Sterol concentration and distribution in sunflower seeds (Helianthus annuus L.) during seed development

Sunflower seeds are currently used for edible oil production. Among oil minor compounds, phytosterols are of special interest due to their cholesterol reducing properties. This paper reports studies on their accumulation and distribution in the embryo and hull, and the effects of temperature on phytosterol contents in sunflower seed produced under both conventional and organic field conditions. An optimised method of sterol determination, adapted to studies on small samples of seed, is presented. Seventy-two percent of phytosterols were found in the embryo, 28% in the hull. The periods of phytosterols concentration varied according to sterol category and seed part. Application of these results to improve production of natural sterols for functional food use is discussed.     

Prosopis farcta Seeds: Potential Source of Protein and Unsaturated Fatty Acids?

The goal of this study is to evaluate the chemical composition of the Prosopis farcta seeds. The Kjeldahl method revealed that the level of the total protein was ca. 18 % on a dry weight basis (DW). Gas chromatographic analysis revealed the presence of six fatty acids. Linoleic acid with 57.55 % was the major fatty acid, followed by oleic and palmitic acids (24.58 and 12.91 %, respectively). Total phenolic content was 1.71 mg GAE/g DW (GAE = gallic acid equivalents). Methanolic extracts showed important antioxidant properties. This work highlights the importance of P. farcta seeds as natural and inexpensive sources of protein, unsaturated fatty acid, and phenolic compounds for both cosmetic and pharmaceutical uses.     

Academic Research on Drying in Brazil 1970–2003

ABSTRACT

Drying research in Brazil started to be significant from the early 1970s. At the end of the 1980s and the beginning of the 1990s, a few authors started to publish their works in indexed journals in English. Even so, many works were published in Portuguese. This compilation has the objective of showcasing the academic research done in Brazil from 1970 to 2003. This search was carried out using existing databases on Brazilian academic research. We located 705 works consisting of 82% M.Sc. and 18% Ph.D. theses. Tables listing the dried products and dryers studied are presented along with a discussion of the historical development of the Brazilian drying research and the new trends as well.     

The total polyphenols and the antioxidant potentials of some selected cereals and pseudocereals

The objective of the present study was to investigate the effect of phenolic substances and proteins on the antioxidant potentials in some cereals and pseudocereals and to compare their bioability. The polyphenol dry matter extracts (PDME) from the investigated seeds of buckwheat, rice, soybean, amaranth and quinoa with 1.2 M HCl in 50% methanol/water (PDME50%Met/HCl) exhibited higher inhibition of lipid peroxidation than the ones extracted with 50% methanol/water (PDME50%Met) and were comparable to the antioxidant activity of butylated hydroxyanisole at concentration of 0.2 mg mL⁻¹. The antioxidant activities of these seed extracts determined by 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonate)-ABTS^●+/K₂S₂O₈, β-carotene bleaching (β-carotene), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging methods showed high correlation coefficients (R ²) such as 0.9515, 0.9058 and 0.8723, respectively, with the presence of total polyphenols estimated by Folin-Ciocalteu assay. These results indicate that the major antioxidant components in these extracts mostly derived from the polyphenols, and proteins showed only minimal values of bioactivity. Based on high contents of polyphenols, anthocyanins, flavonoids and their antioxidant activities pseudocereals such as buckwheat, quinoa and amaranth can be a substitute for cereals for common and atherosclerotic diets and sometimes in the allergic cases.     

Individual and combined application of dry heat with high hydrostatic pressure to inactivate Salmonella and Escherichia coli O157:H7 on alfalfa seeds

Alfalfa sprouts are recurrently implicated in outbreaks of food-borne illnesses as a result of contamination with Salmonella or Escherichia coli O157:H7. In the majority of these outbreaks, the seeds themselves have been shown to be the most likely source of contamination. The aims of this study were to comparatively assess the efficacy of dry heat treatments alone or in conjunction with high hydrostatic pressure (HHP) to eliminate a ∼5 log CFU/g load of Salmonella and E. coli O157:H7 on alfalfa seeds. Dry heat treatments at mild temperatures of 55 and 60 °C achieved ≤1.6 and 2.2 log CFU/g reduction in the population of Salmonella spp. after a 10-d treatment, respectively. However, subjecting alfalfa seeds to more aggressive temperatures of 65 °C for 10 days or 70 °C for 24 h eliminated a ∼5 log population of Salmonella and E. coli O157:H7. We subsequently showed that the sequential application of dry heating followed by HHP could substantially reduce the dry heating exposure time while achieving equivalent decontamination results. Dry heating at 55, 60, 65 and 70 °C for 96, 24, 12 and 6 h, respectively followed by a pressure treatment of 600 MPa for 2 min at 35 °C were able to eliminate a ∼5 log CFU/g initial population of both pathogens. Finally, we evaluated the impact of selected treatments on the seed germination percentages and yield ratios and showed that dry heating at 65 °C for 10 days did not bring about any considerable decrease in the germination percentage. However, the sprout yield of treated alfalfa seeds was reduced by 21%. Dry heating at 60 and 65 °C for 24 and 12 h respectively followed by the pressure treatment of 600 MPa for 2 min at 35 °C did not significantly (P > 0.05) affect the germination percentage of alfalfa seeds although a reduction in the sprouting yield was observed.     

