• Korean journal of food and cookery science
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• v.25 no.4
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• pp.435-444
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• 2009

In this study, Paeonia japonica powder was extracted with ethanol, and its antimicrobial activity was investigated. The ethanol extract of the P. japonica had antimicrobial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus. The inhibition zones of the P. japonica ethanol extract (3 mg/disc) against B. subtilis, E. coli and S. aureus were 10, 11, 8.5 mm, respectively. To test the food preservation effect of P. japonica and determine the optimal ratio of the P. japonica extract in the formulation, Sulgidduk samples were prepared with substitutions of 0, 0.25, 0.5, 0.75 and 1% P. japonica extract, and the quality characteristics of the samples were then investigated over 4 days of storage. In these experiments, total cell counts tended to decrease as the amount of added P. japonica extract increased. Moisture contents were not significantly different among the Sulgidduk samples. As the content of the P. japonica extract increased, the L-values of the samples decreased and the a- and b- values increased. In regards to the textural characteristics, the hardness, gumminess, and chewiness of the Sulgidduk samples decreased as the amount of P. japonica extract increased; however, they increased with the progression of storage time. Adhesiveness, springiness and cohesiveness were not significantly different at the different P. japonica extract concentrations and decreased with storage time. In the sensory evaluation, the control group had significantly higher scores for color, flavor and after taste as compared to the P. japonica extract added groups. When the P. japonica extract content was increased, the flavor and overall acceptability decreased, while Bakjakyak flavor, bitterness and off-flavor increased. Softness was not significantly different among the samples. In conclusion, the results indicate that substituting $0.25{\sim}1%$ P. japonica extract in Sulgidduk is optimal for quality and provides a product with reasonably high overall acceptability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1075-1080
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• 2014

The purpose of this study was to evaluate the physicochemical and sensory characteristics of Sulgidduk substituted with 2%, 4%, 6%, or 8% Shinan Seomcho (spinach, Spinacia oleracea L.) powder (SSP). The moisture content was lowest in the control (38.54%) and increased with greater SSP content, whereas water activity showed the opposite pattern. For color values, lightness significantly decreased with increasing SSP content. For texture analysis, hardness was lowest in Sulgidduk substituted with 4% SSP (154.97 g), and fracturability was lowest at a substitution level of 8%. Adhesiveness was not significantly different among the samples. Springiness significantly increased with greater SSP content. Gumminess and chewiness were highest at a substitution level of 2%. In the sensory evaluation, grass-flavor, bitterness, and off-flavor significantly increased with greater SSP content. Moisture was not significantly different among the samples. Sweetness, color, flavor, softness, and overall acceptability significantly decreased with greater SSP content. However, the overall acceptability scores of all samples substituted with SSP were higher than average. From the results, the optimum level of SSP substitution for production of Sulgidduk is be suggested to be 2~4%.

• Food Science and Preservation
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• v.20 no.4
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• pp.488-494
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• 2013

The study was done in order to investigate the effects the red onion powder on the quality characteristics of the Korean steamed rice cake, Seolgiddok, with 3%, 6%, 9% and 12% of the red onion powder weight in control. The moisture content of the control with 0% red onion was 43.74% and it steadily decreased with the increase in powder (12%) resulting to the lowest at 37.02% for the cake. The springiness, adhesiveness and chewiness of the cake decreased according to the increase in powder content, while the hardness and cohesiveness increased together with the increase in powder content. The Hunter color value L in the chromaticity of the cake significantly decreased with the increase in powder content. The a value of the control was 2.18 and was redder with the increase in powder content, while the b value significantly increased together with the increase in powder content. The sensory characteristics of the cake such as color, flavor, taste and softness and chewiness increased along with increase in powder content. The overall taste was judged to be the best for the sample with the 9% added powder.

