master's thesis
Properties of corn extrudates with addition of brewer’s spent grain

Antonio Zečević (2015)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Food Technologies
Sub-department of Carbohydrates Technology
Metadata
TitleSvojstva kukuruznih ekstrudata s dodatkom pivskog tropa
AuthorAntonio Zečević
Mentor(s)Đurđica Ačkar (thesis advisor)
Abstract
Ekstruzija, kao jedinični proces u proizvodnji hrane, bilježi sve veću primjenu i pruža obilje mogućnosti poboljšanja nutritivnih svojstava namirnica. Ekstruzijom se uglavnom procesira hrana bogata škrobom i proteinima, a kao glavna sirovina ističe se kukuruzna krupica te razni dodaci. Cilj ovog rada bio je ispitati utjecaj dodatka pivskog tropa u svrhu obogaćivanja ekstrudiranih proizvoda na bazi kukuruzne krupice te njegov utjecaj na svojstva ekstrudata. Omjeri smjesa (kukuruzna krupica : pivski trop) korištenih u istraživanju su: 95:5, 90:10 i 85:15. Smjese vlažnosti 15% ekstrudirane su pri temperaturnom profilu 135/170/170 °C. Dobivenim ekstrudatima ispitana su fizikalna, termofizikalna i reološka svojstva u odnosu na neekstrudirane uzorke. Dodatak pivskog tropa imao je za posljedicu smanjenje ekspanzijskog omjera i povećanje nasipne mase ekstrudata. Tvrdoća ekstrudata se povećala dodatkom pivskog tropa, dok se s druge strane lomljivost smanjila. Dodatak pivskog tropa uzrokovao je potamnjivanje uzoraka, dok sam proces ekstruzije nije imao preveliki utjecaj na promjenu boje. Indeks apsorpcije vode i indeks topljivosti u vodi znatno su se povećali nakon provedene ekstruzije. Procesom ekstruzije nije značajno promijenjen udio pepela u uzorcima, ali se udio masti smanjio. Dodatak pivskog tropa i proces ekstruzije uzrokovali su smanjenje viskoznosti vrha, viskoznosti pri 92 °C i viskoznosti pri 50 °C te su ekstrudirani uzorci bili manje skloni retrogradaciji.
Keywordsextrusion corn meal brewer’s spent grain
Parallel title (English)Properties of corn extrudates with addition of brewer’s spent grain
Committee MembersDrago Šubarić
Đurđica Ačkar
Jurislav Babić
Borislav Miličević
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Food Technologies
Sub-department of Carbohydrates Technology
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 date2015-05-29
Parallel abstract (English)
Extrusion, as an operation in food production, is being used more often as time goes by and it offers a variety of possibilities for improvement of the nutritional properties of food. Foods rich on starch and proteins are mostly being processed via extrusion and corn meal is considered as the main raw material in extrusion cooking technology. The aim of this research was to determine the influence of brewer’s spent grain addition on properties of extruded products based on corn meal. Mixture ratios (corn meal : brewer’s spent grain) used in this study were: 95:5, 90:10 and 85:15. Mixtures with 15% moisture content were extruded at temperature regime 135/170/170 ⁰C. Physical, thermophysical and rheological properties of the obtained extrudates were investigated in relation to non-extruded samples. It was found that with addition of brewer’s spent grain expansion ratio decreased and bulk density of extrudates increased. The hardness of extrudates increased with adding of brewer’s spent grain in mixture, but on the other hand fracturability decreased. Brewer’s spent grain addition caused darkening of the samples, although extrusion didn’t have significant influence on the color. Extrusion also resulted in the increase of water absorption index (WAI) and water solubility index (WSI). While the ash content in samples is slightly changed, fat content is decreased. Addition of brewer’s spent grain and extrusion process caused the reduction of peak viscosity and viscosities at 92 °C and 50 °C, and the extruded samples were less prone to retrogradation.
Parallel keywords (Croatian)ekstruzija kukuruzna krupica pivski trop
Resource typetext
Access conditionOpen access
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:011657
CommitterSanda Hasenay