Carotenoids extracts as natural colorants in poly(lactic acid) films

Intelligent and active biodegradable biopolymeric films containing carotenoids

There is growing interest in the use of natural bioactive compounds for the development of new bio-based materials for intelligent and active food packaging applications. Several beneficial effects have been associated with the antioxidant and antimicrobial potentials of carotenoid compounds. In addition, carotenoids are sensitive to pH changes and oxidation reactions, which make them useful bioindicators of food deterioration. This review summarizes the current research on the application of carotenoids as novel intelligent and active biodegradable food packaging materials. Carotenoids recovered from food processing by-products can be used in the development of active food packaging materials due to their antioxidant properties. They help maintain the stability of lipid-rich foods, such as vegetable oils. Additionally, when incorporated into films, carotenoids can monitor food oxidation, providing intelligent functionalities.

Recent Advances in the Carotenoids Added to Food Packaging Films: A Review

Food spoilage is one of the key concerns in the food industry. One approach is the improvement of the shelf life of the food by introducing active packaging, and another is intelligent packaging. Detecting packed food spoilage in real-time is key to stopping outbreaks caused by food-borne diseases. Using active materials in packaging can improve shelf life, while the nonharmful color indicator can be useful to trace the quality of the food through simple color detection. Recently, bio-derived active and intelligent packaging has gained a lot of interest from researchers and consumers. For this, the biopolymers and the bioactive natural ingredient are used as indicators to fabricate active packaging material and color-changing sensors that can improve the shelf life and detect the freshness of food in real-time, respectively. Among natural bioactive components, carotenoids are known for their good antimicrobial, antioxidant, and pH-responsive color-indicating properties. Carotenoids are rich in fruits and vegetables and fat-soluble pigments. Including carotenoids in the packaging system improves the film's physical and functional performance. The recent progress on carotenoid pigment-based packaging (active and intelligent) is discussed in this review. The sources and biological activity of the carotenoids are briefly discussed, and then the fabrication and application of carotenoid-activated packaging film are reviewed. The carotenoids-based packaging film can enhance packaged food's shelf life and indicate the freshness of meat and vegetables in real-time. Therefore, incorporating carotenoid-based pigment into the polymer matrix could be promising for developing novel packaging materials.

Fabrication, performance, and potential environmental impacts of polysaccharide-based food packaging materials incorporated with phytochemicals: A review

Although food packaging preserves food's quality, it unfortunately contributes to global climate change since the considerable carbon emissions associated with its entire life cycle. Polysaccharide-based packaging materials (PPMs) are promising options to preserve foods, potentially helping the food industry reduce its carbon footprint. PPMs incorporated with phytochemicals hold promise to address this critical issue, keep food fresh and prolong the shelf life. However, phytochemicals' health benefits are impacted by their distinct chemical structures thus the phytochemicals-incorporated PPMs generally exhibit differential performances. PPMs must be thoughtfully formulated to possess adequate physicochemical properties to meet commercial standards. Given this, this review first-time provides a comprehensive review of recent advances in the fabrication of phytochemicals incorporated PPMs. The application performances of phytochemicals-incorporated PPMs for preserving foods, as well as the intelligent monitoring of food quality, are thoroughly introduced. The possible associated environmental impacts and scalability challenges for the commercial application of these PPMs are also methodically assessed. This review seeks to provide comprehensive insights into exploring new avenues to achieve a greener and safer food industry via innovative food packaging materials. This is paramount to preserve not only food shelf life but also the environment, facilitating the eco-friendly development of the food industry.

Effect of Birch Sap as Solvent and Source of Bioactive Compounds in Casein and Gelatine Films

Birch sap consists of a natural water-based solution with valuable compounds such as minerals, sugars, organic acids and phenolic compounds that can be used advantageously in the preparation of edible films. In this study, gelatine- and casein-based films were prepared using birch sap as biopolymer solvent and source of bioactive compounds with the aim of developing new bioactive materials for food packaging. The physical, mechanical, barrier, antioxidant and iron-chelating properties of the obtained films were investigated. Birch sap enhanced the mechanical properties of the films by increasing puncture strength and flexibility, as well as their ultraviolet-visible light barrier properties. In addition, the presence of bioactive compounds endowed the birch sap films with an antioxidant capacity of almost 90% and an iron-chelating capacity of 40-50% with respect to the control films. Finally, to test these films as food packaging material, a photosensitive curcumin solution was packed and exposed to ultraviolet light. Tested films were able to protect curcumin against photodegradation, and the presence of bioactive compounds inside the birch-sap-enriched materials offered an additional 10% photoprotective effect compared to control films. Results showed the potential of birch sap as an environmentally friendly biopolymer solvent and plasticizer that can improve the mechanical and photoprotective properties of the prepared materials.

