This study investigated phenolic compounds and radical scavenging activities of rapeseed plants according to cultivar and growth stage. For 1st, 2nd, and 3rd harvested rapeseed plants, total polyphenol contents were 12.56~15.85, 10.28~13.17, and 9.94~16.01 mg gallic acid equivalents/g sample, respectively; total flavonoid contents were 9.86~11.05, 10.41~13.06, and 8.18~16.64 mg catechin equivalents/g sample, respectively; total chlorophyll contents were 17.26~21.66, 19.31~24.95, and 22.16~38.39 mg/g sample, respectively; and total glucosinolates contents were 31.13~46.22, 28.51~34.72, and 22.18~30.58 mg SE/g sample, respectively. DPPH and ABTS radical scavenging activities of rapeseed plants were 3.26~5.91 and 10.69~17.17 mg trolox equivalents/g sample, respectively. FRAP activities of 1st, 2nd, and 3rd harvested rapeseed plants were 142.88~63.93, 37.97~61.24, and 32.93~52.36 mM/g sample, respectively. Phenolic compounds and radical scavenging activities of rapeseed plants were found to be high in Halla, Yuryeo, and Yeongsan cultivars. Overall, phenolic compounds and radical scavenging activities of rapeseed plants tended to decrease as the harvest time was delayed. These results indicate that more research on functional ingredients and physiological activities of rapeseed plants is needed to diversify their fields of use.

Volatile organic compounds (VOCs) can adversely affect human and plant health by generating secondary pollutants such as ozone and fine particulate matter, through photochemical reactions, necessitating systematic management. This study investigated the distribution characteristics of gaseous VOCs in ambient air, with a focus on interpreting data from a photochemical pollution perspective. This paper analyzed the presence and concentration distribution of VOCs in industrial areas, identifying toluene, m-xylene, p-xylene, and n-octane as the most frequently detected components. Particularly, toluene was found to significantly contribute to the formation of ozone and fine particulate matter, highlighting the need for stricter regulation of this compound. Although n-octane and styrene were present in relatively low concentrations overall, their significant contributions to ozone generation and secondary organic aerosol formation, respectively, emphasize their importance in air pollution management.

This study was conducted to secure basic data for developing technologies to reduce the generation of odor substances by investigating the effects of environmental temperature on growth performance and the generation of odor substances from feces in growing pigs. A total of 16 pigs (Landrace × Yorkshire × Duroc, average body weight 56.49±0.47kg) were randomly assigned to two treatments: thermal-neutral (TN) and heat stress (HS) conditions. The experiments were conducted for two weeks, with average temperature-humidity indices of 68.91±0.09 for TN and 85.98±0.08 for HS. The results showed that HS significantly decreased average daily feed intake (ADFI, 33.3%) and average daily gain (ADG, 25.8%) compared with TN (p<0.05). Non-esterified fatty acid in serum was lower (36.2%) in HS compared with TN (p<0.05). However, protein, blood urea nitrogen, cholesterol, triglyceride, glucose, and IgG in serum showed no difference between HS and TN. Phenol (350.0%) and skatole (416.3%) were significantly higher in HS than in TN (p<0.05). The decrease in growth performance is attributed to reduction in ADFI. The increase in phenol and skatole in HS is presumed to be due to the effect of HS on the metabolism of intestinal microbial composition. Digestion rate, intestinal microbial composition, and urine emissions are known to affect odor substances. Further research on the content of odor substances in urine, nutrient digestion rate, and intestinal microbial composition is considered necessary to determine the exact associations.

This study evaluated the importance of assessing personal exposure to volatile organic compounds (VOCs) by monitoring indoor, outdoor, and personal VOC levels in 15 Seoul residents over a 3-month period using passive samplers. Results indicated that limonene had the highest concentrations across indoor, outdoor, and personal samples, with this compound primarily originating from household cleaners and air fresheners. Other VOCs, such as 2-butanone and toluene, also varied by location. Health risk assessments showed that most VOCs had a Hazard Index (HI) below 1, while the HI of individual exposures were relatively higher. Notably, cancer risk assessments for chloroform and ethylbenzene exceeded permissible levels in some scenarios, suggesting potential cancer risks. This underscores the importance of diverse microenvironment monitoring for accurate health risk evaluations, as relying solely on indoor and outdoor levels can underestimate actual exposure risks. This study highlights the need for future research to monitor VOC levels in various microenvironments, in addition to the necessity of investigating personal activity patterns in depth to accurately assess personal exposure levels. Such an approach is crucial for precise health risk assessments, and it provides valuable foundational data for evaluating personal VOC exposures.

