master's thesis
Influence cold pressing walnut on utilization of oil and rheological properties spread of walnut johnnycake

Diana Foruglaš (2016)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Food Technologies
Sub-department of Food Engineering
Metadata
TitleUtjecaj hladnog prešanja oraha na iskorištenje ulja i reološka svojstva namaza od orahove pogače
AuthorDiana Foruglaš
Mentor(s)Tihomir Moslavac (thesis advisor)
Abstract
U ovom radu istraživan je utjecaj procesnih parametara hladnog prešanja oraha na iskorištenje orahovog ulja. Prešanje jezgre oraha provedeno je na laboratorijskoj kontinuiranoj pužnoj preši. Prilikom prešanja mijenjani su procesni parametri: nastavak za izlaz pogače, temperatura glave preše i brzina pužnice. Nakon prešanja provedeno je prirodno taloženje i vakum filtracija sirovog ulja. Primjenom standardnih metoda određeni su osnovni parametri kvalitete proizvedenog ulja: peroksidni broj, slobodne masne kiseline, udio netopljivih nečistoća te udio vlage. Također, cilj ovog rada je ispitati utjecaj sastojaka na reološka svojstva namaza od orahove pogače. Mjerenja reoloških svojstva su provedena na rotacijskom viskozimetru s koncentričnim cilindrima pri temperaturi od 60 ˚C. Iz dobivenih podataka su izračunati reološki parametri namaza: indeks tečenja, prividna viskoznost i koeficijent konzistencije. Dobiveni rezultati ukazuju da ispitivani procesni parametri prešanja oraha utječu na iskorištenje ulja. Također, iz rezultata može se zaključiti da namaz od orahove pogače pripada ne-Newtonskim sustavima. Veća viskoznost namaza se postiže dodatkom kakao praha, dok manju viskoznost ima namaz od jezgre oraha. Manja se viskoznost namaza postiže sa smanjenjem uljne faze.
Keywordsoil walnut oil cold pressing spread of walnut johnnycake reological properties
Parallel title (English)Influence cold pressing walnut on utilization of oil and rheological properties spread of walnut johnnycake
Committee MembersVedran Slačanac (committee chairperson)
Tihomir Moslavac (committee member)
Stela Jokić (committee member)
Jurislav Babić (committee member)
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Food Technologies
Sub-department of Food Engineering
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Engineering
Study programme typeuniversity
Study levelgraduate
Study programmeFood Engineering
Academic title abbreviationmag. ing. techn. aliment.
Genremaster's thesis
Language Croatian
Defense date2016-10-10
Parallel abstract (English)
In this thesis author researches the influence of process parameters of cold pressing walnut on utilization of walnut oil. The pressing of walnut core was conducted on a laboratory continuous worm screw press. During pressing following process parameters varied: johnnycake output extension, press head temperature and cochlea frequency. After pressing, natural sedimentation was conducted and vacuum filtration of crude oil. Walnut oil quality parameters were determined applying standards methods: peroxide number, free fatty acids, the proportion of insoluble impurities and moisture. Second goal of this thesis is to examine the influence of ingredients to the reological properties of spread walnut johnnycake. Measurements on reological properties were conducted on rotation viscosimeter with circular cylinder at a temperature of 60 ˚C. From conducted experiment following reological butter parameters were calculated: flow index, apparent viscosity and consistent coefficient. The results showed that the studied process parameters pressing walnut affect utilization of oil. From obtained data, it is possible to conclude that spread belongs to non-Newtonian systems. Greater viscosity was gained by cocoa powder, while walnut core has lower viscosity. With reduction in the oil phase you achieve lower viscosity of spread.
Parallel keywords (Croatian)ulje orahovo ulje hladno prešanje namaz od orahove pogače reološka svojstva
Resource typetext
Access conditionOpen access
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:077009
CommitterIvana Šuvak