This study investigated the antioxidant characteristics of sweet potato according to different plant parts and drying methods. The sweet potato plant parts were divided into root tubers, stems, stalks, leaves, and tips, and the drying methods were freeze-drying and hot air drying. Total polyphenol and flavonoid contents and radical scavenging activity of the sweet potato plant parts were significantly different depending on the plant parts and drying methods. The total polyphenol content of freeze-dried sweet potato leaves and tips were 52.76 and 46.19 mg chlorogenic acid equivalents/g sample, and the total flavonoid contents were 222.47 and 214.12 mg quercetin equivalents/g sample, respectively, and decreased with hot air drying. DPPH radical scavenging activity was higher in freeze-drying than hot air drying and was significantly different depending on the plant parts. The ABTS radical scavenging activity of freeze-dried sweet potato leaves and tips were 43.48 and 44.68 mg Trolox equivalents/g sample, respectively, and decreased with hot air drying. Therefore, additional studies on the functionality of using by-products from sweet potato cultivation are needed.

This study was carried out to investigate the effects of supercritical carbon dioxide (SC-CO2) extracts from sweet potatoes (SP) and watermelon (WM) on the oxidative stability of perilla seed oils (POs) over the existing ones. A comparison was done between the oxidative stability of perilla oil (PO) after the addition of 0.1% of SP, and WM extracts and PO without extract. The oxidative stability was measured based on the viscosity, acid value (AV), peroxide value (POV), antioxidant (DPPH) activity, p-anisidine value (p-AV), and fatty acid composition. The viscosities ranges were: PO without extract, from 53.99±0.99 to 74.38±1.61 cps, PO with SP extract, from 53.99±0.10 to 58.73±0.8 cps, and PO with WM extract, from 53.98±0.10 to 56.00±0.70 cps. While the PO containing the SC-CO2 extracts had significantly lower AV, POV, and p-AV, their antioxidant activity was approximately 10 times higher than that of the PO without extract. There were no significant differences in fatty acid composition between SC-CO2 extracts added groups and PO without extract (p<0.05). The findings of this study confirmed that the SC-CO2 extracts from sweet potatoes and watermelon enhanced the oxidative stability of perilla seed oils, and are potential natural antioxidants for use in the food industry.

This study examined the quality characteristics of Makgeolli to investigate the availability of Korean sweet potato cultivars as alcoholic beverages. The following sweet potato varieties were used: Gogunmi, Daeyumi, Shingunmi, Shinyulmi, Shincheonmi, Jinyulmi, Jinhongmi, Jeungmi and Pungwonmi; their alcohol contents ranged from 12.20% to 14.20%, with the lowest value in Makgeolli made with Jeungmi and the highest value in Makgeolli made with Jinhongmi. The DPPH radical scavenging activity was in the range of 37.51~77.02%, with the lowest value in Makgeolli made with rice (control) and the highest value in Makgeolli made with Gogunmi. As a result of analyzing the aroma component of sweet potato Makgeolli, 27 kinds of aroma components were detected, and six kinds of alcohols, 13 kinds of esters, four kinds of acids, and four kinds of other compounds were found. Regarding the number of aroma compounds, Makgeolli made with Shinyulmi showed the lowest number with 14 kinds, while Makgeolli made with Pungwonmi showed the highest number with 27 kinds.

