Il Kyung Chung

Enhanced Extraction of Bioactive Compounds from Bee Pollen by Wet-grinding Technology

Bee pollen is produced by honeybees and is considered one of the most balanced and nourishing nutritional supplements available. Historically, bee pollen has been prescribed for its healing properties and consumed for its high-energy supply. Recent research has provided evidence that bee pollen has diverse biological activities, such as anti-oxidant, anti-inflammatory, anti-bacterial, and even anti-cancer effects. However, the outer membrane of the pollen grain, exine, is highly resistant to most acidic solutions, high pressure, and even digestive enzymes, and the resulting low bioavailability limits its nutritional and clinical applications. This study applied a wet-grinding method to destroy the exine effectively, and it then examined the pollen’s enhanced biological activity. First, microscopic observations provided strong evidence that wet grinding destroyed the exine time-dependently. In addition, the content of polyphenols, well-known ingredients of bee pollen and used as internal standards for the quality control of commercial pollen preparations, increased up to 11-fold with wet grinding. Further, the anti-oxidant activity demonstrated on the ABTS anti-oxidant assay, as well as the DPPH radical scavenging assay, was also dramatically increased. Together, the results presented here support a new technology by which bee pollen can be used as a resource for medical, nutritional, and cosmetic applications.

Construction of a genetic map using EST-SSR markers and QTL analysis of major agronomic characters in hexaploid sweet potato (Ipomoea batatas (L.) Lam)

The Sweet potato, Ipomoea batatas (L.) Lam, is difficult to study in genetics and genomics because it is a hexaploid. The sweet potato study not have been performed domestically or internationally. In this study was performed to construct genetic map and quantitative trait loci (QTL) analysis. A total of 245 EST-SSR markers were developed, and the map was constructed by using 210 of those markers. The total map length was 1508.1 cM, and the mean distance between markers was 7.2 cM. Fifteen characteristics were investigated for QTLs analysis. According to those, the Four QTLs were identified, and The LOD score was 3.0. Further studies need to develop molecular markers in terms of EST-SSR markers for doing to be capable of efficient breeding. The genetic map created here using EST-SSR markers will facilitate planned breeding of sweet potato cultivars with various desirable traits.

Effect on flower thinning by using nano-processing technology chemicals in plum (Prunus salicina Linnaeus)

In this study, we investigated the effect of flower thinning chemicals using wet nano-technology on the rate of flower thinning and yield of high-quality fruit. We confirming the flower thinning rate, crop load and fruit set rate, the rate of flower thinning of 500 times and 250 times diluted solution was 5.7 times and 3.8 times higher than that of the control, respectively and the fruit set rate was 2.2 times, 3.4 times. To confirm the fruit quality characteristics of the plums of different cultivars, we sprayed the flower thinning chemicals prepared through the nano-processing on the Royaldaeseok, Formosa and Hongosen cultivars and compared the crop load, fruit weight and fruit size. Overall, the fruit weight and fruit size were higher in the plums of all cultivars sprayed with flower thinning chemicals than the control group. We were concluded that the use of flower thinning chemicals by wet nano-process technology could inhibit the number of fruit set and produce high-quality fruit in fruit trees other than plums. In addition, it is expected to be applicable to various fields because it can be used in natural products and bio industries as well as plant nutrients.

Comparison of the quality of dried persimmon (Diospyros kaki THUNB.) treated with medicinal plant extracts and food additives

Abstract We evaluated the direct application of different extracts from plant‐derived compounds at different ratios. The best effect was observed with the combination of 18.18% clove, 9.90% cinnamon, 9.09% licorice, 4.55% firmament, 4.55% grapefruit seed extract, and 54.54% apple cider vinegar. The combination of these compounds improved the moisture content of the fruit and showed antifungal, antibrowning, and antifungal/antibrowning effects as compared with the control following 6‐week treatment. The treatment resulted in an increase in the overall sugar concentration of dried persimmons. Antibrowning/antifungal test showed high sugar content of 30–39 °brix. The hardness of the treatment groups was similar to that of the control and decreased by 0.5 to 0.8 after 6 weeks. The evaluation of color change revealed a decreasing tendency in the value of △E during the drying period. Thus, natural extracts effectively suppressed the quality degradation during drying of persimmon and may be used to replace sulfur fumigation.

QTLs and analysis of the candidate gene for amylose, protein, and moisture content in rice (Oryza sativa L.)

Abstract In this study, we determined using NIRS the heritability percentage of amylose, protein, and moisture content in polished and unpolished rice in a CNDH population derived from a cross between Cheongcheong and Nagdong rice varieties. The results revealed a higher heritability percentage for the amylose content and compromised heritability for protein and moisture contents. We also conducted QTL analysis of rice for these major components and identified their chromosomal locations on a physical map. We found a total of four QTLs affecting the amylose, protein, and moisture contents of grain on chromosome 7. We constructed physical maps of seven DNA markers responsible for amylose content, six responsible for protein content, and three responsible for moisture content. Furthermore, we classified these genes according to their functions and found 17 genes (over 77%) to be involved in secondary metabolite synthesis, two genes (about 9%), each related to cell function and abiotic stress, and one gene (about 5%) involved in redox signaling.