• Culinary science and hospitality research
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• v.17 no.5
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• pp.184-192
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• 2011

This study aims to provide preliminary data to popularize Sulgitteok with optimum mix proportion of Curcuma longa L. powder by conducting moisture content, color values, texture and quantitative descriptive evaluations on Sulgitteok with 0 to 2.4% of Curcuma longa L. powder. The chemical composition of Curcuma longa L. powder was $12.6{\pm}0.21%$ of moisture, $1.8{\pm}0.12%$ of protein, $1.0{\pm}0.00%$ of fat, $1.3{\pm}0.01%$ of ash, and that of rice flour was $11.7{\pm}0.17%$ of moisture, $7.6{\pm}0.32%$ of protein, $2.1{\pm}0.01%$ of fat, $1.6{\pm}0.01%$ of ash. As the content of Curcuma longa L. powder increased, L-values significantly decreased while a-value and b-value significantly increased. The hardness of the texture characteristics significantly increased with increasing the amount of Curcuma longa L. powder(p<0.05). As for gumminess, cohesiveness, and chewiness, there was no significant difference(p<0.05) depending on the amount of Curcuma longa L. powder. The quantitative descriptive analysis of the color, flavor, moistness and chewiness of Sulgitteok showed that one with 0.8% of Curcuma longa L. powder was evaluated the highest.

• Food Science and Preservation
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• v.17 no.6
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• pp.908-913
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• 2010

Modified atmosphere packaging (MAP) was evaluated for the storage of pumpkin rice cake as a means of preserving quality and extending shelf-life. Retail-sized amounts of rice cake were packaged in trays under different modified atmosphere conditions (air, vacuum, 60% $CO_2$/40% $N_2$ and 100% $CO_2$) using gas-barrier plastic film; control was in air-permeable stretch wrap. The packages were stored at $20^{\circ}C$ with periodical measurement of package atmosphere and cake quality attributes. The modified atmosphere packages of 60% $CO_2$/40% $N_2$ and 100% $CO_2$ inhibited the growth of molds/yeasts completely and significantly retarded the growth of aerobic bacteria. All the packages except that of 100% $CO_2$ showed the reduction of internal $O_2$ concentration and increase of the $CO_2$ with storage time due to the microbial activity. There has been slight decrease of $CO_2$ concentration for 60% $CO_2$/40% $N_2$ and 100% $CO_2$ packages just after start of the storage possibly due to dissolution of headspace $CO_2$ into the cake. Any MAP conditions did not affect the retrogradation of the rice cake. Surface color of the cake within affordable microbial quality limit was not affected significantly by packaging conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.993-998
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• 2011

Citrus peel powder was used to substitute 2%, 4% and 6% rice flour for making sulgidduk. Proximate composition, sensory characteristics, and principle components of sulgidduk containing citrus peel were analyzed and compared with those of sulgidduk. Protein, fat, carbohydrate, ash, color b-value (yellowness index), springiness, and adhesiveness of sulgidduk all significantly increased, whereas color L- and a-values, hardness, cohesiveness, and chewiness of sulgidduk decreased with the addition of citrus peel powder. No significant differences were observed regarding the contents of moisture and carbohydrates, or fracturability in any of the samples. Substitution of rice flour with citrus peel powder showed acceptable sourness and bitterness sensory scores, which were comparable to sulgidduk. Principle components analysis revealed total variation of 94% in the main structured information: PC1 and PC2 showed 79.31% and 14.69% variation. CP-B (citrus peel powder 4%) and CP-C (citrus peel powder 6%) associated the strongest with PC1 and sulgidduk without citrus peel powder associated with PC2. Attributes associated strongly with PC1 were color, bitterness, adhesiveness, and sourness. Therefore, sulgidduk containing CP-B can be developed based on its favorable quality characteristics and sensory evaluation.

• Korean journal of food and cookery science
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• v.22 no.5 s.95
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• pp.650-658
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• 2006

