Abstract

Our work aimed to investigate the incorporation of spirulina extract (which was extracted by different solvents) in edible pectin solution to produce eco-friendly edible coating materials. Ethanolic Spirulina extract (SE) showed the highest yield (17.5%), phenolic content (19.55 mg GAE/g), total carotenoids (5.54 mg/g) and antioxidant activity (78.26%). The dried SE showed the highest inhibition zone for all tested microbial strains at concentration of 350 and 500 mg/ml. Incorporation of dried SE in pectin coating solution at concentration of 200 mg/ml led to curb the bacterial growth and increased the inhibition rate of E. coli 0517-H7; and S. aureus. Guava and Apple slices samples coated with pectin solution containing 1% SE showed lower total bacterial count, also weight loss was reduced from 11.5% to 0.4% at Guava fruit, and apple slices from 7.8% to 2.5% during 24 days at cold storage. Infected fruits were decreased over a period of storage. Rate of firmness loss was reduced from (-13.9 to -5.05 gf/d) for Guava fruit and from (-9.1 to -1.05 gf/d) for apple slices which coated with 1% SE with pectin film solution during storage.

Key words: Spirulina, pectin coating, Guava, Apple, microbial quality, Sensory attributes.