Areas of competencePhoto: Manuel Gutjahr
The working group Packaging and Storage focuses on development and testing of innovative technologies for maintaining quality and shelf life of fruit and vegetables and optimising packaging and storage along supply chain of horticultural commodities (see also 'Rethinking packaging').
Our research topics are Modified Atmosphere Packaging (MAP), Modified Atmosphere and Humidity Packaging (MAHP), Controlled Atmosphere (CA) Storage, Ethylene Management and Packaging Design based on Mathematical Modelling.
Modified Atmosphere Packaging (MAP) involves the packaging of whole or fresh-cut horticultural commodities in plastic tray covered with a permeable film. In MAP, the equilibrium concentrations of O2 and CO2 in the package are a function of the product mass and respiration rate and permeability to gases of films used in packaging. Our aim is to ﬁnd the most appropriate packaging material or the number and size of perforations required to match the respiration rate for each speciﬁc fresh product at given supply chain conditions.
Modified Atmosphere and Humidity Packaging (MAHP): Most of the packaging films used in MAP have low gas permeability leading to moisture condensation. In turn, condensation favours growth of spoilage microorganism which subsequently accelerates decay of the produce. Our aim is to develop different moisture control strategies and evaluate their efficacy in maintaining quality and safety of fresh produce.
Controlled Atmosphere (CA) Storage: In CA storage, O2 and CO2 concentrations are monitored and controlled within the preselected limits. A new trend is "dynamic CA system" in which the conditions are constantly adjusted to the fruit’s respiratory activity. Such system offers control of O2 concentration according to the respiratory quotient (RQ) that gives safe lowest O2 limit during long-term storage of fruits. Our aim is to develop and apply sensor-based system for real-time in-situ monitoring of respiration rate and RQ in the DCA system.
Ethylene Management: Ethylene is a colourless and odourless gas. It is produced by fresh produce and speeds up their ripening and decay. Controlling ethylene is also very important as even with best refrigeration, high ethylene accumulation will ripen fruits quickly. We are working on novel methods of ethylene removal such as photocatalysis, photolysis and nano-clay materials for integration into packaging and storage systems.
Packaging Design based on Mathematical Modelling: Packaging design for fresh produce needs appropriate selection of materials based on the gas and water vapour permeability, respiration rate and transpiration of a specific fruit, while considering the storage temperature, package size, amount of product and optimum O2, CO2 and humidity conditions for that product and minimise moisture condensation. Our engineering background helped us to develop predictive mathematical models for packaging design and shelf life of fresh produce. Such models are now applied for packaging material selection, simulations and validation with lab-scale and commercial-scale trials for a variety of products.
Matlab code for simulation of package headspace and shelf life: The simulation program provides a flexible system to input predefined supply chain conditions and the properties of fresh produce and packaging material. It supports, thus, minimizing the costly and time-consuming experimental procedures for selecting the optimum packaging material for fresh produce. Produce-package-atmosphere systems are integrated into the form of ordinary differential equations and solved using numerical methods in MATLAB.
The simulation program is useful for designing the size and number of perforations to achieve equilibrium modified atmosphere packaging (EMAP) alone or in combination with packaging material having a higher water transmission rate or active moisture absorber. It is also useful for predicting the shelf life of fresh produce under the actual supply chain conditions.
More information open access (Please cite this paper when using the software in scientific papers): Jalali A., Linke M., Geyer M. and Mahajan P. (2021). Integrative programming for simulation of packaging headspace and shelf life of fresh produce. MethodsX, 8, 101514. https://doi.org/10.1016/j.mex.2021.101514
Matlab code download: https://github.com/B-PM-375/Food-Packaging-Simulation
- Respiration measurement systems, different types: stationary, mobile or modular
- Cooling rooms, with computerised control and monitoring system
- CA chambers, total 24 chamber with individual control of O2 and CO2 gases
- Ethylene measurement, ETD-300 for precise ethylene measurement
- GC, dedicated for use in high ethylene concentrations
- GC-MS, for analysing volatile organic compounds
- Thermographic camera system, for fruit surface temperature measurement
- Sensors and data loggers, for measurement of temperature, humidity, gases, air flow
- Gas mixer, for any combination of O2, CO2, N2 and C2H4
- Packaging machine, with modified atmosphere and tray heat sealing
- Gas analyser, with manual/automatic measurement of O2 and CO2
- Permeability system, for measurement of O2, CO2, H2O of packaging material
- Packaging materials, different polymers including bio-based and biodegradable polymers
- Scavenging materials, for ethylene and moisture ab/adsorption
- 3D system, for measurement of true surface and volume of fruit and vegetables
- Software programs, for packaging design, shelf life prediction and respiration analysis
- Photo camera system, for still and time lapsed photo recording
- Photo-catalytic reactor, for ethylene oxidation using TiO2 and UV lights
- Photolysis, for ethylene oxidation using vacuum UV lights
- Humidity generator, for calibration and creation of stable humidity conditions
- Standard gases, for calibration and preparation of modified atmospheres
- Ethylene removal system, for continuous air cleaning in the laboratory
- Ozone system, for generation and filtration of ozone in the chambers