Consumption of fruits and vegetables has been conducted to be effective in the prevention of chronic diseases. In this study, 70% methanol, 70% ethanol and chloroform-methanol mixture (CM, 2:1, v/v) were used as solvents in the extraction of apple peels. The total phenol content, total flavonoid content and antioxidant activity of various extracts were investigated using in vitro assays. The extract obtained by 70% methanol showed the highest total phenol content (20.87±0.17 mg CAE/g), ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity and ferric reducing antioxidant power. However, 70% ethanol extract possessed the strongest antioxidant activity assayed by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and β-carotene bleaching method. And CM extract was found to show the highest total flavonoid content with the value of 9.26±0.06 mg QE/g. These results indicated that apple peels can be used in dietary applications with a potential to reduce oxidative stress.

In this study, the antioxidant and tyrosinase inhibitory activities of aqueous ethanolic extract from the immature fruits of Malus pumila cv. Fuji were evaluated. The antioxidant capacities of the extract was investigated employing radical scavenging assays using DPPH and ABTS+ radicals. The skin-whitening effect of M. pumila cv. Fuji extract was tested using mushroom tyrosinase assay. In addition, the total phenolic content was measured by a spectrophotometric analysis. All tested samples showed a dose-dependent radical scavenging and tyrosinase inhibitory activities. Among the tested samples, the ethyl acetate (EtOAc)-soluble portion from the immature fruits of M. pumila cv. Fuji was showed the significant DPPH and ABTS+ radicals scavenging activities. Also, the tyrosinase inhibitory activity of the ethyl acetate (EtOAc)-soluble portion from immature apples was higher than other solvent-soluble portion. These results suggest that unripe fruits of M. pumila cv. Fuji could be considered as a new valuable source of natural antioxidant and skin-whitening agents. Systematic investigation of immature fruits of Malus pumila cv. Fuji will be performed for the further development of its biological properties.

The effects of pretreatment by pulsed electric fields (PEFs) on the juice expression characteristics of the Malus pumila fruit were investigated. Fresh fruits were divided into quarters, were produced on a laboratory scale (100 g apples per lot) by pretreatment with electric fields at two different field intensities (1, 2 kV/cm; n=50, 100, 200, and 400 pulses), and were then pressed at room temperature. Relative to the control samples, the juice yield increased with increasing field intensities. The total phenolics and antioxidant activity were higher in the juice from the PEF-treated fruit than in the juice from the untreated fruit. There was no significant difference in soluble-solid and reducing sugar contents between the PEF-treated and untreated fruits. These results suggest that PEF pretreatment may be useful for increasing the juice yield, total phenolics, and antioxidant activity of the Malus pumila fruit.

사과 대목 M.26은 준왜성대목으로 뿌리의 토양 지지력이 약해 지주 재배를 해야 하는 단점이 있다. 발근력이 향상된 M.26 왜성 대목 형질전환체를 육성하기 위하여 rolC 유전자 전환을 실시하였다. 항생제가 첨가된 재분화 선발 배지에서 재분화된 M.26 신초 1개체의 genomic DNA를 추출하여 PCR과 Southern 분석을 실시한 결과 유전자의 도입을 확인할 수 있었다. 유전자 도입이 확인된 형질전환체의 기내 발근 상태에서의 식물체 특성을 조사