• Preventive Nutrition and Food Science
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• v.8 no.3
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• pp.278-283
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• 2003

Textural properties of tofu manufactured with micronized full-fat soyflour (MFS) were enhanced by the addition of soy protein isolate, whey protein concentrate, chitosan oligosaccharide and mushroom powder. The MFS solution (14.2% solid content) was converted to semi-solid tofu by a two-stage heat treatment with the addition of 4% coagulant mix. The MFS tofu was evaluated by a compression test as well as sensory evaluation. To produce the semi-solid gel (MFS tofu) with reasonably high strength and toughness, the MFS solution with 14.2% solid content and 7.0% protein had to be heat treated at 121$^{\circ}C$ for 3min. The relative toughness of MFS tofu was increased by the addition of SPI, showing a 144% increase. The toughness of MFS tofu prepared with the MFS/SPI mixture was greatly increased by the addition of WPC at the level of 0.7% and the water separation from MFS tofu was greatly reduced. Furthermore, the toughness and strength of MFS/SPI tofu was enhanced by the addition of 0.1% chitosan oligosaccharide and 0.2% mushroom powder. The sensory evaluation of the tofu fortified with SPI, chitosan oligosaccharide and mushroom powder was superior to that of MFS tofu, with a higher score for overall preference.

• Korean journal of food and cookery science
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• v.26 no.5
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• pp.586-595
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• 2010

This study was conducted to examine the quality characteristics of tofu prepared with Lycii fructus powder(LFP) during storage for 15 days at $5{\pm}1^{\circ}C$. The moisture content, yield rate, tofu whey content and turbidity of soaking solutions of tofu prepared with LFP increased upon the addition of LFP. The pH of tofu prepared with LFP decreased while the acidity increased lightly; however, the acidity of the tofu did not differ significantly according to the level of added LFP. The L value of tofu decreased as the amount of LFP in the formulation increased, whereas the a and b values increased. The color value of tofu prepared with LFP did not depend upon the storage period. The hardness increased significantly with the level of LFP, but it did not differ significantly according to the storage period. The microbial count of tofu prepared with LFP was lower than that of control tofu during the storage period. In terms of overall preference, the preferred tofu contained 1.0% LFP tofu.

• Korean journal of food and cookery science
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• v.18 no.2
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• pp.129-135
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• 2002

The effects of adding green tea powder on the quality and storage characteristics of tofu were studied. As the addition of green tea powder increased, the moisture content of tofu was decreased but those of crude protein and the crude ash were increased. The addition of green tea powder increased the production of whey and consequently decreased the yield of tofu. At the beginning of storage, the pH of the tofu with green tea powder was increased, but decreased rapidly at the eighth day of storage. The pH of tofu-soaking solution was decreased during the storage period. The L and b values showed no significant changes but a value was increased during storage. Textural characteristics of tofu added with green tea powder also did not show significant changes during storage. Although the total plate counts and absorbances of soaking solution of tofu were increased during storage, the samples with 1.0% green tea powder had the lowest TPC (3.0$\times$10$\^$6/ CFU/ml) and the lowest absorbance (0.175) at the eighth day of storage.

• Korean Journal of Food Science and Technology
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• v.51 no.6
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• pp.537-542
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• 2019

Proteins were isolated from four species of edible insects, Bombyx mori, B; Tenebrio molitor, T; Protaetia brevitarsis, P; and Gryllus bimaculatus, G, and their properties were analyzed and compared with those of whey proteins. The yield of the protein isolated from raw materials was 65.0-75.0%. Among three branched chain amino acids (BCAA), the amounts of valine in all the insects were similar to that of the whey protein. The BCAA content was 16.8 and 16.4% in G and T, respectively. The total polyphenolic content and the antioxidant activity of the insect proteins were significantly higher than those of the whey proteins. Based on the sensory test of the protein powder, the whey protein could be replaced by 25% of the isolated protein from the insects, but the taste and flavor needs to be improved. Although the BCAA content of insect proteins was lower than that of the whey protein (by 73-76%), their application could be useful because of high polyphenolic content and the anti-oxidative activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1579-1585
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• 2005

The aim of this study was to propose utilization of tofu whey concentrates separated by ultrafiltration (UF) for yogurt production. The curd yogurt was prepared from whole milk added with skim milk Powder in which UF powder was substituted 0$\%$, 6.25$\%$, 12.5$\%$ or 25$\%$ for skim milk powder. The quality characteristics of yogurt in terms of pH, titratable acidity, viscosity, color and viable cell counts were evaluated. There were no significant differences in pH and titratable acidity between control (yogurt added with only skim milk powder) and yogurt added with UF powder after 24 hr of fermentation at 37$^{\circ}C$. Apparent viscosity of yogurt added with UF powder was lower (2,623 $\∼$ 3,189 cps) than that of the control yogurt (3,196 cps). Lightness and redness value of yogurt added with UF powder were not significantly different from control yogurt, while yellowness value increased as the amount of UF powder increased. Addition of UF powder stimulated the growth of lactic acid bacteria. Gas chromatographic analysis detected acetaldehyde, diacetyl, and organic acids, and more volatile compounds were detected in yogurt added with UF powder. Sensory analysis showed that yogurt added with UF powder were evaluated as acceptable as control yogurt. Therefore, UF powder could be substituted for skim milk powder without depressing yogurt qualify.

