• Korean journal of food and cookery science
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• v.26 no.5
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• pp.545-551
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• 2010

In this study, Sulgidduk samples were prepared with 0%, 3%, 5% and 7% yacon powder. Sulgidduk samples were then examined for quality characteristics such as moisture content, general components, color, texture profile analysis, sensory qualities, and sugar content, in order to determine the optimal ratio of yacon powder in the formulation. Regarding the general components of yacon Sulgidduk, the contents of crude protein and lipid decreased as the ratio of yacon powder increased. The L-value for color decreased, whereas a- and b-values increased. In the texture profile analysis, 7%-added yacon showed significantly lower hardness, whereas 7% yacon powder showed the highest values for cohesiveness, springiness, and chewiness. The contents of sucrose, fructose, and glucose in yacon Sulgidduk were found to be 3%, 5%, and 7% by LC, respectively. Sucrose showed a decreasing trend with increased yacon powder content, but fructose and glucose increased with increased amount of yacon powder. For sensory qualities, taste/flavor, texture, hardness, and overall acceptability were not significantly different among the 0%, 3%, and 5% yacon powder samples.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.3
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• pp.378-385
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• 2012

This study carried out to investigate the effects of yacon powder on yellow layer cake made with weak flour. After making yellow layer cake with yacon powder, water activity, crumb texture, crumb color, and sensory characteristics were investigated. After 1 day of storage, Aw value of control cake with weak flour did not show any significant differences, whereas those with 2, 4, and 6% yacon powder showed a significant increase in Aw. During storage, the Aw values of yellow layer cakes containing yacon powder decreased. Hardness and gumminess of yellow layer cakes containing yacon powder decreased compared to those of control, whereas springiness and cohesiveness of yellow layer cakes increased compared to those of control. Hardness, springiness, cohesiveness, and gumminess all increased with storage time. Further a higher percentage of yacon powder was associated with lower L and b values as well as a higher a value. The micrographs of yellow layer cakes with yacon powder showed slightly coarser porosity than that of control. The results of the sensory test showed that the overall acceptability of 2% yacon powder cake was the highest.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.3
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• pp.374-381
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• 2013

The purpose of this study was to analyze the antioxidant effects and antimicrobial activity of extracts from yacon powder. The total polyphenol contents of yacon powder extracted with methanol was 38.5 mg/g, while extracted with water was 24.0 mg/g. Extractions with methanol were therefore more effective than with water. The total flavonoid contents of yacon powder extracted with methanol was 9.2 mg/g, while that with water was 7.8 mg/g. The electron donating ability of yacon powder extracts, natural antioxidant, and artificial antioxidant at 1.0 mg/mL arranged in order of decreasing concentration were ascorbic acid (98.7%) > BHT (44.7%) > methanol extract (12.1%) > water extract (7.8%). Nitrite-scavenging ability of yacon powder extracted with methanol at pH 1.2 was 13.1%, while that of powder extracted with water at pH 1.2 was 6.8%. And, the hydroxyl radical scavenging activities of yacon powder with methanol at 5 mg/mL was 40.2%. The antimicrobial activity of yacon powder extracted with methanol could be detected on Bacillus cereus ($10,000{\mu}g/disc$) and Staphylococcus aureus ($10,000{\mu}g/disc$).

• Culinary science and hospitality research
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• v.20 no.4
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• pp.14-26
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• 2014

This study investigated the physicochemical and sensory characteristics of muffins prepared with various amounts(0, 3, 6, 9, 12%) of yacon powder. The specific gravity of the muffins prepared by adding yacon powder was higher than that of the control group. The height of the muffins added with 3% yacon powder was higher than that of the other groups. The weight of the muffins prepared with yacon powder showed no significant difference among all the sample groups. The volume and specific loaf volume of the muffins were decreased by addition of yacon powder. The baking loss rate of the muffins prepared by adding yacon powder showed no significant difference among all the sample groups. The moisture content of the muffins was increased, but their pH was decreased significantly by addition of yacon powder. DPPH radical scavenging activity of the control group was 21.45%, whereas the muffins prepared with yacon powder ranged from 57.23~85.46%. The a value of redness was increased, but L and b values were decreased significantly by addition of yacon powder. The springiness, cohesiveness and brittleness of textural properties of the muffins were decreased significantly by addition of yacon powder. Sensory evaluation scores in terms of appearance, taste, texture and overall preference for the muffins showed that 6~9% substituted sample groups were higher than those of the others. The results of this study suggest that adding 6~9% of yacon powder was the best substitution ratio for muffins.

