National Repository of Grey Literature 12 records found  previous11 - 12  jump to record: Search took 0.00 seconds. 
Developement and validation of method for ferulic acid isolation from wheat bran
Nábělek, Jakub ; Obruča, Stanislav (referee) ; Pořízka, Jaromír (advisor)
This master thesis deals with an optimization of processes of isolation of ferulic acid from wheat bran. Process of isolation based on alkaline hydrolysis from the substance and its adsorption was tested. In the theoretical part were described wheat bran, adsorption proces and used methods. For adsorption were tested five types of adsorbents. Especially these adsorbents: activation carbon (2,53 ± 1,16 mg.l-1), Amberlyst A-21 (105,73 ± 11,87 mg.l-1, Amberlit XAD-16 (241,55 ± 10,42 mg.l-1), Amberlit IRA-900Cl (5,90 ± 0,68 mg.l-1) and Amberlit IRA-96 (189,16 ± 6,49 mg.l-1). As the most efficient adsorbent was determine Amberlit XAD-16. The whole process has underwent detailed optimization in order to maximize the purity of the final product. The isolate was characterized by HPLC and FTIR techniques for ferulic acid and related phenolic acids. Based on FTIR analysis was discovered that the isolate was contamined by proteins. A purification procedure based on deproteination of the raw material before the hydrolysis itself was proposed. As the ultimate solution that eliminated the presence of proteins in the isolate was determine ultrafiltration with capture of molecules with Mw > 10 KDa. Ferulic acid yield from one kilo of wheat bran was 1,00 ± 0,22 g.
Characterization of different bran species in terms of ferulic acid content
Nábělek, Jakub ; Štursa, Václav (referee) ; Pořízka, Jaromír (advisor)
This bachelor’s thesis works with an alkaline extraction of a ferulic acid from different kinds of cereal bran. Another researched issue was extraction of nutritionally interesting elements extracted from bran and from hydrolysed waste. Those extracts has possible usage as a mineral fertilizer for plants. In the theoretical part, this thesis deals with problematice of cereals, composition and differences in a cereal grain depending on kinds of cereal and an enviromental conditions. Chemical composition of cereal materials, focused on phenolic acids are also described. Another part deals with theoretical background of methods for the extraction of phenolic acids from bran with description of advantages and disadvantages. Methods for alkaline hydrolysis and extraction of minerals from different kind of bran bran are described in experimental part of this work. Sodium hydroxide (0,5 M) was used for the hydrolysis of bran material. For the determination of the yields of ferulic acid, HPLC method with UV/VIS detection at wave-length 330 nm with usage of mobile phase mixture of methanol and 0,5 % solution of formic acid was used. Acidified deionized water was used for the extraction of nutritionally interesting elements from bran and also from the hydrolyzed material. For the determination of the elemental composition of extracts (Cu, Fe, Zn, Mn, P, Ca, K, Mg), ICP-OES method was used. It was found, that differences in wheat bran species in terms of yields of Ferulic acid are satistically important. The biggest yields of ferulic acid was obtained from the sample of spelt. The smallest yields of this acic was obtained from the sample of oat. Content of micro and macro-elements showed statistical important differences in different kinds of bran and their hydrolyzed waste. Most abundand elemets were obtained from rice bran and from spelts hydrolyzate. The smallest abundand elemens were obtaned from oat bran and hydrolyzate.

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