Phytochemical composition of onion during long-term storage

Onion cultivar “Sunpower” has growing popularity in Korea due to high storability. The present study considers changes in flavonols, sugars, and two amino acids in onion bulbs during a long-term storage in the ambient dark storage room and in glasshouse equipped with a climate control system. Flavonol and sugar contents were found to fluctuate noticeably during the storage period. Amino acid content remained relatively unchanged till the onset of inner sprouting, increasing afterward. Visible sprouts appeared at week 22 in the dark storage room and for four weeks later in the glasshouse. The bulbs lost 20–30% of their weight depending on storage conditions at the end of the storage trials. At the same time, the content of nutraceutics in study expressed on the dry weight basis remained of the same order of magnitude. The nature of observed variations in chemical composition of onions as well as relation of this phenomenon to physiological development of stored onion bulbs is discussed. A conclusion is made that the “Sunpower” onion cannot sustain overwinter storage.     

广州地区十字花科蔬菜花叶病的传染途径及流行规律的初步研究

广州地区十字花科蔬菜花叶病(主要病毒是芜菁花叶病毒的油菜毒系和芜菁毒系)的越夏寄主,根据11年来的观察特别是1956—1958年间的实地调查结果,主要是小白菜、菜心和西洋菜。在野生植物中曾发现过2株蔊菜和1株荠菜自然感病,说明野生植物不是本病的重要毒源。室内试验结果证明,此病的自然传染媒介为萝卜蚜、桃蚜和普通红蜘蛛。黄条跳(虫甲)、斜纹夜盗蛾和菜粉蝶都不是本病的虫媒,病株的种子不会传病,中国菟丝子也不会传递本病。在带有未腐熟的病菜残体的土里进行直播,长出来的菜苗没有发病的;但是把菜苗移植在这样的土里,会有极小量的植株感病。根据1956年7月至1958年6月,每十日田间调查一次结果:萝卜蚜是广州地区最重要的传病媒介,桃蚜每年只在3—4月间略有发生,作用不大。根据这24个月的田间发病率,萝卜蚜(有翅蚜及无翅蚜)的虫口密度和气候情况,我们认为本地区本病的发生及流行程度主要受降水量和降水天数所影响,并认为可以从降水情况来预测约30日后的病害流行程度。     

Durable press finish of cotton via dual curing using UV light and heat

Continuous photografting/crosslinking of polyethyleneglycol dimethacrylate oligomers onto cotton using a water-soluble benzophenone photoinitiator was investigated. Photografting increased with increasing irradiation dose, oligomer concentration and photoinitiator concentration. Maximum grafting efficiency of DM 400 and 600 were 83% and 79%, respectively. The photografting increased the wrinkle resistance of cotton implying surface crosslinking of cotton. Both surface crosslinking and bulk crosslinking of cotton were accomplished via dual curing of a mixed formulation containing both a thermally curable component (BTCA/SHP) and a UV-curable component. The wrinkle resistance of the crosslinked cotton was found to be higher when cured by thermal curing after UV curing rather than by UV curing after thermal curing due to the facile post-polymerization of the UV active component. The presence of crosslinks in the dually crosslinked cotton was verified with FT-IR and thermogravimetric analysis.     

New Benzoxazine Secondary Metabolites from an Arctic Actinomycete

Two new secondary metabolites, arcticoside (1) and C-1027 chromophore-V (2), were isolated along with C-1027 chromophore-III and fijiolides A and B (3–5) from a culture of an Arctic marine actinomycete Streptomyces strain. The chemical structures of 1 and 2 were elucidated through NMR, mass, UV, and IR spectroscopy. The hexose moieties in 1 were determined to be d-glucose from a combination of acid hydrolysis, derivatization, and gas chromatographic analyses. Arcticoside (1) and C-1027 chromophore-V (2), which have a benzoxazine ring, inhibited Candida albicans isocitrate lyase. Chromophore-V (2) exhibited significant cytotoxicity against breast carcinoma MDA-MB231 cells and colorectal carcinoma cells (line HCT-116), with IC₅₀ values of 0.9 and 2.7 μM, respectively.     

Identifying Type of Refined Petroleum Products in Environmental Media: Thin-Layer Chromatography (TLC) as a Quick Methodology

The ultimate goal of our study is to establish thin-layer chromatography (TLC) as a quick and simple method for identifying the type of refined petroleum products present in the environmental media. As a preliminary step, TLC chromatograms of different petroleum products, including gasoline, kerosene, and diesel, were characterized and compared. Methanol was determined as the optimum carrier solution in TLC analysis. The spherical-shaped TLC chromatogram of gasoline showed the longest migration distance, and thus the highest retardation factor (R _f) of 0.91. This was followed by that of kerosene (0.63) with an elliptical-shaped, and diesel (0.24) with an elongated trapezoid-shaped chromatogram. R _f of kerosene and diesel increased with the dilution factor, while gasoline showed a constant value. Additionally, it was observed that the TLC chromatograms of oils produced the same peak pattern with the corresponding petroleum products in gas chromatography (GC). A mixed sample of kerosene and diesel presented a triangular shaped chromatogram, underlining the need to consider the shape of chromatogram in addition to the R _f value, as an indicator of the petroleum type. The findings indicate that TLC has a huge potential to be used as a quick and reliable method for identifying the type of refined petroleum products in the environmental media.     

Age and sex related variations in protein and carbohydrate levels of Galleria mellonella (Linnaeus, 1758) (Lepidoptera: Pyralidae) in constant lightness and darkness

Variations in protein and carbohydrate levels correlated with the age and sex of Galleria mellonella (Linnaeus, 1758) (Lepidoptera: Pyralidae) in constant lightness and darkness were investigated. Tests were conducted under laboratory conditions at 28 +/- 2 degrees C temperature and 65 +/- 5% relative humidity. Insects were fed on combs without honey. Protein level in 100 mg of adults increased in the first days of adult life of females in connection with their age and then decreased. No difference was observed in males. Carbohydrate level in 100 mg of adults increased in both sexes in connection with their age. In all tests carbohydrate and protein levels of females were found higher than males. Protein and carbohydrate levels of adult G. mellonella varied in connection with the photoperiod regimes implemented. Decrease in the nutrient levels was observed in constant darkness.     

Reliability of InGaAs focal plane array imaging of wheat germination at early stages

To assist our Kansas breeding program, we have developed nondestructive methods to test new lines of wheat for resistance to premature germination. The high sensitivity of subsurface imaging, compared with visual detection, α-amylase determination, or viscosity testing, permits germination detection at early stages. This report is concerned with detection reliability via chemical imaging of intact wheat kernels at early stages of germination by using an InGaAs focal plane detector array in the 1100–1700 nm range. Ninety kernels from each of six different cultivars, including HRW and HWW wheat, were exposed to moist conditions for 6, 12, 24, 36, and 48 h. Images of each 90 kernel group were examined, and images of those kernels exposed to moisture for 36 h were compared with images of kernels treated for 3 h as a control. Images of each were classified as sprouted or unsprouted. Criteria for classification included images of log 1/R at select wavelengths or images of select factors resulting from principle component analysis (PCA) treatment of reflectance intensity data from each pixel. Sprouted kernels determined by PCA factors 1 and 4 from 90 kernels tested in a 36-h moisture exposure numbered 87, 85, 80, 74, 70, 48 for six cultivars tested. Cultivar KS-2174 was shown to be distinctly more resistant to germination than the other cultivars. When KS-2174 was compared with Betty wheat, for all exposure times, Betty had approximately 45% more germinated kernels.