• Korean journal of food and cookery science
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• v.8 no.1
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• pp.15-20
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• 1992

The changes in color of spinach leaves upon blanching in boiling water and by microwave oven were investigated. The noticible changes in color of leaves were observed above $70^{\circ}C$. The values of L (lightness), a (redness) and b (yellowness) were decreased upon blanching. The value of the under surface of leaves was decreased by 2~3 times compared to that of the upper surface. The noticible color changes occured from 15 sec and the absorbance at 432 nm of water increased rapidly from 2 min of blanching in boiling water. Salt (0.5 and 0.9%) decreased the absorbance at 432 nm of water. The changes of L and b of the under surface of leaves upon heating with a microwave oven were less compared with those in boiling water. Based on the color differences of leaves upon blanching in boiling water, the optimum ratio of spinach to water was 1:4 or 1:5.

• Journal of Bio-Environment Control
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• v.13 no.2
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• pp.73-80
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• 2004

Two red pepper(Capsicum annuum L.) cultivars, 'Geumtap' and 'Bugang', were cultivated at main producing areas in Korea and harvested four times in 1998 and 1999. Length, weight, dry matter ratio and color of red peppers were measured at each harvest. The relations between external characteristics with regional climatic elements such as total accumulated air temperature, total amount of precipitation and duration of sunshine during the fruit growing periods were compared. Length and fruit weight decreased by delayed harvest. These characteristics were shown significant difference according to cultivars, but not to growing year. Dry matter ratio had a tendency to increase at the 3rd and 4th harvest. The red color as measured a${\times}$L values of pepper powder, increased with being later in harvesting, but the trend was uncertain. In fruit growth, fruit length showed a positive correlation with total accumulated air temperature in later growth period of fruits(from 1st to 20th day before harvesting), and fruit weight had relationships with accumulated air temperature and total amount of precipitation in later growth period of fruit. There was no relation between dry matter ratio and climate elements. The red color was shown high correlations with total amount of precipitation and duration of sunshine. There was highest coefficient of determination($r^2$) in all external characteristics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.759-765
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• 2013

In this study, we investigated the quality characteristics of Sikhye, a traditional Korean drink, made with various amounts (0.5, 1, 2, and 3%) of powder from the roots of Doraji (RPD), for different storage periods (1, 3, 5, 7, 10, 13, or 15 days). The pH and Hunter's L value of Sikhye decreased with higher amounts of added RPD, while saccharinity as well as "a" and b values increased. During storage, pH and Hunter's L value of Sikhye tended to decrease while "a" and b values increased. The saccharinity of Sikhye with 0.5% and 1% RPD reached its maximum values on the tenth storage day and continuously decreased during the storage period. In contrast, the saccharinity of Sikhye with 2% and 3% RPD increased during the storage period, and had its maximum saccharinity on the fifteenth storage day. During the storage of Sikhye the total microbial cell count, typically $3.19{\sim}0.35{\times}10^2$ CFU/mL on the third storage day, was undetected in Sikhye with 3% RPD. The total microbial cell count of Sikhye without RPD increased to $1.91{\times}10^9$ CFU/mL by the fifteenth storage day, while Sikhye with 0.5, 1, 2, and 3% RPD added contained $8.43{\times}10^8$, $9.77{\times}10^7$, $2.10{\times}10^7$, and $7.21{\times}10^6$ CFU/mL, respectively. Thus, the total cell count was lower with higher additions of RPD. In sensory tests, the Sikhye control, or with 0.5% and 1% RPD added, didn't show significant differences in the texture of rice granules, plumpness of rice granules, floating of rice granules, taste, flavor, and sweetness values. The overall preference was highest (5.38) for Sikhye with 0.5% RPD, followed by the control, 1% RPD, 2% RPD and 3% RPD. In conclusion, according to preference tests, we recommended the addition of 0.5% or 1% RPD in Sikhye.