본 연구에서는 고구마(Ipomoea batatas L.) 수확 후 버려지는 잔재물의 활용가치를 위해 이들로부터 추출한 발효 추출물과 열수 추출물의 생리활성과 세포독성을 분석 하였다. 추출물의 pH는 모두 산성을 나타내었고, 유기물 함량은 발효 추출물과 열수 추출물에서 각각 0.98%와 0.97%로 비슷하게 나타내었다. 다량원소 중 인산, 칼륨, 칼슘, 마그네슘 성분의 함량은 열수 추출물에서 발효 추출물보다 모두 높게 나왔고, 질소 함량만 두 추출물에서 동일하게 나왔다. 미량원소 함량은 아연을 제외하고 발효 추출물보다 열수 추출물에서 높게 나타내었다. 총 폴리페놀 함량은 열수 추출물에서 60.5±2.7 mg/g로서 발효 추출물의 총 폴리페놀 함량의 22.7±4.2 mg/g 보다 37.8 mg/g 높은 함량을 나타내었다(p<0.05). 총 플라보노이드 함량은 열수 추출물에서 50.7±2.7 mg/g로서 발효 추출물의 함량인 14.0±2.1 mg/g 보다 36.7 mg/g 높은 함량을 나타내어 총 폴리페놀 함량과 마찬가지로 열수 추출물이 발효 추출물보다 높은 함량을 나타내었다(p<0.05). DPPH와 ABTS radical 소거능력은 모두 열수 추출물에서 발효 추출물 보다 높은 항산화력을 보였다(p<0.05). MTT assay를 이용한 추출물의 세포독성 실험에서는 두 추출물의 모든 농도에서 세포독성이 미약한 것으로 확인되었다. 따라서 고구마 수확 후 잔재물의 추출물이 향후 각종 바이오 소재로 이용 시에도 큰 문제가 없을 것이라 판단된다.

This study was carried out to obtain the basic quality characteristics, like moisture contents, hunter color value, total polyphenol, starch, amylose, and ash contents and pasting characteristics of sweet potato cultivars according to storage periods. Moisture contents of all the varieties decreased with long storage period, and were lower in dry type than tender and moist type sweet potato. Lightness(L value) of sweet potato flesh was decreased in Shinyulmi, Daeyumi, Shinhwangmi but other seven cultivars showed increasing trend. Redness(a value) was increased in Sinyulmi, Sinhwangmi, Sinjami and yellowness (b value) increased in Yeonjami only. The total polyphenol contents increased in Dahomi, Sinjami up to 4 months of storage and all other varieties showed decrease during storage period. The starch contents also decreased with storage period. The amylose contents showed different by the cultivars. The ash contents in all varieties ranged from 1.1 to 1.7%, and there was no difference among varieties and storage periods. There was no change in pasting temperature during storage periods. Peak viscosity, through viscosity, breakdown and final viscosity were different according to storage periods and cultivars. But setback tended to increase in all cultivars.

The most common method of vegetative propagation of virus free plantlets is the use of shoots meristem culture in solid medium culture. This study was to investigate the effect on liquid medium culture for the growth of virus-free sweetpotato plantlets. Single-nodes derived from meristem culture of sweetpotato was examined in this experiment and three sweetpotato varieties ‘Singeonmi’, ‘Sinhwangmi’, and ‘Sinjami’ was used. The growth of plnatlets was greater in liquid medium culture than that of solid medium culture after longer incubation in 3 varieties. The total fresh weight of 5 week old plantlets after planting in solid culture were 2.17 g (‘Singeonmi’), 2.49 g (‘Sinhwangmi’), and 2.18 g (‘Sinjami’), but the fresh weight in liquid medium culture was 3.87, 3.88, and 3.35 g, respectively. Leaf number of ‘Singeonmi’ and ‘Sinjami’ plantlets after 5 weeks of liquid medium culture was 21.1 and 22.6, respectively and liquid medium culture showed 3 and 6.2 more leaf number than that of solid medium culture. Plant height of ‘Sinhwangmi’ and ‘Sinjami’ plantlets after 3 weeks of liquid medium culture was 4.1 cm and 3.4 cm, respectively, and liquid medium culture showed 1.1 cm longer stem length than solid medium. Overall, liquid medium culture of sweetpotato plantlets was more effective than solid medium in terms of leaf and stem growth.

