This document discusses the use of chitosan for managing post-harvest diseases of fruits and vegetables. It provides background on chitosan, including its extraction from crustacean shells, properties, and commercial products. The document examines chitosan's effectiveness against bacterial and fungal diseases through mechanisms like disrupting microbial membranes. Factors like pH, concentration, and molecular weight are found to influence chitosan's antimicrobial activity. Studies demonstrate chitosan's ability to inhibit the growth of fungal pathogens like Colletotrichum and reduce decay in fruits. Overall, the document reviews the role of chitosan in post-harvest disease management.

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Dept. of Plant Pathology
WELCOME

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Importance of fruits and vegetables
(Jideani et al., 2021)
Antioxidants are important ingredients present in fruits
and vegetables

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What is post harvest diseases
The diseases which develop on harvested parts of the plants
like seeds, fruits and also on vegetables are known as post-
harvested diseases
(Wan et al., 2021)

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Dept. of Plant Pathology
Importance of post harvest diseases

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Some important post harvest diseases of fruits and
vegetables

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Anthracnose Stem end rot
Gray mold
Blacke mold

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Anthracnose Cigar end rot
Crown rot Fruit rot

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Anthracnose Fruit blight Stem end rot

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Gray mold Rhizopus rot
Ripe rot Blue mold rot

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Bacterial soft rot Grey mold

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Soft rot
Gray mold
Sclerotium rot

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Adverse effect of chemicals in post harvest management
(Quin et al., 2021)

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Dept. of Plant Pathology
Role of Chitosan in Post harvest Disease
Management
Arun A.T.
2020-21-011
Dept. of Plant Pathology

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1. Introduction
2. What is chitosan
3. Importance of chitosan in post harvest disease management
4. Management of bacterial diseases by chitosan
5. Mechanism of action of bacterial disease management
6. Management of fungal diseases by using chitosan
7. Mechanism of action of fungal disease management
8. Effect of chitosan coating on physiological quality parameters
9. Problems associated with the usage of chitosan
10. Conclusion
11. Future perspective
Contents

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What is chitosan
Chitosan is a high molecular weight cationic
polysaccharide consisting of β-(1-4)-linked D-glucosamine
(deacetylated unit) and N-acetyl-D-glucosamine and usually
refers to a family of chitin derivatives obtained after partial
deacetylation
(Haghighi et al., 2020)

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NHCOCH3
NH2
Difference between chitin and chitosan
Chitin Chitosan
(Bibi et al., 2021)

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Prof. C. Rouget
(1859)
Discovery of chitosan
(Torres-Rodriguez et al., 2021)

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Sources of chitosan
Fungal cell walls
Insect exoskeletons
Crustacean shells
Crab
shell
Shrimp
shell
(Yang et al., 2021)

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Extraction of chitosan
1.Biological method
2.Chemical method
Different Methods
(Varun et al., 2017)

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Major steps
1.Demineralization
2.Deproteination
3.Deacetylation
Extraction of chitosan
(Varun et al., 2017)

22. Dept. of Plant Pathology (Schmitz et al., 2019)
Biological method
Shrimp
shell waste
Crude shell
material
Demineralized
shell material
Chitin
Deproteinated
shell waste
Chitosan
Washing and drying
Lactic acid bacteria
Deacetylases
Proteolytic bacteria
Deminaralization
Deproteination
Deacetylation
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Chemical method
Shrimp
shell waste
Deminaralized
powder
Chitin
Chitosan
Washing and drying
2N HCl (1:15), 2h,
150 rpm
2N NaoH (1:20), 2h, 150
rpm at 50°C
50%
NaOH, 1h
at 121°C,
15 psi
Demineralization
Deproteination
Deacetylation
Shrimp shell
powder
(Varun et al., 2017)

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Various applications of chitosan
Agriculture
Food industry
Pharmaceutical industry
Cosmetic industry
Water treatment
Paper industry
(Sigroha and Khatkar, 2017)

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Application of chitosan in agriculture
Biopesticide
Growth promoter
Post harvest disease management
(Bandara et al., 2020)

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Importanant charecteristics of chitosan
Antioxidant
Biodegradability
Chemical stability
Antimicrobial
Non-toxicity
Film-forming
(Haghighi et al., 2020)

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Chitosan treatment -fresh products - safe -consumer &
environment
Chitosan - approved
United State Food and Drug Administration (USFDA)
Generally Reconized as Safe (GRAS) food additives
(Bibi et al., 2021)

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Preparation of chitosan solution
1. Chitosan solutions were prepared by dissolving Chitosan (1%
(w/v)) in 0.25N HCl.
2. The solution was centrifuged to remove undissolved particles
and the pH was adjusted to 5.6 with 1N NaOH.
At this pH, Chitosan is positively charged and exhibits
maximal biological activity.
(Prabha and Sivakumar, 2017)

