• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.571-578
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• 2015

This study was carried out to investigate the quality characteristics of bread containing sweetpotato (Ipomoea batatas (L.) Lam) leaf powder (0, 2, 3, 5, and 7% of the total flour). We found that the addition of sweetpotato leaf powder decreased the pH of the dough, whereas the total titratable acidity increased and the specific volume and baking loss of bread were decreased. However, the moisture content of the bread did not show any significant differences. The L and a values of the bread inner crumb were decreased by the addition of sweetpotato leaf powder, however, the b value was increased. The 2,2-diphenyl-1-picrylhydrazyl-radical scavenging activity, total polyphenol, lutein and ${\beta}-carotene$ contents were increased significantly by the addition of sweetpotato leaf powder. The taste, color, flavor, chewiness and overall acceptability of bread containing 2~3% sweetpotato leaf powder were better than those of the controls. We found that the sample group with 2~3% sweetpotato leaf powder is the optimum content for making bread.

• The Korean Journal of Food And Nutrition
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• v.20 no.1
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• pp.14-19
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• 2007

Caffeine is one of the most well known stimulants which can potentially increase mental performance, release fatigue and decrease depression. Green beans from different soils and climates contain different levels of caffeine, and as well as extracted coffee with different roasting and extracting methods. An investigation looking at pH, acidity, extractable solid and caffeine contents was assessed according to roasting and extracting conditions of various coffee beans. Brazilian coffee beans did not show much variation in pH with respect to roasting and extracting temperature, however, acidity increased in low roasting and extracting temperatures. This was however most prominently observed in Ethiopian and Indonesian coffee beans. The large expansion of coffee bean cells renders them highly porous to the passage of water, consequently extracted solids were found to increase with increasing temperature. This was especially apparent in Columbian coffee which had the highest extracted solids. The amount of caffeine extracted from coffee beans also increased with the higher temperature extraction. The Indonesian and Vietnam robusta coffee varieties showed the highest caffeine content.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.433-440
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• 2016

Purpose: To provide the nutritional information of sweet peppers, we have evaluated changes of nutrient content and retention rates by different sweet pepper types and blanching method. Methods: Four types of raw and blanched ($100^{\circ}C$, 30 sec) sweet peppers were prepared and their weight, nutrient content (3 water soluble vitamins, 10 minerals) and retention rates were analyzed. Results: The weight of blanched sweet peppers was decreased than that of raw sweet peppers. From the results of the two-way analysis, the type of sweet pepper had a greater influence than blanching method used on the thiamine, riboflavin, folate and vitamin C contents (but not niacin) (p<0.05). Red pimento contained the most thiamine (0.1 mg/100 g), riboflavin (0.16 mg/100 g), folate ($47.89{\mu}g/100g$) and total niacin (0.11 mg/100 g). Red paprika contained high levels of riboflavin (0.15 mg/100 g) and folate ($44.96{\mu}g/100g$). Orange paprika contained the highest vitamin C content (116.29 mg/100 g). In addition, the mineral content, with the exception of Se, was strongly influenced by the type of sweet pepper rather than the blanching method (p<0.001). The K content of sweet peppers was higher than other minerals. Overall, after blanching, high retention rates (over 70%) were observed in all types of sweet peppers. However, the retention rates of thiamin, vitamin C and Se showed lower levels (less than 70%). Conclusion: The vitamin and mineral contents depends more on the type of sweet pepper; although vitamin and mineral (except Se) contents showed some changes after blanching. Our results can be utilized to determine the effects of cooking processes on nutritional information.

• Food Science of Animal Resources
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• v.24 no.3
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• pp.209-215
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• 2004

In a trial involving 120 pigs, the growth performance of finishing pigs and proximate composition, physicochemical properites and fatty acid composition of loin muscle were investigated by feeding the high-energy density diet and low-energy density diet. The treatments included feeding 1) the low-energy density diet (3,290 cal/kg DE, 14.50% CP, 0.70% lysine and 0.78% Ca) for 38 days and 2) the hight-energy density diet (3,350 cal/kg ME, 15.0% CP, 0.70% lysine and 0.78% Ca) for 27 days. The average daily gains were significantly higher for pigs fed the high-energy density diet than those fed the low-energy density diet, but average daily feed intake and feed conversion rate were significantly lower than those fed the low-energy density diet (p<0.05). The cooking loss and yellowness of pork were significantly (p<0.05) lower for pigs fed the low-energy density diet than those fed the high-energy density diet. There were no significant differences in carcass characteristics, proximate composition and fatty acid composition of pork. In conclusion, the results of the experiment suggested that the high-energy density diet for pigs tended to improve the growth performance, but the cooking loss and yellowness of pork were higher for pigs fed the high-energy density diet than those fed the low-energy density diet.

