• Korean Journal of Plant Resources
• /
• v.30 no.3
• /
• pp.311-317
• /
• 2017

This study was conducted with the aim of evaluating the antibiotic effects of leaves, stems, and roots in yacon (Smallanthus sonchifolius). Antibacterial activity of leaf extract by disk diffusion method with Bacillus subtilis and Escherichia coli respectively showed 13.3 and 13.75mm diameters of clear zone. There was no significant difference between the stems and leaves. The minimum inhibitory concentration of leaves' heating and agitation extraction showed a restrain of strain at 1mg/ml, but the stems and root extract did not appear. Yacon is a functional antibacterial material, and methanol extraction is more effective than water. This research was to investigate the growth stage of collection has the most effective antibacterial effects. It has collected yacon's leaves from June to October, which is an appropriate time for collection right before reaping. Yacon leaf has antibacterial effects on Bacillus subtilis, Escherichia coli, Enterococcus faecium, and Salmonella enteritifis. There were no significant differences by the growth stage of collection. Leaves collected in July are high in phenol which helps in sulfating activity works well considering the high scavenging capability of DPPH. Leaves collected in September are high in total flavonoid.

• Journal of the East Asian Society of Dietary Life
• /
• v.22 no.3
• /
• pp.408-413
• /
• 2012

This study aimed to evaluate the physiochemical properties and fermentation qualities of kimchi supplemented with yacon (Smallanthus sonchifolius) during fermentation. Kimchi supplemented with 0%, 0.1%, 0.5%, 1%, and 5% yacon were investigated. As fermentation proceeded, pH decreased from 5.5~5.7 on the first day to 4.6~4.8 on day 21, whilst total titratable acidity (TTA), lactate levels, and number of microbes increased. The kimchi with 5% yacon showed a higher production of lactate concentration at 7 days fermentation than other groups, which is consistent with the observed high numbers of viable Leuconostoc sp. cells at 7 days fermentation. These observations demonstrate that 5% yacon stimulates the growth of kimchi microbes, particularly of Leuconostoc sp..

• Biomedical Science Letters
• /
• v.26 no.3
• /
• pp.201-209
• /
• 2020

The effect of mulberry leaves and yacon tuber extracts (MYE) on antioxidant was tested in this study. The present study investigated the in vivo effects of the anti-oxidative effect of MYE on catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GSH-Px), and thiobarbituric acid reactive substances (TBARS). The seven-day acclimation of the mice was divided into six groups: Normal diet group (NOR), high fat diet group (HFD), high fat diet with 0.5% hydroxycitric acid group diet group for positive group (HHCA), high fat diet with 1% mulberry leaf and 1% yacon diet group (MYE-1), high fat diet with 3% mulberry leaf and 3% yacon group (MYE-3) and high fat diet with 5% mulberry leaf and 5% yacon group (MYE-5). The effect of serum antioxidant in the catalase of MYE-1, MYE-3, and HHCA comparing to HFD by 31.0%, 27.7% and 45.2%, respectively (P<0.05~0.01). The effect on hepatic antioxidant in the catalase of HFD was significantly increased 3.7 (77.3%) times than that of NOR (P<0.01). But, the activities of catalase were decreased significantly in MYE-1, MYE-3, MYE-5 and HHCA by 21.7%, 24.2%, 24.9%, and 28.8% compared to HFD, respectively. GSH-Px was significantly decreased in MYE-1, MYE-3, MYE-5 and HHCA by 15.5%, 37.1%, 23.4%, and 23.7% compared to HFD, respectively (P<0.05). The activities of CAT, SOD, GST, GSH-Px, and TBARS were more significantly decreased in MYE-1 and MYE-3 than those of HFD and HHCA. MYE have shown significant effects on anti-oxidative function against high fat diet.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.6
• /
• pp.759-765
• /
• 2012