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Dipping method of chitosan application
(Romanazzi, 2010)

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Product trade name Company (Country) Formulation Active
ingredient (%)
Chito plant ChiPro GmbH (Bremen, Germany Powder 99.9
Chito plant ChiPro GmbH (Bremen,
Germany)
Liquid 2.5
OII-YS Venture Innovations (Lafayette,
LA, United States)
Liquid 5.8
KaitoSo Advanced Green
Nanotechnologies Sdn Bhd
(Cambridge, United Kingdom)
Liquid 12.5
Armour-Zen Botry-Zen Limited (Dunedin,
New Zealand)
Liquid 14.4
Biorend Bioagro S.A. (Chile) Liquid
Kiforce Alba Milagro (Milan, Italy) Liquid 6
(Romanazzi et al., 2018)
Commercial products of chitosan
1.25

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Product trade name Company (Country) Formulation Active
ingredient (%)
FreshSeal BASF Corporation (Mount Olive,
NJ, United States)
Liquid 2.5
ChitoClear Primex ehf (Siglufjordur,
Iceland)
Powder
Bioshield Seafresh (Bangkok, Thailand) Powder
Biochikol 020 PC Gumitex (Lowics, Poland) Liquid 2
Kadozan Lytone Enterprise, Inc. (Shanghai
Branch, China)
Liquid 2
Kendal cops Valagro (Atessa, Italy) Liquid 4
Chitosan 87% Korea Chengcheng Chemical
Company (China)
TC (Technical
material)
87
Commercial products of chitosan
(Romanazzi et al., 2018)
100
100

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pH
pH
Concentration
Molecular weight
Degree of deacetylation
Derivatives of chitosan
 Type of organisms
Source of chitosan
Chitosan complexes
Factors affecting microbial activity of chitosan
(Ke et al., 2021)

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pH
Higher antimicrobial activity at low pH; Ideal pH ≤ 6
Anti
microbial
activity
(Kravanja et al., 2019)
pH

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Concentration
Effects of chitosan concentration on spore germination (A) and germ tube
elongation (B) of Botrytis cinerea and Penicillium expansum 12 h after
incubation at 25 °C.
(Liu et al., 2007)

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Molecular weight
Effect of low molecular weight chitosan (LMWC) and high molecular weight
chitosan (HMWC) on decay of citrus fruits caused by Penicillium digitatum,
Penicillium italicum, Botrydiplodia lecanidion and Botrytis cinerea
(Zhang et al., 2011)
HMWC
LMWC

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Degree of deacetylation (DD)
Degree of deacetylation Class Property
70–85% Middle Partly dissolved in water
85–95% High Good solubility in water
95–100% Ultrahigh Excellent solubility in
water
(Zhuang et al., 2019)

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Derivatives of chitosan
Carboxymethyl chitosan
Quaternized carboxymethyl chitosan
(Sun et al., 2006)

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Effect of chitosan and oligochitosan with different concentrations on brown rot
diseases of peach fruit stored at 25 0C after 4 days
(Ma et al., 2013)
Role of chitosan and oligochitosan on peach fruit decay

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Type of organisms
Bacteria generally less sensitive to the antimicrobial action of
chitosan than fungi
(Kong et al., 2010)

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Source of chitosan
Fungal chitosan exhibited low antimicrobial activity as
compared to what crustacean shell chitosan
(Jeihanipour et al., 2007)

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Chitosan complexes

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Reduction in the linear growth and spore germination (%) of Penicillium
digitatum and P.italicum in citrus fruits as affected by different concentrations
of chitosan, lemongrass and citral essential oils on PDA medium
(El-Mohamedy et al., 2015)

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Chitosan
+Ve
-Ve
+Ve
-Ve
Electrostatic interaction
General antimicrobial action of chitosan
Pathogen
(Xing et al., 2015)

44. Chitosan-DNA/RNA interactions
• Chitosan able to pass through the microbial cell membrane
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mRNA
Proteins
Chitosan
(Xing et al., 2015)

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Management of bacterial diseases by using chitosan
The in vitro antibacterial activity of different molecular weights of chitosan products
against A. tumefaciens, C. fascians, E. carotovora, and P. solanacearum and in
combination with different concentrations of geraniol and thymol by nutrient agar (NA)
dilution technique.

