Fluorometric method for determination of vitamin B6 in soya bean

Summary The simple fluorometric method for determination of added pyridoxine-HCl in enriched food, based on oxidation of pyridoxine to 4-pyridoxic acid by means of KMnO₄, has been modified for determination of total B₆ in soya bean. In comparison to the other fluorometric procedures, the proposed method is the simplest one, rapid and easy to perform, demanding the least time for oxidation and not using hazardous chemicals (KMnO₄ instead of KCN). Good recovery, low relative standard deviation and low total error allow the proposed procedure to be included into the group of excellent methods.

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Die fluorometrische Methode zur Vitamin B₆-Bestimmung in Soja

Zusammenfassung Die einfache fluorometrische Methode zur Bestimmung von zugegebenem Pyridoxin in angereicherten Lebensmitteln basiert auf der Oxidation des Pyridoxins mit Kaliumpermanganat zur 4-Pyridoxinsäure und wurde für die Bestimmung des gesamten Vitamin B₆ in Soja modifiziert. Im Vergleich mit anderen fluorometrischen Methoden ist die vorgeschlagene, einfach, schnell und leicht durchzuführen. Diese Methode braucht nur wenig Zeit für die Oxidation und verwendet ungiftige Chemikalien (KMnO₄ statt KCN). Die gute Wiederfindung, die geringe relative Standardabweichung und der geringe Gesamtfehler reiht das vorgeschlagene Verfahren in die Gruppe der ausgezeichneten Methoden ein.

     

Wheat flour confectionery products as a source of inorganic nutrients: zinc and copper contents in hard biscuits

Cereal-based confectionery products being consumed through whole human life are considered mainly to be a source of carbohydrates, that is energy, although cereals are a rich source of minerals as well. To evaluate some hard biscuits produced in Croatia as a source of different trace elements in nutrition, in this study Zn and Cu contents were determined in classic wheat flour biscuits and in dietetic biscuits enriched with whole wheat grain flour or whole wheat grain grits, soya flour and skimmed milk. Zn was determined by flame atomic absorption spectrometry (AAS); Cu was determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results show that the Zn content in different kinds of biscuits ranges from 5.89 up to 17.64 mg/kg and the Cu content ranges from 1.15 up to 2.79 mg/kg depending on the type of wheat milling products and mineral content of other ingredients used. Enriched dietetic biscuits produced from wheat flour type 850 and whole wheat grain flour and/or soya flour and skimmed milk were almost 200% and 150% higher in Zn and Cu, respectively, in comparison to classic white wheat flour biscuits and can be considered as good sources of Zn and Cu in nutrition.     

Evaluation of functional properties of offal proteins

Evaluation of functional properties of beef heart and lip tissue proteins was based on the data obtained in the following determinations: protein extractability, fat emulsifying capacity, emulsion stability, gel forming ability, and water holding capacity after heat treatment. Beef skeletal muscles were used as the control. It was found that extractability of proteins of the raw materials was low as well as their ability to stabilize emulsions was on a low level. Proteins soluble at high ionic strength (fraction HIS) of beef heart and lip tissue emulsified 80.7 ml and 68.9 ml of oil/100 mg of protein, respectively, as compared to 106.6 ml in the control group. Analogically, protein soluble at low ionic strength (fraction LIS) emulsified 77.9 ml, 61.2 ml and 100.4 ml of oil, respectively. Emulsion stability of offal proteins appeared to be dependent on ionic strength. Generally at higher concentrations of salt their ability to stabilize emulsions was better as well as their water holding capacity increased. Their gelation properties as compared to control were also low. In each case, the functionality of cardiac proteins proved to be better than that of beef lip tissue.     

Ability of Lactobacillus gasseri K 7 to inhibit Escherichia coli adhesion in vitro on Caco-2 cells and ex vivo on pigs' jejunal tissue

The ability of Lactobacillus (Lb.) gasseri K 7 to inhibit adhesion of Escherichia coli O8:K88 to intestinal mucosa was studied on cultured Caco-2 cells and ex vivo on pigs' small intestinal tissue. Lactobacilli were added simultaneously with E. coli, before E. coli and after E. coli for competition, exclusion and displacement assays. The concentration of lactobacilli on fully differentiated Caco-2 cells was 4.5+/-0.3 x 10(8) cfu/well, while the concentration of E. coli varied from 1.5 x 10(6) to 4.3 x 10(8) cfu/well. The number of E. coli adhered to Caco-2 monolayer (cfu/well) was lineary correlated (R(2)=0.97) to the concentration of added cells. In the assay simulating exclusion, E. coli adhesion was reduced by Lb. gasseri K 7 strain by 0.1 to 0.6 log cfu/well. The binding of E. coli was inhibited even more when incubated simultaneously with lactobacilli, particularly at the lowest concentration of E. coli (ratio E. coli/lactobacilli 1:248), where five-times reduction (or 0.7 log) was observed. When adhesion to tissue derived from pigs' jejunum was tested, concentration of E. coli was constant (6.9+/-0.14 x 10(7) cfu/ml), while the concentration of Lb. gasseri K 7 was 5.9 x 10(7) and 1.3 x 10(7) cfu/ml in two independent experiments, respectively. The adhesion of E. coli and Lb. gasseri K 7 cells to jejunal mucosa was similar (1.0+/-0.17 x 10(6) and 1.54+/-0.10 x 10(6) cfu/cm(2)) when the concentrations of single strains in suspensions were approximately the same. No significant competition, exclusion or displacement of E. coli by lactobacilli was observed on jejunal tissue. In conclusion, Lb. gasseri K 7 was found to be effective in reducing E. coli adhesion to Caco-2 enterocytes, but it was not able to do so in ex vivo conditions tested for pig jejunal tissue.     

