Characterization of Sodium Alginate-Based Films Blended with Olive Leaf and Laurel Leaf Extracts Obtained by Ultrasound-Assisted Technology.

Due to environmental concerns, there is an increasing need to reduce the use of synthetic and non-renewable packaging materials to reduce waste and increase sustainability. This study aimed to characterise sodium alginate edible-based films (SA) incorporated with laurel leaf extract (LLE) and olive leaf extract (OLE) obtained by ultrasound-assisted extraction. Determination of total phenolic content, antioxidant, and antimicrobial activity was performed for the extracts and films. Also, thickness, tensile strength, elongation at break, modulus of elasticity, opacity and colour, moisture content, water vapour permeability (WVP), Fourier-transform infrared spectroscopy (FTIR) spectra, and surface morphology by scanning electron microscope (SEM) analyses were performed for the films. LLE yielded better results in terms of phenolic content (195 mg GAE/g), antioxidant (2.1 TE/g extract) and antimicrobial activity (MIC at 1% for Listeria monocytogenes and Staphylococcus aureus, and 1.8% for Enterococcus faecalis). For the films, the simultaneous incorporation of LLE 1% (w/v) and OLE 1% (w/v) resulted in a significant reduction of approximately 2 log CFU/g against S. aureus. The addition of LLE and OLE extracts also proved to improve barrier properties (lower WVP for SA films with LLE 1% + OLE 1%, 3.49 × 10-11 g m-1 s-1 Pa-1) and promoted changes in resistance and flexibility. The results demonstrated that active alginate-based films can be valuable for enhancing food preservation.

Herbicide and Cytogenotoxic Activity of Inclusion Complexes of Psidium gaudichaudianum Leaf Essential Oil and ß-Caryophyllene on 2-Hydroxypropyl-ß-cyclodextrin.

The present investigation aimed to develop inclusion complexes (ICs) from Psidium gaudichaudianum (GAU) essential oil (EO) and its major compound ß-caryophyllene (ß-CAR), and to evaluate their herbicidal (against Lolium multiflorum and Bidens pilosa) and cytogenotoxic (on Lactuca sativa) activities. The ICs were obtained using 2-hydroxypropyl-ß-cyclodextrin (HPßCD) and they were prepared to avoid or reduce the volatility and degradation of GAU EO and ß-CAR. The ICs obtained showed a complexation efficiency of 91.5 and 83.9% for GAU EO and ß-CAR, respectively. The IC of GAU EO at a concentration of 3000 µg mL-1 displayed a significant effect against weed species B. pilosa and L. multiflorum. However, the ß-CAR IC at a concentration of 3000 µg mL-1 was effective only on L. multiflorum. In addition, the cytogenotoxic activity evaluation revealed that there was a reduction in the mitotic index and an increase in chromosomal abnormalities. The produced ICs were able to protect the EO and ß-CAR from volatility and degradation, with a high thermal stability, and they also enabled the solubilization of the EO and ß-CAR in water without the addition of an organic solvent. Therefore, it is possible to indicate the obtained products as potential candidates for commercial exploration since the ICs allow the complexed EO to exhibit a more stable chemical constitution than pure EO under storage conditions.

Current Applications of Bionanocomposites in Food Processing and Packaging.

Nanotechnology advances are rapidly spreading through the food science field; however, their major application has been focused on the development of novel packaging materials reinforced with nanoparticles. Bionanocomposites are formed with a bio-based polymeric material incorporated with components at a nanoscale size. These bionanocomposites can also be applied to preparing an encapsulation system aimed at the controlled release of active compounds, which is more related to the development of novel ingredients in the food science and technology field. The fast development of this knowledge is driven by consumer demand for more natural and environmentally friendly products, which explains the preference for biodegradable materials and additives obtained from natural sources. In this review, the latest developments of bionanocomposites for food processing (encapsulation technology) and food packaging applications are gathered.

Methodologies to Assess the Biodegradability of Bio-Based Polymers-Current Knowledge and Existing Gaps.

Our society lives in a time of transition where traditional petroleum-based polymers/plastics are being replaced by more sustainable alternative materials. To consider these bioproducts as more viable options than the actual ones, it is demanded to ensure that they are fully biodegradable or compostable and that there is no release of hazardous compounds to the environment with their degradation. It is then essential to adapt the legislation to support novel specific guidelines to test the biodegradability of each biopolymer in varied environments, and consequently, establish consistent data to design a coherent labeling system. This review work aims to point out the current standards that can serve as a basis for the characterization of biopolymers' biodegradation profile in different environments (soil, compost, and aquatic systems) and identify other laboratory methodologies that have been adopted for the same purpose. With the information gathered in this work, it was possible to identify remaining gaps in existing national and international standards to help establish new validation criteria to be introduced in future research and policies related to bioplastics to boost the sustainable progress of this rising industry.

Bio-Based Sensors for Smart Food Packaging-Current Applications and Future Trends.

Intelligent food packaging is emerging as a novel technology, capable of monitoring the quality and safety of food during its shelf-life time. This technology makes use of indicators and sensors that are applied in the packaging and that detect changes in physiological variations of the foodstuffs (due to microbial and chemical degradation). These indicators usually provide information, e.g., on the degree of freshness of the product packed, through a color change, which is easily identified, either by the food distributor and the consumer. However, most of the indicators that are currently used are non-renewable and non-biodegradable synthetic materials. Because there is an imperative need to improve food packaging sustainability, choice of sensors should also reflect this requirement. Therefore, this work aims to revise the latest information on bio-based sensors, based on compounds obtained from natural extracts, that can, in association with biopolymers, act as intelligent or smart food packaging. Its application into several perishable foods is summarized. It is clear that bioactive extracts, e.g., anthocyanins, obtained from a variety of sources, including by-products of the food industry, present a substantial potential to act as bio-sensors. Yet, there are still some limitations that need to be surpassed before this technology reaches a mature commercial stage.

Understanding the Barrier and Mechanical Behavior of Different Nanofillers in Chitosan Films for Food Packaging.

The continuous petroleum-based plastics manufacturing generates disposal issues, spreading the problem of plastic pollution and its rise in the environment. Recently, innovative techniques and scientific research promoted biopolymers as the primary alternative for traditional plastics, raising and expanding global bioplastic production. Due to its unmatched biological and functional attributes, chitosan (Ch) has been substantially explored and employed as a biopolymeric matrix. Nevertheless, the hydrophilicity and the weak mechanical properties associated with this biopolymer represent a significant intrinsic restriction to its implementation into some commercial applications, namely, in food packaging industries. Distinct methodologies have been utilized to upgrade the mechanical and barrier properties of Ch, such as using organic or inorganic nanofillers, crosslinkers, or blends with other polymers. This review intends to analyze the most recent works that combine the action of different nanoparticle types with Ch films to reinforce their mechanical and barrier properties.