PAPAYA LATEX (Carica papaya) AND FIG LEAVES (Ficus carica)

ENZYMATIC DEPOLYMERIZATION OF CHITOSAN USING VEGETABLE EXTRACTS:
PAPAYA LATEX (Carica papaya) AND FIG LEAVES (Ficus carica)
Costa, M.F., Sales, S.L., Oliveira Junior, E.N. Campus Alto Paraopeba, Universidade Federal
de São João del Rei – UFSJ, Rodovia MG 443, Km 7 – Fazenda do Cadete, 36.420-000 Ouro
Branco, Minas Gerais, Brasil.
The growing demand for foods without chemical preservatives has focused efforts in the
discovery of new biodegradable packaging films and antimicrobials. Chitin and chitosan are
aminoglucopyranans composed of N-acetylglucosamine (GlcNAc) and glucosamine (GlcN)
residues, and are renewable resources currently being studied by academic and industrial
groups owing to their attractive properties and biological activities. Chitosans have been
indicated for the preservation of foods, juices and other material from microbial deterioration
due their action against different groups of microorganisms, such as bacteria, yeast and fungi.
Studies with chitosan on coating of fruits have been described in the literature. The objective of
this study was to examine the enzymatic depolymerization of chitosan with aid of papaya latex
(Carica papaya) and crude extract obtained by maceration of fig leaves (Ficus carica). Chitosan
stock solution were prepared by dispersing chitosan 1% (m/v) in sodium acetate buffer (0.1 mol
-1
× L , pH = 5.0±0.2). Sources of enzymatic crude extracts, 5 g (papaya latex) and 1 g (fig
leaves) were transferred separately to 20 mL of chitosan stock solution and shaken in an orbital
shaker at 20°C under agitation of 120 o.p.m (orbits per minute) for up to 1.5 hours. The extent
of enzymatic depolymerization of chitosan was assessed by viscometry with Cannon Fenske nº
200 viscometer. Kinematic viscosity values indicated a significant reduction of viscosity,
approximately 97% after 1.5 hours of reaction for both sources of enzyme extracts. The data
suggest that enzymes in the extracts act as hydrolytic enzymes that reduce the molar mass of
chitosan.