bio-plastics and edible films for food packaging
TRANSCRIPT
Bio-plastics and Edible Films for Food Packaging
Mohammed Sabbah 1*, Asmaa Al-Asmar2, Nesreen Mansor, Dana Yaseen
1 Department of Nutrition and Food Technology, An-Najah National University, Nablus, Palestine 2 Analysis, Poison Control and Calibration Center (APCC), An-Najah National University, Nablus, Palestine
* Corresponding author: [email protected]
Challenges of Environment in the Arab Region Conference
Plastic revolution
Plastic bottles were first used commercially in 1947 but remained relatively expensive until the early 1950s when high-density
polyethylene was introduced.
Plastics production (tonnes x 10⁶)
Global plastics production
60,000 plastic bags, used every five seconds
2,000,000 plastic bottles, used every 5 minutes
Disadvantages of plastic
Anti-pollution strategy
Bioplastics
- bio-based, biodegradable… or both
- similar properties of conventional plastics
- additional advantages (reduced carbon footprint,
additional waste management options, composting).
1- Bio-based monomers obtained by fermentation or conventionalchemistry (e.g. lactic acid) and polymerized in a second step topolylactic acid (PLA).
2- Biopolymers synthesized directly in microorganisms or ingenetically modified crops (e.g. polyhydroxyalkanoate, PHA)
3- Natural biopolymers (e.g. polysaccharides and/or proteins)recovered from organic wastes.
Bioplastics of different origin
Bioplastics production (tonnes x 10⁶)
Global production capacities of bioplastics
Bioplastics application
Mulchingsheets
Edible films: coating and wrapping
Bio-plastics from Starch-based polymers Mater-Bi®
• Maize and/or potatoe starch in blend withpolycaprolactones and other biodegradable esters
• Europeas most common bioplastic
Source: www.novamont.com
Advantages Disadvantages
Polysaccharide-based
❑ Structural stability and goodmechanical properties.
❑ Poor water vapor and gasbarrier properties.
Protein-based ❑ Good mechanical, optical, andgas barrier properties.
❑ High sensitivity tomoisture and poor watervapor barrier properties.
Hydrocolloid materials
Nigella sativa defatted seed cake (NsDSC)
❑ Seed high nutritional value❑ Seed high yield
❑ UP to 50% proteins in the DSC❑ High protein solubility
Nigella sativa (Ns) seeds
Ns oil
Defatted
cake of Ns
Acid/base protein
extraction
❖Chitosan is a linear cationic polysaccharidederived from chitin,
❖is water-soluble, non-toxic, biocompatible, andexhibits antibacterial, antifungal and antitumoractivities,
❖adheres to negatively charged surfaces,
❖is widely used in food, agriculture, medicine,pharmaceutics and cosmetics.
More than 100 billion tons of chitin are annually produced
(Muxika et al., 2017)
Chitosan
Ref: Ciriminna et al., 2015, Biofuels, Bioprod. Bioref.
Pectin preparation
Film preparation
Film preparation procedure
NsDSCFilm
Zetasizer nano ZSP
TotalPerm apparatus
permeability meter
Instron universal testing
instrument model no. 5543A
FFS and film characterization
Scanning electron
microscope (SEM)
Bruker model ALPHA
FTIR-ATR spectrometer
Sealing machine with vacuum
Micrometer
2. Nanoparticles 1. Plasticizing
Improvements of bioplastics and edible films features
Improvement
3. Cross-linker
1. Plasticizers
SorbitolGlycerol (GLY)
Generally small and non-volatile organic additives used to:✓ increase film flexibility✓ reduce material cristallinity and brittleness✓ reduce intermolecular forces✓ increase free volume and polymer chain movements
Most used plasticizers
Polyamines
Spermine (SPM)
Spermidine (SPD)Putrescine
Development of chitosan (CH)-based films plasticized with SPD ± GLY
Ref: Sabbah et al., (2019) Food Hydrocolloids 96 (2019) 29–35
Film Thickness(µm)
TS (MPa)
EB(%)
YM(MPa)
Viscofan NDX 30.0 ± 3.0 36.6 ± 8.1b 13.1 ± 2.9 356.2 ± 29.1b
CH 0.6% 31.5 ± 4.2 52.2 ± 4.2a 10.1 ± 2.5 3438.1 ± 506.3a
+ 5 mM SPD 49.8 ± 4.2a,b 30.3 ± 4.5b 30.4 ± 3.5a,b 965.4 ± 36.6a
+25 mM GLY 80.7 ± 3.1a,b 12.5 ± 2.3a,b 82.5 ± 2.0a,b 130.5 ± 5.2a,b
+ 5 mM SPD + 25 mM GLY 82.0 ± 2.5a,b 8.5 ± 2.5a,b 118.7 ± 5.2a,b 24.4 ± 2.2a,b
Effect of SPD ± GLY on CH film mechanical properties
*Significantly different values compared to those observed analyzing Viscofan NDX (a) and to
those observed analyzing CH film obtained in the absence of plasticizers (b).
