• Preventive Nutrition and Food Science
• /
• v.9 no.2
• /
• pp.107-112
• /
• 2004

Texture hardening of Yackwa during storage is the major quality deterioration of Yackwa. In this study the effects of gellan gum and xanthan gum on texture hardening of Yackwa during storage were studied. Instrumental hardness and sensory evaluation results showed that addition of 0.05 % and 0.1 % of gellan gum or 0.1 % and 0.5 % of xanthan gum significantly decreased the hardness of Yackwa by 32 ∼ 63 % after 4 weeks of storage. Retardation of texture hardening was obtained even at the 0.05 % level of gellan gum, indicating that gellan gum was a more potent texture modifier for Yackwa than xanthan gum. Correlation analysis between moisture content and hardness of Yackwa showed that there was high correlation between moisture content and hardness of Yackwa after 4 weeks storage ($r^2$=-0.998), regardless of the initial moisture content. These results suggest that retardation of texture hardening during storage is primarily related to moisture retention of Yackwa during storage.

• Journal of the Korean Society of Food Culture
• /
• v.9 no.4
• /
• pp.335-340
• /
• 1994

The objective of this study was to determine effects of soybean oil(SO), cottonseed oil(CO) and ricebran oil(RO) on stability and flavor of yackwa. This study consisted of yackwa fried in 3 differnet oils, then stored for 0, 3, 6 weeks in normal wrap at room temp. or vaccum package at $4^{\circ}C$. The moisture, oil contents, Hunter color values(L, 'a' and 'b'), % free fatty acid(FFA), thiobarbituric acid(TBA) value and sensory scores for color, flavor and acceptability were analyzed. The foam height of the oil after frying was also determined. Yackwa fried in RO was more red('a'=11.43) than yackwa fried in SO(10.64) or CO(10.51). TBA value of yackwa showed no difference among frying oils. Yackwa fried in SO showed better acceptability than those fried in CO. Yackwa fried in RO showed similar acceptability to yackwa fried in SO. The % FFA and TBA value of yackwa averaged across oil and package showed increasing tendency during 6 weeks storage.

• Korean Journal of Human Ecology
• /
• v.15 no.4
• /
• pp.669-674
• /
• 2006

In this study the properties of Yackwa partially replaced wheat flour with black rice flour were examined in the three factors: the physicochemical, the textural and the sensory. When the amount of black rice flour increased, dehydration and oil absorption of Yackwa decreased while frying it. The color of black rice flour Yackwa was darker yellowish than that of wheat flour Yackwa. When black rice flour was added more in making Yackwa, the results are as follows: first, its hardness increased, second, the external and internal color of Yackwa got significantly darker, finally, its greasiness decreased. As a result, up to 20% of wheat flour may be replaced with black rice flour without diminishing acceptability.

• Journal of the Korean Society of Food Culture
• /
• v.17 no.3
• /
• pp.260-266
• /
• 2002

This study was performed to know effect of Yackwa quality when sucrose fatty acid esters(S-570, S-970, S-1570) were added as an emulsifier. In mechanical characteristics, the Yackwa of sucrose fatty acid esters did greatly decrease the hardness, cohesiveness, springiness and gumminess, respectively, and increase the brittleness compared to the Yackwa of non-emulsifier and egg yolk. This tendency showed at the above level of 1.0% S-570, and 0.5% S-970 and S-1570, respectively. In sensory evaluation, the Yackwa of sucrose fatty acid esters increased the softness compared to the Yackwa of non-emulsifiers and egg yolk. There were significantly differences in the preference at 0.5% level of S-970 and 1.5% level of S-1570, respectively compared to other treatments. In conclusion, the 0.5% level of S-970 would be mostly useful level of emulsifier for making Yackwa.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.8
• /
• pp.1285-1291
• /
• 2003

This study was carried out to find optimum substitution amounts of garlic juice for the purpose of garlic-Yackwa development. Five experimental groups containing 0 t.s, 1/2 t.s, 1 t.s, 1 and 1/2 t.s, and 2 t.s of garlic juice per 1 cup of flour were compared with basic group containing 2 t.s of ginger juice per 1 cup of flour (ginger-Yackwa), by Hunter's colorimetry, texture profile analysis and sensory evaluation. In Hunter's color value, Yackwa, substituted garlic juice from 1/2 t.s to 2 t.s per 1 cup of flour for ginger juice, were lower than ginger-Yackwa. The higher amounts of garlic juice in garlic-Yackwa showed the lower tendancy of L and a values. The b value of garlic-Yackwa containing from 0 t.s to 2 t.s of garlic juice was higher than that of ginger-Yackwa. The higher amounts of garlic juice in garlic-Yackwa showed the higher tendancy of b value. In the texture characteristics, hardness, adhesiveness, springiness and chewiness of all garlic-Yackwa were significantly lower than those of ginger-Yackwa. Cohesiveness of garlic-Yackwa containing from 1 t.s to 2 t.s of garlic juice was significantly higher than that of ginger-Yackwa. Gumminess of Yackwa with garlic juice was higher ($1_{1/2}$ t.s, 2 t.s) than that of ginger-Yackwa, or lower (0 t.s∼l t.s) than that of ginger-Yackwa. The higher amounts of garlic juice in garlic-Yackwa showed the higher tendancies of hardness, cohesiveness and gumminess, while springiness and chewiness showed vice versa. In sensory evaluation, the higher amounts of garlic juice in garlic-Yackwa showed the better color, appearance, flavor, taste and overall acceptability. Especially garlic-Yackwa with 2 t.s of garlic juice showed the best color, appearance, taste, overall acceptability among them. Garlic-Yackwa with 2 t.s of garlic juice evaluated the best, while ginger-Yackwa evaluated the worst. In conclusion, these results indicated that 2 t.s of garic juice per 1 cup of flour could be very useful as a substitute for ginger juice in developing garlic-Yackwa.