Transport of testosterone and estrogen from dairy-farm waste lagoons to groundwater

Although concentrated animal feeding operations constantly generate physiologically active steroidal hormones, little is known of their environmental fate. Estrogen and testosterone concentrations in groundwater and their distribution in sediments below a dairy-farm wastewater lagoon were therefore determined and compared to a reference site located upgradient of the farm. Forward simulations of flow as well as estrogen and testosterone transport were conducted based on data from the sediment profile obtained during drilling of a monitoring well belowthe dairy-farm waste lagoon. Testosterone and estrogen were detected in sediments to depths of 45 and 32 m, respectively. Groundwater samples were directly impacted by the dairy farm, as evidenced by elevated concentrations of nitrate, chloride, testosterone, and estrogen as compared to the reference site. Modeling potential transport of hormones in the vadose zone via advection, dispersion, and sorption could not explain the depths at which estrogen and testosterone were found, suggesting that other transport mechanisms influence hormone transport under field conditions. These mechanisms may involve interactions between hormones and manure as well as preferential flow paths, leading to enhanced transport rates. These types of interactions should be further investigated to understand the processes regulating hormone transport in the subsurface environment and parametrized to forecast long-term fate and transport of steroidal hormones.     

Selective and effective functionalization of alkanes and cycloalkanes with CO by polyhalomethanes combined with aluminum halides in organic media

Effective and selective transformations of propane, butane, cyclopentane, cyclohexane, methylcyclopentane and adamantane under the action of CO mediated by polyhalomethanes combined with aluminum halides (in the presence of hydride or alkyl (aryl) group donors or without them) resulting in esters, ketones and aldehydes are summarized. This revised version was published online in June 2006 with corrections to the Cover Date.     

Recycled Polyolefin Blends: Effect of Modified Natural Zeolite on their Properties and Morphology

The purpose of this study is to investigate the effect of treated natural zeolite on the flow behavior, morphology, thermal, and mechanical properties in recycled polyolefin blends. A model polymer blend consisting of 95 wt% polyolefines and 5 wt% polystyrene was studied. Compositions from this recycled blend and dehydrated zeolite in a narrow concentration range (0–5 wt%) were treated with maleic anhydride-grafted polypropylene and initiator dicumyl peroxide. The compositions were characterized by capillary rheometry, wide-angle X-ray scattering, differential scanning calorimetry, scanning electron microscopy, and mechanical tests. The results show a compatibilizing effect of treated zeolite expressed by increase of shear viscosity and improvement of interfacial interactions and impact strength. The results can open wide possibilities for utilization of treated zeolite in recycling of unsorted polymer wastes.     

Mid-infrared luminescence properties of Dy-doped silver halide crystals

The absorption and the kinetics of the emission in the mid-infrared (mid-IR) were investigated in AgCl(x)Br(1-x) crystals doped with Dy(3+) ions. Strong emission bands were detected at 3, 4.4, and 5.5 μm and attributed to the (6)H(13/2)→(6)H(15/2), (6)H(11/2)→(6)H(13/2), and (6)F(11/2)+(6)H(9/2)→(6)H(11/2) transitions. Various optical parameters were calculated for the Dy(3+) doped crystals, using the Judd-Ofelt approximation and the rate equations. The measured results and the calculated parameters indicate that these doped crystals could be used for the development of mid-IR solid-state lasers or mid-IR fiber lasers.     

Sugar fatty acid ester surfactants: Structure and ultimate aerobic biodegradability

Ultimate aerobic biodegradabilities of an array of sugar ester surfactants were determined by International Standards Organisation method 7827, “Water Quality—Evaluation in an Aqueous Medium of the Aerobic Biodegradability of Organic Compounds, Method by Dissolved Organic Carbon” (1984). The surfactants were nonionic sugar esters with different-sized sugar head groups (formed from glucose, sucrose, or raffinose) and different lengths and numbers of alkyl chains [formed from lauric (C₁₂) or palmitic (C₁₆) acid]. Analogous anionic sugar ester surfactants, formed by attaching an α-sulfonyl group adjacent to the ester bond, and sugar esters with α-alkyl substituents were also studied. It was found that variations in sugar head group size or in alkyl chain length and number do not significantly affect biodegradability. In contrast, the biodegradation rate of sugar esters with α-sulfonyl or α-alkyl groups, although sufficient for them to be classified as readily biodegradable, was dramatically reduced compared to that of the unsubstituted sugar esters. An understanding of the relationship between structure and biodegradability provided by the results of this study will aid the targeted design of readily biodegradable sugar ester surfactants for use in consumer products.