Teresa Fortuna

Phenolic profile and antioxidant activity in selected seeds and sprouts.

The aim of this study was to investigate the effect of germination on the phenolic acids and flavonoids profile, as well as antioxidant activity (AA), in selected edible seeds of mung beans, radish, broccoli and sunflower. Germination increased the total phenolic (TP) and flavonoid (TF) levels, as well as the AA of the seeds, and influenced the profile of free and bound phenolic compounds. Among the samples, mung bean was characterised by lowest levels of TP and TF, as well as AA, evaluated using ABTS, DPPH and FRAP assays. Sunflower and radish sprouts were the most rich in phenolic compounds. Insignificant amounts of free phenolic acids were found in the free phenolic acid fraction; alkaline hydrolysis of the seeds and sprouts extracts provided the majority of the phenolic acids. The amounts of free and bound flavonoids were inconsiderable both for seeds and sprouts.

Characteristics of cereal starch granules surface using nitrogen adsorption

Abstract Surfaces of several types of cereal starch granules are investigated using low-temperature nitrogen adsorption. The specific surface, the volume of mesopores and the mean pore diameter are determined using the BET method. Furthermore, pore size distribution, cumulative surface area, volume and mean pore diameter in the range 1.7–300 nm are determined using the BJH method. Surface characteristics and pore characteristics for various cereal starch granules are found to be different.

Effect of temperature and soluble solids content on the viscosity of beetroot (Beta vulgaris) juice concentrate.

The study investigates the viscosity of clarified beetroot juice as dependent on temperature and soluble solids content. Rheological research was carried out using a rotational rheometer with a system of coaxial cylinders. Flow curves were obtained in the temperature range from 10 to 60°C and at the soluble solids content of 50° to 67.1°Bx. The concentrate under study showed a Newtonian behaviour. Dynamic viscosity ranged from 5.2 to 320 mPa·s and depended on soluble solids content and temperature of measurement. The effect of temperature was described using an Arrhenius equation. Activation energy values were between 24.68 and 39.96 kJ/mol. The effect of soluble solids content was described employing a power-law function and an exponential function. In addition, two equations were proposed to describe the combined effect of temperature and soluble solids content on the viscosity of beetroot juice concentrate.

Effect of Some Hydrocolloids on the Rheological Properties of Rye Starch

The effect of three non-starch hydrocolloids (guar, carob and arabic gums) on some rheological properties of rye starch pastes/gels at a constant 6.5% concentration of polysaccharides was determined throughout: (i) pasting characteristics, (ii) flow curves and apparent viscosity–shear time curves at 50 C and (iii) mechanical spectra at 25 C. The presence of gums in the system modified the rheological properties of rye starch pastes/gels and these alterations depended on the type and concentration of the gum. The systems with guar and carob gums exhibited higher apparent viscosities during pasting and higher shear stresses during flow than the paste of native starch. The viscosity of the system with carob was bigger than the one with guar gum. The presence of arabic gum decreased the apparent viscosity of the system both during pasting and during flow. Replacing part of starch with a gum modified the viscoelastic properties of gels, the changes depended on the kind and concentration of the gum.

Effect of mineral elements on physicochemical properties of oxidised starches and generation of free radicals

The objective of this study was to determine the effect of enrichment of oxidised starches with mineral compounds on their physicochemical properties and capability for free radical generation. Potato and spelt wheat starches were oxidised with sodium hypochlorite and, afterwards, modified with ions of potassium, magnesium and iron. The modified starches were analysed for: content of mineral elements, colour parameters (L*a*b*), water binding capacity solubility in water at temperature of 50 and 80 °C, and susceptibility to enzymatic hydrolysis with α-amylase. In addition, thermodynamic characteristics of gelatinisation was determined by differential scanning calorimetry (DSC), and the number and character of thermally generated free radicals was assayed using electron paramagnetic resonance (EPR). Based on the results achieved, it was concluded that the quantity of incorporated minerals and changes in the assayed physicochemical parameters depended not only on the botanical type of starch but also on the type of the incorporated mineral element.