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(Badawy et al., 2016)

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Photograph of the in vitro growth of A. tumefaciens, C. fascians, E.
carotovora, and P. solanacearum in NA plates incorporated with
chitosan film enriched with thymol (0.5%)
(Badawy et al., 2016)

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Mechanism of action of bacterial disease management
Differences in the cell surface structure G +ve and G -ve bacteria
-distinct susceptibilities to chitosan.
(Pasquina-Lemonche et al., 2020)

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Antimicrobial activity against G +ve bacteria
(Ke et al., 2021)

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Antimicrobial activity against G -ve bacteria
(Ke et al., 2021)

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Management of fungal diseases by using chitosan

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Effect of chitosan on mycelial growth of Colletotrichum capsici
(Akter et al., 2018)
Treatments Average mycelial growth
after 10 days (mm)
% of mycelial growth
inhibition over control
Control 90.00 a -
0.4% chitosan 64.30 b 28.56
0.6% chitosan 36.70 c 59.22
0.8% chitosan 11.00 d 87.78
1% chitosan 0.00 e 100.00
1.2% chitosan 0.00 d 100.00

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Mycelial growth inhibition of C. capsici by chitosan on PDA
Control 0.6% chitosan 0.8% chitosan 1% chitosan
(Akter et al., 2018)

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In vitro development of three chitosan-treated isolates of
Colletotrichum obtained from soursop, mango and banana held
at different concentrations and incubated at 20 ± 2ºC
(Gutierrez-Martinez et al., 2017)

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Mechanism of action of fungal disease management

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Antimicrobial activity against fungi
Fungi
(Ke et al., 2021)

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Effect of chitosan on spore germination
Penicillium expansum
(Li et al., 2019)

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Effect of chitosan on fungal growth
Penicillium expansum
(Li et al., 2019)

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Morphological changes in response to chitosan
Light micrographs of P. expansum mycelia after 7 days of
cultivation with or without 0.05% chitosan treatment
(Li et al., 2019)

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Transmission electron micrographs of P. expansum conidia after
6 h of cultivation with or without 0.05% chitosan treatment

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Effect of chitosan coating on physiological quality
parameters
Total soluble solid
Fungal decay
Weight loss
Firmness
Respiration
(Aziz et al., 2021)

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Respiration
Changes in respiration rate of plum fruits coated with Chitosan during
cold storage.
(Bal, 2013)

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Weight loss
Change in weight loss of fresh-cut mangoes stored at 6°C
(Nongtaodum and Jangchud, 2009)

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Firmness
Effects of chitosan treatments on firmness of banana (cv. Sabri)
during 8 days after storage
(Aziz et al., 2021)
A Firmness scores:
1 = hard green
2 = sprung
3 = between sprung and
eating ripe
4 = eating ripe
5 = over ripe
6 = Blackened / rotten.
T0: Control
T1: 0.50% Chitosan
T2: 0.75% Chitosan
T3: 1.0% Chitosan
T4: 1.5% Chitosan
T5: 2.0% Chitosan

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Fungal decay
(Lin et al., 2011)

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Total soluble solid(TSS)
Effect of chitosan coating on TSS of banana fruit
(Hossain and Iqbal, 2016)

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(Prabha and Sivakumar, 2017)
Effect of chitosan treatments on shelf life of capsicum at
different concentration
4 Fourth
Day
Wrinkle were formed and size
began to shrink
No Change No Change

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(Prabha and Sivakumar, 2017)

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Day 1
Day 3
Day 2
Day 4
(Prabha and Sivakumar, 2017)
Effect of chitosan treatments on shelf life of capsicum at
different concentration
Control; 1% Chitosan; 3% Chitosan

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Day 5 Day 6
Day 7 Day 8
(Prabha and Sivakumar, 2017)
Control; 1% Chitosan; 3% Chitosan
Effect of chitosan treatments on shelf life of capsicum at
different concentration

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Effect of chitosan on tomato
(Prabha and Sivakumar, 2017)

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Day 1 Day 2
Day 3 Day 4
(Prabha and Sivakumar, 2017)
Control; 1% Chitosan; 3% Chitosan
Effect of chitosan treatments on shelf life of tomato at
different concentration

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(Prabha and Sivakumar, 2017)
Day 5 Day 6
Day 7 Day 8
Control; 1% Chitosan; 3% Chitosan
Effect of chitosan treatments on shelf life of capsicum at
different concentration

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Problems associated with the usage of chitosan
•Molecular weight
•Purity
•Solubility
•Its characteristics and biodiversity
• Not sufficient data on different effects on the fungi
affecting the fruits or vegetables
(Verlee et al., 2017)

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Conclusion
•Chitosan, naturally occurring compound, possessing broad-spectrum
antimicrobial effects potential in agriculture with regard to controlling
post harvest diseases
•Its application may counteract the wide use of chemical pesticides, in
part at least
•The polysaccharide chitosans represent a renewable source of natural
biodegradable polymers and meet with the emergence of more and
more food safe problem

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Future perspective
•The mechanisms of growth inhibition of pathogens and induced plant
immunity is unclear
• Chemical modification - enhance its antimicrobial activities, improve
the physical and chemical properties, and make it more suitable for
field applications
•In the case of antimicrobial mode of action, future work should aim at
clarifying the actual target molecule on the cell surface or other
intracellular targets

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Thank You