Ref: Sabbah et al., (2019) Food Hydrocolloids 96 (2019) 29–35
Grape Juice
NsDSCPowder
Grape Juice (GJ)
NsDSCFilm
1 2 4 6 8 10
20
Grape Juice (GJ) concentration (% v/w protein)
NsDSC with different GJ concentrations
Effect of GJ on film of NsDSC mechanical properties
2. Nanoparticles
Nanoparticles(NPs)
NPs
NsDSC
Protein concentratedCarbohydrate residue
Grinding
Dewaxing
Delignification
Bleaching
Hydrolysis
Ns-CNPs
NsDSC protein + Ns-CNPs film
Ns-CNPs
0
20
40
60
80
0 0.5 1 2 3
Ns-CNPs (%)
Thickness (µm)
0
5
10
15
20
25
0 0.5 1 2 3
Ns-CNPs (%)
TS (MPa)
0
5
10
15
20
25
30
0 0.5 1 2 3
Ns-CNPs (%)
EB (%)
0
150
300
450
0 0.5 1 2 3
Ns-CNPs (%)
YM (MPa)
Effect of differen concentration of Ns-CNPs on Ns-DSC films
Incubation at 37ºC for 2 h
mTGaseNsDSC
3. Crosslinking
Microbial transglutaminase
(mTGase) from
Streptoverticillium sp
Intra-molecular crosslink
H2N − CH2CH2CH2CH2
CH2CH2C − NH2
O
CH2CH2C N − CH2CH2CH2CH2
O
H
NH3
TG
+
H2N − CH2CH2CH2CH2
H2N − CH2CH2CH2CH2
CH2CH2C − NH2
O
CH2CH2C − NH2
OO
CH2CH2C N − CH2CH2CH2CH2
O
H
CH2CH2C N − CH2CH2CH2CH2
OO
HH
NH3
TGNH3
TGTG
+
CH2CH2C − NH2
O
NH2
CH2CH2CH2CH2
N
CH2CH2C
O
H
CH2CH2CH2CH2
NH3
TG
CH2CH2C − NH2
O
CH2CH2C − NH2
OO
NH2
CH2CH2CH2CH2 NH2
CH2CH2CH2CH2
N
CH2CH2C
O
H
CH2CH2CH2CH2
N
CH2CH2C
OO
H
CH2CH2CH2CH2
NH3
TGNH3
TGTG
Inter-molecular crosslink
Characteristics of microbial TG (EC, 2.3.2.13): • Active in a wide range of pH (4-9)
• Resistant between 4-60°C
• Commercially available
• Food grade
Characteristics of mTGase
NsDSC films obtained at different concentrations of GLY after incubation with or without TGase (20 U/g protein) at
pH 8.0
* ** *
60
80
100
120
140
160
10 20 30 50
Thic
knes
s (µ
m)
GLY (%)
- TGase + TGase
*
0
1
2
3
4
5
10 20 30 50
TS (
MPa
)
GLY (%)
*
0
10
20
30
10 20 30 50GLY (%)
*
50
100
150YM
(M
Pa)
*
*
0
40
80
120
160
200
240
10 20 30 50
EB (
%)
GLY (%)
Film thickness and mechanical properties of NsDSC films obtained in the presence and absence of TGase (20 U /g
protein) at pH 8
The antimicrobial activity on Staphylococcus aureus of Ns-DSC film with or without mTGase
Food Application
Heat sealability of BVPC and CH films
*Control materials
Film Seal strength (N/m)BVPC + 42 mM, GLY 33.35 ± 4.61
BVPC + 5 mM, SPD 57.44 ± 3.54
BVPC + 42 mM, GLY + 5 mM, SPD 43.61 ± 8.20
CH + 25 mM,GLY 196.42 ± 8.46
CH + 5 mM, SPD 65.06 ± 1.84
CH + 25 mM, GLY + 5 mM, SPD 82.80 ± 6.14
LDPE* 216.80 ± 4.52
HDPE* 205.52 ± 7.12
Mater-Bi* 201.46 ± 6.61
Different food products wrapped under vacuum by BVPC, CH or LDPE films
Sausage
Za’atar
Peanuts
Nabulsi cheese
➢ Fresh semi-hard dairy product with moisture contentranging from 45% to 55%
➢Stored in 15-20% brine solution.
Unwrapped and Film-wrapped Nabulsicheese under vacuum
Titratable acidity
(TA)pH
Unwrapped CH BVPC LDPE
Ref: Sabbah et al., (2019). Food Hydrocolloids 96. 29–35.
Effect of wrapping on cheese pH and TA at different storage times
salted Nabulsi cheese
unsalted Nabulsi cheese
salted Nabulsi cheese
unsalted Nabulsi cheese
Images of unwrapped and wrapped groups of strawberries during storage time (days)
Ref: Al-Asmar et al., (2020). Nanomaterials, 10, 52; doi:10.3390/nano10010052
Innovative bioplastics were produced:a) by using SPD and GJ as second plasticizer
b) by mTGase-crosslinking
- Improvements of the shelf-life of unsalted Nabulsi cheesewas obtained by its wrapping with GLY-plasticized BVPC-and CH-based bioplastics.
- Extended the shelf life ofstrawberry up to 8 day byusing PEC with MSN film
Conclusions
FUTUREPAST
Bioplastics/edible films
Petroleum-basedPlastics