The colored sweet potato, particularly purple sweet potato, has been well known to contain anthocyanins abundantly. This study was conducted to examine the antioxidant properties of purple sweet potato. The chopped purple sweet potato was extracted 2 times with water or acetone for 18 hours at . The antioxidative potential of each solvent extract was assessed by DPPH free radical scavenging activity assay, FRAP assay, and total phenolic contents. The results showed that both extracts had not only high DPPH free radical scavenging activity but had high level of total phenolic compounds. Furthermore, both solvent extracts were found to have antioxidative effects in human colon cancer cells (HCT 116, HT 29) in DCFDA assay. The notable antioxidant activity of purple sweet potato suggests its significant health benefit and deserves further study to develop into functional food ingredient.

백설기 원료인 쌀가루에 당 및 식이섬유의 함량이 높은 것으로 알려진 고구마가루를 5, 15, 25%(w/w, dry-weight basis) 비율로 첨가하여 원료 및 제품에서 나타나는 이화학적 품질과 제품의 관능특성, 및 저장성을 관찰하였다. 쌀가루에 대한 고구마가루 첨가량이 증가할수록 제품의 수분결합력, 팽윤도가 증가하였으며 외관에 있어서 적색도 및 황색도가 증가한 반면 전체적인 외관은 다소 어두워졌다. DSC(Differential Scanning Calorimeter)에 의한 열적특성의 분석결과 고구마가루의 H는 28.1 J/g으로서 19.1 J/g인 쌀가루에 비해 2배 정도로 높아 호화경향이 낮은 것으로 조사되었다. DSC thermogram에 나타난 전분의 노화도 경향은 고구마가루 첨가량이 증가할수록 감소하여 고구마가루 첨가량에 비례한 제품의 노화억제효과가 확인되었다. 제품의 경도, 응집성, 탄력성, 씹힘성 등은 고구마가루 첨가에 따라 감소하였으며 또한 경도증가율이 낮아져 고구마가루의 노화지연 효과가 확인되었다. 백설기 내의 고구마가루 첨가는 상대적으로 낮은 저장온도에서 제품의 경도증가를 억제하는 경향이 있었다. 그러나 제품의 경도변화의 폭은 저장온도 보다 고구마가루 첨가의 영향을 더 많이 받는 것을 알 수 있었다. 미생물적 특성에 있어서 제품을 실온에서 3일간 저장 시 고구마가루 첨가량에 따라 총 미생물수가 미첨가구에 비해 최고 1/10정도까지 낮게 유지되었다. 제품의 외관과 색을 제외한 전반적 기호특성은 고구마가루 첨가에 따라 향상되었으며 특히 15% 첨가구가 가장 좋은 평가를 받았다.

자색고구마 추출물의 항산화 효과와 산화적 스트레스로 유도된 PC12 신경세포에 대한 보호효과에 대하여 연구하 였다. 자색고구마 추출물의 총 페놀함량은 44.25 mg/g, monomeric anthocyanin 함량은 2,394 mg/L로 나타났 다. 자색고구마 추출물의 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylben-zthiazoline- 6-sulfonic acid) (ABTS) radical 소거활성, ferric reducing/antioxidant power (FRAP) 및 환원력은 농도 의존 적으로 항산화 활성이 증가하였다. MTT {3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazoliumbromide} reduction assay를 이용하여 자색고구마 추출물의 신경세포 보호효과를 측정한 결과, 세포 생존율이 두드러지게 증가하는 것으로 나타났다. 산화적 스트레스는 신경세포막 손상 정도를 증가시키기 때문에 lactate dehydrogenase (LDH) release assay와 neutral red uptake assay를 이용하여 세포막 손상 보호효과를 조사한 결과 자색고구마 추출물 처리구는 대조구에 비하여 산화적 스트레스로 유도된 세포막 손상 보호효과가 농도 의존적으로 나타났다. 따라서 자색고구마 추출물은 천연 항산화 소재 및 알츠하이머성 치매와 같은 신경퇴행성 질환의 예방 소재로서의 활용 가능성이 기대된다.