Characterization of Polish Wines Produced from the Multispecies Hybrid and Vitis vinifera L. Grapes

Phenolic profile, antioxidant activity, and color parameters of Polish wines, produced from the multispecies hybrid and Vitis vinifera L. grapes were analyzed. A principal component analysis was applied, in order to differentiate the investigated wines in terms of content of phenolic compounds. The white wines turned out to be similar to each other in terms of color parameters and the results of principal component analysis, while the red wines strongly differed in this respect. However, the white wine produced from the multispecies hybrid grapes contained a higher level of phenolic acids and flavonoids, as compared to the white wines obtained from the hybrid cultivars. Out of the red wines, Rondo wine, produced from the multispecies hybrid grapevine was the richest in total phenolic and phenolic acids content. Caffeic acid and quercetin were the predominant phenolics in majority of the wines tested.

Effect of Maltodextrins on the Rheological Properties of Potato Starch Pastes and Gels

The study examines the effects of maltodextrins saccharified to various degrees on some rheological properties of potato starch dispersions. Pasting characteristics, flow curves, and mechanical spectra were determined for native potato starch and for its blends with potato maltodextrins having dextrose equivalents (DE) of 10.5, 18.4, and 26.5. The results showed that medium-saccharified maltodextrin (DE = 18.4) gave the strongest effect, manifesting itself as a considerable reduction in the viscosity at pasting, a decrease in apparent viscosity during flow, and a decrease in the storage and loss moduli. Addition of high-(DE = 26.5) or low-(DE = 10.5) saccharified maltodextrins had a markedly smaller effect on the rheological properties of starch. The differences in the effects produced by the maltodextrins are closely connected to the degree of polymerisation of the maltooligosaccharides in the systems.

Effect of Sweeteners on Radical Formation in Starch Studied by Electron Paramagnetic Resonance Spectroscopy

The process of radical generation occurring upon thermal treatment of potato and corn starch containing sweeteners: saccharose, acesulfam K, aspartame, and sorbitol was investigated by electron paramagnetic resonance spectroscopy, using Cu2+ ions as a paramagnetic probe. It was found that the influence of acesulfam K and sorbitol on radical formation is stronger than that of other additives. Acesulfam K increased the amount of radicals in the starch compared to native starch, whereas sorbitol significantly decreased their concentration. The influence of sweeteners on radical processes in the starch is because of differences in their molecular structures and presence or absence of OH groups.

PHYSICOCHEMICAL QUALITY OF SELECTED STRAWBERRY JAMS WITH FRUCTOSE

Four different commercially available strawberry jams with fructose were characterized in relation to acidity and reducing sugar, ash, micro- and macroelement contents. The results showed that the jams differed in active and total acidity, ash, as well as reducing sugar content. Differences between the jams were more pronounced for microelements than for macroelements. doi:10.5219/46

Phenolic Profile and Antioxidant Activity of Polish Meads

The purpose of this study was to evaluate phenolic profile and antioxidant activity of ten different meads of 1:1 and 1:2 types, produced with addition of fruit juices, root spices, and herbs. The total phenolic content in meads varied from 15.27 to 70.80 mg/dm3. The meads originated from dark honeys exhibited the highest antioxidant activity. The predominant phenolic compounds in meads were hydroxybenzoic acids, especially gallic and protocatechuic acid, originated mainly from honeys. Whereas, among the hydroxycinnamic acids, the major phenolic was chlorogenic acid, derived mainly from plant additives used in meads production. A principal component analysis was applied in order to differentiate the investigated meads. The 1:2 meads type could be best described by chlorogenic acid. Among the 1:1 meads type, those made from the dark honeys could be best described by gallic, p-coumaric, and protocatechuic acid while those made with addition of blackcurrant and raspberry juice could be described by caffeic and ferulic acid.