Effects of curcumin, phycocyanin, or modified lycopene colorants on the physicochemical and sensory properties of whey protein-cellulose nanocrystal packaging films

To utilize natural hydrophobic/hydrophilic colorants to manufacture good quality and attractive packaging films, we investigated the effects of natural colorants (curcumin, phycocyanin, modified lycopene, and their mixed colorants) on the physicochemical and sensory properties of whey protein isolate-cellulose nanocrystal packaging film. Owing to the improvement in hydrophobicity and spatial density, moisture content (MC) and water vapor permeability (WVP) of films containing curcumin were reduced by 16.91% and 8.49%, respectively, in contrast to that, MC and WVP increased by 10.75% and 4.09%, respectively, in film containing modified lycopene. Mechanical testing, infrared spectra, and X-ray diffraction revealed the retention of structural properties of protein matrix. Rate-All-That-Apply evaluation indicated that films containing colorants enriched tactile and visual sensory characteristics. The eye tracking testing of packed foods showed that preferential attraction depends on the color of the food itself. Thus, a consumer-oriented multi-colored packaging film with good performance was achieved.

Biodegradable sodium alginate films incorporated with lycopene and β-carotene for food packaging purposes

Incorporating carotenoids into sodium alginate films can give them functional properties for food packaging applications. The lycopene and β-carotene were included in the biopolymer matrix at 0.1%, 0.3%, and 0.5% (g carotenoid/g polymer). There was no significant difference (p > 0.05) in film thickness (45 ± 1 μm) of sodium alginate films with carotenoids. Nevertheless, the low quantity of carotenoids was enough to promote significant variations in the tensile properties of films. The films with lycopene or β-carotene showed lower tensile strength and elongation at break than control films. The carotenoid incorporation promoted a reduction (p < 0.05) in water vapor permeability, mainly by adding 0.5%. In the same way, it improved the light transmission and thermal stability of films and did not affect the water solubility of films. The scanning electron microscopy of films showed a homogeneous surface, but the films with lycopene or β-carotene showed a more compact structure than the control film. The sodium alginate films incorporated with 0.3% lycopene or β-carotene showed a remarkable protective effect on sunflower oil against oxidation compared with traditional commercial plastic packaging under accelerated storage conditions (heat and light). Therefore, they can be considered a potential material for food packaging purposes.

Consumer Awareness of Plastic: an Overview of Different Research Areas

Plastic makes our society more practical and safer. It is hard to consider eliminating plastic in some sectors, such as the medical field. However, after use, plastic waste becomes a global problem without precedents, and when not properly disposed of, it can cause several socio-environmental problems. Some possible solutions are recycling, the circular economy, proper waste management, and consumer awareness. Consumers play a crucial role in preventing problems caused by plastic. In this work, consumer awareness of plastic is discussed according to the point of view of the research areas-environmental science, engineering, and materials science-based on the analysis of the main authors' keywords obtained in a literature search in the Scopus database. Bibliometrix analyzed the Scopus search results. The results showed that each area presents different concerns and priorities. The current scenario, including the main hotspots, trends, emerging topics, and deficiencies, was obtained. On the contrary, the concerns from the literature and those of the daily lives of consumers do not seem to fit in, which creates a gap. By reducing this gap, the distance between consumers awareness and their behavior will be smaller.

Physicochemical and Sensory Properties Colored Whey Protein-Cellulose Nanocrystal Edible Films after Freeze-Thaw Treatment

Balancing physicochemical properties and sensory properties is one of the key points in expanding edible packaging applications. The work consisted of two parts, one was to investigate the effects of cellulose nanocrystals (CNC) on the packaging-related properties of whey protein isolate films with natural colorants (curcumin, phycocyanin, and lycopene) under freeze-thaw (FT) conditions; the other was to test oral tactility and visual sensory properties of the edible films and their overall acceptability in packed ice cream. FT treatment reduced the mechanical strength and moisture content and increased the water vapor permeability of the films, as water-phase transformation not only disrupted hydrogen bonds but also the film network structure through physical stress. The oral tactility produced by CNC and the visual effect produced by colorants could affect participants' preference for edible films. This study provides a good reference for the consumer-driven product development of packaged low-temperature products.

