In this study, when manufacturing Yakgwa, 0, 25, or 50% of embryonic rice flour (ERF) was substituted for wheat flour (WF) to make the dough. After making Yakgwa by hot air frying (HF) or deep-fat frying (DF) methods, physicochemical characterization and acceptance tests were conducted. ERF had a higher water-binding capacity and a lower fat-binding capacity than WF (p<0.05). Yakgwa prepared by HF had lower crude fat contents, peroxide values, and expansion rates, but higher hardnesses, lightnesses, and rednesses (p<0.05) than that prepared by DF. Higher ERF substitution ratios reduced acid values and expansion rates and increased hardness (p<0.05). Acceptance testing showed 0% ERF Yakgwa prepared by HF had a significantly higher acceptance than Yakgwa prepared by DF. HF was found to have a positive effect on product acceptability. Yakgwa prepared with the DF method by substituting WF with ERF resulted in better flavor and overall acceptability than Yakgwa prepared with WF alone (p<0.05).

This study investigated the physicochemical properties and acceptability of yellow layer cake prepared using various levels of wet-milled rice flour (RF). RF was used to substitute 0% (control group), 15% (RF-15 group), 30% (RF-30 group) and 45% (RF-45 group) of wheat flour (WF) to manufacture yellow layer cakes. The substitution of WF with RF showed no significant effect on the pH but decreased the specific gravity and viscosity of the batter. Baking loss rates ranged from 4.65% to 5.03%, showing no significant difference among samples. In the color measurement, the experimental groups showed higher redness (a) and yellowness (b) than the control group (p<0.05). The experimental groups showed lower gumminess and chewiness than the control group. According to the results of intensity measurement of sensory properties, the RF-30 and RF-45 groups showed stronger intensities for darkness, sweetness, moistness and softness than the control group. The acceptance test found that the RF-45 group had significantly higher or similar results for all acceptance attributes than the control group. These results indicate that RF addition as a replacement of WF at a ratio of 45% is optimal for producing yellow layer cakes.

This study investigated the effect of dry heat treatment (DHT) on the physicochemical properties of hard type (HR) and floury type (FR) rice to improve the processing aptitude of rice flour. The rice flour was heated at 130oC for 0, 2 and 4 hours, and the color value, water absorption index (WAI), water soluble index (WSI), swelling power, solubility, pasting properties, particle shape and the X-ray diffraction were measured. After DHT, the L value of rice flour decreased, and the b value increased. The WAI, WSI, swelling power and solubility of HR and FR increased with the increase of treatment time. The cold viscosity and setback increased, while breakdown decreased. Cracks and lumps formed with fine particles were observed. The X-ray diffraction pattern was A-type, while the diffraction intensity decreased. According to the results of the two-way analysis of variance (ANOVA) test, the hydration and pasting properties were significantly different between HR and FR and were affected by DHT time. The results suggest that the properties of modified rice flour by DHT can be used in the food industry.

This study was carried out to investigate milling's effect on the pasting properties and storage stability of dry-milled rice flour. Rice flour's moisture content was increased from 9.48% to 9.80% after going through a rice polisher, and the crude fat content of rice flour was decreased from 0.91% to 0.62% after going through a rice polisher. In the color index of rice flour, the rice polisher was only affected by yellowness. The pasting properties were verified through RVA, and it was confirmed that the use of a rice polisher had no significant effect on the pasting properties. As a result of observing the changes in fatty acid value, it was ascertained that the storage period could be increased using the rice polisher. These results suggest that the rice polisher can increase the storage period without changing the pasting properties.

The physicochemical properties of Korean rice flour cultivars (Saemimyeon [SM], Hanareum No. 4 [HA], and Milyang No. 328 [MY]) with different amylose contents were analyzed and the effects of rice flour blending on their physicochemical property changes were investigated in this study. The swelling power of three different cultivars was similar at 60oC, but MY showed significantly enhanced swelling power at 80oC compared to SM and HA. In the pasting profile, MY showed significantly lower final and break-down viscosities than SM and HA due to its weak granular rigidity. In the case of the 1:1 blending of SM-MY and HA-MY, the measured values of swelling power and solubility were greatly decreased at 80oC, and the setback and final viscosity were significantly increased compared to their predicted arithmetic average values, showing the non-additive effects of blending. For the dynamic viscoelastic properties, SM-MY and HA-MY showed significantly decreased G’ and increased k’ and tanδ, compared to their predicted average values. In conclusion, the selected rice flour blends had non-additive effects on swelling power, solubility, pasting, and dynamic viscoelastic properties. These results showed the feasibility of the rice flour blending to diversify the physicochemical properties of rice flour for better processing suitability.