• Korean journal of food and cookery science
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• v.29 no.2
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• pp.129-135
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• 2013

The objective of this research was to investigate physicochemical properties of waxy sorghum flours by different milling methods (pin mill and ultra fine mill). Four different sorghum flours were used for the experiments ; PWS (pin milled whole sorghum flour), PS (pin milled sorghum flour without bran), UFWS (ultra fine milled whole sorghum flour), UFS (ultra fine milled sorghum flour without bran). The contents of crude ash and total dietary fiber were the highest in PWS. Amylose content of pin milled sorghum flour was higher than that of ultra fine milled flour. The mean particle size of pin milled flours was six times lager than ultra fine milled flours. The L values of UFS and UFWS were higher than those of PS and PWS, whereas a and b values were higher in PWS. The water binding capacity was highest in UFWS, and solubility was higher in PS and UFS. Swelling power of flours was highest in UFS. The damaged starch content was higher in PS and UFS, which means damaged starch of sorghum flours significantly affected by polishing than milling method. The pasting properties were higher in the pin milled flours. Initial pasting temperature of pin milled flour was ranging from 70.5 to $73.1^{\circ}C$, which are higher than ultra fine milled flour ($68.6^{\circ}C$). The contents of total polyphenol were higher in PWS and UFWS than those of PS and UFS, there was no difference between the two milling methods. The results of this study indicate that physicochemical properties of sorghum flour were affected by milling methods as well as bran.

• Korean journal of food and cookery science
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• v.33 no.2
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• pp.127-136
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• 2017

Purpose: This study examined the effect of different gluten-free flours on the properties of cookies. Methods: Each gluten-free cookie was made from wheat, brown rice, buckwheat, corn, sorghum, teff, or black rice. Results: Baking loss was highest on sorghum (18.85%) and the lowest on teff (12.73%). The spread factor was highest on brown rice (8.20) and lowest on corn (7.60). The density was similar in all samples (1 g/mL). pH was the highest on buckwheat (6.45) and lowest on wheat (5.96). While L-value, a-value and b-value were lowest on black rice, the ${\Delta}E-value$ was the highest on black rice (35.57). The hardness was highest on wheat (30.28 N) and lowest on teff (14.87 N). The polyphenol and flavonoid content was the highest on buckwheat ($25.97{\mu}g\;GAE/mg$) and the flavonoid content was the highest on black rice ($24.33{\mu}g\;QE/mg$). The DPPH IC50 value was highest on wheat ($352.41{\mu}g/mL$) and lowest on black rice ($33.59{\mu}g/mL$). The ABTS $IC_{50}$ value was highest on wheat ($349.30{\mu}g/mL$) and lowest on black rice ($57.72{\mu}g/mL$). The results of the sensory properties revealed color to be highest on corn (7.33). The top grain was similar in all the samples (5.43-6.57). Flavor was highest on black rice and teff (6.43-6.48). The softness was the highest on wheat, sorghum, teff, and black rice (6.48-7.05). Sweetness was highest on sorghum, teff, and black rice (6.19-6.71). The overall preference also was highest on sorghum, teff, and black rice (6.14-6.48). Conclusion: Gluten-free flours can improve the quality characteristics and antioxidant activities of cookies.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.663-670
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• 1997