The effect of transplanting and harvesting dates on growth, yield, and quality of sweetpotato varieties was studied. Three sweetpotato varieties, Yulmi, Singeonmi, and Dahomi, were transplanted on 23 Apr., 21 May, 5 June, 15 June, 25 June, 5 July, 15 July, and 25 July. Fresh vine weight and marketable storage root yield of the three varieties were the highest in transplanting plots on 23 April and 21 May, respectively, and those tended to decrease when transplanting dates were late after May. GDD (Growing Degree Days) and cumulative radiation seemed to be related to marketable storage root yield. Number of marketable storage root per plant, average weight of marketable storage root, and marketable storage root yield were significantly different according to transplanting dates. Marketable storage root yield showed significantly positive correlations with fresh vine weight, number of marketable storage roots, and average weight of marketable storage roots. Hardness and dry matter content of storage root showed significantly positive correlations with starch content and decreased with late transplanting dates in Yulmi and Singeonmi varieties. Pasting temperature showed significantly positive correlations with soluble solid content, dry matter content, and amylose content, but it showed significantly negative correlations with breakdown. Setback was significantly different among varieties, but it was not significantly different in transplanting dates.

수확과정에서 버려지고 있는 고구마 잎을 이용한 기능성 식품소재로서 활용가능성을 검토하고자, 밀가루 중량 대비 고구마 잎 분말을 2, 3, 5, 7%의 비율로 첨가하여 식빵을 제조 하고, 반죽 및 제빵 특성, 생리활성 및 기능성분 등을 조사하 였다. 반죽의 수분흡수량은 7% 첨가 시 가장 높았고, 반죽시 간은 유의적인 차이를 보이지 않았으며, 반죽의 저항도는 2~3% 첨가할 때가 가장 안정적이었다. 식빵의 수분 함량은 첨가량이 증가하여도 큰 차이를 보이지 않았고, 식빵의 내부색은 첨가량이 증가할수록 L값과 a값은 감소하였으나, b값은 증가하였다. 식빵의 부피와 비용적 및 굽기 손실률은 첨가량 이 증가할수록 감소하였으나, 항산화 활성과 총 폴리페놀, 루 테인 및 베타카로틴 함량은 증가하였다. 관능평가의 결과, 고 구마 잎 분말의 2~3% 첨가 시 맛과 색깔, 조직감, 입안에서의 씹힘성과 종합적인 기호도에서 가장 우수한 값을 얻었다. 이 상의 결과에서 고구마 잎 분말의 2~3% 첨가 시, 제빵 적성과 기능성, 상품성이 우수한 식빵을 제조할 수 있었다.

The purpose of this study was to investigate the effects of dietary purple sweet potato(Ipomoea batatas) powder on serum lipid levels and antioxidative enzymes in normal and pretective effect on hepatotoxicity rats induced by carbon tetrachlolide. Four groups of rats (3-week-old inbred Sprague-Dawley male rats) were normal rats fed control diet(C), induced hepatotoxicity rats fed control diet(EC), normal rats fed purple sweet potato diet(P), and induced hepatotoxicity rats fed purple potato sweet diet(EP). Rats were induced by single injection of 50% carbon tetrachlolide(0.1 mL/100 g B.W., i.p.). The rats were fed ad libitum each of the experimental diet for 5 weeks. After 5 weeks the rats were sacrificed and activities of antioxidant enzymes and lipid peroxidation products were determined in their liver homogenates. But serum concentrations of lipid was not significant in all groups. Serum alanine aminotransferase(ALT/GPT) and aspartate aminotransferase(AST/GOT) of the EC and EP groups were heigher than the C and P groups. The hepatic glucose 6-phosphatase(G6Pase) activity of the group fed purple potato diet(P) was lower than the other groups(p<0.05). However, The glutathione peroxidase(GPx) activities was not statistically different between the groups. Renal glutathione S-transferase(GST) activity of the EC and EP groups were lower than the C and P groups(p<0.05). In conclusion, these results suggest that purple sweet potato is believed to be possible protective effect on hepatotoxicity rats induced by carbon tetrachlolide.

