Influence of ingredients content on rheological characteristics and acceptability of hazelnut butter

Poznavanje reoloških svojstava hrane od velikog je značenja, bilo da se radi o postizanju određenih svojstava hrane ili o vođenju procesa pri proizvodnji hrane. Tekstura proizvoda je jedan od značajnijih čimbenika koji određuju kakvoću namirnica, naročito ako se želi očuvati veća stabilnost tijekom vremena skladištenja. Cilj ovog rada bio je istraživanje utjecaja udjela lješnjaka, vrste ugljikohidrata i mliječne komponente na reološka svojstva i prihvatljivost namaza od lješnjaka tijekom skladištenja. Uzorci namaza od lješnjaka pripremljeni su sa rafiniranim suncokretovim uljem i uz dodatak različitog udjela lješnjaka (40%, 50%, 60%). Za ispitivanje utjecaja vrste ugljikohidrata na reološka svojstva korišteni su glukoza, saharoza, laktoza, inulin HD i bagremov med. Također, ispitan je utjecaj različitog udjela ugljikohidrata na reološka svojstva namaza od lješnjaka. Istraživanje dodatka mliječne komponente na reološka svojstva provedeno je primjenom sojinog mlijeka u prahu, obranog mlijeka u prahu i sirutke u prahu. Namazi sa lješnjakom izrađeni su po tradicionalnoj recepturi bez dodanog konzervansa čime je trajnost proizvoda vremenski ograničena. Mjerenja reoloških svojstava namaza od lješnjaka provedena su na rotacijskom viskozimetru s koncentričnim cilindrima pri temperaturi 25 o Iz navedenih rezultata može se zaključiti da namazi od lješnjaka pripadaju ne-Newtonovskim sustavima (pseudoplastična svojstva). Veća konzistencija namaza dobivena je dodatkom 60% lješnjaka. Dodatak inulina HD, kao i sojinog mlijeka u prahu, dovodi do većeg porasta viskoznosti i konzistencije namaza. C na dan proizvodnje te nakon skladištenja 14 dana u hladnjaku. Reološka svojstva ispitivanih uzoraka prikazana su grafičkim odnosom smičnog naprezanja i brzine smicanja. Iz dobivenih podataka izračunati su reološki parametri koeficijent konzistencije, indeks tečenja i prividna viskoznost namaza od lješnjaka. Ispitivanje prihvatljivosti 4 odabrana uzorka provedeno je uporabom verbalne hedonističke skale s 9 stupnjeva. Prihvatljivost svojstava okusa i mirisa namaza sa bagremovim medom bolja je u odnosu na dodatak drugih ugljikohidrata.Understanding rheological properties of foods is very important both for achieving specific food properties and for controlling the food production process. Product texture is one of the more important factors determining food quality, particularly when it comes to improved product stability during the time of storage. The objective of this work was to investigate the influence of hazelnut content, carbohydrate type, and dairy component on the rheological properties and the acceptability of hazelnut paste during its time of storage. Hazelnut paste samples were prepared with refined sunflower oil and different hazelnut contents (40%, 50% and 60%). Glucose, sucrose, lactose, inulin HD, and acacia honey were added to determine the effect of different carbohydrate types on the rheological properties of hazelnut paste. The effect of different carbohydrate content levels on the rheological properties of hazelnut paste was likewise tested. The effect of the added dairy component on the rheological properties of hazelnut paste was tested by adding powdered soy milk, powdered skimmed milk, and whey powder. Traditional recipes were followed in the making of the hazelnut pastes and no preservatives were added, resulting in limited product durability. The rheological properties of the hazelnut pastes were measured on a concentric cylinder rotational viscometer at the temperature of 25o We may conclude from the specified results that hazelnut pastes are non-Newtonian systems (pseudoplastic properties). 60% hazelnut content resulted in better paste consistency. The addition of inulin HD and powdered soy milk improved hazelnut butter viscosity and consistency. C on the same day when the pastes were made, and again after they had been refrigerated for 14 days. The rheological properties of tested samples were presented as a graphic correlation of shear stress and shear rate. The rheological parameters of consistency coefficient, flow behavior index, and apparent viscosity of hazelnut paste were computed from the data thus obtained. The acceptability of four chosen samples was analyzed by using a nine-point verbal hedonic scale. Compared to other carbohydrates added to hazelnut paste, the addition of acacia honey resulted in the best acceptability of hazelnut paste flavor properties