• Journal of Korean Society of Environmental Engineers
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• v.30 no.8
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• pp.839-846
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• 2008

The flocculation characteristics of polyacrylamide base flocculants were estimated to reduce the moisture content of the dehydrated cakes. The dewaterability for sewage sludge was found to have a marked effect depending on the flocculant type, agitating speed and time, kind of dissolution water, etc. The optimal agitating speed and time were 700 rpm and 3 sec, respectively, in this experimental condition. and the dewaterability was proportion to the agitating speed upto 700rpm. When recycle water as the dissolution water was used, the solution viscosity of all kind of flocculants was decreased. However, the change of its viscosity are not proportioned to the dewaterabilities for each flocculant. Flocculation system of combinations of the first and sencond flocculation using single flocculant was investigated. Effects of the ratio of first and second dosage for dual flocculation on the dewaterability were also investigated. The optimum conditions of dual flocculation system are 75% and 50% as first dosages for low and high viscous flocculant for total dosage of common flocculation, respectively. Based on the results, an overall mechanism of dual flocculation system is proposed and it is envisaged that optimization of flocculation processes in this way can result in considerable savings in cost.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.4019-4023
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• 2014

This study examined the effectiveness of ultrasound on enhancing the dewaterability and volume reduction of bio solids from a waste treatment plant. The test specimen was obtained from a storage tank immediately before the dewatering process at a local treatment plant. The test conditions included the energy levels of ultrasonic waves and treatment time. The tests were undertaken using three types of different treatment processors (7 liter, 1 ton, 7 ton container). The capillary suction time (CST) and the viscosity of sludge, which is one of the influencing factors for dewaterbility, were obtained under various test conditions. The results showed that ultrasound increases the CST of the raw specimens, whereas a significant reduction (20 % of the maximum value) of CST occurred in the sample with ultrasound and flocculent. The decrease in viscosity reached 40 % of the maximum value. A centrifugal test was performed to examine the characteristics of the sludge settlement. The settling rate and time required to reach the final values were both enhanced by the ultrasonic energy. An ultrasonic treatment is potentially useful tool for reducing the amount of released sludge. To examine the possible use of field application, the real scale sonic processor was designed and operated. The results were similar (50 % of the maximum value) to those of laboratory experiments.

• Membrane Journal
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• v.12 no.1
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• pp.41-50
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• 2002

The streaming potential generated by the electrokinetic flow within electric double layer of charged microchannel is applied to determine the zeta potential of hollow-fiber membrane pore by using the general Helmholtz-Smoluchowski equation. The streaming potential is know to provide a useful real-time information on the surface property and the interaction between pore and particles in actual situations and physicochemical conditions. The influence of physicochemical parameters upon the filtration with hollow-fibers has been examined with an in-situ and simultaneously monitoring the streaming potential as well as permeate flux. In particular, the present study examined an experimental method to identify the effect of cake layer which can vary according to the axial position of a hollow-fiber and the progress of membrane fouling by measuring the position-dependent streaming potential. As the latex concentration increases, the permeate flux decreased but the streaming potential increased. The growth of cake layer has been mire developed with increasing latex concentration, however, the effect of surface charges of latexes deposited on the membrane surface leads to increase the streaming potential. With increasing ionic concentration of KCI, both the permeate flux and the streaming potential decrease. The increase of ionic concentration provides a compact cake layer due to the shrinkage of Debye length and the decreased streaming potential results from the weakened ionic flows owing to a thin diffusive double layer.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.8
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• pp.775-780
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• 2008

Sludge conditioning is widely used to improve aggregation and dewaterability of waste sludge in sludge treatment processes. The study aims to examine quantitative correlations between coagulant dosage and sludge cake dewaterability using three kinds of coagulants, such as an aluminum sulfate, a ferric chloride, and a poly aluminum chloride(PAC). When an aluminum sulfate, a ferric chloride, and a PAC were injected with 0.79$\sim$1.19 mmol/g, 0.61$\sim$1.25 mmol/g TSS, and 0.21$\sim$0.39 mmol/g TSS, respectively, specific resistances to filtration of the sludge were decreased at 95.0% or more. This study shows that the correlation between coagulant dosage per g sludge(D) and normalized specific resistance to filtration(R) could be expressed by the exponential functions.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.2
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• pp.238-246
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• 2009