• Korean journal of food and cookery science
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• v.28 no.6
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• pp.857-863
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• 2012

This study prepares dried sweet pumpkins to optimize pretreatment conditions of blanching, steaming and microwave heating and to investigate the quality characteristic of each method. The sweet pumpkin blanching treatment of moisture content decreased gradually with increasing temperature, and soluble solids, and weight loss was increased. Color temperature is lower, and a higher value of L value and b value increased. As for the sweet pumpkin steaming treatment of moisture content, it was observed that the longer the steaming time was decreased, sugar content was increased. Change of color in the L value, the longer the steaming time a and b values. Also, as for the microwave treatment of the sweet pumpkin, the longer the time the moisture content decreased, it slightly increased soluble solids and weight loss. Blanching showed the lowest hardness of texture, followed by steaming, and microwaves, in order. Penetration per 20 hours per type was determined by sensory evaluation of sugar, and sugar:fructose(1:2)ratio were higher in the composition.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.157-161
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• 1996

Physicochemical and microbial characteristics of traditional kochujang (fermented hot pepper-soybean paste) collected from 55 households at different regions were investigated. The traditional kochujang contained $46.71{\pm}5.98%$ moisture, $46.87{\pm}8.83%$ total sugar, $11.77{\pm}3.90%$ crude protein, $15.01{\pm}6.48%$ salt, $27.52{\pm}7.32%$ reducing sugar, $0.26{\pm}0.15%$ amino nitrogen and $2.69{\pm}2.35%$ ethanol. The pH and titrable acidity were $4.60{\pm}0.23$ and $27.26{\pm}10.98\;ml/10\;g$, respectively. The average water activity of traditional kochujang were $0.79{\pm}0.04$. The Hunter L, a, and b values of kochujang were $16.03{\pm}2.89$, $20.42{\pm}4.37$, and $9.71{\pm}1.92$, respectively. The viable cell counts of aerobic, anaerobic bacteria and yeasts in the traditional kochujang were $1.02{\times}10^8{\pm}1.29{\times}10^8\;CFU/g$, $2.24{\times}10^7{\pm}3.90{\times}10^7\;CFU/g$ and $5.90{\times}10^5{\pm}2.25{\times}10^6\;CFU/g$, respectively. The kochujang collected from various regions showed quite strong liquefying and saccharogenic amylase and protease at different level by samples.

• Food Science and Preservation
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• v.14 no.4
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• pp.378-384
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• 2007

Powder, or a concentrate, of maesil (Prunus mume) were used in the making of kochujang, and were added to kochujang at 0.5 or 1.0% (w/w). Kochujang fermented with maesil powder lower moisture content than did samples fermented with maesil concentrate. Moisture content slowly increased during fermentation, and was $3{\sim}4%$ higher than the initial value after 8 weeks of fermentation. Kochujang fermented with maesil powder or maesil concentrate showed lower pH values and higher total acidities than did the control. The total microbial count was $3.6{\times}10^7\;5.4{\times}10^7\;cfu/g$, and yeast and mold levels were $2.0{\times}10^7{\sim}3.6{\times}10^7\;cfu/g$, as kochujang fermentation commenced. Microbial load reached a maximum by 4 weeks of fermentation, and decreased thereafter. L (lightness), a (redness) and b (yellowness) values of kochujang gradually decreased during fermentation. Compared to methanol extracts of kochujang, water extracts and ethanol extracts showed higher free radical scavenging abilities at the initial stage of fermentation. Control, and samples with 0.5% (w/w) maesil powder or maesil concentrate, attained higher scores in sensory evaluation tests than did samples with higher maesil levels, and were not significantly different at P>0.05 as determined by Duncan's multiple range test.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.243-247
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• 2006

To develop the natural brown hair-dye, we investigated the dyeability of hairs dyed with the extracts of Boehmeria tricuspis and chemical hair-dye and the changes in its colors as affected by the number of washing frequencies. When dyed with the extracts of Boehmeria tricuspis, ${\Delta}E$ values was increased over 11 compared with control and dyed an order of descent YR. ${\Delta}E$ values treated the ashing juice of Japanese cleyera with a mordant was mostly increased about 15.52. Hairs was dyed with the extracts of Boehmeria tricuspis and we investigated L, a, b and ${\Delta}E$ values as affected by the number of washing frequencies. When treated the ashing juice of Japanese cleyera with a mordant, L values was mostly decreased, however, a, b and ${\Delta}E$ values was increased significantly. L values of hairs dyed with the extracts of Boehmeria tricuspis and washed over thirty times became low compared with that dyed with chemical hair-dye and changes in a, b and ${\Delta}E$values of that was small.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.222-229
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• 2007

