Edible Coatings and Future Trends in Active Food Packaging-Fruits' and Traditional Sausages' Shelf Life Increasing.

The global food production industry faces environmental concerns exacerbated by substantial food waste. European countries are striving to reduce food waste towards a circular bioeconomy and sustainable development. To address environmental issues and reduce plastic waste, researchers are developing sustainable active packaging systems, including edible packaging made from industry residues. These innovations aim to increase food safety and quality, extend shelf life, and reduce plastic and food waste. Particularly important in the context of the growing demand for fresh and minimally processed fruits, edible coatings have emerged as a potential solution that offers numerous advantages in maintaining fruit quality. In addition to fruit, edible coatings have also been investigated for animal-based foods to meet the demand for high-quality, chemical-free food and extended shelf life. These products globally consumed can be susceptible to the growth of harmful microorganisms and spoilage. One of the main advantages of using edible coatings is their ability to preserve meat quality and freshness by reducing undesirable physicochemical changes, such as color, texture, and moisture loss. Furthermore, edible coatings also contribute to the development of a circular bioeconomy, promoting sustainability in the food industry. This paper reviews the antimicrobial edible coatings investigated in recent years in minimally processed fruits and traditional sausages. It also approaches bionanocomposites as a recently emerged technology with potential application in food quality and safety.

Bioactive Compounds of Portuguese Fruits with PDO and PGI.

The European Union has established two designations, Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI), to guarantee the authenticity of products with valued specificities associated with the regions where they are produced. The valorization of these products, particularly fruits, not only preserves their natural origins but also promotes the cultivalion of specific regional fruit varieties. This contributes to the preservation of biodiversity and the development of innovative bio-based products in the regions of production. In recent years, substantial efforts have been made to characterize PDO and PGI fruits, particularly in relation to the presence of bioactive compounds with antioxidant and antimicrobial properties. Portugal, with its diverse range of climates and geographical characteristics, is home to numerous fruits with unique flavors, textures, and appearances, many of which are now recognized with PDO or PGI seals. This review compiles data from the production of Portuguese fruits with PDO designations, such as the 'Maça Bravo de Esmolfe' (apple) and 'Pera Rocha do Oeste' (pear), and PGI designations, such as 'Citrinos do Algarve' (citrus)and 'Cereja da Cova da Beira' (cherry), and summarizes studies focusing on the bioactive compounds present in these fruits. The presence of bioactive compounds is a significant aspect of nutritious food, associated with health benefits that consumers are increasingly aware of and value.

Microbiological Assessment of White Button Mushrooms with an Edible Film Coating.

The development of edible coatings incorporating bioextracts from mushrooms native to Portuguese forests aims to enhance the value of the endogenous forest and mycological resources by harnessing their potential as a source of antimicrobial and antioxidant compounds. Edible coatings represent an important pathway to decreasing food waste and contributing to implementing a circular bioeconomy. The coating should result in product valorization through improved preservation/conservation, increased shelf life, as well as enhancement of its antioxidant and enzymatic properties. To evaluate the effectiveness of an edible coating on fungal food matrices, a 14-day shelf-life study was conducted, wherein both coated and untreated mushrooms were examined under controlled storage temperatures of 4 °C and 9.3 °C. Agaricus bisporus was chosen as the food matrix for its bioeconomy significance, and Pleurotus eryngii was selected for the preparation of the food-based coating due to its profile of bioactive compounds. Microbiological analysis and physicochemical monitoring were conducted on the food matrices and the coating. Coated mushrooms had less mass loss and color change, and had better texture after 14 days. Microbiological analysis revealed that the coating had no antimicrobial activity. Overall, the coating improved the shelf life of the coated mushrooms but had less effect on the microbial community.

Natural Deep Eutectic Solvent Extraction of Bioactive Pigments from Spirulina platensis and Electrospinning Ability Assessment.

