Development and Evaluation of Antimicrobial Aloe Based Packaging Films
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Date
2012-11
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Addis Ababa University
Abstract
This study was aimed at the development of antimicrobial packaging films, which is one of the
most promising active packaging systems, from aloe and papaya leaves extracts with gelatine
and glycerol. Three different extracts of papaya leaves were analyzed for their antimicrobial
activities. Mechanically obtained papaya leaf extract showed the best result (12.10mm inhibition
zone on S.typhi). Based on antimicrobial activity, film forming ability, transparency, and colour;
Aloe debrana extract was found to be more appropriate for the development of antimicrobial
packaging films than Aloe trichosantha extract. The antimicrobial activity of Aloe debrana
extract was increased by the incorporation of papaya leaf extract up to 30%, above which it did
not bring significant influence on most test organisms. As a result 70% Aloe debrana extract and
30% papaya leaf extract standard solution was prepared. Various concentrations of gelatine and
glycerol were added to the standard solution for packaging films development. Films were
evaluated for their antimicrobial activities, physicochemical, and mechanical properties. The
antimicrobial activities of aloe based films were tested on E. coli, S. typhi, S.aureus, C. albicans,
and F. xylarioides. All films exhibited inhibitory zones on the test microorganisms used in this
study. A wide inhibition zone (6.52cm2) was observed on S. typhi growth whereas the least (4.20
cm2) was on C.albicans. Films were soluble in water with highest solubility (90.49%) for P1,1
(film with 1g glycerol and 1g gelatine) and lowest (44.57) for P0,2(film developed by adding only
gelatine). Film solubility significantly increased as the concentration of glycerol increased and
decreased as the concentration of gelatine increased. Film P0.5,2(with 0.5g glycerol and 2g
gelatine) has showed maximum tensile strength (65MPa) where as the lowest (20MPa) was
obtained by film P0.5,1(0.5g glycerol and 1g gelatine). Increasing gelatine concentrations
significantly increases the tensile strength but glycerol has an opposite effect on the tensile
strength. All the films were highly flexible and stretchable. Film P1,2(1g glycerol and 2g gelatine)
showed the maximum elongation (180%) and the minimum elongation (89%) was obtained for
P0.5,1. This study demonstrated the technological feasibility of developing antimicrobial
packaging films from aloe and papaya leaves extracts.
Keywords: Aloe extracts, Antimicrobial packaging film, Mechanical properties, Papaya
extracts, Pathogenic microorganisms, Physicochemical properties
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Keywords
Aloe extracts; Antimicrobial packaging film; Mechanical properties; Papaya extracts; Pathogenic microorganisms; Physicochemical properties