Piezoelectric composite films which are enabled by inorganic piezoelectric nanomaterials-embedded polymer, have attracted enormous attention as a sustainable power source for low powered electronics, because of their ease of fabrication and flexible nature. However, the absorption of applied stress by the soft polymeric matrices is a major issue that must be solved to expand the fields of piezoelectric composite applications. Herein, a flexible and porous piezoelectric composite (piezoelectric sponge) comprised of BaTiO3 nanoparticles and polydimethylsiloxane was developed using template method to enhance the energy conversion efficiency by minimizing the stress that vanishes into the polymer matrix. In the porous structure, effective stress transfer can occur between the piezoelectric active materials in compression mode due to direct contact between the ceramic particles embedded in the pore-polymer interface. The piezoelectric sponge with 30 wt% of BaTiO3 particles generated an open-circuit voltage of ~12 V and a short-circuit current of ~150 nA. A finite element method-based simulation was conducted to theoretically back up that the piezoelectric output performance was effectively improved by introducing the sponge structure. Furthermore, to demonstrate the feasibility of pressure detecting applications using the BaTiO3 particles-embedded piezoelectric sponge, the composite was arranged in a 3 × 3 array and integrated into a single pressure sensor. The fabricated sensor array successfully detected the shape of the applied pressure. This work can provide a cost-effective, biocompatible, and structural strategy for realizing piezoelectric composite-based energy harvesters and self-powered sensors with improved energy conversion efficiency

The purpose of this study was to investigate the possibility of using air potato (Dioscorea bulbifera) powder to make sponge cakes. The sponge cake batter was made by adding 0, 10, 20, 30, and 40% of air potato powder, and the resultant anti-oxidative properties and quality characteristics were analyzed. The study showed that the height, batter yield, and loss rate of sponge cakes decreased as increasing amounts of air potato powder were added, but the weight, viscosity, moisture content, and specific gravity increased. An evaluation of the color showed that the L and b values were highest in the control group but the a value was highest in the 40% group. There was no significant difference between samples in terms of cohesiveness, although the study showed a significant increase in the hardness, chewiness, and gumminess as the quantity of air potato powder in the sponge cakes increased. The total polyphenol content and DPPH radical scavenging activity increased noticeably as more air potato powder was added to the sponge cakes. The results thus showed that the study groups with the addition of air potato powder showed higher antioxidant activity than the control group.

In this study, the quality properties were compared by replacing allulose with a ratio of 0%-100% instead of sugar used in sponge cake. There was no significant difference in specific gravity, pH, and degree Brix of the dough according to the allulose content, but the brightness decreased and the redness, and yellowness increased as the allulose content increased. The volume of the sponge cake decreased as the content of allulose increased. Symmetry was uniform in the cakes replaced with allulose compared to 100% sugar. There was no significant difference in baking loss and moisture content. Hardness, gumminess and chewiness increased as the replacement rate of allulose increased, and adhesiveness was highest in 100% allulose. In the hedonic evaluation, 100% sugar and allulose 25% samples showed no difference, and the other samples were evaluated lower than the control. The maximum replacement ratio of allulose for sponge cake is considered to be 50%.

This study investigated the physicochemical and antioxidant properties of sponge cakes made using different amounts (2 and 4%) of barley sprout powder (BSP) and green tea powder (GTP), respectively. The results showed that the baking loss rate of GS2 (2% green tea) and GS4 (4% green tea) was 12.39% and 11.96%, respectively in the green tea addition group, which was higher than that of the barley sprout group, but significantly lower than that of the control group at 13.34% (p<0.05). The specific volumes of the sponge cake containing barley sprout and green tea 2% and 4% were between 2.84- 2.95 mL/g, which was significantly higher compared to the control group at 2.69 mL/g (p<0.05). The sugar content was significantly higher in the control group and the barley sprout addition group at 2.30oBrix (p<0.05). As for the volume index, the control group with the lowest value at 13.43 showed a significant difference compared to the addition groups. The volume index significantly decreased as the addition amount increased, measuring 14.07 in BS4 (4% BSP) compared to 14.87 of BS2 (2% BSP) in the barley sprout group (p<0.05). In cross-sectional photography, the color became darker than that of the control group as the quantum of additives increased. In terms of the DPPH and ABTS radical scavenging activity, the total phenol content, and total flavonoid content, the groups with the addition of barley sprout and green tea showed higher antioxidant activity than the control group (p<0.05).

