초당옥수수는 고당도 옥수수 품종으로, 식단 트렌드 변화와 천연 당류에 대한 관심 증가로 인해 수요가 증가하면서 재배가 확대되고 있다. 초당옥수수는 높은 당도로 매우 달고 맛이 좋지만, 전분 함량이 낮아 일반 옥수수에 비해 발아율이 낮은 특징이 있다. 본 연구는 초당옥수수 계통의 전분 함량과 발아율의 상관관계를 조사하여, 우수한 생장과 발아율을 갖춘 고품질 계통을 선발하는 것을 목표로 하였다. 본 연구에서는 10개의 초당옥수수 계통을 대상으로 발아율과 식물체 생장 특성을 평가하였다. 모든 계통이 80% 이상의 발아율을 보였으며, KH51 계통이 53일로 가장 출사일이 빨랐고, KH29W 계통이 148cm로 간장이 가장 크게 나타났다. 고당도 계통을 선발하기 위해 수정 후 20일째에 이삭을 수확하여 유리당 함량을 측정하였다. KH28W 계통이 가장 높은 당 함량(23.3%)을 보였으며, KH45 계통이 가장 낮은 당 함량(8.1%)을 나타냈다. 또한, 전분 함량이 유리당과 비례하여 축적되는지를 확인하기 위해 수분 후 40일째에 이삭을 수확하여 분석한 결과, KH47 계통이 가장 높은 전분 함량(30.1%)을, KH28W 계통이 가장 낮은 전분 함량(23.6%)을 보였다. 전분 함량이 발아에 미치는 영향을 평가하기 위해 발아와 관련된 효소 및 유전자들을 분석하여, 발아 과정에서의 효소 활성 및 유전자 발현 수준을 측정하였다. 낮은 전분 함량은 발아 초기에 효소 활성과 유전자 발현을 저하시켜 발아 지연 및 불균일성을 초래하였으나, 발아 후 생장에는 큰 영향을 미치지 않았다. 이는 초당옥수수 종자의 초기 발아 과정이 유리당과 전분 함량에 의해 영향을 받을 수 있음을 시사한다.

The leaves and stalks of sweet potato have attracted considerable interest as a health food due to numerous studies reporting the presence of functional compounds and various physiological activities. This study analyzed the functional components in the aerial parts of six domestically developed sweet potato cultivars and compared their antioxidant activities. The total polyphenol content, total flavonoid content, and total phenolic acid content ranged from 76.9 to 148.6 mg GAE/g, 3.98 to 11.90 mg CE/g, and 44.19 to 93.56 mg/100 g, respectively. Among the cultivars examined, 'Gogeonmi' and 'Tongchaeru' exhibited high levels of these compounds, and their DPPH and ABTS radical scavenging activities were superior to those of the other cultivars. The GABA content ranged from 0.59 to 2.55 mg/g, with 'Tongchaeru' and 'Jinhongmi' showing the highest levels. Lutein content ranged from 0.10 to 0.24 mg/g, with 'Tongchaeru' reaching its maximum concentration 90 days post-cultivation. Extracts from 'Tongchaeru' significantly inhibited the secretion of interleukin-6 (IL-6) inflammatory cytokines, with the water extract demonstrating a stronger effect than the pretanol extract. These findings suggest that the aerial parts of sweet potato could serve as excellent functional vegetables and bioactive ingredients for health food applications.

This study assessed dried vegetables derived from sweet potato petioles to promote the use of typically discarded aerial parts. The length (18.25 to 35.00 cm) and thickness (4.59 to 6.66 mm) of the petioles varied by variety, with ‘Hophungmi’ and ‘Tongchaeru’ showing promise for dried vegetable processing due to their longer and thicker petioles. In terms of color, ‘Hophungmi’ and ‘Shinmi’ exhibited high lightness, ‘Tongchaeru’ and ‘Hayangmi’ displayed strong redness, and ‘Pungwonmi’ had high yellowness. Rehydration rates and hardness increased over the harvest period, with ‘Pungwonmi’ and ‘Tongchaeru’ demonstrating excellent rehydration capacity. Additionally, ‘Hayangmi,’ ‘Shinmi,’ ‘Tongchaeru,’ and ‘Hophungmi’ maintained lower hardness levels, appealing to consumers who prefer a softer texture. Notably, the substantial polyphenol content (10.70 to 16.20 mg GAE/g) and flavonoid content (4.79 to 8.11 mg CE/g), along with antioxidant activity (DPPH: 1.11 to 2.14 mg, ABTS: 5.51 to 7.78 mg TE/g), indicate their potential as antioxidant-rich functional foods. This research supports the development of dried vegetable products tailored to consumer preferences.

