Experimental investigation of compression strength of ventilated corrugated citrus packaging

Ventilated corrugated paperboard packaging is the most widely type of packaging used in postharvest handling and transportation of fresh horticultural produce, during which the package may be exposed to different environmental conditions. Ventilated packages should be designed in such a way that they can provide uniform airflow distribution without compromising mechanical integrity. This study investigated the effects of different storage conditions (−0.5°C at 90% RH; 4°C at 90% RH, 10° C at 90% RH) on the mechanical performance of two types of ventilated packaging [‘Supervent’ (4.7% vent area) and ‘Standard’ (3.1% vent area)] used for handling citrus fruit. The effects of storage condition on moisture content of package was also studied. Standard packaging showed higher compression strength than supervent packaging, presumably due to less vent area on the package. Maximum compressive strength reduction was found at storage temperature 4°C for both packages. The compressive strength of both packages decreased with increase in moisture content.

Effects of modified atmosphere packaging (MAP) on microbiological and sensory quality of ackee fruit arils (Blighia sapida Köenig) stored under refrigerated regimes

In this study, we investigated the effects of two modified atmosphere packaging films [Osmolux (Osx) and Oriented PolyPropylene (OPP)] on the microbiological and the sensory qualities of ackee fruit (Blighia sapida Köenig) arils stored during eight days under two refrigerated temperatures, 5 ±1°C and 10 ±1°C. The control samples of ackee arils were packaged in a macro-perforated highdensity polypropylene film (MP). The results showed that mesophilic aerobic bacteria (MAB), yeasts and moulds were lower under OPP, although MAB of MP was lower at 5°C. At 10°C, the pH of the ackee arils stored in Osx and OPP did not vary significantly, but the pH ofMP showed an increase from 5.32 to 5.95 and 5.83 at 5°C and 10°C, respectively. Results also showed that under OPP, weight losses were lower and averaged 0.12%and 0.19%after eight days storage at 5°C and 10°C, respectively, while the sensory quality attributes were preserved up to six days. Conclusively, OPP showed better attributes for MAP storage of ackee arils under refrigerated temperatures, although none of the two films were effective to reduce the chilling injury after the eight days storage.

MAP-OPT: A software for supporting decision-making in the field of modified atmosphere packaging of fresh non respiring foods

In this paper,we present the implementation of a dedicated software, MAP-OPT, for optimising the design of ModifiedAtmosphere Packaging of refrigerated fresh, nonrespiring food products. The core principle of this software is to simulate the impact of gas (O2/CO2) exchanges on the growth of gas-sensitive microorganisms in the packed food system. In its simplest way, this tool, associated with a data warehouse storing food, bacteria and packaging properties, allows the user to explore his/her system in a user-friendly manner by adjusting/changing the pack geometry, packaging material and gas composition (mixture of O2/CO2/N2). Via the @Web application, the data warehouse associated with MAP-OPT is structured by an ontology, which allows data to be collected and stored in a standardized format and vocabulary in order to be easily retrieved using a standard querying methodology. In an optimisation approach, the MAP-OPT software enables to determine the packaging characteristics (e.g. gas permeability) suitable for a target application (e.g. maximal bacterial population at the best-before-date). These targeted permeabilities are then used to query the packaging data warehouse using the@Web applicationwhich proposes a ranking of the most satisfying materials for the target application (i.e. packaging materialswhose characteristics are the closest to the target ones identified by the MAP-OPT software). This approach allows a more rational dimensioning of MAP of non-respiring food products by selecting the packaging material fitted to “just necessary” (and not by default, that with the greatest barrier properties). A working example of MAP dimensioning for a strictly anaerobic, CO2-sensitive microorganism, Pseudomonas fluorescens, is given to highlight the usefulness of the software.

Research Article. Role of ascorbic acid and iron in mechanical and oxygen absorption properties of starch and polycaprolactone multilayer film

A trilayer film based on thermoplastic starch (TPS) for the core layer and poly(ε-caprolactone) (PCL) for the skin layers was obtained by coextrusion. Ascorbic acid and iron powder were added at respectively 15% and 1.5% w/w in the TPS layer for their capacity to act as oxygen scavenger, making the film usable as active food packaging. This study demonstrates that these compounds also play a role in the interactions between the different layers. FTIR measurements show that ascorbic acid migrates at the interface between TPS and PCL, where it acts as a compatibiliser between both polymers, probably by creating new interactions between polar functions of both polymers. This leads to a better adhesion of the different layers, demonstrated by the increase of the adhesion energy from 4.10−3 N·mm−1 for the multilayer film TPS-PCL to 12.10−3 N·mm−1 for the multilayer film containing the active components. Thanks to this compatibilising effect, the mechanical properties of the multilayer film containing ascorbic acid and iron are widely improved with an average maximal tensile strength of 7 MPa, against 3.7 MPa for the multilayer film without the active components and with an elongation at break of respectively 1450% against 290%. However, despite the hydrophobicity of PCL, the water sorption of the TPS-based layer is only slightly reduced. The multilayer film shows active oxygen scavenging properties but the rate of this reaction is divided by two compared to the active film without PCL layers (15 days to reach less than 1% oxygen for the active film without PCL layers and approximately 30 days to reach the same oxygen level with the multilayer active film).

Changes in moisture content and compression strength during storage of ventilated corrugated packaging used for handling apples

This study investigated the effects of cold storage (−0.5∘C at 90% RH) on the mechanical performance of ‘MK4’ ventilated packaging used for handling pome fruit. The packages were stored over a period of 43 days. Compression strength of packages was measured by Lansmont squeezer compression testing machine on day 2, 4, 6 and 8 and then weekly over 6 weeks. The effect of storage duration on package moisture content and compression strength was also examined. Maximum compressive strength was reduced from 7351 to 3872 N after 2 days of storage. The package compressive strength decreased with an increase in moisture content. Average compression strength was observed to decrease by 618 N per one percent increase in moisture content. Pseudo first order kinetic model could satisfactorily analyse the adsorption of water by corrugated package with coefficient of determination of 0.9816 and standard error of 0.2554. Relationship between package compression strength with change in moisture during storage showed good correlation.

Applicability of biobased packaging materials for long shelf-life food products

The research aim was to evaluate the applicability of biobased plastics for packing long shelf-life food products, both on laboratory and industrial scale. Therefore, the shelf-life (room temperature) of tortilla chips, dry biscuits and potato flakes packed under air or modified atmosphere (MAP) in xylan and cellulose-based packages was evaluated and compared with their shelf-life in reference (conventional) packaging materials. These tests were followed by packaging trials on industrial lines. Furthermore, overall migration studies and printability tests were performed. Most of the biobased packages showed sufficient barrier towards moisture and gasses to serve as a food packaging material and MAP packaging of long shelf-life food products is possible. But for very moisture-sensitive food products (e.g. dry biscuits), no suited packaging material was found. The quality of the tortilla chips and potato flakes could be guaranteed during their shelf-life, even if packaging materials with lower barrier properties were used. Still, brittleness and seal properties are critical for use on industrial scale (important for use on vertical flow packaging machines). Furthermore, the films were printable and migration tests showed compliance with legislation. This study shows promising results towards the industrial application of biobased packaging materials for long shelflife food products.