Influence of components and homogenisation on rheological properties of salad mayonnaise with addition of pumpkin puree

Reološka svojstva važan su parametar kvalitete majoneze. Poznavanje reoloških svojstava značajno je pri kreiranju željene konzistencije majoneze, u kontroli kvalitete tijekom proizvodnje, skladištenja i transporta. U ovom radu istraživan je utjecaj uljne faze, vrste ugljikohidrata, žumanjka jajeta, kaše bundeve te brzine rotora i vremena homogenizacije na reološka svojstva salatne majoneze. Za ispitivanje korištene su razne vrste biljnih ulja: rafinirano i hladno prešano suncokretovo ulje, rafinirano i hladno prešano repičino ulje i visokooleinsko suncokretovo ulje. Žumanjak jajeta korišten je kao svježi, pasterizirani i zamrznuti pasterizirani. Za ispitivanje utjecaja vrste ugljikohidrata na reološka svojstva salatne majoneze korištena je glukoza, saharoza, laktoza, maltoza, inulin HD i cvjetni med. Ispitivan je utjecaj dodatka kaše bundeve (5 %, 10 %,15 %) na reološka svojstva salatne majoneze. Mehanički proces homogenizacije salatne majoneze (65% uljna faza) proveden je kod različite brzine rotora (10000, 12000, 15000 o/min) i vremenu (1, 3, 5 min). Mjerenja reoloških svojstava salatne majoneze s dodatkom kaše bundeve provedena su na rotacijskom viskozimetru sa koncentričnim cilindrima pri temperaturi 25 ºC. Iz dobivenih podataka izračunati su reološki parametri koeficijent konzistencije, indeks tečenja i prividna viskoznost majoneza. Navedeni rezultati ukazuju da majoneza izrađena sa hladno prešanim suncokretovim uljem ima veću viskoznost i konzistenciju u odnosu na druga ulja. Primjena svježeg žumanjka dovodi do manjih reoloških parametara viskoznosti i konzistencije. Dodatkom maltoze kod izrade ove majoneze dobivaju se veći reološki parametri. Brzina rotora i vrijeme homogenizacije utječu na promjenu reoloških svojstava salatne majoneze.Rheological properties are important quality parameters of mayonnaise. The understanding of rheological properties is important for creating the proper consistency of mayonnaise, for quality control during production, storage and transport. In this master thesis the influence of oil phase, type of carbohydrates, egg yolk and pumpkin puree, as well as rotor velocity and the homogenisation period on the rheological properties of salad mayonnaise have been explored. Different types of vegetable oils were used for testing: refined and cold pressed sunflower seed oil, refined and cold pressed rape seed oil and sunflower seed oil (high oleic). Egg yolk was used as fresh pasteurised as well as frozen pasteurised. Glucose, sucrose, lactose, maltose, inulin and flower honey were used to test the influence of various types of carbohydrates on rheological properties of salad mayonnaise. The influence of pumpkin puree (5%, 10%, 15%) on rheological properties of salad mayonnaise was tested. The mechanical process of homogenisation of salad mayonnaise was conducted under various rotor velocity (10 000, 12 000, 15 000 rpm) and in different time period (1, 3, 5 min). The measurings of rheological properties of salad mayonnaise supplemented by pumpkin puree were conducted on the rotational viscosimeter with the concentric cylinder on the temperature of 25ºC. Rheological parameters, coefficient of consistency, flow indeks and the apparent viscosity of mayonnaise were calculated from the obtained data. The afore-mentioned results indicate that mayonnaise produced from cold pressed sunflower seed oil has grater viscosity and consistency compared to other oils. The application of fresh egg yolk results in minor rheological viscosity and consistency parameters. Grater rheological parameters are obtained by adding maltose in production of this mayonnaise. Modification of rheological properties of salad mayonnaise is affected by rotor velocity and by homogenisation period