Selected physicochemical, thermal, and rheological properties of starches isolated from new Polish potato varieties were determined. The starches contained 25.7-30.0 g/100 g d.m. of amylose and 59.5-90.2 mg/100 g d.m. of phosphorus. Gelatinization temperatures were 62.6-64.0, 68.9-69.9, and 73.6-77.08C for T O , T P , and T E , respectively, whilst enthalpy of gelatinization amounted to 11.1-15.3 J/g. The retrogradation degree of starch was from 52.90 to 78.53%. Pasting curves showed significant differences between the starches. Peak viscosity and final viscosity ranges were 2035-4458 and 1931-2985 mPa Á s, respectively. Starch pastes exhibited non-Newtonian, shear thinning, and thixotropic behavior. After cooling they demonstrated diversified viscoelastic properties, however, all of them were classified as weak gels. Significant linear correlations among selected rheological parameters and amylose and phosphorus content were found. Results of principal component analysis demonstrated an ability to differentiate the starches isolated from different potato varieties.

The aim of this work was to characterize physicochemical, thermal and rheological properties of starches isolated from malting barley varieties. The analyzed starches contained 19.6-25.2 g of amylose, 42.47-70.67 mg of phosphorus, 0.50-1.26 g of protein and 0.10-0.61 g of fat per 100 g of starch dry mass. The clarity of the 1 % (w/w) starch pastes ranged from 5.4 to 9.8 %. Values of the characteristic gelatinization temperatures were in the ranges of 56.5-58.5°C, 61.2-63.0°C and 66.7-68.7°C, respectively for T O , T P and T E , whereas values of gelatinization enthalpy were from 6.49 to 9.61 J/g. The barley starches showed various tendency to retrogradation, from 24.52 to 44.22 %, measured as R = ΔH R /ΔH G value. The pasting curves showed differences in pasting characteristics of the barley starches, where values of peak (PV) and final (FV) viscosities were 133-230 mPa·s and 224-411 mPa·s, respectively. The barley starch pastes exhibited non-Newtonian, shear thinning flow behaviour and thixotropy phenomenon. After cooling the starch gels showed different viscoelastic properties, however, most of them behaved like weak gels (tan δ = G″/G′ > 0.1). Significant linear correlations between the parameters of pasting characteristic and some rheological parameters were found.

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The aim of the study was to characterize the antioxidant properties; establish the profile of polyphenolic compounds and evaluate the content of tocopherols in walnuts of three varieties (Leopold; Apollo; Resovia) differing in the degree of maturity (harvest date). The profile of polyphenolic compounds was established by UPLC-PDA-ESI-MS. The content of tocopherols was determined by HPLC-FLD. It was found that the content of dry matter and fat increased and the antioxidant properties decreased with the maturation of nuts. Walnuts of the Leopold cultivar harvested in July exhibited the highest content of total polyphenol (2149.08 mg/100 g dry mass). In their polyphenolic profile; 26 compounds were identified; mainly belonging to the class of ellagitannins. The polyphenolic content decreased with the maturation of nuts. The total content of tocopherols in the tested nuts increased with ripening and ranged from 1.76 mg/100g (Apollo VII) to 18.30 mg/100g (Resovia IX)

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