Changes on physicochemical properties of fresh Korean ginseng during repeated 9 times steaming processes, steaming $90{\sim}95^{\circ}C$ for $1{\sim}3\;hr$ followed by hot air-drying at $50^{\circ}C$ for $36{\sim}48\;hr$, were investigated. The water contents decreased from 73.4% of fresh ginseng to 13.7% finally. The final yields in bases of total weights and dry matter were 21.0% and 79.0%, respectively. As the times of steaming processes increased, lightness (L value) decreased and redness (a value) increased in color of ginseng powder. Browning index also rapidly increased after 3 times of steaming process in particular. Total water soluble sugar contents decreased from 55.4% in fresh to 38.6% in final processed ginseng, but acidic polysaccharide contents increased by about 50% with increasing times of steaming process. Total phenolic compound contents significantly increased with repeated steaming processes especially after 5 times of steaming processes and crude saponin contents also increased in some degree. In the case of major ginsenosides, the contents of $Rb_1$, $Rb_2$, $Rg_1$, Re (representative ginsenosides in fresh ginseng) decreased, but those of $Rg_2$, $Rh_1$, $Rg_3$ (unique ginsenosides in red ginseng) increased after especially 5 times of steaming processes.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.147-156
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• 2012

This study evaluated the effects of presoaking apple slices in 2 or 5% brine solution prior to air-drying at $50^{\circ}C$. Several quality factors of the dried apples were measured including moisture content (MC), water activity ($a_w$), shear force, color values, appearance and consumer likability. Except at time 0, the $a_w$ of presoaked samples was lower than those of control during and after drying. The relationship between MC and water activity during drying was well-fit by an exponential model. During drying, the moisture contents of presoaked samples were slightly higher than control samples with no presoaking. However, the $a_w$ of presoaked slices were lower than control at a given drying time. At a given $a_w$, presoaked slices had higher moisture content. The shear force was lower for samples presoaked in brine solution, particularly at shorter drying times. Presoaked apple slices also were lighter in color after drying than controls. Sensory evaluations suggest that presoaking of apple slices before drying may help enhance palatability. Samples presoaked in 2% brine solution had the highest scores for taste, texture and overallacceptability, while those presoaked in 5% brine solution had the highest scores for appearance.

• Food Science and Preservation
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• v.19 no.5
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• pp.688-695
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• 2012

The effect of soybean flour (0, 5, 10, and 15%) on the quality characteristics (moisture, color, water absorption, solid content, texture properties, and sensory properties) of Topokkidduk stored for two days was studied. The moisture content of Topokkidduk increased with increasing soybean flour concentration at all the storage times. The moisture contents of SF15 (soybean flour 15%) on storage days 0, 1, and 2 were 46.30, 46.30, and 45.00%, respectively. SF15 had the highest moisture content among all the samples. The color of Topokkidduk (L value) decreased whereas its a and b values significantly increased with increased soybean flour concentration (p<0.05). The cooking properties (e.g., water absorption and solid content) resulted from the opposite conditions. Thus, the water absorption decreased and the solid content increased with increasing soybean flour concentration. The texture analyzer revealed that the hardness, chewiness, and cohesiveness of Topokkidduk decreased and that its adhesiveness increased with soybean flour addition, but there were no significant differences in these according to the soybean powder concentration. The taste, flavor, color, hardness, springiness, and overall acceptability values of Topokkidduk containing SF5 (soybean flour 5%) after two storage days, obtained through a sensory test, were highest among all the samples. These results suggest that soybean flour may be utilized as a functional and valuable ingredient in Topokkidduk.