This study analyzed the effects of different nitrogen sources in substrate composition on the growth of Pleurotus ostreatus, as well as the subsequent changes in flavor and antioxidant activity. The T2, composed of poplar sawdust, beet pulp, cotton seed dregs, and cotton seed coat in a ratio of 40:20:20:20, exhibited the highest yield at 156.6 g. The total polyphenol content and ABTS and DPPH radical scavenging activities were 8.25 mg GAE/g, 70%, and 49%, respectively, showing higher radical scavenging activity compared to the Control and T1. Additionally, varying nitrogen content resulted in distinct aroma patterns and is presumed to influence taste profiles such as sourness, umami, and saltiness.

The n-type Bi2-xSbxTe3 compounds have been of great interest due to its potential to achieve a high thermoelectric performance, comparable to that of p-type Bi2-xSbxTe3. However, a comprehensive understanding on the thermoelectric properties remains lacking. Here, we investigate the thermoelectric transport properties and band characteristics of n-type Bi2-xSbxTe3 (x = 0.1 – 1.1) based on experimental and theoretical considerations. We find that the higher power factor at lower Sb content results from the optimized balance between the density of state effective mass and nondegenerate mobility. Additionally, a higher carrier concentration at lower x suppresses bipolar conduction, thereby reducing thermal conductivity at elevated temperatures. Consequently, the highest zT of ~ 0.5 is observed at 450 K for x = 0.1 and, according to the single parabolic band model, it could be further improved by ~70 % through carrier concentration tuning.

The steamed and freeze-dried mature silkworm powder (SMSP) is developed by the Rural Development Administration (RDA) in 2012. In here, the nutritional components of SMSP produced by rearing white-silk cocoon silkworm, Baekokjam, at high temperatures were compared and analyzed with those produced under optimal temperature conditions of 25°C. The weight of silkworms reared in a high-temperature environment increased compared to that under an optimal condition. However, when the silkworms matured, the difference in weight according to temperature conditions narrowed. As for the growth rate, the 5th instar silkworms grew a day earlier in a high-temperature environment than in an optimal. SMSPs produced in a high-temperature environment showed a difference when comparing the nutritional components with the SMSPs in an optimal condition. Overall, high-temperature-reared SMSPs contained about twice as high carbohydrates and slightly lower protein and fat than the optimal-reared SMSPs. These results show that SMSPs produced in a high-temperature environment have a difference in growth rate and nutritional composition from those produced under an optimal condition.

The two-spotted spider mite, Tetranychus urticae Koch, is one of the economically important agricultural pests globally, as it attacks a wide range of vegetable and horticultural crops. In this study, we evaluated spatial repellent and oviposition deterrent activities of T.urticae in response to fifteen compounds derived from ester-containing natural products. To evaluate the tests, we used bridge two-choice test and host two-choice test in laboratory conditions. Among the eight compounds showed spatial repellent and oviposition deterrent activities against T. urticae at the 20 mg dose and some compounds had the activities at lower dose. We also conducted two-choice test with a blend and single compounds to determine which showed stronger spatial repellent and oviposition deterrent activities. In host two-choice test, we evaluate repellence between distance of compounds. This study concluded that series compounds from ester-containing natural products have the potential to be used managing T. urticae in the field.

Plants synthesize antioxidant compounds as a defense mechanism against reactive oxygen species. Recently, plant-derived antioxidant compounds have attracted attention due to the increasing consumer awareness in the heath industry. However, traditional methods for measuring the antioxidant activity of these compounds are time-consuming and costly. Therefore, our study constructed a quantitative structure-activity relationship (QSAR) model that can predict antioxidant activity using graph convolutional networks (GCN) from plant structural data. The accuracy (Acc) of the model reached 0.6 and the loss reached 0.03. Although with lower accuracy than previously reported QSAR models, our model showed the possibility of predicting DPPH antioxidant activity in a wide range of plant compounds (phenolics, polyphenols, vitamins, etc.) based on their graph structure.