The first ever nanofibers produced by the electrospinning of polyvinyl alcohol (PVA) and Spirulina platensis extracts are presented in this article. Spirulina platensis extracts were obtained by ultrasound-assisted extraction (UAE) using two different solvents: a glucose/glycerol-based natural deep eutectic solvent (NADES) and water. Through spectrophotometry analysis, it was possible to determine the pigment yield of the extractions for both extracts: phycocyanin = 3.79 ± 0.05 mg/g of dry biomass (DB); chlorophylls = 0.24 ± 0.05 mg/g DB; carotenoids = 0.13 ± 0.03 mg/g DB for the NADES/Spirulina extracts, and phycocyanin = 0.001 ± 0.0005 mg/g DB; chlorophylls = 0.10 ± 0.05 mg/g DB; carotenoids = 0.20 ± 0.05 mg/g DB for water/Spirulina extracts. Emulsions were formed by mixing the microalgae extracts in PVA (9%, w/v) at different concentrations: 5, 20, 40, and 50% (v/v). Electrospinning was carried out at the following conditions: 13 cm of distance to collector; 80 kV of applied voltage; and 85 rpm of electrode rotation. After the nanofibers were collected, they were checked under a scanning electron microscope (SEM). ImageJ was also used to determine fiber diameter and frequency. SEM results showed the formation of nanofibers for 5 and 20% (v/v) of NADES/Spirulina extract content in the electrospinning emulsions, presenting diameters of 423.52 ± 142.61 nm and 680.54 ± 271.92 nm, respectively. FTIR confirmed the presence of the NADES extracts in the nanofibers produced. Overall, the nanofibers produced showed promising antioxidant activities, with the NADES/Spirulina- and PVA-based nanofibers displaying the highest antioxidant activity (47%). The highest antimicrobial activity (89.26%) was also obtained by the NADES/Spirulina and PVA nanofibers (20%, v/v). Principal Component Analysis (PCA) revealed positive correlations between both the antioxidant and antimicrobial activities of the electrospun nanofibers, and extract content in the emulsions. Moreover, PCA also indicated positive correlations between the viscosity and conductivity of the emulsions and the diameter of the nanofibers produced.

Food Wastes and Microalgae as Sources of Bioactive Compounds and Pigments in a Modern Biorefinery: A Review.

The United Nations 2030 Agenda for Sustainable Development has created more pressure on countries and society at large for the development of alternative solutions for synthetic and fossil fuel derived products, thus mitigating climate change and environmental hazards. Food wastes and microalgae have been studied for decades as potential sources of several compounds that could be employed in various fields of application from pharmaceutical to textile and packaging. Although multiple research efforts have been put towards extracting rich compounds (i.e., phenolic compounds, tocopherols, and tocotrienols) from these sources, they still remain overlooked as two major sources of bioactive compounds and pigments, mainly due to inefficient extraction processes. Hence, there is a growing need for the development of optimized extraction methods while employing non-organic solvent options following the main principles of green chemistry. This review will focus on delivering a clear and deep analysis on the existing procedures for obtaining bioactive compounds and pigments from food wastes derived from the most consumed and produced fruit crops in the world such as apples, oranges, cherries, almonds, and mangoes, and microalgal biomass, while giving light to the existing drawbacks in need to be solved in order to take full advantage of the rich properties present in these two major biorefinery sources.

Ultrasound-assisted extraction of bioactive pigments from Spirulina platensis in natural deep eutectic solvents.

Spirulina platensis biopigments have been documented as a potential source of nutritional, physiological, and pharmacological purposes due to the presence of bioactive pigments, total phenolic content (TPC) and the consequent antioxidant activity that these compounds present. Bioextracts market has increased in the last decades and is a key option for replacing fossil-derived products and promote the transition for a bio-based economy. To take advantage of these compounds more effectively, optimized extraction processes must be researched and used in biomass sources. The present study focused on optimizing the ultrasound-assisted extraction (UAE) using response surface methodology. Three factor and three level Box-Behnken design was used to optimize the extraction of bioactive pigments, and to investigate the effects of three independent variables, x 1: extraction temperature (40-60 °C), x 2: extraction cycle time (20-40 min), and x 3: solvent-to-biomass ratio (50-70 mL/mg) on total pigment yield, antioxidant assay, and TPC (dependent variables). A second-order polynomial model was used for predicting the responses. Statistically, the model was validated using an analysis of variance. Results revealed that ultrasound-assisted temperature, time, and solvent-to-biomass ratio had a significant (p < 0.05) influence on the total pigment yield, while temperature and solvent-to-biomass ratio had a significant influence in the antioxidant activity, and temperature significantly influenced the total pigment yield. For total pigment yield, antioxidant activity, and total phenol content, the R 2 values of the models generated were 0.8627, 0.8460, and 0.9003, respectively, indicating that the models developed based on second-order polynomials were satisfactorily accurate for analyzing interactions between parameters. Desirability functions showed that the optimal extraction parameters were temperature: 60 °C, extraction cycle time: 20 min; and a solvent-to-biomass ratio of 70 mL/mg. Under optimal conditions, experimental values for total pigment yield, total phenol content expressed as gallic acid equivalent (GAE), and antioxidant activity expressed as Trolox equivalent (TRE) were: 165.19 ± 1.01 mg/g Dry Matter (DM), 36.50 ± 0.98 mg GAE/g DM, and 37.98 ± 0.58 mg TRE/g DM, respectively. The experimental values showed a good agreement with the predicted values with residual standard low 1% under optimum conditions. This optimized ultrasound-assisted method in natural eutectic solvents is effective and scalable to a green extraction of the bioactive pigments from Spirulina platensis with potential application to food, pharmaceutical, functional materials, and packaging.