• Journal of the East Asian Society of Dietary Life
• /
• v.25 no.6
• /
• 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 $40^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.34 no.5
• /
• pp.818-823
• /
• 2002

Effects of pelleting, drying, conditioning, and additives on the characteristics of Yukwa (fried pellet) were determined. RVA maximum paste viscosity of Bandegi (waxy rice pellet) was the highest after 2 days of moisture conditioning process, and decreased 2 days later. Air bubbles in Bandegi were distributed uniformly but were not significantly affected by conditioning time. For higher expansion and softer texture of Yukwa, the optimum moisture content of dried and conditioned Bandegi was $14{\sim}17%$. The addition of soymilk and 25% alcohol (Soju) as additives was also effective for achieving higher expansion and soft texture of Yukwa, respectively. Larger air cells were distributed in the center and smaller ones on the edge of Yukwa.

• Journal of the East Asian Society of Dietary Life
• /
• v.26 no.5
• /
• 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.

• Journal of the Korean Society of Food Culture
• /
• v.29 no.5
• /
• 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.

• Journal of the East Asian Society of Dietary Life
• /
• v.20 no.3
• /
• pp.402-414
• /
• 2010

A survey was conducted to study the ingredient and the nutrition of Yukwa consumed in Jeonbuk region. Additional survey was performed to the adult population in Jeobook region to identify the recognition and improvement of Yukwa. The ingredient and baking process varies from each region. The modernization of Yukwa baking process requires introduction of new flavour using new ingredient and simplification of the baking process as these two factors are holding back the modernization of the Yukwa. Top quality Yukwa can be produced by standardized baking process, using top quality agricultural goods, cultivated in Korea. The key to making Yukwa more accessible to the public is by simplifying the current baking process, including the drying process Bandegi, which is the most complicated process of all.

• The Korean Journal of Community Living Science
• /
• v.17 no.3
• /
• pp.43-53
• /
• 2006

In order to improve on the stability during the storage of Han-gwa, this study measured peroxide value, AOM test of ginseng and antioxidants added to Han-gwa. 1.2% of ginseng added to Han-gwa consists of moisture (3.37%), protein(1.30%), lipids (11.54%), carbohydrate(82.45%) and ash (1.34%). The hardness of Han-gwa was 257.7 for 1.2% of ginseng added to Han-gwa and 269.8 for Han-gwa without ginseng. The expansion coefficient of Han-gwa including 1.2% of ginseng was 12.9 magnification to Bandegi, indicating that it was inversely proportioned to the amount of ginseng. The induction period of the AOM test according to the concentration of ginseng in Han-gwa was extended to $0.53{\sim}0.83$ of magnification than the test of Han-gwa without ginseng. According to changes in AOM, acid value, peroxide value and thiobarbituric acid value of Han-gwa with various packing materials, PP multilayer film packing was the most effective material for storage of Han-gwa at 30C. 1.2% of ginseng added to Han-gwa and rosemary extract in a panel test was the most effective, and using PP multilayer film packing for Han-gwa was found to be the most useful method.

• Korean journal of food and cookery science
• /
• v.19 no.1
• /
• pp.60-64
• /
• 2003

Yukwa is a popular Korean traditional fried rice snack. The high fat content and porous structure of Yukwa cause it to become rancid rapidly. For extending the shelf-life of Yukwa, the Bandegi was fried with palm oil and soybean oil. The stability of Yukwa in lipid oxidation was determined by acid value(AV), peroxide value(POV), composition of fatty acid and sensory evaluation during 8 weeks of storage at 20$^{\circ}C$ and 50$^{\circ}C$ As the storage time increased, the AVs of soybean oil and palm oil during storage at 50$^{\circ}C$ were increased up to 42.64 and 2.09 mg/g, respectively. The POV of soybean oil during storage at 50$^{\circ}C$ was increased up to 4 weeks and then decreased. And as the storage time increased, the contents of stearic and oleic acid were increased, while linoleic and linolenic acid were decreased.

• Korean Journal of Food Science and Technology
• /
• v.33 no.6
• /
• pp.737-744
• /
• 2001

This study was carried to investigate the changes in physical and chemical properties during preparation of Yukwa. Protein content of glutinous rice was decreased during soaking time and acid and pH values were increased while contents of lipid and ash were not changed. Particle size distribution showed thate average particle size of 7 days soaking treatment smaller than those of 3 days and starch damage of glutinous rice flour was increased during soaking time. The major flavor components after soaking were found ethyl ester acetic acid, ethanol, 2-butan -ol, 2-methyl 1-propanol, 1-butanol, 3-methyl 1-butanol and 1-pentanol, propanoic acid. Content of acetic acid and butanoic acid were rapidly increased during soaking time. Results for ratio of storage modulus(G') and loss modulus(G') in glutinous rice flour dough indicated $tan{\delta}$ was increased for a while and decreased as frequency increased. G' value was very similar with G' value after steaming which means rubber-like property while G' and G' value were changed after during storage time. Treatment at $-20^{\circ}C$ had the highest hardness for cutting degree of dough. There was no difference in color value between different water contents. Hardness of Bandegi (sheet) was decreased as water content increased and the highest popping value was obtained at 18% of water contents. Adding 3% soaked bean had higher redness value of Yukwa and lower value in yellowness.