본 연구에서는 단기간의 UV-A 조사가 시금치(Spinacia oleracea L.)의 생장과 생리활성물질에 미치는 영향을 평가 하였다. 시금치 묘는 200μmol·m-2·s-1 PPFD, white LED, 광 주기 12시간, 온도 20°C, 상대습도 70%, 이산화탄소 농도 500μmol·mol-1의 수직농장 모듈에서 재배되었다. 파종 후 5 주된 묘는 7일 동안 20W·m-2와 40W·m-2의 두 가지 에너지 수 준에서 연속적으로 UV-A(피크파장: 385nm) 조사한 후 생육 특성, 광합성 파라미터, 이미지 형광, 총 페놀 함량, 항산화도, 그리고 총 플라보노이드 함량을 분석하였다. 결과적으로, UV-A20W 처리는 시금치의 생체중과 건물중을 증가시켰다. 하지만, UV-A 처리구와 대조구 사이의 광합성 파라미터에는 유의한 차이가 나타나지 않았다. 광계Ⅱ의 최대양자수율 (Fv/Fm)은 모든 UV-A 처리에서 7일동안 지속적으로 감소했 다. 또한, UV-A20W 처리에서 식물체당 총 페놀 함량과 항산화 도는 처리 7일째 증대되었으며, 총 플라보노이드 함량은 처리 5일째부터 유의적으로 증가하였다. 이러한 결과는 UV-A LED 보광이 수직농장과 같은 폐쇄형 식물 생산 시스템에서 재배되는 시금치의 생장과 품질을 향상시킬 수 있음을 시사 한다.

Considering the characteristics of aldehydes among volatile organic compounds, a combined process was established by linking an absorbent and a photocatalytic reactor. Experiments to find the optimal operating conditions of the combined process showed that as the amount of photocatalyst coating increases, the wavelength of the ultraviolet lamp used becomes shorter, the photodegradation rate becomes faster, and the removal efficiency increases. It was also demonstrated that by controlling the relative humidity during the connection process of the combined process, the re-evaporation phenomenon at the front end (absorption area) of the hybrid process can be improved and the removal efficiency at the back end (photocatalytic reaction area) can be significantly enhanced. This confirmed the need for a combined process that complements the advantages and disadvantages of each process.

We conducted research on the removal performance of various odor substances using a deodorizing agent, hypochlorite ion (OCl-), in odor emission sites where various odor-causing substances occur simultaneously. In experiments treating odor gases containing mixtures of aldehydes (acetaldehyde, n-butyl aldehyde, iso-valeraldehyde, propionaldehyde), sulfur compounds (hydrogen sulfide, methyl mercaptan, and dimethyl sulfide), and nitrogen compounds (ammonia and trimethyl amine), it was demonstrated that the introduced odor substances could be simultaneously removed when electrolyzed water was used. The overall removal efficiency was found to be significantly higher than when water alone was used. Particularly, it showed simultaneous effectiveness against acidic, neutral, and alkaline odor substances such as ammonia and hydrogen sulfide. Considering the positive aspects with regard to chemical safety, the use of salt instead of chemicals, and the continuous regeneration of the oxidizing agent, this environmentally friendly deodorization technology is expected to contribute to securing excellent odor removal capabilities and wide-ranging deodorization applications.

Mushrooms have a unique taste and aroma, so in the processing of mushroom products with other ingredients, a separate pre-processing step is often taken to eliminate the mushroom aroma. In this study, we analyzed the changes in the concentration of volatile compounds according to drying conditions to promote the activation of processing using the fruiting bodies of yellow oyster mushrooms(Pleurotus citrinopileatus) and pink oyster mushrooms(P. djamor). The caps and stipes of yellow oyster and pink oyster mushrooms were separated and freeze-dried at -70oC for 120 hours. Subsequently, they were hot air-dried at temperatures of 40, 50, 60, and 70oC for 24, 24, 16, and 12 hours, respectively. The dried samples were pulverized and quantitatively analyzed by SPME-GC-MS. In the case of yellow oyster mushrooms, the concentration of t-2-nonenal in caps and stipes during freeze-drying was 164.43 g/g d.w. and 174.80 g/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 0.35~3.41 g/g d.w. and 0.98~59.88 g/g d.w. In a similar manner, for pink oyster mushrooms, the concentration of 1-octen-3-ol during freeze-drying in caps and stipes was 31.05 g/g d.w. and 176.17 g/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 1.59~9.66 g/g d.w. and 1.96~15.77 g/g d.w. Furthermore, most volatile compounds showed a tendency to decrease in concentration as the temperature during hot air-drying increased.

