Nada Nikolić

Composition and Radical Scavenging Capacity of Phenolic Compounds in Wheat-Chickpea Dough

The content, composition, and radical scavenging capacity of phenolic compounds in wheat-chickpea (60:40, w/w) flour and dough were studied in this research. The content of phenolic compounds in wheat-chickpea dough was almost twice as high as in the flour from which the dough was made. The addition of chickpea flour to wheat flour contributed to the improved scavenging capacity of dough. The wheat-chickpea dough had a lower maximal achieved scavenging capacity than wheat-chickpea flour, but higher than that of the wheat dough. The quercetin, genkwanin, and apigenin glucosides could be considered as stable components during the mixing of the wheat-chickpea dough. The wheat-chickpea bread retained the radical scavenging capacity which the dough had.

The Main Components Content, Rheology Properties and Lipid Profile of Wheat-Soybean Flour

Soybean (Glycine max (L.) Merr.) is a species of legume, native to a Eastern Asia and an important global crop, today. Soybean is rich in high quality proteins, contains essential amino acids, similar to those found in meat, minerals such as Fe, Zn, Cu, Mn, Ca and Mg as well as phytic acid. The bulk of seed soybean proteins contains albumins and globulins as major components, but there are minor, undesirable components such as inhibitors of trypsyn and chymotrypsin, and sugar-binding lecitins. The inhibitors and lecitins are generally inactivated by heat treatment. A new immunochemical methods can be used for quantitative detection of soybean proteins and production of healthful foods (Brandon & Friedman, 2002). The soybean lipid contains a significant amount of unsaturated acids: uf061linolenic acid, known as omega-3 acid, linoleic, uf067-linolenic and arachidonic acid, known as omega-6, and oleic acids known as omega-9 acid and are very important in human nutrition (Liu, 1997). The soybean lipid also contains saturated acids: palmitic and stearic acid (Bressani, 1972; Olguin et al., 2003; Bond et al., 2005), as well as tocopherols (Ortega-Garcia et.al., 2004, Yoshida et al., 2006). These soybean components make the products with soybean have higher nutritional value.

Effect of the silica nanofiller on the properties of castor oil-based waterborne polyurethane hybrid dispersions based on recycled PET waste

The paper describes the chemical depolymerization of the polyethylene terephthalate (PET) waste from postconsumer soft drink bottles and a search for the way to use this product. The depolymerized oligoester obtained from glycolysis of PET waste using tiethylene glycol was transesterified with castor oil which resulted in the formation of hydroxyl-functional polyester polyol, with hydroxyl value of 391xa0mgxa0KOHxa0g−1. In the presented paper, series of castor oil-based waterborne polyurethane (CPU)/silica hybrid dispersions were prepared using dimethylolpropionic acid as an ionic center. The polyurethane prepolymers with pendent castor oil groups were prepared first, and then different concentrations of hydrophilic fumed silicas (0, 0.5, 0.75, 1.0 and 2.0xa0wt%) were added. For waterborne polyurethane dispersions of hydrophilic fumed silica with the surface area (50u2009±u200915xa0m2/g) and a primary particle size of 40xa0nm in the polymer matrix, ultrasound waves were used. The hybrid dispersions were prepared by adding the required amount of triethylamine and water. The molecular structures and mass of glycolyzed PET oligoesters, castor oil-based polyol and castor oil-based polyurethane–silica hybrid dispersions were estimated by FTIR method and gel permeation chromatography.The incorporation effect of SiO2 nanoparticles into the PU matrix on the thermal and mechanical properties of resulting polyurethane films has been examined by Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis, differential scanning calorimetry (DSC), SEM microscope, and measurement of the coatings properties. The DSC data results suggest that hard segment glass temperature decreases, but mixed-phase glass transition temperature increases with increasing SiO2 content. The FTIR deconvolution result of the degree of phase separation between oxide nanoparticles and hard segment supports to the DSC analysis. The addition of silica oxide caused the increase in the thermal stability. The T10% and T50% of CPU films (the temperatures where 10 and 50% weight loss occurred) increased with increasing the SiO2 content. UV–Vis spectrophotometry showed that introduction of nanosilica particles into polyurethane enhanced the shielding property of obtained films for UV light. The hardness, adhesion, and gloss quality of the polyurethane films were also determined considering the effect of the phase separation and the SiO2 content, so this paper confirmed the suitability of using these castor oil-based waterborne polyurethane/silica hybrid dispersions as new materials with high-performance coatings materials.

Total polyphenols from Solanum retroflexum Dun. fruit: extraction and optimization by response surface methodology

Total phenolic (TPC), flavonoid (TFC) content and antioxidant activity (AOA) of Solanum retroflexum fruit extracts obtained by conventional extraction with different aqueous ethanol solution (25, 50, 75% v/v), temperatures (20, 40, 60xa0°C) and extraction time (15, 30 and 45xa0min) were investigated. The extract obtained by 75% aqueous ethanol at 60xa0°C after 45xa0min shows the highest AOA determined by DPPH (EC50u2009=u200960.67xa0mg/ml) and FRAP (1.55xa0µmol Fe2+/mg) methods. TPC and TFC were in ranges from 63.50u2009±u20090.43 to 92.07u2009±u20091.07xa0mg of gallic acid/g of dry extract and from 29.17u2009±u20090.35 to 48.22u2009±u20090.43xa0mg of rutin/g of dry extract, respectively. In order to commercialize the extraction of polyphenolic compounds, as the most important group of the plant bioactive compounds, the extraction conditions were optimized by response surface methodology. Under proposed optimum extraction conditions (60xa0°C, 40.3xa0min and ethanol concentration of 74.7%) extract with the maximal TPC (92.29xa0mg gallic acid/g of dry extract) could be obtained. The set of the extraction conditions which gave the maximum TPC while simultaneously minimizing the time, energy and ethanol consumption were also proposed (economic extraction conditions). The results confirm that this insufficiently tested fruit represent a good source of polyphenolic compounds and are worthy of further investigation.