• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.600-606
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• 2010

The objective of this study was to develop functional rice coated with yacon roots extracts and to evaluate the antioxidant properties and physiological activity of rice coated with yacon extract. The washed rice was coated by spraying yacon extract at 10, 20, 30, and $40^{\circ}Brix$ and dried at room temperature. The moisture contents, color changes, antioxidant properties as total polyphenolics and DPPH radical scavenging activity and instrumental texture property and sensory evaluation change in the yacon root extracts coated rice and uncoated cooked rice were observed during 3 days of storage. Increasing the coating concentration was associated with lower color values(L value) and moisture contents. Total phenolics and DPPH radical scavenging properties generally increased in the cooked rice coated with yacon root extract more than the control (non-coated rice). However, D-20($20^{\circ}Brix$ of the yacon root concentration) resulted in better textural properties and sensory overall acceptability in cooked rice on 0 and 3 storage days. It was concluded that the optimum coating ration of rice and added functional yacon rice were $20^{\circ}Brix$ and 7% respectively, in proportion to the total weight of raw rice.

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

• Korean journal of food and cookery science
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• v.26 no.1
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• pp.95-103
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• 2010

The objective of this study was to develop a functional vinegar beverage using yacon roots, and examine the components' changes during fermentation. The alcohol fermentation was conducted by inoculation of Saccharomyces cerevisiae into yacon root juice with sugars. After 10 days of fermentation at $27^{\circ}C$, yacon wine contained 13% alcohol and $7.8^{\circ}Brix$ sugar contents. The yacon wine at 5% alcohol was fermented by Acetobacter aceti(KCTC1010) with 250 rpm agitation rate at $29^{\circ}C$ for 12 days. The acidity of yacon vinegar reached 4.4% after 12 days' fermentation. Statistically (p<0.05), the amount of Acetobacter aceti, pH, alcohol, with total polyphenol content of samples decreased with acidity, whereas individual sugar contents increased. Furthermore organic acids, total sugar, phenolic acids content, total antioxidant capacity, and color were not different among the five samples. The yacon vinegar beverage was prepared with high fructose syrup through the dilution of yacon vinegar. After making the yacon vinegar beverage, the pH, acidity, total sugar, and total microbial content were examined every week over 4 weeks' storage. There were no changes in the samples during that time.

• Journal of the Korean Society of Food Culture
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• v.28 no.1
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• pp.107-113
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• 2013

Yacon (Smallanthussonchifolius) is a root crop that contains high amounts of fructo-oligosaccharides (FOS). FOS has a sweet taste, is low in calories, and is known to promote intestinal tract health. In this study, various yacon concentrates were substituted for sugar in white pan bread to obtain healthy benefits from the use of FOS. The quality characteristic changes during storage of the white pan breadswith 0, 25, 50, 75 and 100% of added yacon concentrates instead of sugar were investigated. During storage, the water contents and water activities of the breads made with high amounts of yacon concentrates changed less than in those made with only sugar. The hardness and chewiness of the breads made with high amounts of yacon concentrates had lower values than those made with only sugar. Thus, bread made with yacon concentrates might exhibit increased moisture retention and decreased aging velocity. The substitution of yacon concentrates for sugar in pan bread improved the bread quality.

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

• Korean journal of food and cookery science
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• v.26 no.3
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• pp.263-271
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• 2010

The purpose of this study was to measure the antioxidant activity of yacon root and to manufacture yacon pickles for commercialization as a functional food. The total phenol content in yacon roots were the highest, 29.96 mg GAE/ 100 g, in the ethyl acetate fraction and the DPPH radical scavenging activity and ABTS radical scavenging activity was 37.07%, and 91.60%, respectively, in the ethyl acetate fraction. The optimum recipe for the pickling solution was determined to be vinegar, water and high fructose corn syrup, at 34%, 22% and 44%, respectively. The quality characteristics of yacon pickles using this solution were monitored during storage at $25^{\circ}C$ for 43 days. The pH value decreased to 2.98 (42 days) during storage and $^{\circ}Brix$ gradually increased during storage. The L-value decreased significantly during storage but there were no significant changes detected in the a and b values. No significant changes were detected in the hardness of the yacon pickles. According to the sensory evaluation, no significant changes in taste, texture and overall acceptance of yacon pickle were observed during storage. These results indicated that yacon was an excellent functional food in terms of its antioxidant activity and that pickling might be a promising methods to maintain the taste and quality of yacon during storage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.240-244
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• 1993