스펀지 도시는 도시재생 측면에 있어, 우수를 도시 내 흡수, 침투, 정화할 수 있도록 하는 도시 물 순환 시스템의 개념이다. 이 개념은 2012년 중국 저탄소 도시 및 지역 경제 발전과학 기술포럼에서 처음으로 제기되었으며, 이로 인해 스펀지 도시에 관한 중요성이 부각되었다. 하지만, 스펀지 도시 내 중요한 역할을 하는 스펀지형 도시공원은 일반적인 개념 외 실제 적용되는 설계원칙에 대한 내용이 미비하다. 따라서 본 논문은 중국 스펀지 도시의 시범 도시인 싼야(三亚)시가 추진한 솽슈(双修)와 솽청(双城) 프로젝트인 싼야시 동안(东岸) 습지공원을 연구 대상으로 선정하여 선행연구를 통해 추출된 7가지의 스펀지형 도시공원 설계원칙을 대상으로 현장답사를 하였다. 또한, 대상지 이용 시민, 정부 건설 담당 부처의 공무원, 공원 관리인원 등 3개 그룹으로 나누어 인터뷰 조사·분석 방법론을 적용했다. 연구 결과는 다음과 같다. 동안습지공원은 연결성 측면에서 상당히 양호한 연계를 구축하고 있다고 분석되었다. 기능 측면에서는 젊은층과 어린이를 고려한 공간 설계가 없으므로 모든 연령층을 고려한 설계방식이 적용되어야 한다. 또한 인프라 시설 측면에서 공원은 더욱더 많은 휴식과 편의 시설이 필요하다고 분석된다. 스펀지성을 분석한 결과 잔도교(栈道桥)와 계단식 홍수 방지 댐을 조성하여, 양호한 홍수 방지 저류시설이 조성되어 있다. 마지막으로 경제적 측면에서 공원의 유지 보호에 적어도 80명에 달하는 유지 인력이 소요되어 이를 유지할 수 있는 경제적 측면이 고려되어야 함을 알 수 있다. 현재 중국의 스펀지 도시는 여전히 탐색 단계에 대량 실천성 탐구가 필요하다. 즉, 본 연구에서 도출한 연결성, 기능성, 생태성, 지역성, 안전성, 스펀지 도시성, 경제성 등 7개 유형의 스펀지형 도시공원 기본 설계 원칙을 적용한다면 기존 스펀지형 도시공원뿐만 아니라, 향후 새롭게 조성할 스펀지형 도시공원에 기초 자료를 제시할 수 있을 것으로 판단된다.

This study was performed to examine the physicochemical and antioxidative properties of the sponge cakes with different contents (0, 2, 4, 6, 8%, w/w) of lemon balm (Melissa officinalis) powder (LBP). An increase in LBP content in the cake led to a significant increase in the baking loss rate, specific volume, DPPH radical scavenging activity, ABTS radical scavenging activity, total phenol contents and total flavonoid contents of the cakes (p<0.05). As the LBP content increased, significant decreases were shown in the specific gravity of batter, sugar contents, pH, lightness, redness and yellowness of the cakes (p<0.05). Ash contents, uniformity index and other textural properties of hardness, springness, cohesiveness, and brittleness did not show any significant differences between the sample groups (p>0.05). These results suggest that LBP can be applied to sponge cakes to achieve positive textural properties such as uniform pore formation and increased volume with increased antioxidant properties.

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 ΔE 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.

In this study, sponge cakes were prepared with replacement of 1, 3, and 5% spergularia marina griseb powder. The specific gravity tended to increase as the ratio of spergularia marina griseb powder increased. The control group had higher moisture content, volume, and specific volume than the spergularia marina griseb powder samples. As the amounts of spergularia marina griseb powder increased, L and b value increased. In terms of textural characteristics, Sponge cake levels of hardness, springiness, cohesiveness, chewiness and brittleness increased as the amount of spergularia marina griseb powder additive increased. In the sensory evaluation, overall acceptability of 3% spergularia marina griseb powder was the highest. Based on the above results, sponge cake, made by addition of 3% spergularia marina griseb could be helpful in improving physical quality as well as taste enhanc the functionality of the product.

