Određivanje antioksidacijske aktivnosti u ovčjoj i kozjoj sirutki

master's thesis

• Title (english): The determination of antioxidative activity of acid and sweet whey from sheep's and goat's milk
• Author: Karmela Tretnjak
• Mentor: Katarina Lisak Jakopović (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Milk and Milk Products); Zagreb
• Defense date and country: 2019-07-19, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Sirutka je izvrstan izvor visokovrijednih proteina, ugljikohidrata, vitamina, mineralnih tvari te elemenata u tragovima s niskim udjelom masti. U dostupnoj literaturi ne postoje podaci o karakterizaciji ovčje i kozje sirutke dobivene različitim metodama sirenja mlijeka pa je cilj ovog rada bio odrediti antioksidacijsku aktivnost i profil mineralnih tvari u kiseloj i slatkoj, ovčjoj i kozjoj sirutki, a također i kemijski sastav, tj. udio vlage i pepela te kiselost, boju, veličinu čestica i senzorska svojstva sirutke. Radikal koji se koristio za praćenje antioksidacijske aktivnosti sirutke je 2,2-difenil-1-pikrilhidrazil (DPPH), a metoda elektronska spinska rezonancija (ESR). Antioksidacijska aktivnost se određivala u svježim i pasteriziranim uzorcima sirutke te nakon sedam dana, a rezultati su pokazali da ovčja sirutka ima veću antioksidacijsku aktivnost od kozje. Najveću antioksidacijsku aktivnost ima kisela sirutka dobivena sirenjem mezofilnom kulturom, odnosno sirutka koja inače zaostaje pri proizvodnji svježih sireva.

Abstract (english)

Whey is a very good source of valuable proteins, carbohydrates, vitamins, minerals, trace elements with low-fat content. In available literature there is no data about the characterization of sheep's and goat's whey obtained by different methods of milk coagulation, so the aim of this research was to determine- the antioxidant activity as well as a mineral profile in acid and sweet, sheep's and goat's whey, but also the chemical structure ie. the amount of moisture and ash, acidity, color, particle size and the sensory properties of whey. Radical for detecting the antioxidant activity of whey was 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the used method was electron spin resonance (ESR). Antioxidant activity was determined in fresh and pasteurized whey samples and after seven days, and the results showed that sheep's whey has higher antioxidant activity than goat's whey. The highest antioxidant activity has acid whey obtained by mesophilic culture, i.e. the whey that remains after the production of fresh cheeses.

• Keywords: antioksidacijska aktivnost; DPPH; ESR; kozja sirutka; ovčja sirutka
• Keywords (english): antioxidative activity; DPPH; ESR; goat's whey; sheep's whey
• Language: croatian
• URN:NBN: urn:nbn:hr:159:078758
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2019-12-05 11:49:43