showed the highest activity.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.367-375
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• 2011

For this study, Korean-type Koumiss was made by the fermentation of mixed cultures, in which yeast, Kuyveromyces, and microflora, Streptococcus thermophiles and Lactobacillus bulgaricus, were inoculated into 10% skimmed milk with added whey powder(control: A, 2%: B, 4%: C, 6%: D, and 8%: E). Fat, protein, lactose, titratable acidity, pH, the number of lactic acid bacteria, the number of yeast, alcohol content, volatile fatty acids, volatile free amino acids and minerals were measured in the products. The results were as follows: As the dosage of whey powder increased, fat increased from 0.74% in the control to 2.30% in sample E, protein increased from 2.95% in the control to 4.39% in sample E and lactose increased from 3.10% in the control to 7.43% in sample E. Titratable acidity and pH increased gradually. The number of lactic acid bacteria increased from $10^9\;cfu/m{\ell}$ in the control to $3.8{\times}10^9\;cfu/m{\ell}$ in sample E, and the number of yeast increased from $6.1{\times}10^7\;cfu/m{\ell}$ in the control to $1.65{\times}10^8\;cfu/m{\ell}$ in sample E, according to the increase of whey powder content. For alcohol content, the average values were 0.863%, 0.967%, 0.890%, 1.290%, and 1.313% for the control and samples B, C, D, and E, respectively. As the dosage of whey powder increased, alcohol content showed a tendency to gradually increase. The average alcohol content of E was 1.313 and this was higher than the alcohol content of Kazahstana-type Koumiss with 1.08%. Sixteen types of free amino acids were detected. Glycine was the lowest in the control at $0.38mg/m{\ell}$ and sample E contained $0.64mg/m{\ell}$. Histidine was also low in the control at $0.42mg/m{\ell}$ and sample E contained $0.65mg/m{\ell}$. On the other hand, glutamic acid was highest at $4.13mg/m{\ell}$ in the control whereas sample E had $6.96mg/m{\ell}$. Proline was also high in the control at $1.71mg/m{\ell}$ in control, but E contained $2.80mg/m{\ell}$. Aspartic acid and leucine were greater in sample E than in the control. For volatile free fatty acids, content generally had a tendency to increase in the control, and samples B, C, D, and E. Content of acetic acid gradually increased from $12,661{\mu}g/100m{\ell}$ in the control to $37,140{\mu}g/m{\ell}$ in sample E. Butyric acid was not detected in the control and was measured as $1,950{\mu}g/100m{\ell}$ in sample E. Caproic acid content was $177{\mu}g/100m{\ell}$ in the control and $812{\mu}g/100m{\ell}$ in sample E, and it increased according to the increase of whey powder content. Valeric acid was measured in a small amount in the control as $22{\mu}g/100m{\ell}$, but it was not detected in any other case. Mineral contents of Ca, P, and Mg increased from 1,042.38 ppm, 863.61 ppm, and 101.28 ppm in the control to 1,535.12 ppm, 1,336.71 ppm, and 162.44 ppm in sample E, respectively. Na content was increased from 447.19 ppm in the control to 1,001.57 ppm in sample E. The content of K was increased from 1,266.39 ppm in the control to 2,613.93 ppm in E. Mineral content also increased with whey powder content. In sensory evaluations, the scores increased as whey powder content increased. Flavor was lowest in the control with 6.3 points and highest in E with 8.2 points. Body and texture were highest at 4.2 points in the control, which did not have added whey powder. In the case of appearance, there were no great differences among the samples.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.627-632
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• 1991

The heat treatment indicators such as HMF contents, lactulose contents and whey protein denaturation rates were measured to refer to the heat treatment intensity of domestic market infant formulae. The HMF contents showed $21.0{\sim}43.9{\mu}mol/l:$ in the case of powder types, the HMF contents in enriched nutrient products(ii) were higher whereas in the case of liquid types they were packed in cans(i). The lactulose contents showed $2.5{\sim}11.4mg/100ml$ in the powder type and $27.0{\sim}164.8mg/100ml$ in the liquid type. There was much difference in the lactulose contents according to the product types. Compared with the ADPI standards, most of infant formulae were considered to be medium-heat class. The whey protein denaturation rates were $1.1{\sim}69.4%$ in the powder type and $37.4{\sim}71.3%$ in the liquid type.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1128-1134
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• 1997