Within the framework of a project entitled “Development of Advanced Sweet Potato Cultivation Technology for Smallholder Farmers in Paraguay” implemented by KOPIA Paraguay Center (Korea Partnership for Innovation of Agriculture) in collaboration with Paraguayan Institute of Agricultural T echnology (I PTA) d uring the period 2021-2024, r esults o f four m ain e xperiments are described in this research: selection of suitable varieties, optimal planting and harvesting times, the use of ridges, and optimal chemical fertilization doses. In the selection of suitable varieties for Paraguay, 11 sweet potato varieties were evaluated in departments of San Pedro and Misiones. As a result, varieties Andaí, Jety Paraguay, and Chaco I showed the highest productivity in San Pedro, while varieties Jety Uruguayo, Chaco I, and Taiwanés showed higher productivity in Misiones. The other three experiments were carried out in San Pedro only. Optimal planting and harvesting times were determined with three varieties: Andaí, Pyta Guasu, and Jety Paraguay. For Andaí and Jety Paraguay varieties, they should be planted in December and harvested at 122 days post planting (DPP). For Pyta Guasu, it should be planted in October and harvested at 124 DPP. Regarding productivity response with soil preparation methods, the use of ridges showed higher yields in all planting methods, with the curved method planting being the most productive. Finally, optimal chemical fertilization doses were established in order to improve the total yield. The optimal nitrogen fertilizer dose (urea 45% N) was 40 kg/ha. The optimal phosphorus fertilizer dose (triple superphosphate 45% P2O5) was 80 kg/ha and the optimal potassium fertilizer dose (potassium chloride 60% K2O) was 120 kg/ha.

Sweet potato (Ipomoea batatas L.) is an essential crop in the Paraguayan diet. It plays a crucial role in food security. It is a source of income for family agriculture. It has a significant potential to adapt to various climatic and soil conditions in Paraguay, making it a promising crop for improving productivity. However, Paraguay faces a deficit in the development of sweet potato cultivation technology, resulting in a low productivity of 5.3 ton/ha. Efforts have been made to collect and characterize sweet potato genotypes, covering a diversity of native varieties. These efforts have laid the groundwork for future sweet potato research and development. Still, ongoing research and development of strategies are needed to address existing challenges of improving genetic resource traits and developing cultivation technology and to fully exploit growth opportunities in this sector. This review summarizes sweet potato cultivation in Paraguay, focusing on several key technical aspects. It analyzes current market situation and production conditions as well as the availability of genetic materials adapted to different ecoregions. Additionally, it explores prospects for the development of advanced sweet potato crops, including the production of high-quality, virus-free sweet potato plants with improved productivity.

To produce super sweet corn sikhye, substituted for sweetener, the ratio of rice and super sweet corn was adjusted and processed with complex enzymes during saccharification, and their physicochemical and sensory properties were analyzed. The soluble solid content of the control and Corn-5 showed significantly high content at 13.50 °Brix, and the reducing sugar content of Corn-5 showed the highest content at 9.45%. The control showed the lowest free sugar content among all the experimental groups, excluding maltose content. In the enzyme-treated corn sikhye group, as the amount of super sweet corn increased, the content of sucrose decreased and the contents of glucose and fructose increased. The content of ascorbic acid and polyphenol compounds increased as the amount of super sweet corn increased. DPPH and ABTS radical scavenging abilities increased with increasing ratio of super sweet corn and enzyme treatment compared to the control. In the case of sensory evaluation, Corn-3, which substituted 30% of super sweet corn for rice and treated with enzymes, showed higher evaluations in taste, sweetness, and overall preference than those of the control.

This study examined the impact of two bacterial strains, H05E-12 and H05R- 04, on alleviating non-irrigation-induced stress and its subsequent effects on the fruit productivity of sweet pumpkin plants. When subjected to non-irrigation-induced stress, the lipid peroxidation, proline, total phenol, and total soluble sugar content significantly decreased in plants treated with either H05E-12 or H05R-04 compared to the control. In a greenhouse experiment under non-irrigated conditions, H05E-12-treated plants exhibited higher stomatal conductance than the control, although there was no significant change in the soil plant analysis development (SPAD) value due to treatment. Upon re-watering, an increase in fruit diameter was observed in H05E-12-treated plants, and the L-ascorbic acid content in the fruit also showed a significant increase compared to the control. The H05E-12 strain was identified as Kushneria konosiri. To the best of our knowledge, this is the first report detailing the beneficial effects of K. konosiri on the alleviation of non-irrigation-induced stress and the promotion of plant growth in sweet pumpkin plants.