The value of using rice flour processed into rice powder in preparing porridge was evaluated by measuring the moisture content, pH, total starch, reducing sugar, and color content. The moisture content of the rice flour and the pH of porridge made with rice flour were measured. Rice flour contained 77.55% moisture and the moisture content of the porridge made from rice flour processed into rice powder was 91.40 to 92.47%. The pH of rice flour porridge was acidic at 6.53 to 6.95. The color of the porridge was also measured. The L* values ranged from 82.62 to 97.55, the a* values ranged from －0.09 to 0.08, and the b* values ranged from －2.74 to 1.91.

This study aims to analyze the cooking and sensory characteristics of noodles to which different types and amounts of apples were added. Apple noodles were made by the addition of apple flour and apple concentrate to wheat flour in proportions of 0, 5, 10, 15, and 20%, respectively. Cooking time, weight after cooking, water loss after cooking, and rehydration rate were analyzed as cooking characteristics. Hardness, adhesiveness, cohesiveness, springiness, and chewiness were measured as texture characteristics, whereas sensory evaluation was performed on the appearance, color, taste, aroma, texture, and overall preference of noodles. The cooking time decreased as the amount of apple added increased, and the weight after cooking, water loss after cooking, and rehydration rate increased. The hardness and chewiness were decreased and the adhesiveness was increased as the amount of apple added was increased. The sensory test of apple noodles showed a higher score in taste and overall preference than that of the control. Furthermore, the addition of apples tended to produce a high score in all sensory tests, indicating that the addition of apples has a good effect on the quality of noodles. In particular, the addition of 10% apple concentrate showed high scores in all the tested characteristics.

The study was to investigate the quality characteristics of American waffles substituted with 0, 25, 50, 75, and 100% of kamut whole wheat flour (KWF). The KWF samples had maintaining the specific gravity of the batter until the 25% substitution. The spreadability decreased as the ratio of the KWF increased, and the pH of the 100% substitution sample were the lowest. The KWF samples had increasing baking loss rates until the 75% substitution while decreasing the water activity. Lightness and yellowness significantly decreased with increasing the KWF while redness increased. Hardness, chewiness, and gumminess of the 25% substitution sample were the highest, while the springiness and resilience were maximum with the 100% substitution. The KWF samples had increasing overall acceptability, acceptability of color, flavor, and texture until the 50% substitution. The characteristics intensity rating of crust color, bran flavor, and sweetness increased with increasing the KWF. The KWF samples had significantly higher crispiness than the control group. The frequency of the bran flavor, sweetness, nuttiness, and unpleasant increased while the egg and milk flavor, and flour taste decreased. These results suggest that the substitution of the 25~50% KWF could be the optimal to improve the quality characteristics of American waffles.

쌀 소비 촉진과 쌀가공품의 다양화를 위해 쌀가루를 이용한 이소말토올리고당 제조에 대해 연구하였다. 최적 반응 조건을 확립하기 위해서 상업용 효소인 Termamyl 2X, Maltogenase L, Promozyme D2, Fungamyl 800L, Trnasglucosidase L을 사용하였고, 당류는 HPLC-CAD를 이용하여 말토올리고당과 이소말토올리고당을 동시분석하여 제조 조건별로 당의 구성 및 함량을 확인하였다. 액화반응의 최적화 조건을 탐색하기 위해 효소의 농도 (0.025%, 0.05%, 0.075%, 0.1%)와 시간(1 h, 2 h)에 변화를 주어 반응시켰으며, 가수분해 정도를 확인하기 위해 액화액의 환원당 함량을 측정하였다. 그 결과 Termamyl 2X 를 0.075% 첨가하여 2시간 동안 반응하였을 때 환원당 함량이 138.26 g/L로 가장 높았다. 당화·전이반응의 최적화 조건을 확인하기 위해 효소의 종류, 효소농도, 효소반응시간을 달리하여 이소말토올리고 당을 제조하였다. Maltogenase L, Promozyme D2, Transglucosidase L을 동시에 첨가하여 반응시켰을 때 isomaltose와 panose를 많이 생산하면서 총 이소말토올리 고당의 함량이 가장 높게 나타났다. 그리고 효소의 첨가량을 결정하기 위해 각각 농도에 변화를 주어 시간별로 당 함량을 검토하였다. 그 결과, Maltogenase L은 0.0015%, Promozyme D2는 0.05-0.1%, TransglucosidaseL은 0.1%를 첨가하였을 때, glucose의 함량은 감소되고 중합도가 높은 이소말토올리고당의 함량은 증가하는 효과가 있었다. 최적 효소반응시간 결정을 위해 6시간마다 생성물의 변화를 관찰한 결과, 36시간에 총 이소말토올리고당이 75.36 g/L로 가장 높은 것으으로 확인되었다. 최적 조건으로 제조된 이소말토올리고당은 18 brix였고, isomaltose 35.11 g/L, panose 11.97 g/L, isomaltotriose 19.95 g/L, isomaltotetraose 7.46 g/L, isomaltopentaose 1.05 g/L 이 생성되었으며, 총당 중 이소말토올리고당의 비율은 56.37%였다.