To obtain basic data on the effects of differences cultivation periods and methods on growth and development of sweet potato tuber. We investigated growth and development of six major cultivars showing different characteristics, such as dry type(Yulmi, YM; Jinhongmi, JHM), intermediate type(Pungwonmi, PWM; Hogammi, HGM), and purple type(Sinjami, SJM; Danjami, DJM). The average tuber weight of YM and JHM was 4.1 and 8.6 g respectively, 50 days after transplant. At 80 days, the weight of YM and JHM rapidly increased to 25.2 and 26.1 g, respectively. Finally, at 120 days, the weight of YM and JHM increased to 120.7 and 79.4 g, respectively. The average tuber weight of PWM and HGM was 13 and 3.3 g, respectively, 50 days after transplant. The development pattern of PWM showed a consistent increase in tuber weight during the cultivation period, an average weight of 104.2 g at 120 days. However, the tuber development pattern of HGM was different from that of PWM. The average tuber weight of HGM rapidly increased for 100 days after transplant and then showed no increase at 120 days. In case of purple type sweet potato, the average tuber weight of SJM consistently increased during the cultivation period, whereas DJM showed rapid increase in average tuber weight at 80 days after transplant. Korean consumers prefer small, round sweet potato approximately 100g in weight. Based on the results, YM, PWM and SJM are classified as early developing cultivars that can be harvested approximately 120 days after transplant. On the other hand, JHM, HGM, and DJM are classified as late developing cultivars that can be harvested approximately 130 days after transplant.

Sweet potato (Ipomoea batatas L.) shoot tips grown in vitro were successfully cryopreserved by encapsulationvitrification. Encapsulated explants are very easily manipulated, due to the relatively large size of the alginate beads, and a large number of samples can be treated simultaneously. In this study, the effects of sucrose preculture, cryoprotectant preculture, and post-warm recovery media on regrowth, following liquid nitrogen (LN) exposure, were investigated to establish an efficient encapsulation-vitrification protocol for sweet potato. Shoot tips of plants grown in vitro were precultured in 0.3 M sucrose for 2 d before encapsulation. Encapsulated shoot tips were pre-incubated in liquid MS (Murashige and Skoog) medium containing 0.5 M sucrose for 16 h, before preculturing in sucrose-enriched medium (0.7 M sucrose) for 8 h. Shoot tips were osmoprotected with 35% plant vitrification solution 3 (PVS3) for 3 h, before being dehydrated with PVS3 for 2 h at 25°C. The encapsulated and dehydrated shoot tips were transferred to 2 mL cryotubes, suspended in 0.5 mL PVS3, and plunged directly into liquid N. High levels of shoot formation were obtained for the cv. Yeulmi (65.7%) and Yeonwhangmi (80.3%). The regrowth rates of cryopreserved samples in Yeulmi (78.9%) and Yeonwhangmi (91.3%), following culture on ammonium-free MS medium for 5 d, were much higher than those cultured on standard MS medium (65.7% and 80.3%, respectively). This encapsulation-vitrification is a promising method for the long-term preservation of sweet potato.

Sweet potato has low regeneration capacity, which is a serious obstacle for the fruitful production of transgenic plants. Simple and rapid regeneration method from storage root explants of purple sweet potato (Ipomoea batatas L.) was investigated. The embryogenic callus was observed from 4 cultivars and its highest rate was induced at 1 μM 2,4-D after 5 weeks of culture. Result revealed that a low concentration of 2,4-D and low light intensity was important factors for embryogenic callus formation. After subculture on medium with 5 μM ABA for 4 days, subsequently, occurred the regeneration of shoots within 4 weeks when these embryogenic callus was transferred onto the MS hormone free medium. Regenerated shoots were developed into platelets, and grown normal plants in the greenhouse. We developed a simple and quickly protocol to regenerate plantlets in storage root explants of purple sweet potato. This regeneration system will facilitate tissue culture and gene transfer research of purple sweet potato.

