V zadnjih letih se povečuje zanimanje za uživanje ječmena in ovsa zaradi številnih pozitivnih učinkov na zdravje, ki jih gre pripisati zlasti topni prehranski vlaknini (vključno z beta-glukani) in antioksidantom. Heterogena sestava zrna omenjenih žit omogoča pripravo mlevskih frakcij z različnimi tehnikami mletja in frakcioniranja, ki imajo povečano vsebnost bioaktivnih snovi. V magistrski nalogi smo poskušali z mletjem ječmena in ovsa z mlinom na kamen, v kombinaciji s separacijo mlevskih frakcij po velikosti, pridobiti moke z različno sestavo hranilnih in bioaktivnih snovi. Sprva smo optimizirali pogoje mletja za čim večji delež in donos frakcij bogatih z beta-glukani. V pridobljenih frakcijah ječmena smo določili še vsebnosti topne in netopne prehranske vlaknine, beljakovin, lipidov, pepela in antioksidantov ter potrdili velike razlike. Največji delež materiala predstavljajo delci manjših velikosti, ki so bogati s škrobnimi polisaharidi in vsebujejo manj prehranske vlaknine in pepela od izhodne moke. Delci srednjih velikosti (~20 % materiala) so obogateni z beta-glukani, kjer so deleži več kot podvojeni glede na izhodno moko. Frakcija največje velikosti (~10 % materiala) pa ima visok delež antioksidantov in pepela. Podobno razporeditev v vsebnosti beta-glukanov in pepela smo pokazali tudi po mletju ovsa, kjer so zaradi bolj grobega mletja razlike med frakcijami manj očitne. Tako smo pokazali, da lahko z relativno enostavno metodo mletja in frakcionacije ječmena in ovsa pridobimo moke različnih lastnosti in veliko dodano prehransko vrednostjo. In recent years, there has been an increasing interest in barley and oats consumption, stemming from a number of positive health effects, which originate primarily from water-soluble dietary fibers (including beta-glucans) and antioxidants. The heterogeneous composition of the cereals grains enables the preparation of milled fractions with various milling and fractionation techniques that contain an increased content of bioactive substances. In master's thesis we tried to obtain flour with different compostition of nutrients and bioactive substances by grinding barley and oats with a stone mill and seperating milled fractions by size. We have also determined soluble and insoluble dietary fiber, proteins, lipids, ash and antioxidants in the obtained barley fractions and confirmed great differences. The majority of the material is represented by small particles, that are rich in starch polysaccharides and contain less dietary fiber and ash than the whole grain flour. Medium sized particles (~20% of the material) are enriched with beta-glucans, with proportions more than doubled relative to the whole grain flour. The largest fractions (~10% of the material) contain a high proportion of antioxidants and ash. A similar distribution in the beta-glucans and ash content was also evident after milling of oats, where the differences between the fractions are less obvious, due to a more coarse grinding. In this work we have shown, that with the relatively simple method of grinding and fractionation of barley and oats, we can obtain flour of various properties and a high added nutritional value.