• Food Engineering Progress
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• v.15 no.3
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• pp.269-275
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• 2011

The baking performance of yacon powder as a value-added food ingredient was investigated in a model system of sponge cakes. Yacon powder was incorporated into cake batter at 5 levels (0, 10, 20, and 30%, w/w) by replacing equivalent amount of wheat flour. The specific gravity of batter increased significantly while pH decreased significantly with the increase in yacon powder content (p < 0.05). The specific volume and moisture content of sponge cakes decreased while baking loss increased (p < 0.05). Volume of the cakes decreased with higher amount of yacon powder in the formulation as indicated by the decrease in the volume index. The symmetry index was not affected by the amount of yacon powder in the formulation (p > 0.05). Sponge cakes became darker and firmer with increase in yacon powder content (p < 0.05). Finally, the consumer acceptance test indicated that incorporation of yacon powder up to 20% in the formulation of sponge cakes did not significantly influence the consumers' overall acceptability.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.100-112
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• 2014

This study investigates the characteristics of cookies added with yacon. The addition of yacon powder did not affect the density of the cookies and decreased pH level. The moisture content was the highest in the cookies with 12% of yacon. Spread ratio was the highest in the cookies containing yacon powder. The loss rate and leavening rate of the cookies decreased with increasing amounts of yacon powder. Lightness and yellowness decreased significantly while redness increased significantly with a high content of yacon powder in the formulation. The hardness of the control group was higher than that of the cookies prepared with different levels of yacon powder. The antioxidant activity was estimated by DPPH free radical scavenging activity and the total phenolic acid content in yacon powder and cookies. The consumer acceptability score for the 6% yacon cookie group ranked significantly higher than the other groups in overall preference, appearance, flavor, taste and color. Through this experiment, this study exhibited both the functional and health based benefits of yacon when it is added to cookies and confirmed the development feasibility of yacon cookies considering consumer satisfaction.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.61-68
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• 2014

This study were investigated the effects of dietary supplementation of yacon by-products and mugwort powder on performance, carcass characteristics, pH, TBARS (thiobarbituric acid reactive substance), WHC (water holding capacity), shear force and meat color of broiler thigh meat. Broiler chicks were fed diets for five weeks containing 0% yacon by-products and mugwort powder (Control), 0.5% yacon by-products powder (T1), 1.0% yacon by-products powder (T2), 0.5% mugwort powder (T3), and 1.0% mugwort powder (T4). There were no significant difference in performance among treatments, but mortality was decreased in diets by the supplementation of yacon by-products and mugwort powder than that of control. The total cholesterol, LDL-cholesterol and triglyceride of control were higher than treatment groups and HDL-cholesterol of control was lower than treatment. The TBARS was significantly decreased by the supplementation of yacon by-products and mugwort powder compared to the control (P<0.05), especially, mugwort powder treatment group was significantly (P<0.05) more effective in improving freshness compared to other treatment groups. The WHC and shear force were not significantly different. CIE $L^*$ and $a^*$ value of treatment groups showed significantly higher value compared to the control, however, no difference in the CIE $b^*$ values was observed among treatment groups. In conclusion, a supplementation of yacon by-products and mugwort powder were effective in decreasing TBARS, total cholesterol and LDL-cholesterol and increasing HDL-cholesterol concentration. Mugwort powder supplementation was most effective.

