Effect of storage conditions on the shelf-life extension of fungus-colonized substrates based on Metarhizium anisopliae using modified atmosphere packaging

Metarhizium anisopliae is a promising alternative to chemical pesticides against pine wilt disease caused by Bursaphelenchus xylophilus. Herein, we investigated the efficacy of modified atmosphere packaging (MAP) to prolong the shelf-life of the M. anisopliae conidia. The effects of various conditions on its stability were also examined. M. anisopliae-inoculated millet grains were treated in a MAP system with different packaging materials (polypropylene, PP; polyethylene terephthalate, PET; ethylene vinyl alcohol, EVOH), gas compositions (high CO2 atmosphere, ≈ 90%; high O2 atmosphere, > 95%; high N2 atmosphere, > 95%; 30% CO2 + 70% N2; 50% CO2 + 50% N2; 70% CO2 + 30% N2), and storage temperatures (4 and 25 °C). Results revealed EVOH film as the best for the preservation of gases at all concentrations for 28 days. MAP treatment in the high-barrier EVOH film under an atmosphere of 30% CO2 + 70% N2 achieved 80.5% viability of dried conidia (7.4% moisture content), with 44.2–64.9% viability recorded with the other treatments. Cold storage for technical concentrates formulation promoted extension of shelf-life of MAP-treated conidia. These results imply that MAP under optimized conditions could enhance the shelf-life of fungus-based biopesticides in fungus-colonized substrates formulations.

Effect of Modified Atmosphere Packaging (MAP) and UV-C Irradiation on Postharvest Quality of Red Raspberries

Red raspberries (Rubus idaeus L.) are highly appreciated by consumers. However, their postharvest shelf life scarcely exceeds 5 d under the refrigeration temperatures usually applied during commercialization, due to their high susceptibility to dehydration, softening and rot incidence. Thus, the objective of this study was to investigate the ability of UV-C radiation (UV1: 2 kJ m−2 and UV2: 4 kJ m−2), passive modified atmosphere packaging (MAP) with transmission rates (TR) for O2 and CO2 of 1805 mL d−1 and 1570 mL d−1 (MAP1), and 902 mL d−1 and 785 mL d−1 (MAP2), respectively, and the combination of both technologies to prolong raspberries’ shelf life at 6 °C. Their influence on respiration, physicochemical parameters, and microbiological and nutritional quality was assessed during 12 d of storage. The combination of 4 kJ m−2 UV-C radiation and a packaging film with O2 and CO2 transmission rates of 902 mL d−1 and 785 mL d−1, respectively, produced a synergistic effect against rot development, delaying senescence of the fruit. The UV2MAP2 and MAP2 samples only showed 1.66% rot incidence after 8 d of storage. The UV2MAP2 samples also had higher bioactive content (1.76 g kg−1 of gallic acid equivalents (GAE), 1.08 g kg−1 of catechin equivalents (CE) and 0.32 g kg−1 of cyanidin 3-O-glucoside equivalents (CGE)) than the control samples at the end of their shelf life. Moreover, the mass loss was minimal (0.56%), and fruit color and firmness were maintained during shelf life. However, the rest of the batches were not suitable for commercialization after 4 d due to excessive mold development.

Effect of Locust Bean Gum-Sodium Alginate Coatings Combined with High CO2 Modified Atmosphere Packaging on the Quality of Turbot (Scophthalmus maximus) during Refrigerated Storage

This research was conducted to investigate the effect of active coatings composed of locust bean gum (LBG) and sodium alginate (SA) containing daphnetin emulsions (DEs) combined with modified atmosphere packaging (MAP) on the microbiological and physicochemical properties of turbot during 4 °C refrigerated storage for 32 days. The results revealed that LBG-SA-DE coatings together with high CO2 MAP (60% CO2/35% N2/5% O2) maintained the total viable count (TVC) of H2S-producing bacteria in 4–6 lg CFU/g, which is lower than the limit (7 lg CFU/g). In addition, LBG-SA-DE coatings together with high CO2 MAP (60% CO2/35% N2/5% O2) inhibited the production of odor compounds, including thiobarbituric acid (TBA), trimethylamine-nitrogen (TMA-N), K value, and total volatile basic nitrogen (TVB-N). The low-field NMR analysis (LF-NMR) and magnetic resonance imaging (MRI) indicated that LBG-SA-DE coatings together with high CO2 MAP (60% CO2/35% N2/5% O2) treatments could delay the release of water located in muscle fiber macromolecules or convert it into free water based on muscle fiber destruction, thus maintaining the water content and migration. The results of the sensory evaluation showed that turbot treated with LBG-SA-DE coatings together with MAP could maintain its freshness during refrigerated storage.

Towards Impact of Modified Atmosphere Packaging (MAP) on Shelf-Life of Polymer-Film-Packed Food Products: Challenges and Sustainable Developments

In this article, we report in detail the use of protective gases to extend the shelf-life of polymer-film-packed foodstuff and reduce the most typical bacteria and microorganisms that negatively affect the quality and lifetime of a given packaging. This article provides significant information about the most important advantages of using protective gases and examples of gases or gas mixtures which can be used for almost every kind of foodstuff depending on the application. We also discuss how protective gases change the level of microorganisms in food using gases and how the shelf-life of food can be enhanced using correct gases or gas mixtures. The article also provides imperative information on the selection of correct protective gases for specific applications, especially for food production, to preserve against the most typical threats which can appear during the packaging or production process. Packaging innovations can reduce the environmental impact of food and polymer packaging waste by prolonging products’ shelf-lives and by reducing waste along the production and distribution chain and at the household level.