Stanovení vitaminu C v doplňcích stravy

The thesis „Determination of Vitamin C in Food Supplements“ is concerned with the comparison of vitamin C concentration levels in effervescent tablets and bulk mixtures stored in tubes with different closures (molecular sieve, silica gel, and the solitary closure) after a certain storage time. Two batches of dietary supplements for adult and juvenile populations were analyzed (Revital vitamin C 500 mg and MaxiVita Kids Multivitamin containing 40 mg of vitamin C). Measurements were taken 6 months after production, then after 10 months and after 14 months of storage. The content of vitamin C was determined by the titration method and high performance liquid chromatography (HPLC). The types of closures, batches of products, individual measurements and methods of vitamin C determination were compared. Based on the measurements, it was found that after some time the concentration of vitamin C decreased significantly. Nevertheless, the type of closure did not significantly affect the vitamin C level in effervescent tablets and bulk mixtures

Studium produkce lakázy vybranými druhy hub

The importance of lignin-degrading fungi and their ligninolytic enzymes has been well appreciated globally, because of their potential use in various industries. This bachelor thesis is focused on study of potential production of extracellular ligninolytic enzymes by brown rot fungi. In the literary review selected strains of brown rot fungi and its most studied ligninolytic enzymes are characterized. The use of laccase in various industries especially food industry are summarized. Activity of ligninolytic enzymes produced by brown rot fungi Laetiporus sulphureus, Serpula lacrymans, Gloeophyllum sepiarium, Phaeolus schweinitzii and Laetiporus montanus during submerged cultivation for 24 days was evaluated. Laccase, lignin peroxidase and manganese dependent peroxidase activities were measured spectrophotometrically. For all enzymes, the highest activity was observed on the 12 day. Selected fungi produced the most lignin peroxidase. Laetiporus sulphureus and Gloeophyllum sepiarium showed the highest values of enzyme activities. It has been found that the enzymatic activity of fungi depends on the geographical location and the specific habitat. Enzyme activities of the same strain taken from different locations were different