The principal objective of this study was to develop a processed food using aged garlic. Pound cake samples were prepared with semi-solid aged garlic at levels of 0, 5, 10 and 15% ($25^{\circ}C$, 7 days). The pH of the batter prepared with the aged garlic ranged between 6.79 and 7.01 and the control pH was 7.21. The specific loaf volume of the pound cake prepared with the addition of 5~15% aged garlic decreased, from 2.78 to 2.51 cm3/g. The baking loss rate of the pound cake prepared with 0~15% added aged garlic also decreased by 6.91~6.42%. The lightness, redness, and yellowness values of the pound cake decreased with increases in the percentage of aged garlic. The adhesiveness, gumminess, and chewiness of the samples did not differ significantly with differing amounts of added aged garlic. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, however, was improved significantly via the addition of aged garlic. In the sensory evaluations, the pound cake prepared with 10% added aged garlic received higher acceptance scores for the properties of smell, taste, softness, moistness, adhesiveness and overall acceptability. Consequently, the optimal quality achieved in this set of experiments was with a pound cake to which 10% aged garlic had been added.

• Culinary science and hospitality research
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• v.23 no.8
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• pp.83-89
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• 2017

Dangyuja (Citrus gradis), a native citrus fruit of Jeju Island, has sour and bitter tastes. Dangyuja is rich in dietary fiber and enhance antioxidant activity. In this study, sponge cake was prepared by adding Dangyuja peel powder, and its quality characteristics were investigated. The freeze-dried Dangyuja peel powder was added to sponge cakes at a content of 0% (control), 2% (DP2), 4% (DP4), 6% (DP6) and 8% (DP8) of wheat flour weight. The specific gravity and baking loss of dough tended to increase with the amount of Dangyuja peel powder added, but the pH value as well as volume index of the cake were decreased. The symmetry index of cake tended to increase. Color values of sponge cake crust showed no significant difference, but L value and a value of crumb were decreased. The hardness and chewiness were increased with adding Dangyuja peel powder. Springiness was the highest at DP2 (91.79%). Cohesiveness did not showed significant difference among all samples. In a consumer preference test, cake groups with Dangyuja peel powder was higher than DP0 in color, texture, and overall acceptability. From these results, it was concluded that Dangyuja affects characteristics of sponge cakes. When making Dangyuja peel sponge cakes, it is suitable for adding 4% Dangyuja peel powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.1
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• pp.48-55
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• 2001

This study investigated the quality characteristics of sponge cakes with addition of yam (Dioscorea) powders prepared by different drying methods, hot air (HDYP : hot air dried yam powder) and freeze drying (FDYP: freeze dried yam powder), using several physical and sensory examinations. For the foam forming ability and foam stability, the specific gravities of egg foams containing 5% yam powders were measured by drainage using funnels for 78 hrs. The results showed that HDYP and FDYP did not affect the foam forming ability but FDYP increased foam stability due to increased viscosity. When the strength of 8% gels composed of wheat starch and HDYP/FDYP was measured to predict the setting of cake structure, the strengths of starch gels containing yam powders were higher than those of control without yam powders. The volume of sponge cake containing 5% HDYP increased whereas those containing FDYP decreased at the levels of 5, 7%. From the texture profile analysis data, hardness, gumminess and chewiness of cakes containing yam powders increased. The color of cake crust and crumb became darker as the amount of yam powders increased. The results of sensory evaluation by QDA (quantitative descriptive analysis) to compare two different drying methods showed that appearance and texture of cakes containing 5% HDYP were closer to those of control than cakes containing 5% FDYP but overall acceptability of sponge cakes containing yams were comparable to the control cakes regardless of drying methods. The addition of yam powders to sponge cakes increased yam flavor and decreased egg smell. Therefore, it can be suggested that HDYP and FDYP can be added to the sponge cake formula up to 7% and 5%, respectively.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.392-398
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• 2007