The objective of this study was to assess the quality characteristics of almond Dasik prepared with the addition of purple sweet potato powder (PSPP). Five different levels (0, 5, 10, 15, and 20%) of PSPP were added and the physicochemical properties of the Dasik were examined. Crude protein and crude fat contents decreased as the level of PSPP increased (p<0.05). The Hunter L-value decreased while the a-value increased as the PSPP level increased. Texture measurements showed that the addition of PSPP increased hardness, cohesiveness, and brittleness. Total polyphenol content and antioxidant activity were assessed in terms of estimating the functionality of the Dasik. The results showed that incorporating PSPP into the Dasik provided higher polyphenol content and antioxidant activity compared to the control Dasik (p<0.05). The results of a consumer acceptance test revealed that the Dasik sample made with 15% PSPP was most preferred and the 20% sample was the least preferred. Therefore, it is suggested that purple sweet potato powder can be incorporated into Dasik up to 15% without reducing its quality.

Sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a serious pest of many economically important crops. The insect has developed resistance to chemical insecticides. Therefore, the development of microbial agent such as entomopathogenic fungi, Lecanicillium lecanii is necessary. Spores of L. lecanii Btab01 was collected after cultivation on solid PDA and liquid RB (rice bran amended with 2% molasses) media. The bioassay was carried out with B. taabci nymphs for 7 days at 25℃ and 60% relative humidity. Further, mortality was corrected with appropriate controls. The results revealed that spores obtained from RB medium caused high mortality (98.31%) compared to PDA medium (93.94%). Spore concentrations 105, 106, 107, and 108 colony forming units (c. f. u) ml-1 caused 5.81, 33.80, 77.27, and 98.54% mortality, respectively. The mortality (100%) was observed for 4 days when L. lecanii spores was mixed with 0.1 - 0.3% soybean oil. Hence, it is concluded from this study, L. lecanii Btab01 cultivated on RB medium can be recommended to control the nymphs of B. tabaci. Spore suspension can be expected to high efficacy when soybean oil was blended.

This study was carried out to investigate of the performance for Sweet potato Harvester using Power-tiller. There was highly reduction in energy consumption using by Sweet potato Harvester of Power-tiller. A diesel engine with four cycle with single cylinder, water cooling and rated output 8.1 kW/2200 rpm was selected. The experimental factors for performance test, engine speed ranged from 1000 rpm to 2400 rpm, and BSFC, efficiency, traction power, and vibration were measured. The results obtained were as follows; engine output were increased from 4.4 kW to 5.74 kW at 1800 rpm and increased to 8.83 kW at 2400 rpm The specific fuel consumption was decreased to 320 g/kW.h at engine speed 2200 rpm and the traction power were showed 420~440 kgf.

Dongbu HiTek had a focal group depth interview with pesticide sales dealers and farmers in 2007. With results, dealers assessed a white fly as a most difficult pest in up-land crop cultivation, and answered the increase and change of pests and pathogen from climate change as a most concerned event. Farmers pointed that important jobs in vegetable cultivation were the control of pest and pathogen (34%) and the prevention of pest and pathogen (24%). And difficult works was the control of pest and pathogen (24%), and the climate change (18%). When choosing the insecticide, the long lasting activity (44%) and the completeness of control (34%) were the important factors. Among customers’ claims related with white fly, claims on insufficient efficacy was dominant and occupied 86% in spite of efforts of producers, and it reflected that commercial agrochemicals did not meet the expectation level of the farmers. Common agrochemicals for the control of white fly are Neo-Nicotinoids in Korea today and CGAR of it is about 13% average increased per year from 2003. As Bio Type Q showed higher resistant level to the Neo Nicotinoids than other Bio type (Nauen et al. 2002), Bio Type Q would spread easily and counter-plan is needed.. Market size of agrochemical for white fly is assumed to be about 9.6 million US dollars. The market size is smaller than that of aphids or lepidopterous pests, but the market would increase because of suffering and failure in control due to resistance and resurgence problems. As the increase of vegetable consuming, host crop for the white fly is also increasing. As green house cultivation area of host vegetable increases, natural enemies to foreign invading pest like sweet potato white fly are limited. Also it is important that that management of pest and pathogen in green house environment. It is essential to build pest management model and to develop and commercialize agrochemicals according to the critical customer (farmer) requirement.

This experiment was conducted to investigate population dynamics of white grubs and its damages in sweet potato fields. There were three species of white grubs that fed on the roots of sweet potato in Honam area. Among them, Holotrichia parallela was a major insect pest. Damage rate of sweet potato by white grubs were about 2 to 40% differed with regions. In some region where it was severe the damage rate of sweet potato was about 80% or more. H. parallela overwintered as a late 3rd instar larvae in soil from late October to late-June, and the survival rate of them was 92%. The occurrence pattern of H. parallela larvae varied in different seasons. In sweet potato field, H. parallela larvae populations started being observed during late-July to mid.-August. The damage by the grub began to occur late-August in field and lasted to the harvest time.