• Journal of the Korean Society of Food Culture
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• v.27 no.1
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• pp.82-88
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• 2012

In this study, the effects of yacon (Smallanthus sonchifolius) leaf on the quality characteristics of cookies were examined. In order to investigate its effects, four different amounts (0%: Control, Y-0.5, Y-1.0, Y-1.5) of yacon leaf powder were added to the cookie dough. Among the physicochemical and sensory characteristics, the density and pH of the dough, spread factor, color value, firmness, consumer acceptability, and Pearson's correlation coefficients were measured. Although there was no significant difference in pH of the doughs among the groups, density significantly decreased with increasing amount of yacon leaf powder (p<0.05). While the L, a, b values, and hardness decreased significantly, DPPH free radical scavenging activity increased significantly as the content of yacon leaf powder increased (p<0.05). Overall acceptability, appearance, taste, and texture between the control and Y-0.5 groups showed no significant differences. This study suggests the possibility of yacon leaf as an ingredient that increases the functionality of cookies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.210-218
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• 2010

This study was carried out to investigate the effect of Yacon (Polymnia sonchifolia Poepp. & Endl.) powder on cholesterol-lowering and anti-obesity effects in rats fed a high fat-high cholesterol diet for 4 weeks to induce hyperlipidemic and obese rat model. Weight-matched male Sprague-Dawley rats were assigned to four groups according to dietary fat, cholesterol levels and Yacon powder levels. Experimental groups were normal diet group (N), high fat-high cholesterol diet group (HFC), high fat-high cholesterol diet with 5% Yacon powder group (HFC-PSL) and high fat-high cholesterol diet with 10% Yacon powder group (HFC-PSH). The body weight gain and FER were increased by a high fat-high cholesterol diet, but gradually decreased in the Yacon powder fed groups compared with the HFC group. Food intake was lower in HFC groups compared with N group. The liver and adipose tissue weights of HFC group were heavier than those of N group, whereas those of groups administered Yacon powder were gradually decreased. The serum ALT, AST, ALP and LDH activities elevated by a high fat-high cholesterol diet were significantly decreased by Yacon powder administration. Levels of serum total cholesterol, LDL-cholesterol, atherogenic index and cardiac risk factor showed a decreasing tendency in the Yacon powder fed groups compared with HFC group. The serum HDL-cholesterol level decreased in the HFC group and markedly increased in the Yacon powder fed groups. Levels of total cholesterol and triglyceride in liver and adipose tissues were lower in Yacon powder administered groups than those in HFC group. These results suggest that Yacon powder may improve lipid metabolism of serum, liver, and adipose tissue and potentially reduce lipid storage.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.187-195
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• 2013

This study was investigated the effects of dietary supplementation of Yacon by-products and pine needle powder on growth performance, carcass characteristics, pH, TBARS (thiobarbituric acid reactive substance), WHC (water holding capacity), shear force, and meat color of chicken thigh meat. Broiler chicks were fed diets for five weeks containing 0% Yacon by-products and pine needle powder (Control), 0.5% Yacon by-products powder (T1), 1.0% Yacon by-products powder (T2), 0.5% pine needle powder (T3), and 1.0% pine needle powder (T4). There was no significant difference in growth performance among treatments, but mortality was decreased in diets by the supplementation of Yacon by-products and pine needle powder than that of control. The chicken fed control diet had higher cholesterol. LDL-cholesterol. triglyceride compared to those chicken fed Yacon by-products and pine needle powder regardless of concentrations, and HDL-cholesterol of control was lower than treatment. The pH and TBARS were significantly decreased by the supplementation of Yacon by-products and pine needle powder compared to the control (P<0.05), especially, pine needle powder group was significantly more effective in improving freshness compared to other test groups (P<0.05). The WHC and shear force were not significantly different. CIE $L^*$ and $a^*$ value of test groups showed significantly higher value compare to the control, however, no difference in the CIE $b^*$ values was observed among test groups. In conclusion, a supplementation of Yacon by-products and pine needle powder were effective in decreasing pH, TBARS, total cholesterol and LDL-cholesterol and increasing HDL-cholesterol concentration. Pine needle powder supplementation was most effective (T3 and T4).