This study aimed to examine the possibility of upcycling extracts of Angelica keiskei and Oenanthe javanica juice by-products through comparing enzyme extraction (EE) and complex extraction (CE) methods to increase the extraction yield and flavor of materials. A higher extraction yield was obtained for free amino acid content with EE and CE for A. keiskei and O. javanica juice by-products, respectively, and a higher extraction efficiency was achieved with juice by-products than with extracts prepared from raw materials before juice production. The content of major amino acids varied depending on the extraction method used. When used according to the characteristics of the extract, their use as a functional material was confirmed along with improvement in the flavor of the food. Consistently high extraction yields for organic acid and sugar levels were obtained with CE in A. keiskei and O. javanica juice by-products. The DPPH radical scavenging ability and TPC were consistently high with CE in A. keiskei and O. javanica juice by-products; the increase in extracted content was likely because of the reaction between the ethanol used for CE and the phenolic compounds. However, because the antioxidant capacity of the juice by-product extracts was somewhat lower than that of the extracts from raw materials before juice production, the amount used should be reviewed. The TFC was found to be higher in extracts obtained with EE than with CE for A. keiskei juice by-products; however, no significant difference was observed between EE and CE in the O. javanica juice by-products. Through this study, the taste compounds and antioxidant properties of extracts obtained from juice by-products produced after the production of A. keiskei and O. javanica green juice were analyzed, and the availability of high value-added materials was confirmed. Based on these research results, expanding specific R&D for practical use should be explored.

Radish is a sulfur-containing compound containing the -S group, having bioactive functions such as anticancer, antithrombotic, antioxidant, and antibacterial properties, and is used as a health supplement and pharmaceutical material. This study aimed to compare changes in sulforaphane (SFN) content according to freeze-drying or hot-air drying conditions in Korean radishes. The color of frozen or hot-air-dried radish underwent a browning reaction due to heat treatment; the brightness (L) decreased from 89.3 to 56.1, and the redness (b) increased. The SFN content of freezedried radish was 13.2565 mg/g, the SFN of radish dried at 50oC was 2.64372 mg/g, and the SFN of radish dried at 80oC was 0.0678 mg/g, which was the highest in freeze-dried radish. Therefore, the SFN of radish was found to be insufficient in thermal stability, and freeze-drying was considered a suitable method for drying radish.

This study aimed to investigate the changes in bioactive compounds across the ripening stages of three pepper cultivars, each characterized by unique skin colors. The samples used in this study consisted of three pepper cultivars distinguished by their skin colors as green, purple, and yellow green at breaker ripening stage. Samples were harvested at each of the four ripening stages, including premature, breaker, turning, and mature, and subjected to analysis for various bioactive compounds, including capsaicin, ascorbic acid, kaempferol, quercetin, and sugars. In all cultivars with varying skin colors, the capsaicin content within green pepper fruits consistently increased as the ripening stages advanced. Ascorbic acid was most abundant during the premature stage of development in purple and green cultivars, subsequently declining as maturation progressed. In the case of the purple cultivar, kaempferol content decreased by approximately 30% at the mature stage, while the green cultivar exhibited a gradual increase in kaempferol content with maturation. Conversely, the kaempferol content of the yellow green cultivar rapidly declined as maturation progressed. Regarding quercetin content, the purple and green cultivars tended to decrease with maturity, while the yellow green cultivar displayed an increasing trend. Furthermore, the accumulation patterns of glucose, fructose, and sucrose, the predominant free sugars in green pepper fruit, demonstrated an inclination to increase as the maturation stage advanced in both purple and green cultivars. In contrast, the yellow green cultivar initially showed an elevation in free sugar content during the immature stage, followed by a minor reduction during maturation and a subsequent rise during the mature stage. Each pepper cultivar, distinguished by its unique skin color, exhibits varying levels of bioactive substances at different ripening stages. Therefore, optimal harvesting and utilization should align with periods when the desired substance content is at its peak.

The two-spotted spider mite, Tetranychus urticae Koch, is one of the most important agricultural pests. Therefore, we screened fifteen compounds from natural products for their spatial repellent and oviposition deterrent activities against T. urticae in the laboratory by using two-choice and no-choice tests. In the bridge two-choice test, nine compounds showed the spatial repellent effects on T. urticae at 20 mg dose, resulting in reduced numbers of eggs. Among the nine compounds, at 2 mg dose, two compounds were selected as having more spatial repellent activity than the others. The two compounds also showed spatial repellent and oviposition deterrent effects in the two-choice test from hosts. In the no-choice test from a host, the spatial repellent effects of the two compounds to T. urticae were significantly stronger than that of controls. These results suggest that the findings can be used as potential agents for the prevention and population control of T. urticae in the field.

The cotton aphid, Aphis gossypii glover (Hemiptera: Aphididae), is the world-wide agriculture pest and has the ability to become resistant to many pesticides. Hence, we conducted behavioral tests on apterous and alate aphids for series compounds from natural products by using a two-choice test, a no-choice test, a host choice test and electroantennography (EAG). As a result, we found 3 out of 30 compounds for apterous aphids and 2 out of 15 compounds for alate aphids, both of which showed powerful repellent effects on these aphids. In this study, we suggest that our findings could be useful and eco-friendly spatial repellents for controlling cotton aphid.