Utjecaj obrade ultrazvukom visokog intenziteta na fizikalna svojstva kukuruznog škroba

master's thesis

• Title (english): Influence of high-intensity ultrasound on functional properties of con starch
• Author: Petra Cerovec
• Mentor: Zoran Herceg (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Food Processes Engineering); Zagreb
• Defense date and country: 2008-05, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Cilj ovoga rada bio je ispitati utjecaj ultrazvuka visokog intenziteta (100 i 300 W/cm2), frekvencije 24 kHz, na reološka, teksturalna te fizikalna svojstva kukuruznog škroba (mutnoća, kapacitet bubrenja i indeks topljivost). Ispitivanjem reoloških svojstava utvrđeno je da sve suspenzije pokazuju nenewtonski karakter. Vidljive su znatno veće vrijednosti prividne viskoznosti nativnog škroba u odnosu na modificirane otopine kukuruznog škroba tretirane ultrazvukom. Ispitivanjem svojstva želatinizacije utvrđeno je da je obrada ultrazvukom utjecala na maksimalni viskozitet kod modelnih otopina kukuruznog škroba. Maksimalna viskoznost, mjerena Micro Visco-Amylo-Graph-om, najveća je bila nakon 30 minutnog tretiranja ultrazvukom snage 100 W/cm2. U radu je ispitivan i utjecaj djelovanja ultrazvuka na mutnoću suspenzija. Povečanjem snage ultrazvuka na suspenzije kukuruznog škroba povečavao se kapacitet bubrenja u odnosu na nativne suspenzije Čvrstoća kukuruznih škrobnih gelova rasla je nakon obrade gelova ultrazvukom, i to najviše kod onih tretiranih 300 W/cm2 15 minuta ultrazvukom visokog intenziteta.

Abstract (english)

The aim of this project was to evaluate influence of high-intensity ultrasound (100 and 300 W/cm2), at frequencies of 24 kHz, on reologhical, textural and physical properties of corn starch (turbidity, swelling power and solubility). By examing rheological properties of starch suspensions it has been established that all suspensions had non-Newtonian characteristics. Native corn starch suspension showed the higher viscosity then modified starches treated with high-intensity ultrasound. By examing properties of gelatinization it has been established that high-intensity ultrasound treatment had influence on maximal viscosity model suspensions corn starch. The highest maximal viscosity, measaured using Micro Visco-Amylo-Graph, was noted for suspension treated with ultrasound power 100 W/cm2 for 30 minutes. The influence of ultrasound on turbidity was also examined. As power of ultrasound treatment on suspensions growth, swelling power increased in relation with native suspensions. Hardness of corn starch gels increased after treatment with high-intensity ultrasound and it was highest for gels treated with ultrasound power of 300 W/cm2 for 15 minutes.

• Keywords: ultrazvuk; kukuruzni škrob; funkcionalna svojstva; reološka svojstva; teksturalna svojstva
• Keywords (english): ultrasound; corn starch; functional properties; rheological properties; textural properties
• Language: croatian
• URN:NBN: urn:nbn:hr:159:294478
• Study programme: Title: Biotechnology; specializations in: Biochemical Engineering; Course: Biochemical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo (diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-01 13:08:18