Yacon(Polymina sonchifolia POEPP), an indigenous Andean natural resource food plant, was imported as a new root crop from New Zealand in 1986. However the chemical composition and planting system of it have not been research in Korea. The experimental results for the optimum planting densities and mulching effect are as follows. Height of the main stem of yacon was grown linear from July to October, is showed more fast growth as density increased, and showed highest in 70 ${\times}$ 55cm density. The tiller was bubed 3 month after planting but there was no significant difference among mulching, non-mulching condition and planting density. The fresh weight of root of mulching condition was heavier than that in non-mulching condition and 70 ${\times}$ 40cm mulching condition. In mulching treatment, number of roots in dense planting were more than that in sparse planting. The effect of mulching was not shown significantly in root diameter and root length.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.27-27
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• 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 CROP SCIENCE
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• v.46 no.5
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• pp.407-410
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• 2001

This study was conducted to determine the optimal planting distance in cultivation of yacon (Polymnia sonchifolia Poeppig ＆ Endlicher). Plug seedlings were planted with 6 different plant densities of 80 $\times$ 60, 80 $\times$ 50, 70 $\times$ 50, 70 $\times$ 45, 70 $\times$ 40 and 60 $\times$ 45 cm. The plant height and the petiole length were increased with increasing the planting distance. The tallest plant height of yacon was 165.4cm with the plant density of 80 $\times$ 60 cm. However, branch number per plant, leaf number on main stem and stem diameter were not significantly difference among planting densities. Tuberous root was harvested 31.42 tons/ha in 70 $\times$ 50 cm spacing. The ratio of heavier tuberous roots than 200 g to total tuberous roots decreased significantly according to increase of planting density. Fresh weights of shoot and root, contain the crown bud, were decreased, as planting distance was shorter. Tuberous root number was fewer but its weight was heavier in wide planting than in dense planting. We think that optimal planting density is about 30,000 plants/ha, if it were to be 70 cm row spacing, intrarow spacing should calculate about 47cm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.5
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• pp.356-360
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• 2002

The seedlings of yacon (Polymnia sonchifolia Poeppig ＆ Endlicher), which were cuttings, plug seedling (PS), crown bud before sprouting (CBBS), crown bud after sprouting (CBAS), and divided seedling after budding (DSAB) were planted at 70$\times$50 cm planting distance on ridge; that was interow spacingintrarow spacing, and about 28,500$\pm$71 plants/ha. CBBS didn't need work and equipment to raise seedlings. PS and DSAB grew taller to 140.5 and 143.3cm, respectively, than others at 150 days after planting. In the changes of plant height, PS and DSAB showed taller than others during growth period, cuttings, CBBS, and CBAS grew rapidly in middle growth stage. Excepting main stem and petiole length, other characters were significant for seedling. Fresh weights were different among seedlings. Even though the yield of plants grown from CBAS and CBBS were lower with 34.7 and 36.4 ton/ha, respectively, than 3.6 ton/ha of DSAB; its yield index were over 95%, hence, those of plants grown from cutting and PS were lower with 73 and 87%, respectively. The ratio of tuberous roots over 200g to total tuberous roots per plant was the highest from DSAB. Most of tuberous roots were under 200g per tuberous root from cuttings. CBBS, CBAS, and DSAB are suitable to use seedlings for high yield of yacono. Yacon plant by DSAB much produced tuberous root of over 200g.