본 연구에서는 국내산 자색고구마(Ipomoea batatas L. Lam.) 추출물을 제조하고 이들 추출물에 대하여 항산화 활성을 측정하였다. 자색고구마 추출물은 70% 에탄올 추출물과 그 추출물로부터 에틸아세테이트 분획으로 제조하였다. 추출물 및 분획의 수율은 건조 분말 당 각각 39.2% 및 3.49%이었다. 이들 추출물/분획에 대한 항산화 활성을 확인하기 위해 자유 라디칼(1,1-phenyl-2-picrylhydrazyl, DPPH) 소거활성과 루미놀 발광법을 이용한 총항산화능 그리고 세포손상에 대한 보호효과를 측정하였다. 자유 라디칼 소거활성(FSC50)은 70%에탄올 추출물과 에틸아세테이트 분획이 각각 90.16μg/mL와 7.69μg/mL를 나타내었다. 비교 대조군으로 사용한 (+)-α-tocopherol의 라디칼 소거활성은 8.98μg/mL로, 에틸아세테이트 분획의 라디칼 소거활성이 보다 큼을 알 수 있었다. 루미놀 발광법을 이용한 70% 에탄올 추출물과 에틸아세테이트 분획의 총 항산화능(OSC50)은 각각 5.75μg/mL와 1.92μg/mL이었다. 비교 대조군으로 사용한 항산화 효능이 매우 우수한 L-ascorbic acid의 항산화능은 1.50μg/mL로 추출물의 에틸아세테이트 분획과 유사한 활성을 나타내었다. 1O2로 유도된 사람 적혈구의 세포손상에 대한 보호 효과 실험에서 에틸아세테이트 분획은 농도 의존적(5∼50μg/mL)으로 세포보호 효과를 나타내었다. 에틸아세테이트 분획의 세포보호활성(τ50)은 5μg/mL에서 45.6 min으로 모든 농도에서 비교 대조군인 (+)-α-tocopherol 보다 더 높은 세포보호 효과를 나타내었다. 이상의 결과들로부터 자색고구마의 에틸아세테이트 분획은 뛰어난 항산화능을 나타내며, 이는 피부노화 억제를 위한 항노화 기능성 화장품원료로 응용될 수 있는 가능성을 시사하였다.

고구마 괴근의 표피에 선모양으로 돌출되어 나타나는 피맥의 발생동향을 조사하고, 경감하기 위한 시험의 결과는 아래와 같다. 1. 고구마 피맥은 표피가 줄무늬로 돌출되어 상품성을 저하시키는 증상으로서 피맥발생은 표피층에 전분이 집적되어 발생하는 것으로 관찰되었고, 조기재배보다 보통기재배에서 발생이 많았다. 2. 고구마 품종에 따른 피맥발생은 건풍미, 연황미, 건미 등 7품종이 3%이하로 적었고, 헬씨미, 보라미는 30%이상 발생하였다. 만중은 피맥발생과 정의 상관관계가 있었다. 3. 고구마 피맥은 생육기간이 진전됨에 따라 증가하다가 삽식 후 120일경에 가장 높았다. 4. 고구마 삽식 후 90일의 적심비율에 따른 피맥발생율은 일정한 경향을 보이지는 않았다. 엽면적지수 4에서 피맥발생율이 가장 적었으나, 일정한 경향을 보이지는 않았고, 경엽절제비율이 높을수록 수량감소가 크게 나타났다.

고구마의 연작장해를 경감시키기 위하여, 연작지 토양과 심토반전 토양에서 농가묘와 바이러스 무병묘를 70×25cm 간격으로 재배하였다. 연작지 토양의 시비량은 N-P2O5-K2O = 55-63-156kgha1과 우분퇴비 10tonha1으로 표준시비를 하였고, 심토반전 토양은 질소비료와 퇴비만을 50% 증시하였다. 삽식 30, 120일째의 생육과 수량 및 품질특성을 조사한 결과는 다음과 같다. 1. 삽식 30일경부터 농가묘에서는 바이러스 병징이 뚜렷하였으나, 무병묘에서는 나타나지 않았다. 2. 무병묘의 수량성은 농가묘보다 심토반전 토양 15.0%, 연작지 10.5%의 증가를 보였다. 3. 심토반전 토양에서의 수량성은 연작지보다 농가묘 8.8%, 무병묘 3.2%의 증가를 보였으며, 심토반전 토양에서 바이러스 무병묘 재배는 상저비율이 농가묘(60.1%) 대비 80%로 높아져 경제성이 있었다. 4. 무병묘에서 수확한 고구마의 품질은 농가묘보다 피색이 선명하고, 고구마 모양이 좋아져 외관 품질향상에도 유리하였다. 5. 심토반전 토양 및 무병묘에서 수량증가는 30일째 엽수와 120일째 분지수와 정의 상관관계(p=0.05)가 인정되었으며, 이는 고구마 괴근형성에 초기생육이 중요하다는 것을 보여주었다.

