• 동아시아식생활학회지
• /
• 제25권6호
• /
• pp.1029-1040
• /
• 2015

Effects of punching and drying process on quality of Yukwa were determined. Lightness (L) of Yukwa dough with punching was higher than that with no punching. Air cell distribution of Yukwa dough was fine with higher punching. Microstructure of Yukwa dough showed a broken surface structure with increasing punching. Hardness and adhesiveness of Yukwa dough decreased after 5 min of punching and then increased with higher punching. Expansion ratio of Yukwa base with punching at 155 rpm for 5 min was highest among the samples. Appearance of Yukwa base with no punching showed a poor shape and cross section, whereas Yukwa base with punching at 95 rpm for 10 min showed the best appearance and cross section and Yukwa base with punching at 155 rpm for 5 min also showed good appearance. The moisture content of Yukwa Bandegi after 24 hr of drying was 14.93%. Microstructure of Yukwa Bandegi showed a broken surface structure and empty spaces with increased drying time. Expansion ratio of Yukwa base with 24 hr of drying at $40^{\circ}C$ was highest among the samples. Overall, optimum punching conditions were 10 min of punching at 95 rpm or 5 min of punching at 155 rpm and optimum drying condition was 24 hr of drying at $40^{\circ}C$.

• 한국생활과학회지
• /
• 제7권2호
• /
• pp.149-159
• /
• 1998

This study was carried out to examine the role soy milk in the preparation of Yukwa, possibility of substitution of soy milk to isolated soy protein and the effect of drying condition of Yukwa dough on the quality of Yukwa for the purpose of standardization of Yukwa preparation process. Although isolated soy protein did not make any particular effect on the gelatinization characteristics of waxy rice flour, soy milk lowered peak viscosity to half of waxy rice flour. The optimum moisture content of dried Yukwa dough was about 25%, and it can be reached by drying at $60^{\circ}C$ under atmosphere pressure for $4{\sim}5$ hours. On the basis of the results of morphological observations, mechanical and sensory measurement of hardness, and sensory test of the internal structure, mouthfeel and overall acceptability, soy milk was more desirable than isolated soy protein for the quality improvement of yukwa.

• 한국식품조리과학회지
• /
• 제18권5호
• /
• pp.529-533
• /
• 2002

유색미 첨가량에 따른 반죽물과 유파의 색도는 유색미 첨가 비율이 증가할수록 a값이 유의적으로 증가하였으며 L값과 b값은 유의적으로 감소하였다. 그러나 반죽물에 비해 유과의 a값은 감소하였는데 이는 팽화에 의한 표면적의 증가와 고온에서의 가열에 의한 안토시아닌색소의 파괴에 의한 결과로 생각된다. 또한 유색미의 첨가량에 따른 물성 변화는 첨가량이 증가할수록 부착성은 감소하였으며 이를 제외한 다른 물성의 경우 큰 차이점이 없는 것으로 보아 유색미 첨가는 유과의 물성에 큰 영향을 주지 않는 것으로 생각된다. 유과의 품질 특성인 팽화도 역시 대조구는 13.34, 10% 첨가구는 10.75로 유색미 첨가에 의해 큰 차이를 보이지 않았다. 관능검사 결과 유색미 첨가 비율에 따른 색도의 선호도는 대조구와 7% 첨가구가 가장 높았으며 대조구와 7% 첨가구는 유의적인 차이가 없었다. 전체적인 수용도는 7% 첨가구에서 가장 높았고 3% 첨가구에서 가장 낮았다.

• 한국식품영양과학회지
• /
• 제19권6호
• /
• pp.617-624
• /
• 1990

유과제조에 좋은 특성을 갖는 일반계 찹쌀(품종： 신선)을 이용하여, 유과의 기업적 생산에 필요한 유과의 제조조건 및 팽화기작 추적 시험을 실시하였다. 유과 반데기 제조를 위한 증자시간은 증기가열로 5, 10, 15, 30, 45, 60분 처리에서 15분이 가장 적당하였고. 반죽의 수분함량은 48, 51, 53%를 시험한 결과, 48% 수준에서 조직이 가장 치밀하였다. 꽈리치는 시간은 1, 3, 4분간에 유의적인 차이가 없이 품질이 우수하나. 전혀 꽈리치기를 하지 않은 처리구는 조직의 치밀성이 낮고, 경도가 아주 유약하였다. 습식 및 건식제 분등 제분방법별 고온처리에 의한 공정단순화 시도에서 습식제분이 건식제분보다 팽화율이 높았으나, 고온처리 시간이 길어질수록 팽화율이 낮아졌고, 환원당량도 증가하여 전분의 분해가 이루어짐을 알 수 있었고. 이들이 유과의 팽화에 부정적인 영향을 주었으나. 각종 두류를 첨가한 결과 단백질 함량이 높아짐에 따라 유과특성이 개선되었다. 반데기는 장기저장시 RM에 따라 흡습정도가 달라졌고, 저장기간에 따라 팽화후 유과 바탕의 품질은 열화 되었다. 유과제조시 주류로서 막걸리, 소주, 청주를 각각 다른 양 첨가하여 품질을 비교한 결과, 첨가량이 중량비로 15%에서 30%로 증가함에 따라서 팽화율 및 조직특성이 다소 향상되었다.