Total of 36 sweet potato field soils were sampled to survey the occurrence of the root-knot nematodes (RKN). The 61% of sweet potato fields in Haenam, 40% in Iksan and 31% in Yeju were infested with RKN, respectively. Average population density of RKN was 324 juveniles per 300 g soil. The resistance screening of sweet potato cultivars against RKN was carried out by using clay pots in a greenhouse. Average temperature under ground 10 ㎝ in pot was 21.5℃ during the test. There was no difference in number of egg sacs among different inoculation methods, however the egg-inoculation method was easy for treatment and had stable for results. The multiplication ratio of Melioidogyne incognita differed from 6.3 times (Jeungmi) to 63.2 times (Yulmi) by sweet potato cultivars. There were no cultivars showing resistance to M. incognita, but Jinmi, Jeungmi and Borami had resistance to M. arenaria, M. hapla and M. javanica.

실험실 조건에서 고구마 뒷날개흰밤나방의 교미 전 행동습성을 관찰하였다. 짝이 있고 어두운 상태에서 안테나를 치켜세우고 날개를 진동하는 습성을 보였으며, 암컷과 수컷 모두 날개를 진동하고 안테나를 치켜세우는 행동을 보이다가 수컷이 암컷에게로 날아가는 습성을 보였다. 불이 꺼진상태로 20여분이 지나면 안테나를 치켜세우는 반응을 보이기 시작하였으며 40분이 지났을 때부터 마치 짝을 유인하는 음향을 생성하듯이 날개를 빠르게 진동하는 반응을 보였다. 짝짓기는 우화 후 이튿날부터 관찰되었으며 대부분 4일에서 6일 사이에 짝짓기를 하였다. 짝짓기는 평균 207분 동안 지속되었고, 대부분 3회까지 반복적으로 교미를 하였다. 관찰결과를 종합적으로 분석해보면 암컷이 신호를 보내고 수컷이 이에 반응하는 것으로 보이며, 암컷이 내는 음향이 뒷날개흰밤나방의 교미전 행동습성에 관련되어 있을 가능성이 높은 것으로 판단되었다.

War against Japanese(1592-1599) and war against Manchurian(1636-1637), which had been occurred in Korean Peninsula throughout the history, and frequent trade with foreign countries since 18th century have led to a distribution of foreign food into Korea. Several examples for this include tomato, apple, watermelon, maize, pea, cowpea, peanut, potato from China and red pepper, pumpkin, and sweet potato from Japan. Since these foods had been brought into Korea, they have been cultivated suitable for Korea's climate and land. Foreign foods with a few exceptions tend to have high calories. For instance, along with potato and sweet potato, pumpkin is considered a high-calorie food containing lots of starches as it becomes ripening. This helped a wide spread of the foreign foods across the nation where intake of high-calorie foods was critical for Korean people's nutrition at that time. Among those foods introduced from foreign countries, red pepper had a greatest impact on the dietary life-style of Chosun Dynasty. The use of red pepper has been greatly expanded from main ingredient to seasoning and garnishing in various forms of red pepper such as red pepper paste, red pepper powder, and thick soy paste mixed with red pepper. Red pepper was made eating habits is hot besides dye red colored to traditional food, because steaming and boiling is frequently cook method, fermentation food also food color is achromatic therefore food color is and mixture with red pepper, picked fish and chinese cabbage new kimchi culture came into being.

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.