In this study we investigated the physical and sensory characteristics of sponge cakes prepared with different levels(0, 2, 4, 6, 8 and 10%) of freeze-dried steamed garlic and Yuza(Citrus junos Sieb ex Tanaka) powder, combined at the same ratio. The cake height and specific loaf volume were highest in the 4% steamed garlic and Yuza powder group. Moisture contents were significantly higher in the 2 and 4% steamed garlic and Yuza powder groups than in the other groups. With increasing steamed garlic and Yuza powder content, the L- and b-values of the crust decreased, but the a-value increased, when compared to the control group. The L-value of the crumb was insignificant within each group. Compared to the a-value of the $0{\sim}2%$ added groups, the a-value of the $4{\sim}10%$ added groups, increased with increasing steamed garlic and Yuza powder contents. However the b-value decreased in the 8 and 10% steamed garlic and Yuza powder groups. The hardness and chewiness of the $6{\sim}10%$ added groups, and the gumminess of the 10% addition group, were significantly higher than in the control group. The results of the sensory evaluation showed there were not significant differences amoung the groups, except for moistness. Therefore, we suggest that the recommended optimal level of steamed garlic and Yuza powder in sponge cake is a 4% addition.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.578-590
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• 2017

An agricultural waste, pomegranate (Punica granatum L.) peel is known to be rich in total phenolics, which are flavonoids having strong antioxidant effects. In this study, pomegranate peel sponge cakes were prepared with varying ratios of freeze dried pomegranate peel powder (0, 1, 3, 5, 7% (w/w)) to examine their effect on quality characteristics, retrogradation and antioxidant activities. The specific gravity and moisture contents of 3, 5, and 7% pomegranate peel powder showed higher values than the control and 1% group. Addition of pomegranate peel powder increased the batter yield, while there was a significant decrease in baking loss. Increasing pomegranate peel powder content significantly decreased the lightness (L) (from 75.03 to 57.04) and pH values, whereas redness (a), yellowness (b) and ${\Delta}E$ were increased. Increasing concentration of the peel powder also increased the hardness and chewiness, while the springiness and cohesiveness decreased. Considering the Avrami equation, Avrami exponene (n) decreased from 1.8055 (control) to 0.9199 (7% pomegranate peel powder). Time constant (1/k) was lowest in control (at 17.64) and highest in the 7% group (39.84). Total polyphenol, flavonoid content, DPPH and ABTS radical scavenging activities significantly increased with increments in the content of pomegranate peel powder. A sensory evaluation by the 7-point scaling method showed that the sponge cake containing 7% pomegranate peel powder had the highest scores in color, flavor, sweetness, chewiness and overall acceptability. Hence, it is considered that sponge cake supplemented with 7% pomegranate peel powder is the most appropriate for quality characteristics, retrogradation and antioxidant activities.

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.436-446
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• 2012

A study was undertaken to examine the effect of the addition of coriander leaves(Coriandrum satovim L.) and brocolli stem powder addition on the quality attributes of pound cakes. Coriander leaves & brocolli stem powder was added to the batter, at a ratio of 10, 12.5 and 15%, respectively. The antioxidant activity was estimated by a DPPH free radical scavening activity, the total phenolic compounds content and flavonoid content in coriander leaves & brocolli stem powder and pounds cakes. Antioxidative activity had correlated highly with the total flavonoids contents of coriander leaves & brocolli stem powder of pound cakes, respectively(r=0.9096). The quality characteristics of coriander leaves & brocolli stem powder pound cakes were estimated in terms of the specific load volume, hardness, hunter value of crumb and crust, and the sensory quality of the cakes. The specific volume decreased significantly, with increasingly substituted level of coriander leaves & brocolli stem powder(p<0.01). The lightness was significantly decreased with increases in the coriander leaves & brocolli stem powder of pound cake crust and crumb(p<0.01). The hardness, chewiness and gumminess tended to reduce, and the cohesiveness decrease in both of powder. The consumer acceptability score for 10% coriander leaves & brocolli stem powder of pound cakes ranked significantly(p<0.01) higher than those of the other groups in taste, flavor and color. These results showed that coriander leaves & brocolli stem powder are good ingredients to increase the consumer acceptability and the health.