Egg Yolk Oil as a Plasticizer for Polylactic Acid Films

Polylactic acid (PLA) is known to be one of the most extensively used biodegradable thermoplastic polyesters, with the potential to replace conventional petroleum-based packaging materials; however, the low flexibility of films prepared using PLA has limited the applications of this biopolymer. In this study, in order to improve the mechanical properties of PLA films and to provide them with antioxidant properties, egg yolk oil was used as a biobased plasticizer. For this purpose, PLA films with increasing concentrations of egg yolk oil were prepared and the effects of this oil on the light transmission, transparency, colour, water vapour permeability, solubility, antioxidant activity and mechanical properties of the films were characterized. In addition, electron microscopy of the structure of the transverse section of the films was also performed. Results showed that the formulations with higher concentrations of egg yolk oil increased the films’ elasticity, and their light barrier and antioxidant properties. Finally, in order to test the films as a packaging material for food applications, extra virgin olive oil and resveratrol, both photosensitive compounds, were packed and exposed to ambient light. Overall, the results show the potential of egg yolk oil as an environmentally friendly plasticizer that can improve the flexibility of PLA films and provide them with additional photoprotective properties.

Recent Advances in the Development of Smart and Active Biodegradable Packaging Materials

Interest in the development of smart and active biodegradable packaging materials is increasing as food manufacturers try to improve the sustainability and environmental impact of their products, while still maintaining their quality and safety. Active packaging materials contain components that enhance their functionality, such as antimicrobials, antioxidants, light blockers, or oxygen barriers. Smart packaging materials contain sensing components that provide an indication of changes in food attributes, such as alterations in their quality, maturity, or safety. For instance, a smart sensor may give a measurable color change in response to a deterioration in food quality. This article reviews recent advances in the development of active and smart biodegradable packaging materials in the food industry. Moreover, studies on the application of these packaging materials to monitor the freshness and safety of food products are reviewed, including dairy, meat, fish, fruit and vegetable products. Finally, the potential challenges associated with the application of these eco-friendly packaging materials in the food industry are discussed, as well as potential future directions.

Active food packaging of cellulose acetate: Storage stability, protective effect on oxidation of riboflavin and release in food simulants

In this work, cellulose acetate films were prepared with the incorporation of different carotenoids (lycopene, norbixin, and zeaxanthin). The effect of adding these natural antioxidants was evaluated through stability during storage under controlled conditions (temperature and light), degradation rate coefficient, release in food simulants and protective effect on oxidation of vitamin B₂. During storage at 25 °C or 40 °C the light showed a greater effect on the stability of the carotenoids, with significant increase in reaction constants (k) and decrease in half-life (t_1/2). The degradation of the carotenoids was followed by a variation in the color parameters and mechanical properties. The films with norbixin showed the highest barrier to the transmission of UV-Vis light, consequently preserving 72% of a vitamin B₂ stored under a photooxidative environment. Lycopene presented a higher release rate than norbixin and zeaxanthin to a fatty food simulant.

Bio-Based Packaging Materials Containing Substances Derived from Coffee and Tea Plants

The aim of the research was to obtain intelligent and eco-friendly packaging materials by incorporating innovative additives of plant origin. For this purpose, natural substances, including green tea extract (polyphenon 60) and caffeic acid, were added to two types of biodegradable thermoplastics (Ingeo™ Biopolymer PLA 4043D and Bioplast GS 2189). The main techniques used to assess the impact of phytocompounds on materials’ thermal properties were differential scanning calorimetry (DSC) and thermogravimetry (TGA), which confirmed the improved resistance to thermo-oxidation. Moreover, in order to assess the activity of applied antioxidants, the samples were aged using a UV aging chamber and a weathering device, then retested in terms of dynamic mechanical properties (DMA), colour changing, Vicat softening temperature, and chemical structure, as studied using FT-IR spectra analysis. The results revealed that different types of aging did not cause significant differences in thermo-mechanical properties and chemical structure of the samples with natural antioxidants but induced colour changing. The obtained results indicate that polylactide (PLA) and Bioplast GS 2189, the plasticizer free thermoplastic biomaterial containing polylactide and starch (referred to as sPLA in the present article), both with added caffeic acid and green tea extract, can be applied as smart and eco-friendly packaging materials. The composites reveal better thermo-oxidative stability with reference to pure materials and are able to change colour as a result of the oxidation process, especially after UV exposure, providing information about the degree of material degradation.