Utjecaj ultrazvuka na taloženje proteina u slatkoj sirutki nakon toplinske obrade

master's thesis

• Title (english): Influence of ultrasound on protein precipitation after heat treatment in sweet whey
• Author: Marina Marinčić
• Mentor: Rajka Božanić (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: 2017-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj rada bio je ispitati utjecaj ultrazvuka visokog intenziteta primjenom sondi različitih promjera (12,7 mm, 19 mm i 22 mm) na taloženje proteina u slatkoj sirutki. Sirutka je tretirana s 2 različita režima ultrazvuka 20kHz/8min/40% i 20kHz/5min/60% nakon čega su uzorci toplinski obrađeni pri 72 °C/20 s ili 95 °C/5 min te analizirani. Osim određivanja količine taloga i senzorske analize, praćena jekiselost (pH, °SH), distribucija veličine čestica te boja. Prema dobivenim rezultatima zaključeno je da ultrazvuk ima pozitivan utjecaj na smanjenje količine nastalog taloga u sirutki nakon toplinske obrade. Promjer sonde značajno utječe na efikasnost primijenjenog ultrazvučnog režima, kao i na senzorske karakteristike tretiranih uzoraka sirutke. Najbolji rezultati postignuti su tretiranjem sondom od 19 mm i režimom 20kHz/8min/40% te pasterizacijom pri 72°C/20s (postotak smanjenja taloga 59,09%) s obzirom na to da su postignuta zadovoljavajuća senzorska svojstva tretirane sirutke.

Abstract (english)

The purpose of this study was to examine influence of high intensity ultrasound with different probe diameters on protein percipitation in sweet whey. Whey samples were treated with ultrasound with two different treatmants 20kHz/8min/40% and 20kHz/5min/60% and three different probe diameters of 12,7 mm, 19 mm and 22 mm. After the ultrasound treatment, whey samples were treated with heat 72 °C/20s or 95 °C/5min. Despite protein percipitation and sensory characteristics, pH, °SH, particle size and color were examined. According to results, ultrasound has positive influence on reduction of protein percipitate after heat treatment. Probe diameter has huge influence on efficiency of ultrasound treatment as well as sensory characteristics. Considering good sensory characteristic the best results were achieved with probe diameter19 mm and ultrasound treatment 20kHz/8min/40% and pasteurization 72 °C/20 s (percentage of sediment reduction 59,09%).

• Keywords: sirutka; ultrazvuk; proteini sirutke; talog
• Keywords (english): whey; ultrasound; whey proteins; percipitate
• Language: croatian
• URN:NBN: urn:nbn:hr:159:866683
• 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: 2017-11-13 10:16:50