| Abstract | Majoneza je polukruta emulzija tipa ulje/voda dobivena od jestivog biljnog ulja, žumanjaka
jajeta, octene i/ili druge jestive organske kiseline, šećera, aditiva, sa ili bez začina. Poznavanje
reoloških svojstava značajno je pri kreiranju željene konzistencije majoneze, u kontroli
kvalitete tijekom proizvodnje, skladištenja i transporta. Cilj ovog rada bio je ispitati utjecaj
različitih vrsta biljnih ulja i njihovih kombinacija, vrste ugljikohidrata i žumanjaka jajeta na
reološka svojstva majoneze tijekom skladištenja. Za ispitivanje korištene su različite vrste
biljnih ulja: suncokretovo ulje, orahovo ulje, laneno ulje i ulje kukuruzne klice te kombinacija
dvije vrste ulja različitog omjera. Za ispitivanje utjecaja vrste ugljikohidrata na reološka
svojstva majoneze primjenjivana je glukoza, fruktoza, laktoza, maltoza i trehaloza. Žumanjak
jajeta korišten je kao svježi, pasterizirani, u prahu te kombinacija u prahu i svježi žumanjak
(30:70). Majoneze sa 75% uljnom fazom izrađene su po tradicionalnoj recepturi bez dodanog
konzervansa čime je trajnost proizvoda vremenski ograničena. Mjerenja reoloških svojstava
majoneza provedena su na rotacijskom viskozimetru s koncentričnim cilindrima pri
temperaturama 10 °C i 25 °C na dan proizvodnje te nakon skladištenja 14 dana u hladnjaku. Iz
dobivenih podataka izračunati su reološki parametri koeficijent konzistencije, indeks tečenja i
prividna viskoznost majoneza. Iz navedenih rezultata može se zaključiti da majoneze
pokazuju ne-Newtonvska pseudoplastična svojstva sa manje ili više izraženom površinom
tiksotropne petlje. Uzorci majoneze pokazuju različita reološka svojstva u ovisnosti od vrste
biljnih ulja i njihovom udjelu u uljnoj fazi. Dodatak trehaloze dovodi do veće vrijednosti
koeficijenta konzistencije i prividne viskoznosti majoneze u odnosu na primjenu drugih
ugljikohidrata. Primjena svježeg žumanjka jajeta kod izrade majoneze dovodi do većeg
koeficijenta konzistencije i prividne viskoznosti, a manjeg indeksa tečenja. |
| Abstract (english) | Mayonnaise is semirigidemulsion made of water/oil which is prepared with
refined plant iol, egg yolk, vinegar or other edible organic acid, sugar, aditive, with or
without flavours. Rheological properties make an important factor in production wanted
consistency of mayonnaise, in control quality during of production, storage and
transportation.
The objective of this work was to investigate te various of plants oils and theirs
combinations, various carbihidrates and egg yolk on rheological properties and
acceptability mayonanise during storage.
Sunflower oil, walnut oil, linseed oil , corn oil and combination two various of oil in
different part are used.
Glukose, fructose, lactose, maltose and trehalose were added to determinate the effect of
different carbohidrate types on rheological properties of mayonnaise. Egg yolk werw
used lake fresh, pasteurization, powder and combination powder egg yolk and fresh yolk
(30:70). Tradicional recipes werw followed in the making of the mayonnaises with 75%
oil phases, and no preservatves were added, resulting no limited product durability.
The rheological properties of the mayonnaise were measured on a concetrc cylinder
rotatinal viscometer at the temperature 10 °C i 25 °C on the same day when the
mayonnaise were made, and again after they had been refrigerated for 14 days.
The rheological parameters of consisting coefficient, flow behaviour indeks and apparent
viscosity of mayonnaise were computed from the dana thus obtained. The acceptability of
four chosen samples was analized by using a nine-point verbal hedonic scale.
All mayonnaise samples showed non-Newtonian, pseudoplastic flow with different area
of thixotropy loop.The saples of mayonnaise are shown different rheological properties in
correlation of various plants oils and part of oil phases. Compared to other carbohidrates
added to mayonnaise, the addition of trehalose resulted in the better paste consistency and
apparent viscosity. Using fresh egg yolk improved mayonnaise beter paste consistency
and aparent viscosity, and lower flov behaviour indeks. Compared to other various plants
oils the addition of corn oil resulted in the best acceptability of mayonnaise. |
