Evaluation of barley grass as a potential source of some nutritional substances

Barley green matter was analysed for the contents of vitamin C, total polyphenols, phenolic compounds, proteins, amino acids, and saccharides; the activity of catalase was also determined. The contents of vitamin C, total polyphenols, and ferulic acid decreased with the age of barley plants. The influence of the variety has not been proved unequivocally. The contents of vitamin C between 0.107-6.357 g/kg DM, of total polyphenols between 17.167-35.559 g/kg DM, and of ferulic acid between 0-5.916 g/kg DM were found. Catalase activity amounted to 4.5-29.7 TSU. The monosaccharide profile showed high contents of glucose (15.40-88.40 g/kg DM) and fructose (37.60-81.40 g/kg DM) which decreased with the plant growth. The contents of saccharose and galactose were low, ranging between 0-7.70 g/kg DM and 3.70-5.30 g/kg DM, respectively. The relations between their contents and the growth phase were insignificant. The total amino acid content decreased with the plant age. High contents of aspartic (15.232-28.682 g/kg DM) and glutamic acids (16.694-35.526 g/kg DM), as well as minimal contents of sulphur amino acids, especially methionin (2.586-5.03 g/kg DM), could be noted. The highest catalase activity was found in the early growth phase (18.5-35.1 TSU), being higher in all samples grown at the location Kromeriz. The yield of juice pressed out from frozen green matter amounted to 68%. The pressed out juice was preserved by fluid drying, freeze drying, and freezing. In respect to folates and total polyphenols contents and the antioxidant activity, freezing appears the most suitable procedure for preserving.