This document summarizes the development of an edible coating using ginger peel. Key findings include: 1) Ginger peel extracts showed good antioxidant properties in various assays. Methanolic extracts had higher antioxidant activity than ethanolic extracts. 2) An edible coating was developed by incorporating 5% ginger peel extract into a starch-based film. The coating showed improved water solubility and opacity compared to the control. 3) The ginger peel extract-based coating exhibited low antimicrobial activity against E. coli and S. aureus in assays. Further research incorporating other natural antimicrobials may improve its antimicrobial efficacy. 4) Overall, the study demonstrated the potential of using ginger peel extract, a

1. DEVELOPMENT OF GINGER
PEEL BASED EDIBLE COATING
Submitted by- Suvajit Majumdar
Regd. No- 1732069
M.Sc. Food Technology
Department of Food Science and Technology
I.K. Gujral Punjab Technical University (Main Campus)

2. INTRODUCTION
Edible coating/film -thin layer of physical component - can be eaten - barrier against
oxygen, microbes, moisture and intrinsic chemical/physical changes. (Raghav et
al.,2016)
Natural additives in edible coating preferred- antioxidants and antimicrobial
properties. (Ali et al., 2019)
Natural additives - essentials oils and plant extracts- GRAS - used in development of
biodegradable coatings (Khaneghah et al., 2018; Ali et al. 2019)
• EDIBLE COATING

3. Sources of
edible
biopolymers
LIPIDS
- Oils
Free fatty acids
PROTEINS
- Soy protein
Pea protein
POLYSACCHRIDES
– Starch
Pectin
(Shit et al., 2014)

4. • Edible coating - used in food industries from early centuries.
• Problems of plastic waste - research's focus on- biodegradable
packaging material/compounds - minimize plastic waste.

5. ADDITIVES
IN EDIBLE
COATING
FLAVOURING
PIGMENT
TEXTURE
ENHANCER
PROBIOTICSANTIOXIDANT
ANTIMICROBIAL
PLASTICIZER

6. Natural additives: edible coatings
• Plant extract and essentials oils - good replacement of chemicals -
generally regarded as safe (Embuscado et al., 2009)
• Natural antioxidants - extracted from fruits, vegetables, residual parts
of plant based foods etc.
• Consumer prefer minimal processed food - no synthetic additive
(Adilah et al., 2018).

7. Ginger (Zingiber officinale)
• Zingiber officinale eaten as a dietary condiments across globe
• Monocotyledonous rhizome - family Zingiber aceae - medicinal, antimicrobial,
antioxidant properties (Grace et al., 2017; Maoet al., 2019)
• India - largest cultivator of ginger
• Used as flavoring agent and medicine traditionally (Liet al., 2019)
• Gingerols, shogaols and paradols - main active phytochemicals (Virendra et al.,
2013)
• Starch, lipids, proteins, and inorganic compounds - main components (Virendra et
al., 2013)

8. Functional properties of ginger
(Kumar et al., 2011)

9. Ginger (Zingiber officinale) peel :Waste utilization
Ginger peel is considered as a waste all over the world; only ginger
pulp is used in food and medicine, as the peels are inedible parts of the
rhizome.
However, ginger peels have higher total phenols and total flavonoids
than ginger pulp. (Marrelli et al., 2015)
Residual material contains several useful components (Goula &
Lazarides, 2015)

10. The aim of the present study is to develop ginger peel based edible coating
To evaluate proximate composition of ginger peel
To prepare ethanolic and metanolic extract of ginger peel and evaluation of
antioxidant properties
To evaluate antimicrobial properties of ginger peel extract
Development of starch based edible coating incorporating ginger peel extract
To analyze physical properties of edible coating
To evaluate total phenol content and antimicrobial activity of the edible coating
AIM
OBJECTIVES

11. METHODS
1) Proximate analysis of ginger peels:
 Moisture content - AOAC 2000, 934.06
 Total ash content – AOAC 2000, 900.02A
 Crude fiber content – AOAC 1990,962.09
 Crude fat content – AOAC 1995, 920.39
 Protein content - Lowry et al., 1951
 Carbohydrate content – Difference method

12. 5g of dried sample + 200 ml of solvent (methanol: water/ ethanol:
water)
Continuous shaking at incubator shaker at 40°C (180 rpm for 12
hrs)
Centrifugation for 20 minutes at 7500 rpm
Filtration and collection of the supernatant
The same process repeated with the residues and supernatant was
collected
Concentration under vacuum (rotary evaporator at 45°C)
Freeze drying
Storage in amber coloured airtight containers
2) Preparation of ginger peel extract
for antioxidant assays
(Serrano-Díaz et al., 2013; Sánchez-Vioque et
al., 2012)