Lactobacillus helveticus was inoculated to the fermentation liquid containing skin milk powder(SMT) plus soymilk, SMP plus isolated soybean protein(ISP), SMP plus ISP plus whey powder(WP) to increase the nutritional and economic value of commercial soy yogurt. The yogurt fermented with soymilk and SMP showed the lower acid production than of SMP and had significant beany flavor in the product. The yogurt prepared with ISP and SMP showed the higher cell number and lower acid production than that of SMP. Also, the partial substitution of SMP with ISP over 6%(w/w) produced less acceptable product due to gel production. The yogurt prepared by the partial substitution of SMP with ISP, WP and SMP showed the higher cell number and lower acid production than that of SMP and not bring about gel formation unlike the case of ISP. Sensory properties of yogurt substituted SMP with ISP and WP(38:62 mixture) below 4% were not significantly different from that of SMP and the sample containing the mixture over 6% and 0.067% artificial flavor showed lower sensory score due to beany taste than that of SMP. But increase of yogurt flavor up to 0.1% resulted in significantly high score in organoleptic acceptability. The separation of water occured in yogurt prepared by the combined mixture of ISP, WP and SMP, and this problem could be resolved by addition of Na-alginate and PGA at the concentration of 0.1%(w/w).

• 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.

• Applied Biological Chemistry
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• v.27 no.1
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• pp.7-13
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• 1984

The effects of various nutrients added to soy milk on the growth of Lactobacillus acidophilus were investigated. Soy milk was prepared from defatted soy flour and various nutrients such as sugars, growth stimulating agents, amino acid and milk by-products. The growth curve obtained from the experiment suggested that the log phase ended after 12hr. Glucose and fructose greatly enhanced the acid production by L. acidophilus. The optimum concentration of these two sugars in the media was approximately 3% each. Among the tested growth stimulating agents, yeast extract stimulated the acid production by L. acidophilus, and the optimum concentration of this additive was approximately 0.5%. L-methionine reduced the acid production by L. acidophilus. Whey powder and skim mills powder did not significantly stimulated the growth and acid production by L. acidophilus. Concentration of protein in soy milk did not affect the growth and acid production by L. acidophilus.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.890-897
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• 2006

The aim of this study was to develop muffins with whey protein concentrate (WPC) substituted for fat at the content of 10%, 20%, 40% or 80%. The quality characteristics were compared with those of a full-fat counterpart. With increasing WPC content, moisture, protein, and ash contents increased, fat content decreased, volume and specific volume of muffin decreased, but weight was unaffected. Crust lightness and yellowness of muffins increased, but redness decreased with increasing amount of WPC. Hardness, cohesiveness, springiness, gumminess and brittleness were the highest in muffin substituted with 80% WPC. Results of sensory evaluation indicated that muffin with up to 40% of the butter substituted by WPC was considered to be as acceptable as the control muffin prepared without WPC.

• Journal of Dairy Science and Biotechnology
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• v.25 no.1
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• pp.55-60
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• 2007

Contents of scorched particles in infant formula were studied to provide a scientific evidence for standardization of Food Regulation in Korea. The specification of scorched particles in infant formula in Korea was satisfied with CODEX, USDA and so on. But food regulations for scorched particles in baby food are not mentioned in Korea. Nowadays social interests of scorched particles in infant formula are being increased in the respect of safety for baby food. The composition and contents of scorched particles were analyzed with Scanning Electron Microscope-Energy Dispersive X-ray Spectrometer(SEM-EDS) and Inductively Coupled Plasma Mass Spectrometer(ICP-MS). The results indicate that the scorched particles consist Ca, Na, Fe, Mg and trace elements derived from the ingredient of infant formula. Infant formula are composed of milk, skimmed milk, whey, mixed vegetable oils, minerals and vitamins. These results also show that the contents of scorched particles of infant formula in Korea are little or similar level to those reported in other countries. In general, heavy metals derived from scorched particle are originally used as a source of minerals in infant formula. And it has been thought that they doesn't effect on Provisional Tolerable Weekly Intake set by FAO/WHO for contents and composition of scorched particles.