This study was performed to investigate improvements in diabetes mellitus by extracts of yacon in streptozotocin (STZ)-induced diabetic rats. Fifty rats were divided into a normal group and four experimental groups. STZ (45 mg/kg) was injected intraperitoneally to induce type I diabetes in the four experimental groups. Yacon extracts were administered for 5 weeks. Forty-five ICR mice were also divided into one positive control group and four experimental groups for the oral glucose tolerance test (OGTT) after fed yacon extract. The control group did not eat any yacon extracts, while Group 1 (GI) was fed 125 mg/kg of yacon extracts, Group 2 (GII) was fed 250 mg/kg of yacon extracts, and Group 3 (GIII) was fed 500 mg/kg of yacon extracts. After treatment for 5 weeks, blood glucose in GIII group showed decreased tendency at the 5 week. In OGTT by glucose, the glucose level of yacon treatment group in diabetic rats was significantly decreased compared to the glucose level of the control group, but there was no difference in OGTT by maltose. In ICR mice, the glucose level of the experimental group in OGTT by maltose was significantly decreased compared to the control group. The area of the islets of Langerhans was increased by yacon treatment in a dose-dependent manner on diabetic rats. Insulin concentration of the GIII group was also decreased compared to the control group, while the concentration of fructosamine, total cholesterol, and triglycerides in serum showed no difference. OGTT by glucose or maltose in ICR mice or diabetic rats, area of the Islets of Langerhans, and insulin concentration improved. Yacon treatment may be a useful therapeutic and preventive strategy for diabetes mellitus.

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

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2021.04a
• /
• pp.27-27
• /
• 2021

Yacon [Samallanthus sonchifolius (Poepp. & Endl.) H. Robinson], a member of Compositae plants, has sweet taste and crisp texture. Unlike other Andean root crops such as potato and sweet potato, the cultivation area of yacon has increased recently, since it is known to have large content of fructooligosaccharides (FOS). Since there are no yacon varieties bred in Korea, we have been trying to create new genetic resources using gamma-ray. The optimal gamma-ray dosage for mutation breeding in yacon was investigated. Crown bud and green bud of yacon were exposed to doses of gamma rays from 20 Gy to 80 Gy, and subsequently planted in a greenhouse. After 50 days of sowing, the survival rates and growth decreased rapidly at doses above 40 Gy, while all of crown bud individuals died above 60 Gy. The median lethal dose (LD50) of crown bud and green bud was 22.4 and 36.6 Gy, and the median reduction doses (RD50) for plant height, fresh weights, and tuberous root weight were 20-40 Gy, respectively. A dose of 20-40 Gy was found to be optimal for mutation breeding in yacon. Considering the growth factors, the optimum doses were determined to be within the range of 20-40 Gy for the selection of useful mutant lines. M2-M3 mutant lines were obtained from 20-60 Gy gamma-ray-irradiated M1 plants through clonal propagation. These mutant lines will be used for the development of a new variety of yacon plant with high FOS and no crack tuberous root.

• Korean Journal of Poultry Science
• /
• v.40 no.1
• /
• pp.1-9
• /
• 2013

This study was investigated the effects of dietary supplementation of Yacon by-product powder on performance, pH, total phenol contents, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, TBARS, WHC, shear force, meat color, and sensory evaluation of chicken thigh meat. Broiler chicks were fed diets for five weeks containing 0% Yacon by-products powder (Control), 0.5% Yacon by-products powder (T1), 1.0% Yacon by-products powder (T2), and 2.0% Yacon by-products powder (T3). There was no significant difference in performance among treatments, but mortality was decreased in diets by the supplementation of Yacon by-product powder than that of control. The total cholesterol, LDL-cholesterol and triglyceride of control were higher than treatment groups and HDL-cholesterol and glucose of control was lower than treatment. The pH and TBARS were significantly decreased by the supplementation of Yacon by-product powder compared to the control (P<0.05). The total phenol contents and DPPH radical scavenging activity were significantly increased by the supplementation of Yacon by-product powder compared to those of the control group (P<0.05), and especially, T3 was significantly (P<0.05) more effective in improving freshness compared to other treatment groups. The WHC (water holding capacity) and shear force were not significantly different. CIE $L^*$ and $a^*$ value of treatment groups showed significantly higher value compare to the control, however, no difference in the CIE $b^*$ values was observed among treatment groups. In conclusion, a supplementation of Yacon by-product powder was effective in decreasing pH and TBARS (thiobarbituric acid reactive substance), and increasing total phenol contents and DPPH radical scavenging activity.