13. 3) In-vitro antioxidant activity
100µl of sample + 2 ml of Na2CO3
Incubate for 2 minutes at room temperature
Add 100µl of 50% F.C. reagent and mix properly
Incubate at room temperature
Absorbance at 720 nm
• Total phenol content
(Ferreira et al., 2007)

14. • Total flavonoid content
(Xu and Chang , 2007)
500µl of extracted sample + 2 ml distilled water + 150 µl
NaNO2
Incubate for 6 minutes at 25°C
Add 150 µl of AlCl3
Incubate for 6 minutes at 25°C
Add 2 ml of NaOH (1mM) + 200 µl of distilled water
Absorbance at 510nM
v
v
v
v

15. • Ferric reducing antioxidant power assay
(Benzie and Strain,1996)
100µl Sample/Standard + 2.9 ml FRAP reagent
(300 mM acetate buffer + 10mM TPTZ + 20 mM Fecl3 +
Distilled water)
Mix thoroughly
Incubate at 37°C for 30 minutes
Read absorbance at 593 nm

16. 3) Antimicrobial analysis of ethanolic extract of ginger peel
Microbial growth estimation in ginger peel extract
Minimal inhibitory concentration of ethanolic extracts (Balouiri et al., 2016)

17. 4) Development of edible coating
The method for developing starch based edible coating was as described by Ali et al., (2019)
5 gram of cornstarch + 100 ml distilled water
Heating and stirring until gelatinization
Cooling 25°C
Add glycerol 30% (v/w) of the starch weight in the solution
Stirring for 10 minutes
Add 5 % of ginger peels extract (200mg/ml) (v/v) of the starch solution and mixing
Pouring of the solution

18. 5) Physical properties of edible coating
• Water solubility of edible coating- method by Adilah et. al., (2018)
• Colour estimation of the edible coating- measured using colorimeter (Chroma meter
CR-400)
• Estimation of opacity of edible coating -method described by Siripatrawan and Harte
(2010)
• Film thickness- measured using a vernier caliper

19. 6) Evaluation of total phenolic content of edible coating (Xu et al., 2018)
Small film pieces (2.54cm × 2.54cm) + 10 ml 100% ethanol
24 hours at room temperature in incubator shaker
Centrifugation at 3500 rpm
Collection of the supernatant
• Total phenol content of edible coating - analyzed by the FCR method
• TPC of the film was expressed as μg gallic acid equivalent / mg edible coating (μg GAE/mg of coating)
on a dry weight basis.

20. 7) Antimicrobial activity of edible coating
• Disc diffusion method was used for determine the antimicrobial activity of edible coating.

21. 8) Statistical analysis
The data is presented as mean ± SD
Statistical analysis of the data was done using unpaired t test
Antioxidant assays of crude extracts and proximate analysis of ginger peel was carried out
in triplicates
For estimation of antioxidant activity of the edible coating, the sample size n=5

22. • Proximate analysis of ginger peels
RESULTS
Material Moisture
(%)
Ash
(%)
Fat
(%)
Protein
(%)
Crude fiber
(%)
Carbohydrate
(%)
Ginger
peels
88.04± 0.45 12.83±1.53 3.53± 1 18.80 ± 4.08 21.05±4.40 52.56
Data presented as mean ±S.D

23. • Total phenolic content (TPC)
Extract
Concentration
(mg/ml)
µg GAE
(ethanolic
extract)
µg GAE
(methanolic
extract)
5 33.79 ± 0.00 106.28± 0.001α
10 213.87 ±0.01 264.14 ± 0.01$
15 593.95 ±0.05 659.91 ±0.05
30 1149.15 ±0.009 1046.89 ±0.004#
α
$
#
0
200
400
600
800
1000
1200
1400
5 10 15 30
µgGAE
Extract concentration (mg/ml)
Ethanolic extract Methanolic extract
(Data presented as mean ± SD; p≤ 0.05; α significant difference vs ethanolic extract at 5 mg/ml; $ significant difference vs
ethanolic extract at 10mg/ml; # significant difference vs ethanolic extract at 30 mg/ml.)

24. • Total flavonoid content (TFC)
Extract
concentration
(mg/ml)
Ethanolic extract
(µg QE)
Methanolic extract
(µg QE)
2.5 100.97±0.05 127.33±0.01
5 161.78 ±0.005 316.06±0.009$
10 408.44±0.02 746.37±0.09@
15 993.98 ±0.10 1072.98 ±0.17
30 1608.81 ±0.20 1624.25 ±0.02
60 2240±0.07 2962.52±0.43&
$
@
&
0
500
1000
1500
2000
2500
3000
3500
2.5 5 10 15 30 60
µgQE
Extract concentation (mg/ml)
Ethanolic extract Methanolic extract
(Data were represented as mean ± S.D.; n=3; p≤ 0.05;$ significant difference vs ethanolic extract at 5 mg/ml; @
significant difference vs ethanolic extract at 10mg/ml ; & significant difference vs ethanolic extract at 60 mg/ml)

