PHYSICO-CHEMICAL PROPERTIES OF PROPOLIS AND ITS APPLICATION AS A FOOD PRESERVATIVE IN FISH KOFTA

Abstract

In the current study, the local Egyptian and imported propolis were characterized. The effect of addition of local propolis at different levels (0.5, 1.0, and 1.5%) on the fish (Oreochromis niloticus) kofta shelf life and its qualityduring storage at 4±2°C for twenty days was estimated. The dominant components found in all propolis samples were guaia-1(10)-en-11-ol (Bulnesol) ranging between 7.32 to 19.5%, guaiol 8.67 to 12.7%, pinostrobin chalcone, 6.66 to 12.2%, α-curcumene 7.31 to 12.0% and β-curcumene 4.07 to 8.73%. The highest element content was potassium followed by calcium, sodium and barium for local and imported propolis, respectively. The addition of local propolis to fish kofta had no negative effect regarding the sensory properties at the beginning of storage. It was clearly noticed that the addition of propolis to fish kofta decreased the malondialdehyde production, total counts of bacterialdevelopment, and increased the DPPH inhibition in the cold stored fish kofta. And also, the lowest color changes were observed in 1.5% sample followed by 1.0%, 0.5% and finally control. It could be noted that the addition of local propolis to fish kofta prolonged its shelf life.