• Korean Journal of Plant Resources
• /
• v.26 no.1
• /
• pp.9-18
• /
• 2013

The aim of this study is to provide the basic data for yacon [Samallanthus sonchifolius (Poepp. & Endl.) H. Robinson] in dietary food. The nutritional compositons, such as protein, ash, carbohydrate, dietary fiber, vitamin and fructooligosaccharide, were analyzed for 4 yacon germplasm lines. Yacon has low calories with only 46~56 kcal/100 g. The contents of water, fat, ash, protein, carbohydrate and dietary fiber were ranged 85.9~86.8%, 0.1~0.2%, 0.2~0.3%, 0.5~0.7%, 12.2~13.1% and 1.05~1.14%, respectively. The iodine-starch test did not show any color or precipitation reaction, which indicates that yacon has no starch content. However, in the absence of starch, yacon is rich in fluctooligosaccharide, which is between 9.6~11.1%. Maltose is present in the larger amount, followed by sucrose, glucose, and fructose in terms of free sugars. The analysis of minerals revealed that yacon contains potassium in the larger amount of 141~176 mg/100 g F.W., followed by magnesium at 8.2~10.6 mg, calcium, and sodium representing the least present mineral. Yacon proved to have a total of 17 types of amino acids, which are between 404.0~581.8 mg per 100 g of yacon. Glutamic acid, the main sweetening component, is present in the large amount of 94.0~182.2 mg/100 g F.W., followed by aspartic acid, arginine, and alanine. The proportion of the essential amino acid was 24.8~33.6%. Results of analysis also showed that yacon contains 0.001~0.024 mg, 0.03~0.11 mg, 0.02~0.3 mg, 0.3~0.4 mg and 14.1~20.6 mg of ${\beta}$-carotene, thiamin, riboflavin, niacin, and ascorbic acid, respectively. It is also likely to be highly used as functional food material in the future because it is abundant in both fluctooligosaccharide and antioxidants which are important functional components.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.2
• /
• pp.79-82
• /
• 2000

Tuberous root of yacon (Polymnia sonchifolia Poeppig ＆ Endlicher) has not starch, and its brix degree changes during the curing. Therefore its chemical composition changes were investigated according to different curing conditions. Tuberous root contained 87.1% moisture at harvesting, that was decreased to 84.1-86.0% at 30 days after curing in different curing conditions. Brix degree was increased from 5.7 to 14.2-15.8% at 30 days after curing in comparison to at harvesting. Free sugars were detected from tuberous root in yacon by HPLC; that were fructose, glucose and sucrose. Fructose contents were increased from 0.09 to 1.04-1.79% during 30 days in five curing conditions. Glucose contents were shown to increase from 0.03 to 1.04-1.37 %. Sucrose contents were shown to increase from 0.04 to 0.13-0.43%. Tuberous root contained fructose, glucose and sucrose in order of amount that were highest in single-polyethylene film covered green house. Sucrose was little as comparison with fructose and glucose. Fructose and glucose were increased to 16.7 and 40.7 times, respectively, but sucrose was increased little about 6.8 times.

• Biomolecules & Therapeutics
• /
• v.17 no.3
• /
• pp.256-262
• /
• 2009

Smallanthus sonchifolius (Yacon, Asteraceae) was originally cultivated in South America and used in food and traditional medicine by Andean inhabitants. Yacon is potentially beneficial for the management of diabetes and is composed of fructooligosaccharides, proteins, minerals and phenolic compounds. The aim of this study was to investigate the hypoglycemic effect of Yacon tuber extract (YTE) and its constituent, chlorogenic acid (CGA), in streptozotocin (STZ)-induced diabetic rats. In this study, a HPLC method was developed for simultaneous determination of major active phenolic components, CGA and caffeic acid in YTE. We investigated the hypoglycemic effect of YTE and CGA in STZ-induced diabetic rats and studied glucose tolerance test (GTT). The effect of orally administered multiple doses of YTE and CGA on plasma biochemical parameters was examined using diabetic rats. We also measured free radical scavenging activity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Oral administration of YTE (200 mg/kg) and CGA (10 mg/kg) for 6 weeks produced a significant hypoglycemic effect in STZ-induced diabetic rats. YTE and CGA-treated groups exhibited significantly decreased plasma glucose surge during the GTT. Total cholesterol (TC) and triglyceride (TG) concentrations were significantly decreased by 33% and 49%, respectively, in YTE-treated rats. TC and TG concentrations were also significantly decreased by 26 % and 41%, respectively, in CGA-treated rats. In the DPPH assay, free radical scavenging activity of CGA was similar to that of vitamin E, a positive control. This study suggests that YTE and its constituent, CGA, may be a useful option for management of hyperglycemia and diabetic nephropathy.