고구마는 우리나라와 같은 온대지역에서 개화(開花)가 잘 되지 않고 자가부화합성(自家不和合性)으로 알려져 있지만 자가화합성(自家和合性) 품종도 있으며 품종간(品種間)에 교잡부화합성(交雜不和合性)이 존재한다. 그러나 국내에서는 지금까지 이러한 특성(特性)들이 연구되지 않아 육종효솔(育種效率)이 매우 낮다. 따라서 본 연구는 고구마 교잡육종(交雜育種) 효솔증진(效率增進)을 위한 기초자료로 활용하고자 국내에서 육성된 33개 품종의 개화성(開花性)을 조사하였다. 1. 자근(自根) 개화성(開花性)은 10~10.5시간의 일장(日長)에서 신미(新美) 등 14개 품종, 10.5~12시간(時間)의 일장(日長)에서는 홍미(紅美) 등 3개 품종만이 다소 개화되었고 그 이외의 품종들은 개화(開花)되지 않았으며, 12~14시간의 일장(日長)에서 개화되는 품종은 없었다. 2. 나팔꽃 대목(臺木)에 접목(接木)하였을 때는 자근상태(自根狀態)에서 거의 개화가 안되었던 품종들이 모두 개화되었고, 일장처리(日長處理) 방법에 있어서는 접목(接木)된 식물체(植物體)를 암실(暗室)로 이동시키는 방법에 의해 인위적(人爲的)으로 10시간의 단일처리(短日處理)를 하는 것보다 동계(冬季) 자연단일(自然短日) 상태(狀態)에서 개화성(開花性)이 더 증진되었다. 3. 품종별(品種別)로는 목계(木系)1호(號) 등 8개 국내품종은 접목(接木)과 단일상태(短日狀態)에서도 개화성(開花性)이 양호(良好)하지 못하였고 그 이외의 품종들은 개화성(開花性)이 양호(良好)하였다. 4. 화기특성(花器特性)은 조사품종 전체평균 화경(花梗)길이 56.2±21.2mm , 화경폭(花梗幅) 3.2±0.5mm , 소화경(小花梗)길이 6.8±2.1mm , 소화경폭(小花梗幅) 2.4±0.3mm , 암술길이 19.3±1.7mm , 최장(最長)수술길이 20.2±2.7mm , 최단(最短)수술길이 14.6±1.9mm 로서 화경(花梗)길이를 제외하고는 품종간(品種間)에 거의 차이가 없었다. 화주(花柱), 주두(柱頭) 및 화분(花粉)의 색(色)은 대부분의 품종이 백색(白色)이었으나 건미(健美) 등 2개 품종은 화주(花柱)가, 선미(善美) 등 4개 품종은 주두(柱頭)가 옅은 분홍색(粉紅色)이었고, 자방(子房)은 모든 품종이 옅은 갈색(褐色)이었다. 화관폭(花冠幅)은 36.7±6.0mm , 화통폭(花筒幅)은 12.8±1.5mm , 화관(花冠)길이는 40.2±6.5mm 이었고, 화관(花冠) 및 화통(花筒)의 색은 모든 품종이 분홍색(粉紅色)이었으며, 화분직경(花粉直徑)은 131±1.5um 였다.