A analysis crew on the University of Cadiz (Spain), along with researchers from the University of Aveiro (Portugal) from the analysis group Biopol4fun, have developed a bioactive or functionalised plastic constituted of nanofibrillated cellulose and mango leaf extracts that preserves meals longer than non-functionalised plastics.
This packaging is meant to keep up the properties of meals for an extended interval with out the necessity to add chemical additives, because the packaging itself acts as an energetic barrier that favors preservation. This is as a result of this biodegradable movie comprises antimicrobial and antioxidant compounds from mango leaf extract which have been examined in vitro, whereas on the similar time providing a extra highly effective ultraviolet gentle filter that delays meals spoilage.
In order to succeed in these conclusions, the researchers in contrast two totally different strategies for acquiring the packaging. The typical one consists of dissolving the elements in a solvent, which is later eliminated. The different various process doesn’t require the usage of chemical solvents, however makes use of supercritical CO2 to functionalize the polymer, which supplies the bioplastic with simpler physico-chemical and bioactive properties than these obtained by typical remedy. The novelty of this examine lies in the truth that it validates the latter technique of acquiring this movie which prolongs meals preservation and, on the similar time, acts as a barrier towards meals pathogens.
This bioactive packaging, that’s, with antimicrobial and antioxidant properties from mango leaf extract, will increase the protecting barrier towards ultraviolet gentle. “Thanks to it, food wrapped in this film could be preserved longer without the addition of preservatives. The film itself replaces the chemical additive, since the active substance exerts its effect via the packaging without the need to add anything to the food,” Cristina Cejudo, researcher on the University of Cadiz and co-author of the examine, identified to Fundación Descubre.
To develop this bioplastic, the specialists used mango leaf extracts from pruning stays from the cultivation of this fruit on the experimental farm of the Institute of Subtropical and Mediterranean Horticulture “La Mayora’ in Malaga (Spain). The nanofibrillated cellulose that kinds the polymer comes from the chemical and enzymatic remedy of a paper business waste product.
Conventional solvent casting vs supercritical solvent impregnation
With these supplies, the analysis crew has used two totally different procedures to match their bodily properties and bioactive perform, as defined within the examine, titled “Biobased films of nanocellulose and mango leaf extract for active food packaging: Supercritical impregnation versus solvent casting,” printed within the journal Food Hydrocolloids.
On the one hand, researchers used the standard casting technique, which consists of including the energetic compound earlier than polymerising the plastic, that’s, earlier than binding its compounds. The course of due to this fact consists of dissolving the mango leaf extract and the nanocellulose and subsequently polymerising and drying the solvents at a temperature of 45ºC.
For the remedy based mostly on the supercritical impregnation know-how, they used an extract beforehand obtained by the identical approach. “By doing so, a better dissolution of the extract is achieved during the impregnation of the polymer, since the mango extract penetrates into the composition of the nanocellulose at the surface level, which favors the migration of the active compounds, thereby taking less time to exert its preservative action,” explains researcher Cejudo.
An extra benefit of the supercritical approach is that the pathogen inhibition is larger because of the number of probably the most bioactive compounds in mango extract for supercritical impregnation. This provides the plastic the next focus of those compounds than the standard approach. “As a result, the active properties of the mango remain intact after impregnation, which increases the film’s ability to protect food,” says Cejudo.
With these outcomes, the analysis crew has verified the effectiveness of the supercritical impregnation approach to acquire this new bioactive packaging. “This treatment is effective and valid because it helps to preserve food with a more perishable shelf life and also offers the advantage that it can be applied without the use of solvents or artificial chemical compounds,” says the professional.
Whereas with the standard technique the container is orange-colored resulting from a stronger interplay of the mango with the polymer, with the supercritical impregnation it acquires a greenish shade, just like that of the unique combination, as a result of the deposition is extra superficial, which additionally favors a sooner efficiency of the compounds throughout packaging.
In vitro checks on meals pathogens
At the identical time and with a purpose to check the efficacy of the brand new packaging obtained by supercritical impregnation, the analysis crew evaluated in vitro the antimicrobial efficiency towards two meals pathogens: Staphylococcus aureus and Escherichia coli.
With this check, they discovered that the mango polyphenols current within the bioactive movie stop the unfold of each microorganisms resulting from their antimicrobial properties. “This result shows that the new bioplastic can be used as packaging to inhibit the spread of pathogens and prevent food spoilage,” factors out Cejudo.
Besides, the presence of the extract within the movie will increase the UV-barrier, which scale back the quantity of incident gentle that additionally causes meals spoilage, particularly on meals containing oxidable compounds reminiscent of lipids.
This examine is along with an analogous one they carried out a yr in the past to design one other novel type of packaging utilizing a meals plastic to which they added beetroot extract, wealthy in antioxidant compounds. After finishing up a preliminary check, they achieved a product that goals to enhance the traits of the containers presently used to offer longer shelf life to the food with out it dropping its properties.
The subsequent step for this analysis crew might be to check how this bioactive packaging responds to preserving especific meals and to analyse its efficiency at pilot scale.
Cristina Cejudo Bastante et al, Biobased movies of nanocellulose and mango leaf extract for energetic meals packaging: Supercritical impregnation versus solvent casting, Food Hydrocolloids (2021). DOI: 10.1016/j.foodhyd.2021.106709
Bioplastic manufactured from nanocellulose and mango to enhance meals preservation (2021, July 26)
retrieved 26 July 2021
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