Four kinds of commercial vinegars were investigated to compare physicochemical properties (pH, acidity, color, tannin and metal content), minor components (free sugar, free amino and organic acid), and their organoleptic tastes. The ratio of nonvolatile organic acid to the total organic acid was decreased in the order of brewed, cider, brown rice, and persimmon vinegar. Especially malic acid content was appeared to be highly remarkable in cider vinegar. Glucose and fructose were the predominant components among free sugars regardless of the kinds of vinegar. Free amino acid contents in cider, brown rice and persimmon vinegars have shown a little deviation among the same kind of vinegar samples, but were obviously more abundant than those in brewed vinegars. Color preference, sourness and sweetness of the vinegars were not statistically different (p>0.05) among four kinds of vinegars, whereas overall taste preference, background taste preference and intensity showed significant differences (p<0.05) with respect to the type of vinegar. Brewed and cider vinegars have revealed higher sensory scores in overall and background taste preference than the persimmon and brown rice vinegars. Even though there were no high relationships between minor components and organoleptic taste in commercial vinegars the ratio of acetic acid to the total organic acid was significantly correlated (p<0.01) with the overall taste preference.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.860-868
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• 1997

The effects of oil unsaponifiables (8 species) and methanolic plant extracts (53 species) on the thermal oxidation of oils during 14 or 16 hour heating at $180^{\circ}C$ were studied by analyzing the fatty acid composition of soybean oil or cottonseed oil. All the unsaponifiables tested did not show any antioxidative activities on the thermal oxidation of soybean oil. However, among the 53 species of methanolic plant extracts, some species (Rheum undulatum L., Chelidonium majus L. var. asiaticum and Eugennia caryopyllata T.) showed very strong antioxidative activities on the thermal oxidation of cottonseed oil. The antioxidative activities of methanolic extracts of these 3 species on thermal oxidation of cottonseed oil during an extended heating period were also studied by heating cottonseed oils for 7 hours a day for 8 days at $180^{\circ}C$. The methanolic extracts of Chelidonium majus L. v. asiaticum and Eugennia caryopyllata T. greatly reduced both polymer formation and linoleic acid decomposition after the 8 day heating at $180^{\circ}C$. However, the methanolic extracts of Rheum undulatum L. was effective for the reduction of polymer formation, but not for the reduction of linoleic acid decomposition.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.353-357
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• 1995

The purpose of this study was to evaluate the possibility of the laboratory-made rice straw pulp tray(RSPT) for mushroom(Agaricus bisporus) pre-packaging. The quality changes of mushrooms packaged respectively in the RSPT and 'commercial' expanded polystyrene tray(EPST) were observed during storage. The weight losses of mushrooms in the two types of trays were maintained below 5% and the Hunter L values were showed above 76 at $4^{\circ}C$, while mushrooms in RSPTs had better lightness than those in EPSTs during storage at $25^{\circ}C$. There were no significant differences in the hardness values and cap openings between mushrooms in the two types of trays at $4^{\circ}C$. The cap openings of mushrooms were more proceeded in RSPTs than in EPSTs at $25^{\circ}C$ and the weight increases of RSPTs were greater than those of EPSTs during storage at $4^{\circ}C,\;25^{\circ}C$. As a result, it may be favorable to apply the environmentally-friendly RSPT to mushroom pre-packaging under the condition of low storage temperature.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.329-335
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• 1995

Rheological properties of whole soybean gel(soygel) were investigated as affected by the water addition ratio, stirring time and Ca salts. The soygel was prepared by suspension of whole soy flour(WSF, 300 mesh) in boiling water, addition of sodium alginate and Ca salts followed by thorough mixing and gel formation at $4^{\circ}C$. The texture properties of hardness, adhesiveness and cohesiveness of the gel were increased as the stirring time prolonged from 5 to 30 minutes. From the results of the rheological and sensory properties, 20 minutes of stirring time was selected for whole soybean gel preparation. Eventhough increase in water addition ratio from 8 to 12 times(water/WSF, v/w) resulted a decrease in hardness and adhesiveness, 10 times ratio was chosen as proper the water addition based on textural uniformity. Among the Ca salts, $CaSO_4$ produced the highest hardness followed by Ca $gluconate-CaSO_4$ mixture(413g) and Ca gluconate at the water addition level of 10 times. In order to determine the amounts of Ca salts, and 0.125g of Ca gluconate or $CaSO_4$ per g WSF were found to be optimum in terms of textural and sensory properties. The proper mixing ratio of Ca gluconate and $CaSO_4$ was found to be 50 : 50, 25 : 75 and 0 : 100.