TITLE:
Does Chitosan Extend the Shelf Life of Fruits?
AUTHORS:
Tahsin Islam Sakif, Adam Dobriansky, Kelly Russell, Tofazzal Islam
KEYWORDS:
Fruit Shelf Life, Alternative to Formalin, Health Hazards, Use of Chitosan, Fruit Preservation
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.7 No.8,
August
3,
2016
ABSTRACT: The use of hazardous formalin in increasing shelf life of fruits and protecting them from microbial
decay by unscrupulous traders is a big health concern for the consumers in Bangladesh. Chitosan
is a natural biopolymer produced from the exoskeletons of shrimp and crab, which slows antimicrobial
activities and induces immunity of plants against microbial pests. This study aimed to
evaluate the efficacy of chitosan on the shelf life extension of some local ripened fruits compared
to untreated control. Three doses of chitosan solution viz. 0, 500 and 1000 ppm were sprayed in
alternate day on banana (cvs. Shabri and Champa), strawberry, tomato, and oranges. It revealed
that chitosan extended shelf life of all fruits by delaying the decay; however, level of protection varied
in different kinds of fruits as well as in doses of the chitosan used. Among the tested fruits,
decay of tomatoes was most delayed by chitosan. Spraying of both 500 and 1000 ppm of chitosan
equally protected 100% decay in tomatoes until 8 days of treatments at room temperature. More
than 80% protection of other fruits viz. banana, orange and strawberries by chitosan were recorded
at 8, 8 and 4 day after treatment, respectively, which were remarkably higher than the untreated
control. Interestingly, 500 ppm of chitosan spray gave better protection than 1000 ppm in
all the tested fruits. These results suggest that lower doses of chitosan can be utilized as a natural
preservative of fruits alternative to hazardous formalin. A further study with higher number of
fruits, and at varying temperature and chitosan doses are needed for recommending it for practical
application as a fruit preservative.