Studies on Antimicrobial Activity and Certain Chemical Parameters of Freeze-Dried Wild Plums (Prunus Spp.)

Abstract

The freeze-drying was applied to increase the shelf life and to preserve the quality of the wild plum (Prunus spp.), an economically important fruit and it has almost the same nutritional quality when compared with the fresh ones. Certain chemical and physical properties of the wild plums were investigated like vitamin C content, pH, titratable acidity, total sugar content, soluble solids, fat and ash content, anthocyanins etc. and it was found that no significant changes were observed when compared with fresh. When its antimicrobial property was tested on various food borne pathogens; the rehydrated extract inhibited important species like Klebsiella pneumoniae and Escherichia coli 0157: H7-933. The inhibitory substance was characterized as benzoic acid. While the concentrated strong acid, weak acid and strong base treatment (1 N) significantly effected the anthocyanin pigments, a treatment of 0.1 N showed no effect. The freeze-dried and the freeze-dried and rehydrated group of wild plums were found to be the most preferred ones by the taste panelists (p<0.01).