25. • Ferric reducing Power assay (FRAP)
α
$
@
#
0
2
4
6
8
10
12
14
16
18
2.5 5 10 15
mMFSE/ml
Extract concentration (mg/ml)
Ethanolic extract Methanolic extract
Extract
Concentration
mg/ml
Ethanolic extract
(mM FSE)
Methanolic extract
(mM FSE)
2.5 0.1532 ±0.02 1.25881 ±0.2 α
5 1.127 ±0.2 4.182842 ±1.8$
10 8.7283 ±1.06 12.92071 ±0.7@
15 11.5238 ±0.07 15.78134 ±0.07#
(Data were represented as mean ± SD; p≤ 0.05; α significant difference vs ethanolic extract at 2.5 mg/ml;$ significant difference vs
ethanolic extract at 5 mg/ml;@ significant difference vs ethanolic extract at 10mg/ml; # significant difference vs ethanolic extract at 15
mg/ml)

26. • Microbial growth estimation in ginger peel extract
Extract
Sample
Concentration
(mg/ml)
Growth
media
Incubation
time
(hours)
Incubation
temperature
(°C)
Microbial
growth
Ginger
Peel
1mg/ml NA 18-24 37 No
Ginger
Peel
1mg/ml SDA 18-24 20 No
Ginger
Peel
1mg/ml EMB 18-24 37 No
(NA: nutrient agar media; SDA: sabouraud dextrose agar media; EMB: eosin methylene blue media)
NA
SDA
EMB

27. • Minimal inhibitory concentration of ethanolic ginger peel extract
A: sterility control; B: –ve control for E-coli; C: –ve control for S. aureus; D: +ve control (neomycin) for E-
coli; E: +ve control (neomycin) for S. aureus; F: +ve control(ampicillin) for E-coli; G: +ve control
(ampicillin) for S. aureus; H: ginger peel ethanolic extract for E-coli; I ginger peel ethanolic extract for S.
aureus
S. No. Sample Microorganism Growth
media
MIC
(mg/ml)
1 Ginger
peel
extract
E. coli Muller
Hinton Broth
200
2 Ginger
peel
extract
S. aureus Muller
Hinton Broth
200

28. Representative picture of edible coating
A: Control coating B: Ginger peel extract based coating
A B

29. • Physical properties of ginger peel based edible coating
Color
parameters
Control edible
coating
Extract based
edible coating
L* 39.395±0.55 44.01±0.55
a* -0.5±0.49 -1.155±0.49
b* -0.125±0.03 1.57±0.03
ΔL -55.195±0.55 -54.76±0.55
Δa 4.55±0.02 4.23±0.02
Δb -9.26±0.04 -7.56±0.042
ΔE 56.15±0.55 55.44±0.55
 Color
(Data presented as total difference Δ and * shows the significant
difference)

30.  Water solubility
Sample Initial dry
weight (g)
Final dry
weight (g)
Water
solubility (%)
Control 0.266 0.1903 28.45
Ginger peel
extract based
coating
0.119 0.0789 33.69

31.  Opacity
Coating Opacity (T-value)
Control – starch based 1.26± 0.5
Test – ginger peel based 7.8± 2.8

32. Thickness
S. No Ginger peel based
edible coating (mm)
Control coating
(mm)
1 0.1 0.1
2 0.2 0.1
3 0.1 0.2
Mean 0.1 0.1
Total phenolic content of the edible coating
Concentrations of ginger
extract added (mg/ml)
µg GAE/ mg of coating
200 328.725 ± 0.009

33. S.N. Sample M.O Temperature
(◦C)
Inhibition time
(Hours)
Diameter
of zone
(mm)
1 Ginger
Peel
Extract
E. coli 37 24 1mm
2 Ginger
Peel
Extract
S.
aureaus
37 24 1mm
STANDARD
1 Neomycin E. coli 37 24 10mm
2 Neomycin S.
aureaus
37 24 14mm
3 Ampicilli
n
E. coli 37 24 13mm
4 Ampicilli
n
S.
aureaus
37 24 12mm
• Antimicrobial activity of edible coating
Zone of inhibition of ginger peel extract
against E coli.
Zone of inhibition of ginger peel extract
against S. aureaus.

