nanopacksafer – um novo sistema de embalagem de alimentos antónio a. vicente departamento de...
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NanoPackSafer – um novo sistema de embalagem de alimentos
António A. Vicente
Departamento de Engenharia Biológica
Universidade do Minho
Instituto para a Biotecnologia e a Bioengenharia
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):
Nanotechnology
According to the US Food and Drug Administration (FDA):
Functionality
Motivation
Consumers
Environment
All bio-materials from renewable sources
All food-grade, edible materials
Nano-sized systems
Ethical aspects
Nano-engineered films and coatings- Clay nanoparticles
Nano-engineered films and coatingsNano-engineered films and coatings- Clay nanoparticles
Nano-engineered films and coatingsNano-engineered films and coatings- Clay nanoparticles
Nano-engineered films and coatingsFrom Macro to Micro to Nano- Can you see me?
Can
you
see
me?
Materials at the nano scale have different properties
Improved sensorial properties
Healthier and more nutritious foods
Better packaging systems
Traceability and monitoring along food chain
Nano-engineered films and coatings- Clay nanoparticles
Nano-engineered films and coatingsNano-engineered films and coatings- Clay nanoparticles
Nano-engineered films and coatingsNano-engineered films and coatings- Clay nanoparticles
Nano-engineered films and coatingsNanotechnology – the promise of a food revolution
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
Alginate layers
Chitosan layers
Nano-engineered films and coatings- nanolaminates
11
Characterization of the nanolayered film
Films Thickness (µm)
WVP x 1011
(g.m-1.s-1.Pa-1)Improved
barrierO2P x 1014
(g.m.Pa-1.s-1.m-2)
Improved barrier
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 %
Gas barrier properties
1 Hoagland and Parris (1996). Journal of Agricultural and Food Chemistry, 44, 1915-19192 Fajardo et al. (2010). Journal of Food Engineering.
Nano-engineered films and coatings- nanolaminates
aminolyzed PET
Positively Charged:0.2 % chitosan, pH 3 or 0.3 % of Methylene Blue, pH 7
water water
-carrageenan/chitosan nanolayered film with a model compound
(Methylene Blue) incorporated on the 2nd, 4th or 6th layer
Negatively Charged:0.2 % -carrageenan pH 7
+++
++- -
- ---
0
5
10
15
20
25
30
0 500 1000 1500
Adso
rptio
n (u
g/cm
2 )
Time (s)
MB in second layer
MB in fourth layer
MB in sixth layer
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
400 450 500 550 600 650 700
Abs
orba
nce
Wavelength (nm)
MB in second layer
MB in fourth layer
MB in sixth layer
UV-VIS spectroscopy, 190-
800 nm
Real time deposition Quartz Crystal Microbalance
Release from chitosan nanolayered films in liquid medium
Nanolayered films with MB in the:
2nd Layer
4th Layer
6th Layer
MB release from nano layered films
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
Nanolayered films with MB in the 6th Layer
MB release from nano layered films
0
0,2
0,4
0,6
0,8
1
1,2
-20 60 140 220 300 380
Mt/M
∞
time (min)
ExperimentalEq. 1Eq. 2
0
0,5
-15 -5 5 15
Fick´s transport
Anomalous behaviour – Fick + 1 main reconfiguration
ok
Release from chitosan nanolayered films in liquid medium
Nanolayered films with MB in the 2nd and 4th Layers
MB release from nano layered films
Fick´s transport
Anomalous behaviour – Fick + 1 main reconfiguration
pH=7
+ + + + + + + + ++- - - - - - - - - - -
+ + + + + + + + ++- - - - - - - - - - -
Strong electrochemical interaction - affects the transport mechanism, which cannot be described by neither Fickian nor anomalous behaviour
+ + + + + + + + ++
+ + + + + + + + +++ + + + + + + + ++
+ + + + + + + + ++
Fick´s transport
Anomalous behaviour – Fick + 1 main reconfiguration
pH=2
ok
“Normal” interaction -behaves as a “macro” polymeric network
Release from chitosan nanolayered films in liquid medium
Application on mangoes
Contact angle
Applications
Application on mangoes – Shelf-life analysis
Weight loss
The pectin/chitosan nanolayers reduced the weight loss of the mangoes.
Applications
Application on mangoes – Shelf-life analysis
Soluble solids (SS) Titratable acidity (TA)
Mangoes with nanolayers: Lower SS variation and lower redution of TA
Delay in ripening
Applications
Applications
Application on mangoes – Appearance after 45 days
Without coating
With pectin/chitosan
nanolayers
Application on pears – Appearance after 7 days of refrigerated storage
Applications
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