본 연구에서는 기능성 제빵제품 개발의 일환으로 라디치 오 분말을 첨가하여 스펀지 케이크를 제조하고, 분말 첨가 비 율(1~7%)에 따른 스펀지 케이크의 품질 특성 및 항산화 활성을 분석하여 적절한 라디치오 분말 첨가량을 제시하고자 하 였다. 라디치오 스펀지 케이크의 pH는 라디치오 분말을 첨가 함에 따라 유의적인 차이를 보이지 않았다으나, 감소하는 경 향이 나타났다. 스펀지 케이크의 비중은 유의적으로 증가하 는 결과를 보였다. 수분 함량은 감소하였으며, 굽기 손실률은 증가하는 경향을 보였다. Crust의 색도는 라디치오 분말의 첨 가 수준에 따라 L, a, b값이 유의적으로 감소하였고, Crumb의 색도는 L값과 b값이 감소하고, a값은 증가하는 경향을 보였 다. 조직감 측정에서는 경도와 씹힘성이 점차 감소하였고, 응 집성과 탄력성은 유의적인 차이가 없었다. 라디치오 분말 첨 가량에 따라 총 폴리페놀 함량이 유의적으로 증가하였고, DPPH 라디칼 소거능 측정에서 IC50은 점점 감소하여 라디치 오 분말을 첨가할수록 스펀지 케이크의 항산화력이 높아지 는 것으로 나타났다. 관능검사 결과, 향미, 단맛, 촉촉함, 씹힘 성 등이 분말 첨가에 따라 감소하였으나, 3% 첨가군에서 색 상 및 전반적인 기호도에서 높은 점수를 받아, 라디치오 분말 을 첨가한 스펀지 케이크 제조 시 밀가루의 3%를 라디치오 분말로 대체하는 것이 가장 적절한 것으로 사료된다.

The quality and characteristics of purple sweet potato sponge cake were studied with the addition of different proportions of purple sweet potato powder depending on storage period The pHs, heights, and weights of doughs were in the ranges of 6.3~6.5, 4.8~4.4 cm and 397~418 g, respectively. The sponge cake groups with the addition of different proportions of purple sweet potato powder showed significantly different characteristics in hardness, adhesiveness, cohesiveness, gumminess, and chewiness, according to texture profile analysis. The difference in colors of sponge cakes with addition with purple sweet potato revealed that L-value and b-value were significantly reduced but a-value especially increased according to the density. Using scanning electron microscopy (SEM), it was confirmed that the stoma size of purple sweet potato sponge cake become smaller and the stoma wall became thicker in proportion to the contents of purple sweet potato powder, which could result in an increased level of water content after a long period pf storage. According with the observations, water content remarkably increased after 4~6 days of storage and the ability to keep water content seemed to contribute to extention the shef-life of sponge cakes. In sensory evaluation, sponge cakes with high contents of purple sweet potato were preferred and cakes with the addition of 25% and 30% purple sweet potato powder was most preferred. It was expected that the shelf-life of purple sweet potato sponge cake was 4 days under the normal temperature.

This study was conducted to evaluate the quality characteristics and antioxidant activities of rice flour sponge cakes containing 0, 20, 30, 40, and 50% Helianthus tuberosus powder (HTP). As HTP content of sponge cake increased, the pH of sponge cake batter significantly decreased, whereas specific gravity significantly increased (p<0.05). Meanwhile, volume and symmetry indices of sponge cake were inversely proportional to HTP amount. Further, with higher HTP content in sponge cake, L and b values of crumbs significantly decreased (p<0.05), whereas a value significantly increased (p<0.05). L, a, and b values of crust significantly increased with higher HTP content. For texture characteristics, hardness, cohesiveness, gumminess, and chewiness of sponge cake significantly increased (p<0.05),whereas cohesiveness did not significantly change. In the sensory evaluation test, rice sponge cake prepared with 10% HTP showed the highest sensory scores in terms of color, flavor, taste, softness properties, and overall preference. The levels of total polyphenol compounds and DPPH radical scavenging activities of rice sponge cakes significantly increased with higher HTP contents (p<0.05). The results of this study suggest that rice sponge cake containing 10% HTP is the most appropriate for quality characteristics and sensory evaluation. This study also provides a way to increase the quality, texture characteristics, and organoleptic properties of sponge cake while reducing HTP content to less than 10% in order to satisfy consumer tastes.

In this study, to explore the use of lotus leaf powder, quality characteristics of sponge cake manufactured with different levels of lotus leaf power were investigated. We discovered that the pH, gravity, and cooling temperature of sponge cake increased as the content of lotus leaf power additive increased compared with those of the control group. Likewise, L and b levels of sponge cake increased with increasing level of lotus leaf power; 20% lotus leaf powder appeared to show the highest L and B levels, but levels were lower than those of the control group. Sponge cake levels of hardness, springiness, and cohesiveness increased as the amount of lotus leaf powder additive increased. In sensory evaluation, overall acceptability of 5% lotus leaf powder was the highest. Thus, it is possible to develop sponge cake with improved healthoriented aspects by addition of 5% lotus leaf powder.

This study was performed in order to investigate the quality characteristics of sponge cake made with Laminaria japonia powder. To evaluate the physical and sensory analysis, Laminaria japonia powder was added to wheat flour in various ratio (3, 5, 7, 9%, w/w). The specific gravity and loss rate increased with the addition of Laminaria japonia powder. The crude protein and ash levels in the sponge cakes increased linearly with the addition of 0 9 g of Laminaria japonia powder/100 g of wheat flour. For the crumb color values, lightness (L) and yellowness (b) decreased with the addition of Laminaria japonia powder, whereas redness (a) significantly increased (P<0.05). In the texture analysis, the hardness, gumminess and chewiness were increased; however, the cohesiveness and resilience were reduced by the addition of Laminaria japonia powder. When the sensory characteristics were evaluated, 5% Laminaria japonia sponge cake showed the highest sensory properties, except for color. Therefore, the results suggested that 5% Laminaria japonia sponge cake could be helpful in improving the physical quality as well as the taste.