Five-color bread was prepared by adding herb powder to Korean whole wheat triticum aestivum flour and the quality of baking was analyzed. The pH of the control bread was 6.15±0.12 while that of the whole wheat flour test group was 6.35±0.11, 6.29±0.12, 6.36±0.12, 6.19±0.11, and 6.01±0.13, respectively. The L value of the control bread was 67.78±0.03 and that of the whole wheat flour test group was 69.66±0.02, 60.01±0.12, 64.23±0.01, 63.34±0.01, and 61.64±0.04, respectively. The water activity was slightly increased at 2 days of storage due to the difference in water absorption and water retention. However, on the third day, the water transfer phenomenon in the bread showed water activity decrease in all wheat flour test groups. On the 1st day of the whole wheat flour test bread, the hardness values were 186.86±4.81, 165.89±3.73, 189.71±3.32, 198.38±2.19, and 184.29±3.40 g/cm2, respectively, and that of the control group was 138.84±3.72 g/cm2. The hardness of the control group and the whole wheat flour test group showed a significant difference. The internal structure of the bread in the whole wheat flour test group (100x, 500x) was not smoother than the control’s. The swelling degree of the starch particles and the cracking of the crumbs were confirmed by the adding of five-colored herbs to whole wheat flour.

본 연구는 기능성 팽화 스낵의 개발을 위하여 우수한 식이섬유소원인 차전자피를 첨가한 쌀 압출성형물의 물리적 특성에 대하여 살펴보았다. 원료 배합비는 쌀을 기본 원료로 하여 차전자피의 함량(0, 7, 14, 21%)을 달리하였고, 압출성형 공정변수는 스크루 회전속도 200 rpm, 사출구 온도 140oC, 수분함량 20%로 조절하였다. 압출성형 후 직경 팽화율, 비길이, 밀도, 겉보기 탄성계수, 파괴력, 조직감, 색도, 수분용해지수, 수분흡착지수, 미세구조를 측정하였다. 직경 팽화율은 차전자피 함량이 증가할수록 감소하였으며, 비길이, 밀도, 겉보기 탄성계수와 파괴력은 증가하는 경향을 보였다. 부착성은 차전자피 함량이 증가할수록 증가하였으며 21% 첨가에서 급격히 증가하였다. 차전자피의 첨가량이 증가할수록 명도는 감소하였고 적색도, 황색도, 총 색도차는 증가하는 경향을 보였다. 수분용해지수와 수분흡착지수는 압출성형 공정 후 모두 증가하였으며 차전자피의 함량이 증가할수록 증가하였다. 미세구조는 차전자피 첨가량이 증가할수록 팽화와 기공의 크기가 감소하여 압출성형물의 밀도가 증가하였다. 결론적으로 차전자피의 첨가량이 증가할수록 팽화를 감소시켜 단단한 조직감을 나타내었고 높은 수분흡수력으로 인해 부착성이 증가하여 14% 이하로 첨가 하는 것이 바람직하다. 또한 차전자피의 함량이 높은 팽화 스낵을 개발하기 위하여 유화제의 첨가 뿐만 아니라 차전 자피의 전처리 등 추가적인 연구가 필요할 것이다.

This study was undertaken to examine the quality characteristics of glutinous barley flour (GBF) Yakgwa produced by air frying. To achieve this, the pH of the dough as well as expansion ratio, color, texture, and sensory evaluation of Yakgwa were measured. The pH of the Yakgwa dough significantly decreases with increasing amount of GBF, over the range 5.35-5.45. Lightness (L), redness (a), and yellowness (b) also decrease with increasing amount of GBF. Furthermore, significant decrease was observed in the hardness, proportionate to the ratio of GBF added (p<0.001). Generic descriptive sensory evaluation results reveal that samples with high ratio of GBF show increased grain aroma, burnt aroma, grain flavor, nutty flavor, astringency, chalky taste, and hardness. The acceptance test determined the GBF-20 sample group to be high in flavor and texture (p<0.05). Therefore, it would be appropriate to apply to 20% GBF for alternative and the addition of GBF would be considered to have positive effects on the quality characteristics of Yakgwa using air fryer.