Solution Grown Se/Te Nanowires: Nucleation, Evolution, and The Role of Triganol Te seeds

We have studied the nucleation and growth of Se–Te nanowires (NWs), with different morphologies, grown by a chemical solution process. Through systematic characterization of the Se–Te NW morphology as a function of the Te nanocrystallines (NCs) precursor, the relative ratio between Se and Te, and the growth time, a number of significant insights into Se–Te NW growth by chemical solution processes have been developed. Specifically, we have found that: (i) the growth of Se–Te NWs can be initiated from either long or short triganol Te nanorods, (ii) the frequency of proximal interactions between nanorod tips and the competition between Se and Te at the end of short Te nanorods results in V-shaped structures of Se–Te NWs, the ratio between Se and Te having great effect on the morphology of Se–Te NWs, (iii) by using long Te nanorods as seeds, Se–Te NWs with straight morphology were obtained. Many of these findings on Se–Te NW growth can be further generalized and provide very useful information for the rational synthesis of group VI based semiconductor NW compounds.     

植物种子油体的提取及其性质的初步研究

植物种子油体是一种天然的微胶囊,含有丰富的不饱和脂肪酸和磷脂、维生素E及植物甾醇等生物活性小分子。因此,在食品、化妆品和制药等领域有很大的运用潜力。本研究选取8种植物种子(椰子、油菜籽、核桃仁、南瓜籽、花生、油茶籽、杏仁和红花籽),在尿素条件下提取不同种子油体,考察并比较不同种子油体的表观、粒径大小、pH稳定性及蛋白组成,为植物种子油体的利用提供参考。研究表明,利用8 mol/L尿素可获得高纯度的油体,不同植物种子油体的颜色和风味各不相同;显微镜(400×)下观察到8种植物种子油体乳液分散较为均匀,其中除油菜油体太小观察不到外,其他油体均呈球形;不同植物种子油体粒径大小不同;pH对于8种植物种子油体乳液的分散稳定性的影响各不相同;通过电泳表征和质谱分析发现8种植物种子油体蛋白分子质量分布情况差别很大。     

Effect of extraction and isolation on physicochemical and functional properties of an underutilized seed protein: Gingerbread plum (Neocarya macrophylla)

The effect of extraction and isolation on the physicochemical and functional properties of gingerbread plum seed protein isolate was studied. Gingerbread plum seed protein isolate was extracted from defatted gingerbread plum seed flour (DGPSF) by alkali solution along with isoelectric precipitation. The protein isolate was subjected to freeze or vacuum drying process. Freeze dried gingerbread plum seed protein isolate (FGPSPI) and vacuum dried gingerbread plum seed protein isolate (VGPSPI) were evaluated for their physicochemical and functional properties (protein solubility, water/oil binding capacity, emulsifying capacity, foaming capacity). Among physicochemical parameters, the proximate composition, amino acid composition, minerals, differential scanning calorimetry (DSC), SDS-PAGE and color attributes were studied. Both FGPSPI and VGPSPI contained over 90% protein versus DGPSF (56.72%) used as raw material. The method of drying had significant effect (p < 0.05) on the physicochemical characteristics of FGPSPI and VGPSPI except for amino acids composition. The functional properties were variable among samples. DGPSF had higher emulsifying, water holding and oil binding capacities compared with FGPSPI and VGPSPI. FGPSPI exhibited better emulsifying capacity and water holding capacity than VGPSPI. FGPSPI also showed comparable oil binding capacity and bulk density to commercial soy protein isolate (SPI). The results indicated that FGPSPI and VGPSPI could be a good source of protein fortification for a variety of food products for protein deficient consumers as well as a potential food ingredient.     

USB在单光子计数种子活性快速检测仪中的应用

研制了一种超微弱发光单光子计数种子活性快速检测仪（FSAA），该仪器利用单光子计数手段，能够灵敏、直接并有对照性检测种子的超微弱化学发光（TUCL），获得种子的活力信息，该检测仪可以区分老化程度相差1季的水稻种子的超弱发光。本系统利用Cypress公司的EZ-USB AN2131Q芯片实现了单片数据采集和控制。介绍了通用串行总线（USB）的特点及其在数据采集过程中的优点。     

Growth of high-quality, uniform c-axis-oriented zinc oxide nano-wires on a-plane sapphire substrate with zinc oxide templates

High-quality, vertically aligned zinc oxide (ZnO) nano-wires were grown by the vapour-transport method on (1 1 2¯ 0) (a-plane) sapphire substrate covered by a uniform ZnO nano-crystalline seed layer which was deposited in a preceding growth step via simple chemical vapour deposition. A thin layer of close-packed nano-seeds with an average size of 12 nm was formed rapidly on the substrate by sublimation and thermal decomposition of zinc acetate dihydrate as the precursor at moderate temperatures and pressures. Subsequently, growth of ZnO nano-wires was performed by a carbo-thermal vapour-transport method yielding nano-wires with high reproducibility and homogeneity. The as-grown, c-axis-oriented nano-wires exhibit excellent luminescence properties and perfect alignment with respect to the substrate surface.