Utjecaj ultrazvuka visokog intenziteta na fizikalna svojstva, aktivnost polifenol oksidaze i bioaktivni potencijal pšeničnih posija

master's thesis

• Title (english): The influence of high intensity ultrasound treatment on physical properties, polyphenol oxidase activity and bioactive potential of wheat bran
• Author: Gabrijela Šišić
• Mentor: Dubravka Novotni (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Cereal Chemistry and Technology); Zagreb
• Defense date and country: 2019-12-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U svrhu poboljšanja tehnoloških karakteristika pšeničnih posija i utjecaja na senzorsku kvalitetu hrane istražuje se primjena novih metoda obrade hrane, među kojima je i ultrazvuk. Cilj ovog rada bio je ispitati utjecaj različitih uvjeta tretmana ultrazvukom visokog intenziteta na fizikalno-kemijske karakteristike i bioaktivni profil pšeničnih posija (polifenolni spojevi i antioksidacijski kapacitet). Tretman je proveden izravnim uranjanjem ultrazvučne sonde (promjera 22 mm, 400 W, 24 kHZ) u uzorke pri različitim amplitudama (60 – 100 %) i vremenu tretiranja (5 – 15 min). Ultrazvuk visokog intenziteta utjecao je na povećanje vrijednosti kapaciteta zadržavanja vode i bubrenja te na značajno (p<0,05) smanjenje aktivnosti polifenol oksidaze. No, ultrazvučni tretman utjecao je i na smanjenje udjela ukupnih polifenola i antioksidacijske aktivnosti, pri čemu je najmanje smanjenje pokazao uzorak tretiran 10 minuta 80 %-tnom amplitudom.

Abstract (english)

In order to improve the technological properties of wheat bran and their effect on sensory quality of food, the application of new methods of food processing is being explored, including ultrasound. The aim of this study is to investigate the influence of different conditions of high intensity ultrasound treatment on the physical-chemical properties and bioactive profile of wheat bran. The treatment was performed by direct immersion of an ultrasonic probe (400 W, 24 kHZ) into the samples at different amplitudes (60 – 100 %) and treatment time (5 – 15 min). The treated samples and the non-ultrasound control sample determined the physico-chemical characteristics and examined the bioactive profile (polyphenolic compounds and antioxidant capacity) by spectrophotometric methods. High-intensity ultrasound had an impact on increasing the water retention capacity and swelling, and significant (p <0.05) decrease in polyphenol oxidase activity. However, ultrasound treatment also resulted in a decrease of the total polyphenols content and antioxidant activity. The best bioactive profile among the treated samples is the sample treated for 10 minutes with 80% amplitude.

• Keywords: antioksidacijska aktivnost; polifenoli; polifenol oksidaza; pšenične posije; ultrazvuk visokog intenziteta
• Keywords (english): antioxidant activity; high intensity ultrasound; polyphenols; polyphenol oxidase; wheat bran
• Language: croatian
• URN:NBN: urn:nbn:hr:159:755418
• 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: Open access
• Created on: 2019-12-31 10:21:18