• 동아시아식생활학회지
• /
• 제25권4호
• /
• pp.643-650
• /
• 2015

The principal objective of this study was to evaluate the quality of Yukwa prepared with mulberry leaf (Morus alba Linne) powder. The moisture, crude protein, crude lipid, crude ash, dietary fiber, and rutin contents of used mulberry leaf powder were 6.65%, 19.50%, 3.26%, 18.24, 38.91 and 0.54%, respectively. The tested concentrations of mulberry leaf powder were 0, 3, 5, and 7%. The Yukwa were stored at $45^{\circ}C$ for 40 days. Yukwa dough prepared with mulberry leaf powder had a lower pH compared to the control group. As more mulberry leaf powder was added, the spread ratio, moisture content, and volume increased. As more mulberry leaf powder was added, L-value decreased while a and b values increased with increasing mulberry leaf powder content. The hardness of Yukwa made with 7% mulberry leaf powder was the highest among the samples. In the sensory tests, Yukwa with 5% mulberry leaf powder received the highest scores. The acid value and peroxide values were lower in Yukwa prepared with mulberry leaf powder than control. Yukwa prepared with mulberry leaf powder strongly inhibited oxidation of lipids. The thiobarbituric values were lower in Yukwa prepared with 5% mulberry leaf powder than in Yukwa prepared with 3% and 7% mulberry leaf powders and control Yukwa. These results suggest that mulberry leaf powder can be applied to Yukwa to achieve high quality and functionality.

• 동아시아식생활학회지
• /
• 제26권5호
• /
• pp.407-417
• /
• 2016

Effects of resistant starch as a functional substitute on the quality of Yukwa were determined. Replacement ratios of resistant starch were 2, 4, and 6% of glutinous rice flour. Regarding pasting properties of Yukwa dough replaced with resistant starch, initial pasting temperature significantly increased and peak viscosity significantly decreased with increasing resistant starch. The moisture contents of bandegi and Yukwa base replaced with resistant starch were higher than that of the control. The expansion ratio of Yukwa base replaced with resistant starch significantly decreased with increasing resistant starch, and there were no significant differences in the oil absorption ratio. Lightness (L) of Yukwa base replaced with resistant starch increased significantly with increasing resistant starch. Appearance of Yukwa base replaced with resistant starch showed a shortened length and increased width with increasing resistant starch, and cross-section showed an oval shape, fine air cell distribution, and increased outer layer thickness. Hardness and peak number increased significantly with increasing resistant starch. The overall acceptability of Yukwa base replaced with 6% resistant starch was the highest among the samples, but the result was not significant. The above results show that resistant starch substitution in Yukwa improved the texture and further could improve health functionality due to its dietary fiber content. Resistant starch was appropriate as a 6% replacement for glutinous rice flour in Yukwa.

• 한국식생활문화학회지
• /
• 제29권5호
• /
• pp.428-436
• /
• 2014

This study was conducted to investigate the use of sugar alcohols (sorbitol, erythritol, and xylitol) as alternative sweeteners for replacing sucrose in Yukwa (traditional Korean oil-puffed rice snack). The moisture contents of Bandegi (dried Yukwa dough) and Yukwa containing sugar alcohols were higher than that of control (containing only sucrose). The microstructures of control and Bandegi containing sugar alcohols showed uniformly and finely distributed air holes. Expansion ratio and oil absorption of Yukwa containing sorbitol and 30% erythritol were higher than those of control. Appearance and cross section of control and Yukwa containing sorbitol, 30% erythritol, and 30% xylitol showed a good shape. The lightness (L) of control was significantly lower than Yukwa containing sugar alcohols, whereas redness (a) and yellowness (b) were higher than those in Yukwa containing sugar alcohols. Hardness of Yukwa containing sugar alcohols was significantly lower than that of control, and that of Yukwa containing sorbitol was the lowest. Peak number of Yukwa containing sugar alcohols was significantly lower than that of control, and that of Yukwa containing 60% erythritol and 60% xylitol was the lowest among all samples. In the sensory evaluation, color of control was deepest, whereas that of Yukwa containing 60% xylitol was lightest. Volume and air hole uniformity of Yukwa containing 60% erythritol and 60% xylitol were inferior than those of other samples. Sweetness of Yukwa containing sugar alcohols was lower than that of control, whereas oily flavor was stronger. Hardness of Yukwa containing sugar alcohols was lower than that of control, and Yukwa containing xylitol showed the lowest hardness among the samples. Crispness of Yukwa containing sugar alcohols was lower than that of control. There were no significant differences in overall acceptability between control and Yukwa containing 30% sorbitol and 30% erythritol. Overall, sorbitol and erythritol were appropriate as a 30% replacement for sucrose when preparing Yukwa.

