Changes of quality and antioxidative potential by raspberry freezing

Abstract

More recently the interest for antioxidant properties of food was increased, due to their health-promoting properties. In the analysis of food, in addition to finding the usual quality parameters, one more often determines its antioxidant potential. The present study evaluated the effect of freezing process on raspberry fruits changes. The content of dry matter, total sugars and acids, vitamin C, as well as sensory analysis of quality were determined. Antioxidant potential was measured by DPPH method, testing the ability of DPPH radical neutralization. The results indicate that the freezing caused minor changes in chemical quality parameters. The changes in sensory quality characteristics were higher. The most marked was the loss of consistency, then flavor changes, and the taste of raspberry fruit was some modified.

U novije vreme antioksidativnim svojstvima hrane pridaje se veliki značaj zbog pozitivnog uticaja na zdravlje ljudi. Pri analizi hrane, pored utvrđivanja uobičajenih parametara kvaliteta, sve češće se određuje i njen antioksidativni potencijal. U radu su analizirane promene do kojih dolazi pri smrzavanju maline. Utvrđivan je sadržaj suve materije, ukupnih šećera i kiselina, vitamina C, kao i senzorna analiza kvaliteta. Antioksidativni potencijal meren je metodom DPPH, ispitivanjem sposobnosti neutralizacije DPPH radikala. Dobijeni rezultati ukazuju da pri smrzavanju dolazi do neznatnih promena hemijskih parametara kvaliteta. U senzornim karakteristikama promene su nešto veće. Najupadljiviji je gubitak konzistencije, zatim arome, a donekle je izmenjen i ukus plodova.