• Journal of Dairy Science and Biotechnology
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• v.19 no.1
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• pp.13-21
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• 2001

Milk can be regarded as a complete food, containing protein, fat, lactose, vitamins and minerals. Milk is heated for a variety of reasons. The main reasons are: to remove pathogenic organisms; to increase shelf-life. But, when milk is heated, many changes take place: denaturation of whey proteins and interaction with casein, Maillard browning, losses of vitamin and minerals. The addition of a additive and milk powder to flavor and taste may cause undesirable change of quality during heating milk. The reconstituted milk is the milk product resulting from the addition of water to the dried or condensed form in the amount necessary to re-establish the specified water solids ratio. Therefore, according to the increasement of consumption of processed milk, the necessity for study about the quality of processed milk mixed with reconstituted milk arose.

• Journal of Dairy Science and Biotechnology
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• v.22 no.2
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• pp.131-141
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• 2004

The FTA(Free Trade Agreements) are loading the world trade liberalization. Entering into FTA with Chile on 1 Apr 2004, Korea is trying to tie with Singapore and Japan in FTA. It also has a long-term plan for free-trading with China, USA, ASEAN, Canada and India. The portion of the dairy products imported from Chile, Japan and Singapore is under 1% of total dairy product imports. However, in the long run the conclusion of FTA with dairy product exporting countries such as USA, Australia, New Zealand and Netherlands will give a big impact on the dairy industry with abrupt increment in dairy product imports. Especially, whole and skim milk powder imports which are imported on the high tariff rate expect to increase. Furthermore mixed milk powder(Food preparations of goods and other whey powders) imports which domestic price is higher than world market also will dramatically increase. The milk powder stocks have increased since 2002. That made the government carry out some policies. Those include slaughtering milking cow(2002) and terminating the dairy farm enterprise and decreasing in milk production(2003). Also the case of artificial insemination by a Hanwoo fertilized egg has increased with the rise of Hanwoo farm price in 2003. By those reason, it is forecasted that the downward trend in the number of cow will be continued in 2004. It is also forecasted that the raw milk production in 2004 will decrease 4.4% compared to last year due to decreasing in the number of milking cow and raw milk collecting quota.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.345-349
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• 2016

This study was performed to evaluate the quality characteristics of curd yogurt with different contents [0.5~2.0% (w/w)] of Korean rice wine lees powder (KRWLP). Yogurt was fermented with commercially available mixed lactic acid bacteria (Lactobacillus acidophilus, Bifidobacterium longum, Streptococcus thermophiles) at $40^{\circ}C$ for 15 h. Acid production (pH and titratable acidity) of yogurts increased with increasing KRWLP content. After 12 hours fermentation, titratable acidity of KRWLP yogurt was 1.19~1.29 % and was higher than that (1.07 %) of yogurt made without KRWLP. And also, the number of viable lactic acid bacterial cell increased and the culture time to obtain maximum number of lactic acid bacteria cell decreased with the addition of KRWLP. The curd stability in yogurt was significantly enhanced by repression of whey separation in KRWLP yogurt. In sensory evaluation, there was a similar preference for KRWLP yogurts and the control. These results suggest that KRWLP can be used as foodstuff to improve the quality characteristics of yogurt.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.99-116
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• 2016