To improve usability of super sweet corn, extracts were prepared with hydrolytic enzyme and changes in physicochemical and antioxidant properties were analyzed. Soluble solids and reducing sugars contents were higher in all enzyme treatment groups than in the control. When enzyme treatment time increased, contents of soluble solids and reducing sugars were also increased. There was no significant difference in lightness between treatment groups, with redness showing the highest value in the control and yellowness showing the highest value in the invertase treatment group. Free sugar content in the control was the lowest. However free sugar content in the enzyme combination treatment group was increased by more than four times compared to that in the control. Contents of ascorbic acid, flavonoids and polyphenols were higher in the enzyme treatment group than in the control. In particular, the enzyme combination treatment group showed the highest content. DPPH and ABTS radical scavenging abilities were significantly higher in all enzyme treatment groups than in the control. Radical scavenging abilities of cellulase treatment group and enzyme combination treatment group showed high activity. The activity increased when enzyme treatment time increased. The combined enzyme treatment method for super sweet corn was suitable for food processing.

The key to invasive pest management lies in preemptive action. However, most current research using species distribution models is conducted after an invasion has occurred. This study modeled the potential distribution of the globally notorious sweet potato pest, the sweet potato weevil (Cylas formicarius), that has not yet invaded Korea using MaxEnt. Using global occurrence data, bioclimatic variables, and topsoil characteristics, MaxEnt showed high explanatory power as both the training and test areas under the curve exceeded 0.9. Among the environmental variables used in this study, minimum temperature in the coldest month (BIO06), precipitation in the driest month (BIO14), mean diurnal range (BIO02), and bulk density (BDOD) were identified as key variables. The predicted global distribution showed high values in most countries where the species is currently present, with a significant potential invasion risk in most South American countries where C. formicarius is not yet present. In Korea, Jeju Island and the southwestern coasts of Jeollanam-do showed very high probabilities. The impact of climate change under shared socioeconomic pathway (SSP) scenarios indicated an expansion along coasts as climate change progresses. By applying the 10th percentile minimum training presence rule, the potential area of occurrence was estimated at 1,439 km2 under current climate conditions and could expand up to 9,485 km2 under the SSP585 scenario. However, the model predicted that an inland invasion would not be serious. The results of this study suggest a need to focus on the risk of invasion in islands and coastal areas.

This study was to evaluate the values of Korean native sweet sorghum as a new feed crop for ruminants. Sweet sorghum was the Muan native species (Bioenergy Crop Research Center, National Institute of Crop Science), and cultivated from May to October 2021 at Sangji University (Wonju-si, Gangwon-do, Korea). There were a non-treated group (Con), a recommended amount treatment (RD) and a treatment with double the recommended amount (Double RD) by an oil cake fertilizer. Plant height was measured at weekly intervals for 12 weeks after planting sweet sorghum seedlings, and was a significant difference in the order of Double RD, followed by RD and Con in 7 weeks (p<0.05). Feed values and sugar contents were measured in 7, 9, and 11 weeks. Crude protein of Double RD was higher than that of the other treatments in 7 and 9 weeks (p<0.05). Crude fat was higher at Double RD than the other one in 9 weeks (p<0.05). ADF and NDF of Double RD were higher than the other one (p<0.05). When it was compared to corn and sudangrass hybrids grown on farms, Crude protein was lower in sweet sorghum than other crops (p<0.05), and crude fat was higher in sweet sorghum than corn (p<0.05). Crude fiber, ADF and NDF were higher in sweet sorghum compared to corn and sudangrass (p<0.05). The sugar contents of sweet sorghum were 4.07 ± 0.12∼7.63 ± 0.21 brix, and showed higher than corn and sudangrass hybrid (p<0.05). The rumen in situ digestibility of sweet sorghum was 30.73∼38.13% at the 9th and 11th weeks, and showed higher than that of corn and sudangrass hybrids (p<0.05). Therefore, it is considered that Korean native sweet sorghum has sufficient value as a new forage crop for ruminants, and good value as yield, nutrients and digestibility, when the grass height is 273.33~332.50 cm.

Sweet persimmons are valuable commodity in the export market. However, present of insect pest such as Asiacornococcus kaki can cause limit to many export markets. In this study, ethyl formate(EF), as alternative to methyl bromide(MB), was used in scale-up commercial trial(20ft reefer). Application of 50 g/m3 of EF for 6 hours at 5 ℃ showed proven efficacy against all developmental stages of A. kaki without LLDPE-packaging fruits and no phytotoxic damage on sweet persimmons. This study demonstrated that EF fumigation can be effectively control to target A. kaki before packaging with LLDPE-film of fruits.