34. Conclusion
• Ginger peels extract possess good antioxidant activities
TPC, TFC and FRAP assay - methanolic extracts showed higher
antioxidant activity than ethanolic extract
• Ginger peel extract - can be used in edible coatings
• Low antimicrobial properties of ginger peel extract against E. coli and S.
aureus observed
• Combination of ginger peel extract with other natural antimicrobial agents
can be done for increasing the antimicrobial efficiency of the edible coating

35. Future scope
• Application in food product i.e. meat products
• Estimation of mechanical properties of the coating

36. References
• Addis, M., (2015). “Major Causes of Meat Spoilage and Preservation Techniques”: A. changes, 41.
• Adilah, A.N., Jamilah, B., Noranizan, M.A. and Hanani, Z.N., (2018). “Utilization of mango peel extracts on the
biodegradable films for active packaging.” Food packaging and shelf life, 16, pp.1-7.
• Adugna, F., Pal, M. and Girmay, G., (2018). “Prevalence and Antibiogram assessment of Staphylococcus aureus
in beef at municipal abattoir and butcher shops in Addis Ababa, Ethiopia”. BioMed research international, 2018.
• Aisyah, Y., Irwanda, L.P., Haryani, S. and Safriani, N.,(2018), May. “Characterization of corn starch-based edible
film incorporated with nutmeg oil nanoemulsion”. In IOP Conference Series: Materials Science and
Engineering (Vol. 352, No. 1, p. 012050). IOP Publishing.
• Alamed, J., Chaiyasit,W., McClements, D. J., & Decker, E. A., (2009), “Relationship between free radical
scavenging and antioxidant activity in foods,” J. Agri. Food Chem., 57, pp. 2969–2976.
• Ali, A., Chen, Y., Liu, H., Yu, L., Baloch, Z., Khalid, S., Zhu, J. and Chen, L., (2019). “Starch-based antimicrobial
films functionalized by pomegranate peel”. International journal of biological macromolecules, 129, pp.1120-
1126.
• AOAC, (1995), “Official Methods of Analysis”, 16th ed. Association of Official Analytical Chemists, Arlington,
VA, USA.
• AOAC, (2000), “Official Methods of Analysis”, 17th ed. Association of Official Analytical Chemists, Arlington,
VA, USA.
• Bagamboula, C.F., Uyttendaele, M. and Debevere, J., (2004). “Inhibitory effect of thyme and basil essential oils,
carvacrol, thymol, estragol, linalool and p-cymene towards Shigella sonnei and S. flexneri”. Food
microbiology, 21(1), pp.33-42.
• Bourtoom, T., (2008). “Edible films and coatings: characteristics and properties”. International Food Research
Journal, 15(3), pp.237-248.
• Cerveny, J., Meyer, J.D. and Hall, P.A., (2009). “Microbiological spoilage of meat and poultry products”.
In Compendium of the microbiological spoilage of foods and beverages (pp. 69-86). Springer, New York, NY.

37. • Font-i-Furnols, M. and Guerrero, L., (2014). “Consumer preference, behavior and perception about meat and meat
products”: An overview. Meat science, 98(3), pp.361-371.
• Godfray, H.C.J., Aveyard, P., Garnett, T., Hall, J.W., Key, T.J., Lorimer, J., Pierrehumbert, R.T., Scarborough, P.,
Springmann, M. and Jebb, S.A., (2018). “Meat consumption, health, and the environment”. Science, 361(6399),
p.eaam5324.
• Gómez-Estaca, J., López-de-Dicastillo, C., Hernández-Muñoz, P., Catalá, R. and Gavara, R., (2014). “Advances in
antioxidant active food packaging”. Trends in Food Science & Technology, 35(1), pp.42-51.
• Hailemichael, G. and Tesfave, K., (2008). “The effect of seed rhizome size on the growth, yield and economic re-turn of
ginger (Zingiber officinale Rosc.)”. Asian J. Plant Sci, 7, pp.213-217.
• Islam, K., Rowsni, A.A., Khan, M.M. and Kabir, M.S., (2014). “Antimicrobial activity of ginger (Zingiber officinale)
extracts against food-borne pathogenic bacteria”. International Journal of Science, Environment and Technology, 3(3),
pp.867-871.
• Jacob, J., Peter, G., Thomas, S., Haponiuk, J.T. and Gopi, S., (2019). “Chitosan and polyvinyl alcohol nanocomposites with
cellulose nanofibers from ginger rhizomes and its antimicrobial activities”. International journal of biological
macromolecules, 129, pp.370-376.
• Jiménez, A., Fabra, M.J., Talens, P. and Chiralt, A., (2012). “Edible and biodegradable starch films: a review”. Food and
Bioprocess Technology, 5(6), pp.2058-2076.
• Khaneghah, A.M., Hashemi, S.M.B. and Limbo, S., (2018). “Antimicrobial agents and packaging systems in antimicrobial
active food packaging”: An overview of approaches and interactions. Food and bioproducts processing, 111, pp.1-19.
• Kizhakkayil, J. and Sasikumar, B., (2011). “Diversity, characterization and utilization of ginger: a review”. Plant Genetic
Resources, 9(3), pp.464-477.
• Kumar, G., Karthik, L. and Rao, K.B., (2011). “A review on pharmacological and phytochemical properties of Zingiber