Utjecaj promjera sonde ultrazvuka visokog intenziteta na stupanj homogenizacije i fizikalna svojstva kravljeg mllijeka

master's thesis

• Title (english): Influence of high intensity ultrasound with different probe diameter on degree of homogenization and physical properties of cow milk
• Author: Kornelija Tot
• Mentor: Mladen Brnčić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Unit Operations); Zagreb
• Defense date and country: 2009-12-17, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog istraživanja bio je ispitati utjecaj promjera sonde (7 i 10 mm) ultrazvuka visokog intenziteta konstantne frekvencije od 24 kHz na stupanj homogenizacije kravljeg mlijeka kao i prikaz utjecaja različitih promjera sonde na fizikalna svojstva kravljeg mlijeka. Praćen je utjecaj na promjenu temperature, pH–vrijednosti i gustoće pri slijedećim procesnim parametrima: amplituda (A = 20, 60, 100 %); vrijeme obrade (t = 2, 6, 10, 15 minuta); primijenjeni ciklus (c = 0,6; 0,8; 1). Dobiveni rezultati statistički su obrađeni pomoću programskog paketa „Statistica 8“. Mikroskopske slike masnih globula obrađene su „Image J“ softverom i veličina masnih globula prikazana je Log–N distribucijom. Utjecaj promjera sonde i procesnih parametara prikazani su Pareto dijagramom (ANOVA). Utjecaj promjera sonde pokazuje značajan utjecaj na sva fizikalna svojstva osim gustoće. Povišenjem amplitude i vremena pokazuje značajan utjecaj na varijancu (stupanj homogenizacije).

Abstract (english)

Main goal of this research is analysis of the influence of probe diameters (7 and 10 mm) of the high-intensity ultrasound with constant frequency (24 kHz) on degree of homogenization of cow milk. Influence of different probe diameters on physical properties of the cow milk is also tested. Changes in temperature, pH value and density were measured under following conditions: amplitude (A = 20, 60 and 100 %); processing time (t = 2, 6, 10 and 15 minutes); applied cycle (c = 0.6, 0.8 and 1). Obtained results are processed in the Statistica 8 software. Microscopic images of fat globules are edited in ImageJ software, while size of the fat globules was represented with Log-N distribution. Influence of probe diameter and process parameters is shown in Pareto graphs (ANOVA). Changes in probe diameter have significant influence on the all physical properties except milk density. With increase of the amplitude and time, significant influence on variance (degree of homogenization) is observed.

• Keywords: ultrazvuk; homogenizacija; kravlje mlijeko; fizikalna svojstva
• Keywords (english): ultrasound; homogenization; cow milk; physical properties
• Language: croatian
• URN:NBN: urn:nbn:hr:159:616357
• 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: 2017-08-31 12:26:46