Karakterizacija i procjena kvalitete rakija "Biska"

master's thesis

• Title (english): Characterization and quality evaluation of mistletoe spirits
• Author: Maja Rupert
• Mentor: Damir Stanzer (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Fermentation and Yeast Technology); Zagreb
• Defense date and country: 2017-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Moderate and regular consumption of phenolic-containing alcoholic beverages has been associated with health benefits. The aim of this work was to evaluate mistletoe spirits quality and whether they contain polyphenols and have antioxidant activities. The total polyphenol content (TPC) and antioxidant activity were estimated using spectrophotometric methods (Folin-Ciocalteu, DPPH and FRAP). Some spirits have high TPC, DPPH and FRAP antioxidant activities and stimulation of moderate consumption of mistletoe spirit is justified. As analysis of aroma compounds is one of the most important steps in the evaluation of spirit quality, the aroma composition of mistletoe spirits was determinated for the first time, using GC/MS, solid-phase microextraction (SPME). A total number of 166 aroma compounds in mistletoe spirit samples were determinated. FTIR spectra were registered to create calibration models to predict TPC and antioxidant activities in unknown mistletoe spirits. The determination coefficients in calibration and prediction models were greater than 0.8, suggesting strong correlation of predicted parameters based on the FTIR spectra.

Abstract (english)

Umjerena konzumacija alkoholnih pića koja sadrže polifenole povezana je s pozitivnim učincima na zdravlje. Cilj ovog rada bio je procijeniti kvalitetu rakija "Biska" i utvrditi sadrže li polifenole i imaju li antioksidativnu aktivnost. Ukupni polifenoli i antioksidativna aktivnost određeni su spektrofotometrijskim metodama (s Folin-Ciocalteu reagensom, DPPH i FRAP metodom). S obzirom da neki uzorci sadrže visok udjel polifenola i imaju visoku anitoksidacijsku aktivnost, umjerena konzumacija "Biske" je opravdana. Određivanje aroma važan je korak u procjeni kvalitete. U ovom radu po prvi put su određeni spojevi rakija "Biske" koji pridonose sveukupnoj aromi. Koristeći GC/MS SPME metodu, detektirano je 166 spojeva aroma u uzorcima rakije "Biske". Snimljeni su spektri pomoću FTIR-a s ciljem kreiranja modela za brzu procjenu udjela polifenola i antioksidacijske aktivnosti u nepoznatim uzorcima "Biske". Determinacijski koficijenti u primijenjenim modelima bili su viši od 0.8, što dokazuje da su modeli kvalitetni i pouzdani.

• Keywords: mistletoe; spirit; polyphenol; FTIR; aroma
• Keywords (english): Biska; rakija; polifenoli; FTIR; aroma
• Language: english
• URN:NBN: urn:nbn:hr:159:627482
• Study programme: Title: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra nutricionizma (magistar/magistra nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-11-07 10:31:25