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

• 한국식생활문화학회지
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• 제31권2호
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• pp.178-187
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• 2016

The principal objective of this study was to investigate the quality characteristics of Yukwa prepared with chlorella powder. The tested concentrations of chlorella powder were 0, 1, 2, and 3%. As more chlorella powder was added, spread ratio, moisture content, and volume increased, whereas L-value and a-value decreased and b-value increased. The hardness of Yukwa made with 3% chlorella powder was highest among the samples. The results of the sensory evaluation test show that Yukwa with 1% chlorella powder was significantly more preferable in term sof overall acceptability. The acid value and peroxide values were lower in Yukwa prepared with chlorella powder than the control. Yukwa prepared with chlorella powder showed strong inhibition of lipid oxidation. Thiobarbituric values were lower in Yukwa prepared with 2% chlorella powder compared to Yukwa prepared with 1% and 3% chlorella powders and control Yukwa. These results suggest that chlorella powder can be applied to Yukwa for high quality and functionality.

• 동아시아식생활학회지
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• 제25권6호
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• pp.1029-1040
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• 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 $40^{\circ}C$.

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

• 한국식품영양학회지
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• 제26권4호
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• pp.655-662
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• 2013

This study was carried out to investigate the changes in the quality properties of red pepper Yukwa (red pepper liquid fermented with lactic acid bacteria was added to the Yukwa) during the storage period. To determine the shelf life of red pepper Yukwa, the rice Yukwa (control) and red pepper Yukwa were stored at 15, 25, and $35^{\circ}C$ for 70 days. Also, the quality properties of red pepper Yukwa, such as acid value, peroxide value, texture, color, and sensory evaluation were measured. Although the acid value of rice Yukwa and red pepper Yukwa increased during storage, the red pepper Yukwa showed a lower acid value score (1.09mg KOH/g) than that (1.19mg KOH/g) of the rice Yukwa. Nevertheless, these values did not exceed the guideline maximum values of 2.0 g KOH/g specified in the Korean Food Code. The peroxide values of samples had significantly increased after 42 days. Especially, the peroxide value scores for the rice Yukwa and red pepper Yukwa were the highest at 146.49 and 126.79 meq/kg at $35^{\circ}C$, respectively. Hardness and brittleness in textural properties increased up to 70 days. The sensory values for the red pepper Yukwa for overall acceptance, taste;texture and appearance were the highest. The results indicated that by using the 'Visual Shelf life Simulator for foods' of the Korea Food and Drug Administration (KFDA) the shelf life of red pepper Yukwa is estimated to be 274.78 days.

• 한국식품과학회지
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• 제43권5호
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• pp.583-587
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• 2011

불린 찹쌀과 콩에 소주 첨가비율을 0, 25, 50, 75 및 100% 비율로 첨가하여 제조한 유과반대기 및 유과바탕의 품질특성은 다음과 같다. 유과반대기의 두께, 길이, 무게, 부피 및 비용적은 시료 간에 유의한 차이가 없었다. 반면에 유과바탕의 경우 소주 50% 비율 첨가구는 직경, 부피 및 비용적이 가장 높았고, 소주 75% 비율 첨가구는 길이가 가장 길었으며, 무게는 소주 첨가비율이 높을수록 증가하였다. 유과반대기와 유과바탕의 색도는 L값의 경우 소주 첨가비율이 증가할수록 높았고, 유과바탕은 유과반대기에 비하여 L값은 높고 a와 b값은 낮은 경향을 나타냈다. 유과바탕의 형태는 소주 첨가비율이 증가할수록 일정하지 않았고, 소주 첨가비율이 증가할수록 유과바탕의 기공의 크기는 적었고, 기공 수는 많았다. 유과바탕의 압착력 및 전단력은 소주 50% 첨가비율이 가장 낮았고, 소주 무첨가구가 가장 높았다. 유과바탕의 관능검사 결과 향미와 맛에 대한 선호도는 시료 간에 유의한 차이가 없었다. 색에 대한 선호도는 소주 첨가비율이 증가할수록 높았고, 내부 치밀도, 입안에서의 느낌 및 전체적인 선호도는 소주 50% 비율 첨가구가 가장 높았다. 소주를 첨가하여 유과를 제조할 경우 유과바탕의 품질은 첨가된 총 액체량에 대하여 소주 첨가비율이 50-75%일 때 가장 높은 것으로 생각된다.

• 동아시아식생활학회지
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• 제14권5호
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• pp.463-471
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• 2004

The objectives of this study were to investigate quality characteristics of Yukwa which containing 0, 1, 3, 5% of safflower chemical properties showed that degree of expansion of Yukwa were decreased as the amount of safflower increased, while fat absorption increased. Fatty acid of Yukwa were increased as the amount of safflower increased. Sensory properties showed that cripsness of Yukwa were significant difference(P<.001) in the Yukwa with Safflower. L-value decreased by the addition of safflower, while a-value and yellowness increased. The mechanical properties showed that hardness and brittleness was the highest in the Yukwa with 5% safflower. Later 4 weeks and 6 weeks of storage, 3% and 5% safflower containing Yukwa showed decrease peroxide value and acid vale. respectively.

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

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

• 동아시아식생활학회지
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• 제10권1호
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• pp.55-61
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• 2000

Physicochemical and sensory characteristics of Yukwa(fried rice cookie) made by different processing condition were investigated to estabilish the optimum expansion of Yukwa. The expansion rate and crispness of Yukwa prepared by soaking waxy rice for 24 hours was satisfactory . Addition of 15% soy slurry gave better effect on increasing the expantion rate, crispiness and sensory preference than no addition of soy slurry . Yeast, Soju(distilled liquor) , Mackeali(rice wine, turbid) and Chunju(rice wine, clear) as expansion reagent were added to Yukwa prepration . Yeast and Mackeali among tested expansion reagent showed better expansion rate and lower hardness meausred by texturometer than Chunju. Yukwa added chungju showed more fine structure and lower expantion rate than others. Microwave puffed Yukwa was less expansion rate, but same level of crispiness and hardness compared with oil puffed. And no difference in sensory characteristics such as degree of crispiness and stickiness of microwave puffed and oil puffed.