• 한국식품과학회지
• /
• 제23권2호
• /
• pp.212-216
• /
• 1991

유과제조시 가장 걸림돌이 되는 꽈리치기 공정과 반데기 제조공정의 연속공정화 및 표준화를 위하여 기존 chopper의 구조를 변경하고 conveyer를 연결하여 기계화 가능성을 시도하였다. Plate와 die를 새로 제작하여 실험한 결과 꽈리치기 및 반데기를 연속적으로 제조할 수 있었으며, 그 품질도 기존방법에 비하여 차이가 없었다. 반데기의 두께와 폭은 conveyer belt의 속도를 조절하므로써 가능하였으며, chopper에서 반죽의 토출량이 221.8g/sec($Slit\;:\;5{\times}50.5\;mm$)일 때 conveyer의 속도는 87.3 mm/sec가 바람직하였다. Chopper의 구성에서 knife나 plate의 모양 등은 꽈리치기 효과에 큰 영향을 주지 않았으며, 건조 후 반데기의 두께는 $3.0{\sim}3.5\;mm$인 경우 가장 좋은 유과품질을 얻었다. Chopper를 통과하는 횟수는 품질에 큰 영향을 주지 않으나 전연 꽈리치기 하지않은 경우 조직은 대단히 유약하였다.

• 한국식품조리과학회지
• /
• 제24권3호
• /
• pp.340-348
• /
• 2008

The purpose of this study was to develop new method for the manufacture of Yukwa, a Korean oil-puffed rice snack with a soft texture, using a far infrared ray electric roaster. The Yukwa base is traditionally expanded using oil, but the Yukwa base tends to develop unpleasant rancid odors or off-flavors during storage. In this study, the DPPH radical scavenging activity of mugwort powder was evaluated. Baked and fried Yukwa samples were added with 0.5, 1.0, 1.5, and 2.0% of mugwort powder and left untreated as a control, and then tested for moisture content, expansion rate, color, hardness, and sensory evaluations. The samples with higher concentrations of mugwort powder, evidenced a more profound tendency toward DPPH radical scavenging activity. The moisture content of Yukwa dough tended to increase with the addition of mugwort powder. As the mugwort powder content increased, the moisture contents of the Yukwa base and the Baked Yukwa increased. The moisture content and expansion rates of the fried Yukwa did not differ significantly. The samples containing the mugwort power evidenced a lower expansion rate than was observed in the control group. The lightness of the baked and fried Yukwa was reduced with increased mugwort powder content. The greenness of the baked and fried Yukwa was at a minimum upon the addition of 2.0% mugwort powder. The yellowness of the baked Yukwa did not differ significantly between the samples. As the mugwort powder content increased, the yellowness of the fried Yukwa increased. The hardness of the baked and fried Yukwa tended to increase with the addition of mugwort powder. In the sensory evaluations, the baked Yukwa scored higher than the fried Yukwa, and all of the sensory characteristics of baked Yukwa scored highest in the samples without mugwort powder, but also scored fairly well with 1.0 and 1.5% mugwort powder. In conclusion, these results demonstrated that 1.0～1.5% of mugwort powder should be added to Yukwa baked in a far infrared ray electrical roaster in order to optimize physiological functions and keep overall acceptability reasonably high.

• 한국식품과학회지
• /
• 제34권4호
• /
• pp.597-603
• /
• 2002

유과가공공정의 개선 및 새로운 공정개발을 위하여 전통적인 유과가공공정의 올바른 분석이 중요하다. 전통적인 유과제조 공정에서 많은 시간을 필요로 하는 수침공정과 꽈리치기 공정을 분석하였다. 찹쌀의 수침은 증자만을 고려한다면 $15^{\circ}C$에서 3일 수침으로 충분하였지만 전통유과 특유의 부드러운 조직감은 6일 이상의 수침이 필요하였다. 수침한 찹쌀의 변화를 관찰한 결과 찹쌀 과피층에 존재하는 단백질이 감소하였고 수침한 찹쌀가루의 페이스트점도는 7일 수침한 찹쌀가루가 최대점도를 나타내고 감소하는 경향을 보였다. 수침에 의한 찹쌀 전분의 미세구조를 관찰한 결과 수침공정을 통해 전분표면이 손상되었다. 수침시간의 증가와 함께 유과의 팽화도는 증가하는 경향을 보였다. 꽈리치기에서 수침시간이 증가할수록 기공의 크기는 감소하였으며 균일한 기공의 분포를 나타내었고 반죽에너지 투입량은 감소하였다. 전통유과의 특징인 부드러운 조직감은 수침시간의 조절뿐만 아니라 반죽에너지 투입량의 조절에 의해 조절이 가능할 수 있었다.