We herein performed animal safety assessment in accordance with Good Laboratory Practice (GLP) regulations with the aim of developing sialic acid from glycomacropeptide (hereafter referred to as "GMP") as an index ingredient and functional component in functional foods. GMP is a type of whey protein derived from milk and a safe food, with multiple functions, such as antiviral activity. A test substance was produced containing 7% (w/w) sialic acid and mostly-hydrolyzed whey protein (hereafter referred to as "7%-GNANA") by enzymatic treatment of substrate GMP. The maximum intake test dose level was selected based on 5,000 mg/kg/day dose set for male NOEL (no-observed-effect-level) and female NOAEL (no-observed-adverse-effect-level) determined by a dose-range finding (DRF) test (GLP Center of Catholic University of Daegu, Report No. 15-NREO-001) that was previously conducted with the same test substance. To evaluate the toxicity of a repeated oral dose of the test substance in connection with the previous DRF study, 1,250, 2,500, and 5,000 mg/kg of the substance were administered by a probe into the stomachs of 6-week-old SPF Sprague-Dawley male and female rats for 90 d. Each test group consisted of 10 male and 10 female rats. To determine the toxicity index, all parameters, such as observation of common signs; measurements of body weight and food consumption; ophthalmic examination; urinalysis, electrolyte, hematological, and serum biochemical examination; measurement of organ weights during autopsy; and visual and histopathological examinations were conducted according to GLP standards. After evaluating the results based on the test toxicity assessment criteria, it was determined that NOAEL of the test substance, 7%-GNANA, was 5,000 mg/kg/day, for both male and female rats. No animal death was noted in any of the test groups, including the control group, during the study period, and there was no significant difference associated with test substance, as compared with the control group, with respect to general symptoms, body weight changes, food consumption, ophthalmic examination, urinalysis, hematological and serum biochemical examination, and electrolyte and blood coagulation tests during the administration period (P<0.05). As assessed by the effects of the test substance on organ weights, food consumption, autopsy, and histopathological safety, change in kidney weight as an indicator of male NOAEL revealed up to 20% kidney weight increase in the high-dose group (5,000 mg/kg/day) compared with the change in the control group. However, it was concluded that this effect of the test substance was minor. In the case of female rats, reduction of food consumption, increase of kidney weight, and decrease of thymus weight were observed in the high-dose group. The kidney weight increased by 10.2% (left) and 8.9% (right) in the high-dose group, with a slight dose-dependency compared with that of the control group. It was observed that the thymus weight decreased by 25.3% in the high-dose group, but it was a minor test substance-associated effect. During the autopsy, botryoid tumor was detected on the ribs of one subject in the high-dose group, but we concluded that the tumor has been caused by a naturally occurring (non-test) substance. Histopathological examination revealed lesions on the kidney, liver, spleen, and other organs in the low-dose test group. Since these lesions were considered a separate phenomenon, or naturally occurring and associated with aging, it was checked whether any target organ showed clear symptoms caused by the test substance. In conclusion, different concentrations of the test substance were fed to rats and, consequently, it was verified that only a minor effect was associated with the test substance in the high-dose (5,000 mg/kg/day) group of both male and female rats, without any other significant effects associated with the test substance. Therefore, it was concluded that NOAEL of 7%-GNANA (product name: Helicobactrol) with male and female rats as test animals was 5,000 mg/kg/day, and it thus was determined that the substance is safe for the ultimate use as an ingredient of health functional foods.

• Journal of Dairy Science and Biotechnology
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• v.30 no.2
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• pp.93-109
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• 2012

This study was performed to investigate the effects of added whey protein concentrates (WPC) and whey powder (WP) on the quality and shelf life of Tofu, a traditional food in Korea. Combined whey powder and whey protein concentrates were obtained at drainage after the casein was separated by using rennet enzyme or acidification of milk. We manufactured whey Tofu and evaluated its nutritional quality by testing, the general composition for yield, moisture, pH, crude protein, crude fat, carbohydrate, rheology, sensory properties, and change during storage. 1. The general compositions of WPC and WP were as follows: (a) WPC: moisture, 5.9%; crude protein, 56.2%; crude fat, 0.1%; carbohydrate, 32.6%; ash, 5.2%; and pH 5.93 and (b) WP: moisture, 3.7%; crude protein, 13.2%; crude fat, 1.6%; carbohydrate, 74.4%; ash, 7.1%; and pH, 6.65. 2. The yield of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=6:4 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=8:2 and (b) in WP, 2% addition was the highest (265%) at $13.3g/cm^2$, but with 4% addition WP was the lowest (184%) at $22.2g/cm^2$. 3. The moisture content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL = 6:4 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=8:2 and (b) in WP, 2% addition was the highest at 79.82% ($13.3g/cm^2$), but 4% was the lowest at 75.18% ($22.2g/cm^2$). 4. The pH of Tofu was as follows: (a) in WPC, the value was WPC 6% > WPC 4% > WPC 2% > control and $CaCl_2$:GDL=6:4 > $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=7:3 and (b) in WP, WP 4% > WP 2% > control. 5. The ash content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=6:4 > $CaCl_2$:GDL=9:1 and (b) in WP, there was no difference between 2% and 4% addition. 6. The crude protein content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=6:4 and (b) in WP, there was no difference between 2% and 4% addition. 7. The crude fat content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=6:4 and (b) in WP, values decreased with increasing pressed weight. 8. The carbohydrate content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=6:4 > $CaCl_2$:GDL=9:1 and (b) in WP, values increased with increasing pressed weight. 9. The rheology test results of Tofu were as follows: (a) in WPC, hardness and brittleness was highest with $CaCl_2$:GDL=8:2 and 6% added WPC. Cohesiveness was highest with $CaCl_2$:GDL=6:4 and 2% added WPC. Elasticity was the highest with $CaCl_2$:GDL=7:3 and the added WPC control. (b) in WP, hardness was the highest with $22.2g/cm^2$ and added WP control. Cohesiveness was the highest with $17.8g/cm^2$ and added WP 2%. Elasticity was the highest with $17.8g/cm^2$ and added WP 4%. Brittleness was the highest with $17.8g/cm^2$ and added WP control. 10. The sensory test results of Tofu were as follows: (a) in WPC, the texture, flavor, color, and smell were the highest with $CaCl_2$:GDL=6:4 and 6% added WPC. (b) in WP, the texture was the highest in the control with $22.2g/cm^2$. Flavor and smell were the highest in WP 2% and $22.2g/cm^2$. Color was the highest in WP 2% and $17.8g/cm^2$. 11. The quality change of Tofu during storage was as follows: (a) in WPC, after 60 h, all samples began to get spoiled and their color changed, and mold began to germinate. (b) in WP, the result was similar, but the rate of spoilage was more rapid than that in the control.