꾸지뽕잎 분말의 첨가량을 0-20%로 달리하여 스펀지 케이크를 제조한 후 물리화학적 품질특성 및 소비자 기호도를 비교하였다. 꾸지뽕잎 분말의 첨가비율이 증가함에 따라 케이크의 비체적, 높이 및 수분함량은 단계적으로 감소하는 경향을 나타내었고, 케이크의 외관상 특성인 부피지수 및 대칭지수 또한 유의적으로 감소하였다(p < 0.05). 밝기를 나타내는 L*값과 황색도를 나타내는 b*값은 꾸지뽕잎 분말 첨가량이 증가할수록 단계별로 유의적으로 감소하였으며(p < 0.05), 반면 적색도를 나타내는 a*값은 5% 대체군에서 최소값을 나타내고 이 후 증가하는 경향을 나타내었다(p < 0.05). 케이크의 경도는 꾸지뽕잎 분말 첨가량에 따라 0.11-0.66 kgf로 단계별로 유의적으로 증가하였다(p < 0.05). 총 페놀화합물 함량은 0-15% 첨가군 사이에 단계별로 유의적인 차이없이 증가하는 경향을 나타내었고(p > 0.05) 이후 유의적인 증가를 보였다. 소비자 기호도 검사 결과 대조군, 5% 및 10% 첨가군 간 맛과 향미의 유의적인 차이는 발견되지 않았고(p > 0.05), 전체적인 기호도 또한 대조군과 5% 첨가군 사이에 유의적인 차이는 발견되지 않아(p > 0.05), 관능품질을 저해하지 않고 꾸지뽕잎 분말의 건강 기능성 효과 등을 고려할 때 5% 첨가군이 가장 적절한 것으로 판단된다.

야콘 분말의 대체량을 0-30%로 달리하여 스펀지 케이크를 제조한 후 물리화학적 및 관능적 품질특성을 비교하였다. 야콘 분말의 대체비율이 증가함에 따라 반죽의 비중은 단계별로 유의적으로 증가하였고 pH는 감소하는 경향을 나타내었다. 한편 케이크의 비체적과 수분함량은 야콘 분말 대체에 따라 유의적으로 감소하였고 굽기 손실은 증가하였다(p<0.05). 부피지수는 감소하는 경향을 보여 야콘 분말 비율이 높아지면 케이크의 부피 또는 높이가 작아짐을 알 수 있었다. 반면 대칭지수는 야콘 분말 대체량에 따른 유의적인 차이를 나타내지 않았다(p > 0.05). 밝기는 나타내는 L*값은 유의적으로 감소하였으며(p < 0.05), 경도는 점차적으로 증가하였으나 20% 및 30% 대체군 사이에 유의적인 차이는 발견되지 않았다. 소비자 기호도 검사결과 대조군, 10% 및 20% 대체군 사이에 전체적인 기호도에 대한 유의적인 차이는 발견되지 않았으나(p > 0.05), 관능품질을 저해하지 않고 야콘 분말의 건강 기능성 효과 등을 고려할 때 20% 대체군이 가장 적절한 것으로 판단된다.

The focus of the current study was to investigate the physicochemical properties of a corn starch-sponge matrix prepared at a low concentration below gel forming by freeze-drying. The effect of variables(starch concentration, heating temperature, and heating hold time) on the physicochemical properties of the samples was analyzed by response-surface methodology. Regression models on the properties of samples such as hardness, springiness, and water solubility index(WSI) showed high correlation coefficients(r>0.95) and significant F values, but regression models for the other properties(swelling power, apparent viscosity, reducing sugar content, and digestibility) showed them to have relatively low significance. Sample hardness of sample showed the highest value at condition of 90℃ and 5%, whereas springiness was at a maximum at 130℃ and 5%. Also, at 1% of starch concentration, mechanical properties were greatly decreased as the relative humidity increased, compared with the 3% and 5%, especially in the hardness of samples. The WSI showed an increasing trend with heating temperature regardless of starch concentration. Overall, the physicochemical properties of freeze-dried corn starch-sponge matrix were influenced much more by starch concentration and heating temperature than by heating hold time. The results of this study show that the basic properties of freeze-dried corn starch-sponge matrix can be used for the specific food applications or as a functional material for its stability.