Faculty of Food Technology and Biotechnology, University of Zagreb
Abstract
In this work, creosote bush (Larrea tridentata) leaves and pomegranate (Punica granatum) peels were characterized for their use as a source of antioxidants and a support in solid-state fermentation. This work focuses on the kinetic evaluation of physicochemical changes during the fungal fermentation of two tannin-rich plant materials, mainly on the polyphenolic content. Aspergillus niger GH1 was used in the fermentation processes, the cultures were monitored for 96 h. The content of proteins, crude fibres, lipids, reducing and total sugars was evaluated following the AOAC methods. Tannins were analyzed using a spectrophometric method. Biodegradation of ellagitannins was monitored kinetically and the accumulation of gallic and ellagic acids was determined by HPLC. Results demonstrated that pomegranate peel and creosote bush leaves are excellent supports for solid-state fermentation and sources of antioxidants.U radu je istražena mogućnost primjene lišća grma Larrea tridentata i kore šipka (Punica granatum) kao sirovina za dodatak čvrstim podlogama te proizvodnju antioksidanasa. U središtu je istraživanja kinetička procjena fizikalno-kemijskih promjena tih taninima bogatih sirovina, ističući promjenu udjela polifenolnih spojeva tijekom procesa. Za proces je upotrijebljen soj plijesni Aspergillus niger GH1, koji je praćen tijekom 96 sati. Određen je udio proteina, sirovih vlakana, lipida, te ukupnih i reducirajućih šećera standardnim AOAC metodama, a udio i sastav tanina ispitani su Folin-Ciocalteau metodom. Kinetički je praćena biodegradacija elagitanina, a nakupljanje galne i elagične kiseline utvrđeno je HPLC metodom. Dobiveni rezultati pokazali su da su kora šipka i lišće grma Larrea tridentata izvrsne sirovine za čvrste podloge i dobar izvor antioksidanasa
