Piotr Tomasik

Probiotics and prebiotics

ABSTRACT Probiotics, bacteria from the genera Bifidobacterium and Lactobacillus, and yeast, Saccharomyces, as well as prebiotics belonging to the group of dietary fiber (inulin with low degree of polymerization, fructose-derived oligosaccharides, and resistant starch) are natural factors useful in prophylaxis and therapy of several common diseases including some types of cancer. They are available commercially and can be introduced to produce so-called functional food. Probiotics and prebiotics can be utilized either separately or jointly (as synbiotics or eubiotics). Mechanisms of both biotics are discussed. The role of cereals in probiosis is considered. Possibilities for extension of the uses of the original Chinese probiotic, chaw tofu, are also considered.

Sharp green electroluminescence from 1H-pyrazolo[3,4-b]quinoline-based light-emitting diodes

A multilayer organic light-emitting diode was fabricated using a fluorescent compound {6-N,N-diethylamino-1-methyl-3-phenyl-1H-pyrazolo[3,4-b]quinoline} (PAQ–NEt2) doped into the hole-transporting layer of NPB {4,4′-bis[N-(1-naphthyl-1-)-N-phenyl-amino]-biphenyl}, with the TPBI {2,2′,2″-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole]} as an electrontransporting material. At 16% PAQ–NEt2 doping concentration, the device gave a sharp, bright, and efficient green electroluminescence (EL) peaked at around 530 nm. The full width at half maximum of the EL is 60 nm, which is 60% of the green emission from typical NPB/AlQ [where AlQ=tris(8-hydroxyquinoline) aluminum] device. For the same concentration, a maximum luminance of 37 000 cd/m2 was obtained at 10.0 V and the maximum power, luminescence, and external quantum efficiencies were obtained 4.2 lm/W, 6.0 cd/A, and 1.6%, respectively, at 5.0 V.

Interactions of starch with salts of metals from the transition groups

Interpretation of EPR spectra of combinations of gelatinized one of amylopectin, cornstarch, waxy cornstarch, and potato starch with one of Co (II), Cr (III), Cu (II), Fe (III), and Mn (II) produced evidence for the formation of the Werner-type complexes with metal central atom and polysaccharide as the ligand. Ligation of the central atom involved lone electron pairs of the polysaccharide hydroxyl groups. Results of complexation depended on metal cation and polysaccharide as well as a form in which it was examined. Formation of complexes with granular starch was additionally confirmed by appearance of starch granules soaked in aqueous salt solutions in scanning electron microscopy.

Dipyrazolopyridine derivatives as bright blue electroluminescent materials

Very bright blue organic light emitting diodes were fabricated using highly fluorescent dipyrazolopyridine derivatives, 4-(4-substituted phenyl)-1,7-diphenyl-3,5-dimethyl-1,7dihydrodipyrazolo[3,4-b,4′,3′-e]pyridine (PAP–X, X=CN, Ph, and OMe), as emitter by doping the dye in an electron-transporting host, 2,2′,2″-(1,3,5-benzenetriyl)tris-[1-phenyl-1H-benzimidazole] (TPBI). Two hole-transporting layers, 4,4′-bis[N-(1-naphthyl-1-)-N-phenyl-amino]-biphenyl (NPB) and 4,4′-dicarbazolyl-1,1′-biphenyl (CBP) were used to achieve the emission from PAP–X. The devices with a general configuration of indium tin oxide/NPB/CBP/TPBI:PAP(2%)/Mg:Ag showed a bright blue emission. The PAP–CN-based device is exceptionally good, with a brightness of 11 200 cd/m2 at 14.2 V and the peak external quantum efficiency of 3.2%. The efficiency is the highest for the blue emission.

Apple pectin complexes with whey protein isolate

Abstract Complexes of apple pectin and whey protein isolate were available by electrosynthesis from aqueous mixtures. Complex formation followed a first-order kinetic equation. Complexes separated on anode. Their composition and properties depended on initial composition of particular reaction mixtures. They varied in the pectin:isolate composition from 1:0.5 to 1:5. Complexes were examined by means of elemental analysis, infrared spectroscopy, and thermogravimetry. Strong pectin–isolate interactions involved carboxylic groups of pectin and peptide bonds of protein. Complexes did not form films.

Deep-freezing of potato starch.

Samples of oven-dried, air-dried, and moisturised potato starch (5, 13, and 24% w/w moisture content, respectively) were frozen in liquid nitrogen. Samples after thawing were studied by means of cross-polarised light beam microscope (CLBM), Fourier Transformation Infrared Spectroscope (FT-IR), powder X-ray diffractometer, and non-contact Atomic Force Microscope (nc-AFM). Rapid deep-freezing followed by thawing produced changes on the granule surface. They were accompanied by internal alteration manifested by FT-IR spectra and powder X-ray diffractograms. The results depended on the water content in the sample. Deep-freezing of moistened starch resulted in increased crystallinity of granules. It had minor effect on the granule aqueous solubility and characteristics of gelation.

Starch radicals. Part I. Thermolysis of plain starch

Abstract Plain starch from two varieties of potato and wheat, one variety of rye, triticale, oat, corn, waxy corn, cassava and amaranthus was thermolyzed subsequently at 170, 250, 285, 300 and 325 °C for 30min-2h intervals. The concentration of unpaired spins was determined. Among varieties studied, the oat starch is least thermally resistant, and both the triticale and maize starches are most thermally resistant. Radicals generated in such a manner are very stable. The analysis of experimental and simulated EPR spectra points to the unpaired spin delocalization and steric hindrances are responsible for the stability of such radicals.

Effects of hydrogen, oxygen, and ammonia low-pressure glow plasma on granular starches

Cassava, corn, high amylose corn, potato, rice Indica, rice Japonica, sweet potato, waxy corn, and wheat starches were exposed to low-pressure ammonia, hydrogen, and oxygen plasma. In every case, depolymerization of the starch polysaccharides was noted. The extent of the depolymerization depended on the nature of the starch as well as the type of plasma applied. Among three fractions of polysaccharides distinguished by their molecular weight average, the fraction of the highest molecular weight suffered the most efficient depolymerization. The relative depolymerization for the middle- and low-molecular fractions of polysaccharides was found to be starch and plasma specific. The chemical character of the plasma had very little influence on the starch polysaccharides. Only subtle oxidation effects were observed in oxygen plasma. Low-pressure glow plasma treatment appeared to be a convenient tool for a waste-less dextrinization of starch. Manipulation of the plasma variety and the time of exposure resulted in a wide spectrum of dextrins of various molecular weights and paste-forming properties.

Thermal properties of complexes of amaranthus starch with selected metal salts

Metal cations (Cu(II), Fe(III), Mn(II), and Ni(II)) are ligated by amaranthus starch as proven by EPR spectra and conductivity measurements. The hydroxyl groups of starch are the coordination sites. The acetate and nitrate anions of the metal salts behave as bidentate ligands and reside in the inner coordination sphere of resulting polycenter Werner complexes. There is only a weak degeneration of orbitals of central metal ions caused by a shift of unpaired spin from the central atom to the ligand. The ligation of the central metal atoms resulted in a variation of the thermal stability, pathway, and rate of thermal decomposition of starch as proven by thermogravimetric (TG) and differential scanning calorimetric (DSC) measurements.

Electrosynthesis of potato starch–whey protein isolate complexes

Abstract Potato starch–whey protein isolate complexes were prepared electrochemically. The kinetics of complex formation was examined and the complexes characterized by chemical and physical methods. Their composition was examined through the analysis of carbohydrate and nitrogen content. The physical characteristics were examined by FTIR and theromgravimetry.