Sweet pepper(paprika) belongs to the genus Capsicum, and is one of the most important export product from Korea to Japan and Southeast Asia. So it is important to eradicate plant quarantine pests before export sweet pepper. Aphids, whiteflies and mites are major pests that can damage to sweet peppers. Fumigation is normally used to eradicate pests in plant quarantine, but phytotoxicity may can be appeared that affect the quality of the product. Low-temperature treatment, one of the most popular physical treatment, can reduce crop damage to preserve product quality, but it takes long time to kill pests, which can cause quality degradation. In this study, phytotoxicity of fumigants, phosphine(PH3), ethyl formate(EF) and PH3+EF on sweet peppers was investigated to use as basic data for physicochemical treatment. When treated with more than 35 mg/L of EF, phytotoxicity was occurred, and was not occurred with PH3. When low-temperature of 1.7 degrees treated for 15 days after fumigation, it seems to be no direct damage from low-temperature treatment. But quality of top of sweet pepper was decreased from 7 days after fumigation.

Yellow-fleshed "Sweet Gold" kiwifruit on Jeju Island were studied to examine how irrigation and soil moisture control affected changes in photosynthetic traits and fruit quality during fruit maturation (120 to 170 days after full bloom). Concerning photosynthetic characteristics, the photosynthetic rate decreased by 10-19%, stomatal conductance by 24-47%, and transpiration rate by 8-25%, when compared to conventional irrigation, as irrigation was reduced and soil moisture content decreased. Fruit weight showed a tendency to increase until harvest, and while a lower soil moisture content led to a less pronounced increase in fruit weight, this difference was not statistically significant. The dry matter rate exhibited a similar trend to the change in fruit weight. Sugar content demonstrated a continuous increase after 130 days, with lower irrigation amounts resulting in higher levels of sugar content due to decreased soil moisture. The Hue value (h°) exhibited a continuous decrease after 140 days from full bloom, correlating with declining soil moisture content. After 130 days from full bloom, soluble sugar content increased rapidly while starch content gradually decreased after 150 days from full bloom. However, with conventional irrigation, the increase in soluble sugar content tended to be less noticeable. This study confirmed that in yellow-fleshed ‘Sweet Gold’ kiwifruit, managing irrigation and soil moisture reduction during the ripening period can lead to decreased fruit weight but increased dry matter, sugar content, and expression of flesh color, ultimately enhancing fruit quality and expediting ripening.

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 measured coffee’s quality and antioxidant properties by adding sweet sapphire grapes with different extraction conditions to develop materials for a new, healthy, functional coffee menu. As for pH, the control group showed a higher value than the sample group, and ES-SP was the highest at 11.47±0.06oBrix in the soluble solid content. As for organic acids, ES-SP showed the highest values in shikimic acid, formic acid, and acetic acid. In glucose and fructose, ES-SP showed high contents of 19236.80 mg/ml and 24578.21 mg/ml among sample groups. Trigonelin and chlorogenic acid showed the highest values of ES-SP at 1349.44±0.50 mg/mL and 1132.58±0.51 mg/mL. In caffeine, the control group and ES-SP showed high content. In DPPH, all sample groups showed higher values than the control group. The total phenol content was the highest in the control and ES-SP groups. As a result of the above espresso extraction conditions, coffee has high organic acid, free sugar, trigonelin, chlorogenic acid, antioxidant, and total polyphenol content, providing suitable manufacturing method for developing coffee menus using sweet sapphire.

As the average temperature on Earth increases due to global climate change, crops are further needed to overcome this issue. Since sweet potato has high yield potential, can grow in harsh environments, and contains abundant nutrients, it is a potential substitute food in response to environmental crises. Compared to grains such as rice and barley, sweet potato has a lower glycemic load and contains various natural antioxidants, showing a variety of physiological functions. Thus, sweet potato is in the spotlight as a healthy food. Although domestic sweet potato production continued to decrease from 1990 to 2010, its production was maintained or slightly increased until 2020 due to the changes in consumers’ dietary habits that emphasize health. In this regard, steamed or roasted sweet potatoes were consumed as a snack substitute in the previous eating form. Furthermore, sweet potato starch has been used in various industries, including food. Therefore, this study intends to discuss the value of sweet potatoes as food, the production trend and cultivation method of sweet potatoes in South Korea, and the industrial application of sweet potatoes.

생물환경조절학회지 31권 4호에 게재된 논문의 사사가 잘못 기재되어 있어 바로 잡습니다.

생물환경조절학회지 30권 3호에 게재된 논문의 그래프를 수정합니다.