This work was conducted to identify sweet potato [(Ipomoea batatas (L.) Lam.)] cultivars showing high yield and processing suitability in the Jeonbuk region of Korea. Shoot-slips (30 cm in length) of 14 cultivars were planted with a planting density of 75×25 cm on May 30, and cultivated with black film mulching. Vine elongation at 30 days after planting was significantly increased (> 90 cm) in ‘Dahomi’ and ‘Sinhwangmi’, and was excellent (> 250 cm) 120 days after planting in ‘Sinhwangmi’, ‘Shinyulmi’, ‘Daeyumi’, ‘Jinhongmi’, and ‘Yeonhwangmi’. The branch number per plant showed a dramatic increase in ‘Shinzami’ 30 and 120 days after planting. The leaf number per plant showed the highest increase in ‘Shinzami’ 30 days and in ‘Sinhwangmi’ 120 days after planting. Total weight, mean weight, and number of marketable tubers per plant were significantly higher 150 days after planting than that 120 days after planting. Marketable tuber yield at 120 days was high, over 2.5 ton/10a in ‘Daeyumi’, ‘Dahomi’, and ‘Jeonmi’, and was considerably increased, from 3.2 ton/10a to 3.5 ton/10a, 150 days after planting. Total weight of marketable tubers per plant and marketable tuber yield 120 and 150 days after planting had significant positive correlations with vine length and number of nodes 30 days after planting. Starch value was significantly higher 150 days after planting than that 120 days after planting. ‘Daeyumi’ and ‘Jeonmi’ had good growth vigor, high yield, and high starch content; ‘Dahomi’ also exhibited beneficial traits such as good growth vigor, high yield, and bright orange-colored flesh.

For effective control of insect pest which can outbreak in a field during crop cultivation, various control agents such as eco-friendly agricultural materials (EFAM) including microbial control agents and chemical pesticides have been applied at fields and these control agents may be treated simultaneous or sequential in the same field to suppress diverse pests and diseases. The agents may influence each other and control efficacy may also differ from interactions. Therefore we need to test compatibility of microbial control agents with other agricultural agents. In this study, we investigated influence of pre-treated EFAMs, which are registered for whitefly control in greenhouse, on germination, mycelial growth and control efficacy of Isaria javanica isolate against sweet potato whitefly. The results showed that a mixture of paraffin oil+cinnamon oil among 4 EFAMs highly reduced germination (8.9±1.3%~24.5±0.9%) and mycelial growth (0.81±0.01cm~0cm) of I. javanica. To investigate the effects of the treatment interval between EFAMs and I. javanica on sweet potato whitefly control, four different EFAMs were pre-treated 0, 1, 4, and 7 days before applying I. javanica. Pre-treatment of four EFAMs inhibited insecticidal activity of I. javanica against sweet potato whitefly. Therefore when EFAMs and a mycopesticide using I. javanica spray simultaneous or sequential, application of EFAMs need more than 7 days interval after treatment of mycopesticide at field.

본 연구에서는 호박고구마의 산업적 이용 증대 및 식품가공용 소재 개발을 목적으로 분무건조공정을 이용하여 호박고구마 효소 분해물을 분무건조한 다음 물리화학적 특성 및 소화특성을 조사하였다. 호박고구마 효소 분해물의 불용성 식이섬유, 수용성 식이섬유 및 총 식이섬유 함량은 4.17%, 2.07% 및 6.24% 이었다. 호박고구마 효소 분해물의 분무건조분말 제조는 펙틴을 피복물질로 사용하여 분무건조하였으며, 수분함량 및 전분함량은 1.68-2.46 및 45.32-46.51%였다. 색도는 분무건조 분말에서 L 값 및 a 값은 감소하고 b 값은 증가하는 경향을 나타내었다. 입자크기는 분무건조 분말이 37.17-42.32 μm을 나타내어 동결건조 분말 247.79 μm에 비하여 유의적으로 작은 크기를 나타내었으며, 입자모양은 전반적으로 구형의 형태에 펙틴 첨가량이 증가할수록 굴곡이 증가하였다. 수분흡수지수는 분무건조 분말에서 1.74-1.91로 동결건조 분말 2.15에 비해 낮은 수분흡수지수를 나타내었으며, 수분용해지수는 분무건조 분말에서 80.75-87.61%로 동결건조 분말(70.47%)보다 높게 나타났다. 장 상피세포 부착능은 분무건조 분말에서 2.66-6.18%를 나타내어 동결건조 분말 1.79%에 비해 높은 부착능을 나타내 장 내 유용 미생물의 증식을 촉진함을 확인하였다. 분무건조 분말의 인체 내 소화 모델에서, 펙틴 1% 첨가 분말은 최종적으로 장액에서 70.09%의 소화율을 나타내어 동결건조 분말 24.23%에 비해 인체내에서의 높은 소화율이 기대되었다. 따라서 분무건조 분말 제조시 식품산업 활용 측면에서 가공적성이 향상되고 in vitro 인체 내 소화모델에서 소화가 개선된 식품가공용 소재 개발에 있어 산업적으로 적용 가능할 것으로 사료된다.