Antioxidant enzymes in barley green biomass.

Green biomass of young barley plants exhibited statistically significant higher activity of superoxide dismutase (SOD) and catalase (CAT) at sampling I (in the phase of plant development DC 29) compared to the later sampling II (DC 31). Significant effects of varieties, years and interactions of the studied factors on the activity of the studied antioxidants were determined. During the experiment period (2005-2007), the variety Sebastian provided statistically significant higher average SOD activity (486 U.g-1) versus the variety Malz (416 U.g-1 dry matter) and line KM1910 (418 U.g-1 dry matter). No statistically significant difference was recorded between the latter two varieties. Average catalase activity of the varieties did not show any significant difference. Significantly higher CAT activity in the sampling I was recorded on average of years and locations in the variety Sebastian and hull-less line KM1910 (935 and 907 U.g-1) compared to the variety Malz (675 U.g-1). We can state that green biomass of young spring barley plants taken during the growth phase DC 29 was a significant source of enzymes catalase and superoxide dismutase in the course of the experiment (2005-2007).

Changes caused by genotype and environmental conditions in beta-glucan content of spring barley for dietetically beneficial human nutrition.

Over the 5-year period (2000-2004), a significantly higher beta-glucan content was detected in the waxy varieties Washonubet, Wabet, and Wanubet (6.8-7.6%) and lines formed by crossing these varieties with malting varieties (5.8-7.1%). Conversely, the non-waxy hulled malting-type varieties Kompakt (4.0%) and Krona (4.3%) had significantly lower contents of beta-glucan. The observations also showed that concentrations of beta-glucans in 2000-2004 were significantly affected not only by varieties, but also environmental conditions in the growing periods and interactions of these two factors. Higher precipitation during the flowering time and grain filling period and lower temperatures during the flowering time in 2002 had negative effects on concentration of beta-glucans. Conversely, drier and warmer weather in 2003 enhanced the content of beta-glucans. The results show that it is possible to increase the content of beta-glucan in spring barley grain by implementing selective breeding practices. Compared to the parental malting varieties, the mean content of beta-glucans in F(4)-F(8) generations was increased by 1.8 and 2.0% by recombination in lines Kompakt x Wabet and Wanubet x Krona, respectively. Significant effect of environmental conditions and their interactions with varieties indicated the necessity to assess standard qualities of barley as a food material.

Effect of cultivar, year grown, and cropping system on the content of tocopherols and tocotrienols in grains of hulled and hulless barley.

In a three-year period (2000-2002) total tocols (tocopherols and tocotrienols), content of vitamin E and its isomers (alpha-, beta+gamma-, delta-tocopherols and tocotrienols) were assessed in grain of 13 barley genotypes. The highest content of tocols (60.3-67.6 mg kg(-1)) and content of vitamin E (Vitamin E equivalent-18.0-20.1 mg kg(-1)) were determined in the waxy varieties Wanubet, Wabet, and Washonubet. Standard varieties, i.e. of a malting type (Krona and Kompakt), had statistically significantly lower content of tocols (49.9 and 53.6 mg kg(-1)) and vitamin E (15.7-16.1 mg kg(-1)) compared to the waxy varieties. The hulless waxy variety Washonubet had statistically significantly higher total content of tocols (67.6 mg kg(-1)) and alpha- tocotrienols isomer (42.1 mg kg(-1)) versus all other genotypes in the set. Chemical treatment and fertilization statistically significantly increased the content of tocols (by 4.7 mg kg(-1)), vitamin E (by 1.9 mg kg(-1)), isomer alpha-tocopherol (by 0.9 mg kg(-1)) and isomer alpha- tocotrienols (by 3.3 mg kg(-1)). The average values of alpha-tocopherols and alpha-tocotrienols in the set were 6.7 mg kg(-1) and 29.7 mg kg(-1), respectively. Some of the reciprocal lines created by us from the malting and waxy varieties are suitable for food use for high contents of all tocopherols and alpha-tocotrienols.