Ultrazvučna obrada zobenih i ječmenih posija i njihova primjena u tankom kruhu

master's thesis

• Title (english): Ultrasonic treatment of oat and barley bran and their application in flat bread
• Author: Zrinka Pavišić
• Mentor: Dubravka Novotni (mentor)
• Committee member: Nikolina Čukelj Mustač (predsjednik povjerenstva)
• Committee member: Marko Obranović (član povjerenstva)
• Committee member: Klara Kraljić (član povjerenstva)
• 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: 2022-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Zobene i ječmene posije su nusprodukt obrade žitarica kojima bi se mogao nutritivno obogatiti kruh. Cilj ovog rada bio je odrediti utjecaj ultrazvuka visokog intenziteta na funkcionalna svojstva i enzimsku aktivnost (fitaze i β-glukanaze) u zobenim i ječmenim posijama. Tretman je proveden uranjanjem zvučne sonde u 15 %-tnu suspenziju zobenih i ječmenih posija pri 400 W, 24 kHz i različitim utrošcima specifične energije (100 i 250 J mLˉ¹) te radnim ciklusima (kontinuirani i pulsirajući). U svim ultrazvučno obrađenim uzorcima se smanjila koncentracija fitata, a aktivnost β-glukanaze samo u zobenim posijama. Aktivnost fitaze uzoraka pri nižim utrošcima energije raste kao i aktivnost β-glukanaze ječmenih posija. Ultrazvučna obrada povećava kapacitet zadržavanja vode i bubrenja u vodi te smanjuje udio ukupnih fenolnih spojeva i antioksidacijsku aktivnosti. Dodatak (10 % na masu brašna) zobenih i ječmenih posija ne utječe na fizikalna svojstva tankog kruha, osim na tvrdoću i žvakljivost.

Abstract (english)

Oat and barley bran are by-products of grain processing that could be used to nutritionally enrich the bread. The aim of this thesis was to determine the influence of high-intensity ultrasound on functional properties and enzymatic activity (phytase and β-glucanase) in the oat and barley bran. The treatment was carried out by immersing a sound probe in a 15 % suspension of oat and barley bran at 400 W, 24 kHz with different specific energy consumptions (100 and 250 J mLˉ¹) and operation modes (continuous and pulsating). Phytate concentration decreases in all ultrasound treated samples, while β-glucanase activity decreases only in oat bran. The phytase activity of the samples with lower energy consumption increased as well as the β-glucanase activity in barley bran. Ultrasonic treatment increases the capacity of water retention and swelling in water, while it reduces total phenolic compounds and antioxidant activity. The addition (10 % of flour mass) of oat and barley bran does not affect the physical properties of flat bread, except for its hardness and chewiness.

• Keywords: zobene i ječmene posije; ultrazvuk visokog intenziteta; fitati; fitaza; β-glukanaza
• Keywords (english): oat and barley bran; high-intensity ultrasound; phytate; phytase; β-glucanase
• Language: croatian
• URN:NBN: urn:nbn:hr:159:691595
• 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: 2024-04-24 13:26:50