SENSORY EVALUATION, ANTIOXIDANT, ANTIMICROBIAL ACTIVITIES AND COLOUR OF STRAWBERRY NECTAR ENRICHED WITH PRODIGIOSIN PIGMENT PRODUCED FROM SERRATIA MARCESCENS

Abstract

This study was performed to evaluate the impact of natural red pigment (prodigiosin) extracted from local
microorganism of Serratia marcescens as a natural colouring, antioxidant and antimicrobial agents in strawberry
nectar. The local S. marcescens was identified by morphological, biochemical tests as well as sequencing a fragment
of the 16S rDNA gene as new Egyptian strain namely S. marcescens A1A. The antioxidant scavenging of prodigiosin
was examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH). The antibacterial activity of prodigiosin was assayed
against three bacterial indicators (B. cereus, Staph. aureus and E. coli) by measuring the inhibition zones using discdiffusion assay on Muller Hinton Agar. The results revealed that the free radical scavenging activity was increased
in the prepared solutions with increasing the concentration of prodigiosin. The prodigiosin of S. marcescens A1A has
prohibited the growth of tested bacteria effectively. On the other hand, the fortification of strawberry nectar with
prodigiosin pigment improved the antimicrobial, antioxidant activities, colour, taste, clarity, thickness and overall
acceptability of resulted products