Universidade do Minho
Instituto para a Biotecnologia e a Bioengenharia
NanoPackSafer – um novo sistema de
embalagem de alimentos
António A. Vicente
Departamento de Engenharia Biológica
avicente@deb.uminho.pt
NanoPackSafer
OBJECTIVE: This proposal aims at developing
nanotechnology-based food protection strategies by providing
active packaging systems which will proactively act to maintain
or even to increase food quality, safety and health impact of
foods from production to consumption.
Nanotechnology
According to the European Commission’s
Recommendation (EFSA):
Nanomaterial means a material that meets at least one of the following
criteria:
• consists of particles, with one or more external dimensions in the size range
1 nm - 100 nm for more than 50 % of their number size distribution;
• has internal or surface structures in one or more dimensions in the size
range 1 nm – 100 nm;
• has a specific surface area by volume greater than 60 m2/cm3, excluding
materials consisting of particles with a size lower than 1 nm.
Nanotechnology
According to the US Food and Drug Administration (FDA):
Nanomaterial:
• If an engineered material or final product has at least one dimension at the
nanometer scale (1 - 100 nanometers)
• If an engineered material or final product shows properties or phenomena
(including physical, chemical or biological effects) attributable to its
dimensions, including if these lay out of the nanometer scale, up to the
micrometer
Functionality
Motivation
Consumers
Environment
All bio-materials from renewable sources
All food-grade, edible materials
Nano-sized systems
Ethical aspects
Nano-engineered
films
andcoatings
coatings
From
Macro to Microfilms
to Nano
Nano-engineered
and
- Clay
nanoparticles
- Can
you
see me?
Can
you
see
me?
Nano-engineeredfilms
filmsand
andcoatings
coatings
Nanotechnology
Nano-engineered
- Clayrevolution
nanoparticles
– the promise of a food
 Improved sensorial properties
 Healthier and more nutritious foods
 Better packaging systems
 Traceability and monitoring along food chain
Materials at the nano scale have different properties
Nano-engineered films and coatings
- nanolaminates
Nano-engineered films and coatings
- nanolaminates
A nanolaminate is a film or coating composed of two or more layers of material
with nanometer dimension that are physically or chemically bonded to each other
Need for successive layers of materials:
•
•
•
Better physical stability in aggressive environments
Better chemical stability of the incorporated compounds
Improved control of the release rates
•
Coexistence of possibly incompatible functionalities
Advantages of being nano-sized:
•
•
•
Lesser amounts of ingredients needed
Less impact in the sensory attributes of foods
Different behaviour expected in terms of transport properties
-
Of gases
-
Of entrapped (functional) solutes
Nano-engineered films and coatings
- nanolaminates
10
Nano-engineered films and coatings
- nanolaminates
Alginate layers
Chitosan layers
11
Nano-engineered films and coatings
- nanolaminates
 Characterization
of the nanolayered film
Gas barrier properties
Films
1
2
Thickness WVP x 1011
(g.m-1.s-1.Pa-1)
(µm)
Improved
barrier
O2P x 1014
Improved
barrier
(g.m.Pa-1.s-1.m-2)
Aminolyzed
PET
103.00
1.42 ± 0.39
---------
2.50 ± 0.03
--------
PET + 5
layers
103.27
1.08 ± 0.10
---------
2.12 ± 0.03
--------
5 layers
0.27
0.019 ±
0.005
---------
0.069 ±
0.006
--------
Pectin1
100-150
61.9 ± 5.6
14.2 %
------------
---------
Chitosan2
45-50
8.60 ± 0.14
38.9 %
7.12 ± 0.23
170 %
Hoagland and Parris (1996). Journal of Agricultural and Food Chemistry, 44, 1915-1919
Fajardo et al. (2010). Journal of Food Engineering.
Release from chitosan nanolayered films in
liquid medium
K-carrageenan/chitosan nanolayered film with a model compound
(Methylene Blue) incorporated on the 2nd, 4th or 6th layer
UV-VIS spectroscopy, 190-800
1.8
MB in second layer
aminolyzed
PET
1.6
nm
MB in fourth layer
1.4
MB in sixth layer
Absorbance
1.2
1
0.8
0.6
0.4
0.2
- - - -
water
++ +
+ +
0
400
550
600
650
700
Wavelength (nm)
Adsorption (ug/cm2)
Positively Charged:
0.2 % chitosan, pH 3 or
0.3 % of Methylene Blue, pH 7
500
water
Real time deposition
Quartz Crystal Microbalance
30
Negatively Charged:
0.2 % k-carrageenan pH 7
450
25
20
MB in second layer
15
MB in fourth layer
MB in sixth layer
10
5
0
0
500
1000
Time (s)
1500
Release from chitosan nanolayered films in
liquid medium
MB release from nano layered films
Nanolayered films with MB in the:
2nd Layer
4th Layer
6th Layer

Incubation of films in 0.01 M PBS

pH 2 and 7

MB release evaluated by UV-VIS
spectroscopy at 600 nm
Release from chitosan nanolayered films in
liquid medium
MB release from nano layered films
Nanolayered films with MB in the 6th Layer
1,2
1
Mt/M∞
0,8
Experimental
Eq. 1
Eq. 2
0,6
0,5
0,4
0
0,2
-15
-5
5
15
0
-20
60
140
220
time (min)
300
380
Fick´s transport
Anomalous behaviour
ok
– Fick + 1 main reconfiguration
Release from chitosan nanolayered films in
liquid medium
MB release from nano layered films
Nanolayered films with MB in the 2nd and 4th Layers
pH=7
pH=2
Fick´s transport
Fick´s transport
Anomalous behaviour
Anomalous behaviour
– Fick + 1 main reconfiguration
+ + + + + + ++ + +
- -- - - - - - - - + + + + + + ++ + +
- -- - - - - - - - Strong electrochemical
interaction
- affects the transport mechanism,
which cannot be described by
neither Fickian nor anomalous
behaviour
ok
– Fick + 1 main reconfiguration
+ + + + + + ++ + +
+ + + + + + ++ + +
+ + + + + + ++ + +
+ + + + + + ++ + +
“Normal” interaction
-behaves as a “macro” polymeric
network
Applications
 Application
on mangoes
Contact angle
Applications
 Application
on mangoes – Shelf-life analysis
Weight loss
4.5
Mangoes without nanolayers
4
Weight Loss(%)
3.5
Mangoes with nanolayers
3
2.5
2
1.5
1
0.5
0
0
7
14
21
28
35
42
49
Days
The pectin/chitosan nanolayers reduced the weight loss of the mangoes.
Applications
on mangoes – Shelf-life analysis
 Application
Soluble solids (SS)
Titratable acidity (TA)
0.9
19
17
Mangoes without nanolayers
0.7
Mangoes with nanolayers
0.6
TA (%)
15
SS (%)
0.8
13
11
0.5
0.4
0.3
0.2
Mangoes without
nanolayers
9
0.1
7
0
7
14
21
28
Days
35
42
49
0
0
7
14
21
28
35
42
Days
Mangoes with nanolayers: Lower SS variation and lower redution of TA
Delay in ripening
49
Applications
 Application
Without coating
With
pectin/chitosan
nanolayers
on mangoes – Appearance after 45 days
Applications
Application on pears – Appearance after 7 days of refrigerated storage
21
Take-home messages
Plenty of room for improvement of food nano-systems
Need to improve detection/characterization methods
Countless applications in foods
Need to evaluate impact on health
Need to evaluate impact on environment
Ethical aspects?
Thank you for your attention