Accumulation of phospholipids and glycolipids in seed kernels of different sunflower mutants (Helianthus annuus)

Phospholipids are essential components of the oil bodies present in seeds, and they are also the main components of the commercial seed lecithins used in many food formulas. In the present study, we analyzed the characteristics of the polar lipid fraction of seeds from different sunflower FA mutants. In sunflower seeds the accumulation of polar lipids reaches a maximum 25 d after anthesis before diminishing during the final stages of maturation and desiccation. We have developed an HPLC method, using ELSD, that produces optimal separation of all polar seed lipids. This method improves the results that could be obtained with previous HPLC methods and hence, we have used it to analyze the polar lipid fraction of sunflower seeds. We show that this fraction comprises phospholipids and glycolipids, of which PC is the most abundant species. Moreover, we found that the relative polar lipid content in control and mutant seeds is similar, suggesting that the mutant traits do not affect polar lipid synthesis. The degradation of polar lipids in isolated seeds was also examined and we found that the PC and PE present in developing sunflower seed kernels were rapidly degraded owing to the activity of D-type phospholipases.     

The content of tocopherols and oxidative quality of oils prepared from sunflower (Helianthus annuus L.) seeds roasted in a microwave oven

Sunflower seeds ((Helianthus annuus were roasted for 6, 12, 20 or 30 min at a frequency of 2450 MHz using a domestic microwave oven. After the kernels were separated from the sunflower seeds, the quality characteristics and the compositions of the oils were investigated in relation to their tocopherol distributions, and they were further evaluated as compared with an unroasted oil sample. Only minor increases (p < 0.05) in chemical and physical changes of the oils, such as the carbonyl value, the p‐anisidine value and the color development, occurred at a prolonged roasting period. Significant decrease (p < 0.05) was observed in the amounts of phospholipids in the oils after microwave roasting. Nevertheless, compared to the original level, more than 92 wt‐% tocopherols still remained after 30 min of roasting. With a few exceptions, these results indicate that the exposure of sunflower seeds to microwaves for 12 min caused no significant (p < 0.05) loss or change in the content of tocopherols and polyunsaturated fatty acids in the kernels.     

The effects of intercepted solar radiation on sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.) seed composition from different head positions

The effect of intercepted solar radiation during fruit filling on seed weight and oil content from seeds of three sectors of the head in two sunflower (Helianthus annuus L.) hybrids of low and high potential oil percentage was investigated. Seed weight in each sector depended on both the level of radiation intercepted (modified by shading and thinning plants) and the genotype grown. A higher level of intercepted solar radiation increased seed weight in each sector. Central seeds of shaded plants showed the lowest weight. The seed and kernel oil content hierarchy among the three sectors was modified only in the hybrid with high potential oil content. For each head sector, variations in seed oil content associated with changes in the level of intercepted radiation could be accounted for by changes in the kernel oil content, not in the kernel/seed ratio. Significant relationships were found between seed oil and kernel oil contents when analyses between treatments (R>0.86) and sectors (R>0.92) were carried out. These relationships together with the growing conditions of plants during seed filling, the genotype, and the seed position on the head are essential factors that should be taken into account when selecting seeds in sunflower breeding programs since they affect the commercial/industrial quality of seeds.     

Extracting Cu(II) from aqueous solutions with hydrophobic room-temperature ionic liquid in the presence of a pyridine-based ionophore to attempt Cu recovery: A laboratory study

Extraction of Cu(II) from neutral aqueous solutions with the hydrophobic room-temperature ionic liquid (IL) N-butyl-N-methylpyrrolidinium bis((trifluoromethyl)sulfonyl)imide (BMP-TFSI) in the presence of the pyridine-based ionophore N¹,N¹,N⁴,N⁴-tetrakis(2-(pyridin-2-yl)ethyl)butane-1,4-diamine (C₄N₂Py₄) is demonstrated in this study. Although the distribution coefficients, D_M, of Cu(II) extraction depend on the concentration of Cu(II) in aqueous solutions, all values were higher than 200, indicating extremely high extraction efficiency. Based on spectrophotometric, electrochemical, and X-ray crystallography studies, the coordination number of the C₄N₂Py₄-coordinated Cu(II) ions was determined as 2. The voltammetric behavior of Cu(I), Cu(II), and their C₄N₂Py₄ complex ions were also studied. The recovery of Cu from the IL was conducted by washing the IL phase containing the extracted Cu(II) complex with an acidic aqueous phase or by controlled-potential electrolysis. The IL containing C₄N₂Py₄ was employed for two complete rounds and a decrease in extraction efficiency was only observed when higher concentration of Cu(II) was used.