Optimiranje djelotvornosti procesa mikrofiltracije i ultrafiltracije sirutke primjenom keramičkih membrana

doctoral thesis

• Title (english): Optimizing efficiency of whey microfiltration and ultrafiltration by applying ceramic membranes
• Author: Irena Barukčić
• Mentor: Rajka Božanić (mentor); MBZ: 182265
• Committee member: Ljubica Tratnik (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; Zagreb
• Defense date and country: 2013-04-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology
• Universal decimal classification (UDC): 636/637 - Animal husbandry and breeding. Produce of domestic animals and game

Abstract

Mikrofiltracija i ultrafiltracija otvaraju nove mogućnosti iskorištavanja sirutke u prehrambene svrhe. Njihovom primjenom osigurava se mikrobiološka kvaliteta i očuvanje hranjive vrijednosti proizvoda, a glavni nedostatak je pojava začepljivanja membrana. Stoga je svrha ove disertacije optimirati proces mikrofiltracije sirutke kao alternativnog postupka pasterizaciji uz očuvanje nativnih proteina sirutke te ispitati njezin utjecaj kao predtretmana sa ciljem povećanja djelotvornosti ultrafiltracije. Filtracije su provedene pri različitim procesnim temperaturama (20ºC, 40ºC, 50ºC) korištenjem keramičkih membrana različitih graničnih vrijednosti zadržavanja (0,1 μm, 0,5 μm , 0,8 μm, 20 kDa). Izuzetim uzorcima određivana je mikrobiološka kvaliteta te fizikalno kemijska svojstva. Mikrofiltracija primjenom membrana promjera pora 0,5 μm i 0,8 μm pokazala je dobar učinak na očuvanje prehrambene vrijednosti sirutke. Stupanj redukcije prisutnih mikroorganizama opada razmjerno veličini promjera pora primijenjenih membrana. Bez obzira na procesnu temperaturu, membrana od 0,5 μm se pokazala optimalnom u smislu očuvanja hranjive vrijednosti i redukcije pristunih mirkoorganizama. Prema svim praćenim parametrima, ultrafiltracija pri 20°C se pokazala najpovoljnijim režimom za obradu svježe sirutke. Predtretman mikrofiltracijom primjenom membrana promjera pora 0,8 μm nije povećao djelotvornost procesa ultrafiltracije, bez obzira na procesnu temperaturu. Predtretman mikrofiltracijom primjenom membrana promjera pora 0,5 μm povećao je djelotvornost procesa ultrafiltracije, što se očituje prvenstveno u povećanju fluksa permeata i smanjenu formiranih otpora prema začepljivanju. Navedene promjene intenzivinije su pri procesnoj temperaturi od 20ºC.

Abstract (english)

Microfiltration and ultrafiltration enable new opportunities of whey utilization in human nutrition. The implementation of these processes ensures appropriate microbiological quality and the preservation of the nutritional value of the product. The main disadvantage is the phenomenon of membrane fouling. The aim of this dissertation was to optimize the process of whey microfiltration in order to ensure aduequate micorbiological quality, to preserve the native whey proteins and to be tesetd as a pretreatment for enhancement of the ultrafiltration process. The filtrations were performed at different process temperatures (20ºC, 40ºC, 50ºC) by using ceramic membranes with different cut-offs (0,1 μm, 0,5 μm , 0,8 μm, 20 kDa). All samples of whey were analized for microbiological quality, physical and chemical properties. Microfiltration by ceramic membranes with mean pore diameter of 0,5 μm and 0,8 μm allowed preservation of the native wehy proteins. Microbial reduction rates decreased proportionally with the mean pore diameter of the used membranes. Regardless the process temperature, the membrane with mean pore diameter of 0,5 μm appeared to be optimal for purposes of preserving the nutritional value and achieveing proper micribiological quality of whey. According to all measured parameters, ultrafiltration process at 20ºC appeared to be the most appropriate for whey processing. Microfiltration of whey by ceramic membrane with the mean pore diameter of 0,8 μm didn´t significantly affect the efficiency of the ultrafiltration, regardless the process temperature. Microfiltration of whey by ceramic membranes with the mean pore diameter of 0,5 μm affected the efficiency of whey ultrafiltration by siginificantly increasing the permeate flux and reducing the fouling resistance. The described effects are more intensive at the process temperature of 20ºC.

• Keywords: sirutka; mikrofiltracija; ultrafiltracija; keramičke membrane; djelotvornost; začepljivanje; mikrobiološka kvaliteta
• Keywords (english): whey; microfiltration; ultrafiltration; ceramic membranes; efficiency; fouling; microbiological quality
• Language: croatian
• URN:NBN: urn:nbn:hr:159:423690
• Promotion: 2013-09-22
• Study programme: Title: Food Technology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti (doktor/doktorica znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2018-05-17 10:09:15