Faculty of Food Technology and Biotechnology, University of Zagreb
Abstract
Svrha je ovoga rada bila usporediti kvalitetu napitaka od naranče s onom napitaka od naranče i sirutke tijekom 12 mjeseci skladištenja. Napici su sadržavali 12 % ekstrakta, od čega je polovina bila koncentrat naranče. Za proizvodnju napitaka sa sirutkom dodano je 50 % sirutke od ukupne količine dodane vode. Napici od naranče sa sirutkom imali su veći udjel proteina, pepela, glukoze, laktoze i vitamina B2, no manji udjel saharoze, fruktoze i vitamina C, te manju sposobnost uklanjanja DPPH radikala od napitaka napravljenih samo s narančom. Nisu pronađene bitne razlike u udjelu polifenola ili sposobnosti uklanjanja ABTS kationa između ta dva tipa napitaka. Parametri boje mjereni prema CIE sustavu uvelike su se razlikovali, iako je prema senzorskoj procjeni prihvatljivost boje napitaka bila gotovo ista. Sveukupna ocjena senzorske kakvoće napitaka od naranče sa sirutkom bila je 2-10 % lošija od napitaka napravljenih samo s narančom. Intenzitet okusa naranče, te slatke i osvježavajuće arome napitaka od naranče bili su veći u tim napicima nego u onima od naranče i sirutke, u kojima su prevladavali kiseli okus i aroma sirutke. Tijekom skladištenja znatno su se smanjili udjeli saharoze i laktoze, antioksidativna aktivnost, senzorska kakvoća, intenzitet arome naranče, te kiseli i osvježavajući okus napitaka sa sirutkom, dok su se povećali udjeli glukoze i fruktozeThe aim of this study is to compare qualitative changes in orange and orange beverages containing whey during 12 months of storage. The beverages contained 12 % extract, half of which was orange concentrate, the rest was sugar or sugar and whey extract. Acid whey was used in the production of beverages, added at a rate of 50 % of the used water. Orange beverages with whey contained more protein, ash, glucose, lactose and vitamin B2 than the orange beverages, but less sucrose, fructose and vitamin C, and also showed lower antioxidant activity against the DPPH radical. No significant differences between the two types of beverages were found in the polyphenolic content or activity against the ABTS cation radical. The type of beverage had a significant effect on the colour parameter values under the CIELAB system, although no significant differences were found between the beverages in the sensory evaluation of colour desirability. The overall sensory evaluation of orange beverages with whey was 2–10 % lower than of other orange beverages. The intensity of orange, sweet and refreshing taste was greater in orange beverages, while that of sour and whey taste was greater in orange beverages containing whey. There were significant decreases in sucrose, lactose, all indicators of antioxidant activity and sensory quality during storage. Levels of glucose and fructose rose with the storage period, while the intensity of sour, orange and refreshing taste decreased