This study investigated the effects on the quality characteristics of the korean steamed rice cake, Seolgiddok of the addition of aloe powder at 0%, 1.5%, 3.0%, 4.5% and 6.0% and 4-days storage. The moisture content of the control 0% aloe, steamed rice cake was 47.76%, and steadily decreased with increasing powder addition to the lowest of 37.38% for the cake with 6.0% added. The moisture content was decreased with extending storage time in both the control and powder-added groups. The cohesiveness, springiness, adhesiveness, gumminess and chewiness of the cake tended to decrease with increasing powder content, while the hardness increased with both increasing powder content and extending storage time. The Hunter color value L in the chromaticity of the cake was significantly decreased with increasing powder addition. The a value of the control, 0% aloe steamed cake was -0.86, but became positive with red color with increasing powder content, The b value was significantly increased with increasing powder content. The powder addition inhibited the increase in bacteria number. The sensory characteristics of the cake. such as color, aloe flavor and taste, and bitterness were increased with increasing powder content, while the moist and soft feeling of the cake were more highly evaluated at lower powder content. The overall taste was judged to be best for the sample with 3% added powder. Accordingly, it was expected that a highly functional and healthy product with improved quality might be developed by the addition of aloe powder to the Korean steamed cake, Seolgiddok.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.2
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• pp.201-207
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• 2014

This study was conducted to evaluate the quality characteristics of sulgidduck with addition of 0, 1, 3, 5 and 7% turmeric powder. The moisture content of sulgidduck ranged from 33.71% to 37.75. The addition of turmeric powder to sulgidduck tended to decrease the pH value, whereas it did not change $brix^{\circ}$ values of the samples. For Hunter color values, addition of turmeric powder to sulgidduck tended to decrease lightness (L) and increase redness (a) and yellowness (b). For textural characteristics, addition of turmeric powder decreased hardness, whereas adhesiveness and springiness of the samples were unaffected. The addition of turmeric powder to sulgidduk tended to increase gumminess. The addition of turmeric powder to sulgidduk tended to decrease chewiness. In the sensory evaluation, addition of 3% turmeric powder resulted in the best score in terms of taste and overall preference. Therefore, these results suggest that addition of 3% turmeric powder could be applied for making turmeric powder sulgidduk.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.277-283
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• 2017

To produce sweet liquor without artificial sweeteners, 8 traditional rice pre-treatment methods (juk, beombeok, seolgitteok, gumeongtteok, mulsongpyeon, injeolmi, gaetteok, and godubap) were analyzed in this study. The formation of sugars with the help of ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase using nuruk as a substrate has been previously confirmed. During the early stages of the pre-treatment processes, the amount of maltose produced (in descending order of its concentration) by ${\alpha}$-amylase was observed to be as follows: gaetteok > seolgitteok > beombeok > mulsongpyeon > juk > injeolmi > gumeongtteok > godubap. However, changes in maltose concentrations with respect to the pre-treatment processes after 48 hours were observed to be as follows: injeolmi > beombeok = godubap > gumeongtteok > gaetteok = mulsongpyeon > seolgitteok > juk. Maltose produced using either ${\alpha}$-amylase or ${\beta}$-amylase showed similar results. Glucoamylase produced 10 mg/ml of glucose during the godubap process, which was the highest amount of glucose among all the methods. Moreover, when ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase were used concurrently, glucoamylase increased glucose production in the later stages. Therefore, the possibility of producing sweet liquor without employing artificial sweeteners was confirmed, even if the amount of sugar in the liquor varied with the pre-treatment process.

• Korean journal of food and cookery science
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• v.21 no.1 s.85
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• pp.110-116
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• 2005

In order to develop a dandelion (Taraxacum officinale) with natural food applications, the effects of dandelion leaves and roots powder content on the physical, textural and sensory properties of sulggidduk were examined. Dandelion powders of leaves and roots at 0, 1, 2 and $3\%$ were added to the dandelion sulgidduk. In the dandelion roots powder in sulgidduk, the color intensity of L values and the values and moisture content decreased however, the sensory color intensity, dandelion flavor and overall acceptability increased with increasing the dandelion powder content. The sensory overall acceptability indicated the dandelion roots powder content at 3% had the highest overall and flavor scores. As the dandelion leaves content was increased, the moisture contents, lightness, adhesiveness and cohesiveness of sulggidduk decreased, while the sensory color intensity, sensory hardness, hardness of texture properties and dandelion flavor increased. The addition at $1\%$ of the dandelion leaves powder content with the dandelion sulggidduk and the addition at $3\%$ of the dandelion roots powder content with the dandelion sulggidduk showed the highest overall acceptability.