• Journal of the East Asian Society of Dietary Life
• /
• v.24 no.1
• /
• pp.136-142
• /
• 2014

The purpose of this study was to evaluate the quality characteristics of Yackwa added with mulberry concentrate (0, 1, 2, 3%). The sugar concentration ($^{\circ}Brix$) and reducing sugar content (%) increased with higher amount of mulberry concentrate. As the concentration of mulberry concentrate increased, the puffing and oil absorption ratio of Yackwa also increased. Hardness of Yackwa added with mulberry concentrate was lower than that of control. The antioxidant activity as measured by DPPH radical scavenging activity of mulberry concentrate increased with higher mulberry concentrate amount. The sensory results showed that overall preference scores of Yackwa added with mulberry concentrate were higher than that of control. These results suggest that the optimum amount of mulberry concentrate added to Yackwa is 3%.

• Korean journal of food and cookery science
• /
• v.17 no.3
• /
• pp.229-236
• /
• 2001

This study was conducted in order to set the shelf life of Rice Yoogwa, Sesame Yoogwa and Yackwa to marketed in department store. It was investigated acid value, peroxide value, microbiological test and sensory evaluation for 50 days. Acid value of Rice Yoogwa, Sesame Yoogwa and Yackwa were not significantly different during storage period. Peroxide values of Rice Yoogwa and Yackwa were significantly increased after 30 days of storage but there was no different in Sesame Yoogwa. Fungus were appeared Sesame Yoogwa of A company, Rice Yoogwa and Yackwa of B company after 40 days of storage. In sensory evaluation, odor, taste, texture and overall acceptability after 40 days were significantly lower than 10 days of storage and rancid odor was gradually increased with preservation period in all materials. Correlation of acid value and peroxide value were positive throughout whole preservation period and rancid odor was increased. Odor, taste, texture and overall acceptability of Yoogwa and Yackwa were negative correlation with preservation period. In view of the above results, it came to the conclusion that shelf life of Yoogwa and Yackwa was 40 days.

• Journal of the Korean Society of Food Culture
• /
• v.24 no.4
• /
• pp.426-432
• /
• 2009

The quality of baked Yackwa with rice bran oil varied with dipping temperature (80 and 25$^{\circ}C$) and dipping time (5, 10, and 15 minutes at 80$^{\circ}C$, and 60, 90, and 120 minutes at 25$^{\circ}C$). The moisture content and hardness of baked Yackwa increased and decreased, respectively, with dipping time. The expansion ratio increased with time when baked Yackwa was dipped at 80$^{\circ}C$, but decreased with time when dipped at 25$^{\circ}C$. Flavor and color were optimal for product dipped at 80$^{\circ}C$ for 15 minutes followed those dipped at 25$^{\circ}C$ for 120 minutes; the dipping conditions produced no significant difference in the degree of expension, aroma, texture, and overall quality. Baked Yackwa showed better results than fried Yackwa in sensory evaluation.

• Korean journal of food and cookery science
• /
• v.18 no.3
• /
• pp.333-339
• /
• 2002

This study was conducted to examine the effect of emulsifiers on the quality characteristics of Yackwa. Lecithin and various sucrose fatty acid esters (S-570, S-970, S-1570) were used as emulsifiers. The addition of emulsifiers to Yackwa decreased the hardness, cohesiveness, springiness and gumminess, but increased the brittleness. This tendency was most distinct by the addition of S-970. All sensory characteristics of Yackwa such as color, smooth surface, smell, internal layer formation, softness and overall quality, were improved greatly by the addition of emulsifiers. As a result, the mechanical and sensory characteristics of Yackwa were improved by the addition of the emulsifiers, and sucrose fatty acid esters showed better results than lecithin.

• Journal of Nutrition and Health
• /
• v.5 no.2
• /
• pp.69-74
• /
• 1972

The study was made for storage test of Yackwa, which is typical cookies of Korea and contain about 20% of vegetable oil. As the result of investigation the variation of POV and AV of oil contained in Yackwa which was stored in packed or unpacked state for 60 days, at the temperature of $5^{circ}C$ or $30^{circ}C$ respectively, it was found that the Yackwa of AV, about 2, and POV, about 20, was considerably stable for storage. This result of the good storage condition of Yackwa containing a considerable amounts of Vagetable oil which proceed the rancidity, is derived from the formed film on the surface of Yackwa by the sugar syrup afterwards.