Valorisation of blueberry waste and use of compression to manufacture sustainable starch films with enhanced properties

A versatile bilayer smart packaging based on konjac glucomannan/alginate for maintaining and monitoring seafood freshness

This study introduces a novel multi-functional double-layer intelligent packaging. It focuses on developing a dual-function system capable of real-time monitoring and freshness preservation. Specifically, cellulose nanocrystalline (CNC) was obtained through acid hydrolysis, and then CNC/soybean protein isolate (CNC/SPI) complex colloid particles were prepared via antisolvent method. These particles served as stabilizers to prepare oil-in-water (O/W) cinnamon essential oil Pickering emulsion (CSCEO). The CSCEO was then integrated into the emulsified hydrophobic layer of a konjac glucomannan (Kgm) matrix through intermolecular hydrogen bonding. Finally, alginate (Alg) matrix containing alizarin (Al) as an indicator was added to construct the bilayer structure using a layer-by-layer casting strategy. The inner layer Alg/Al was the pH/NH3-responsive indicator layer, while the outer layer Kgm/CSCEO acted as the high-barrier bacteriostatic layer. The obtained dual-function, double-layer film (Alg/Al-Kgm/CSCEO), which possesses a sensitive, reversible and rapid response towards pH/NH3, shows exceptional antibacterial and antioxidant properties, as well as excellent mechanical property, light-blocking capability and hydrophobicity. For monitoring and maintaining the actual freshness of shrimp, such a bilayer packaging displays smallest change of ∆E and TVB-N (18.65 mg/100 g) even after 72 h, which further highlighting its potential in enhancing food safety and extending shelf life.

Ammonia/pH super-sensitive colorimetric labels based on gellan gum, sodium carboxymethyl cellulose, and dyes for monitoring freshness of lamb meat

This study aimed to develop an ammonia and pH super-sensitive label by incorporating methyl red and bromothymol blue (MR-BTB, MB) into gellan gum/sodium carboxymethyl cellulose (GG/CMC-Na, GC). Furthermore, E-nose as an auxiliary tool combined with the labels to monitor meat freshness. Results showed that MB had more color change than pure MR or BTB, and the detection limit of ammonia about the MR-BTB (1:2) group was only 2.82 ppm. The addition of MB significantly increased tensile strength, moisture content, and water solubility, but decreased elongation at break and transmittance of the GC label (p < 0.05). The result of FTIR and SEM indicated the formation of hydrogen bonds and well compatibility between MB and GC. Furthermore, the color of the GC-10.0MB label was constantly obviously changing during meat storage, indicating that the GC-10.0MB label had great potential for monitoring the freshness of the lamb meat. A high correlation was found between ΔE of GC-10.0MB label and TVB-N (R2 = 0.9092) and pH (R2 = 0.9114) of meat. Interestingly, the high correlation between ΔE of GC-10.0 MB label and the response value of S2 (R2 = 0.7531), S6 (R2 = 0.9921), and S7 sensor (R2 = 0.8325) of E-nose was also found.

Cassava pomace-based biodegradable packaging materials: a review

Starch-based biodegradable packaging materials are gaining popularity as an alternative to the adverse environmental effects caused by conventional packaging materials. Despite the fact that cassava can withstand harsh environmental conditions and convert a greater quantity of solar energy into carbohydrates, its postharvest shelf life is extremely short. The preparation of cassava starch is an important method for extending the storage life of cassava. When one ton of cassava is processed, approximately 900 kg of cassava pomace, also known as cassava bagasse and cassava pulp, are produced. Due to the high residual starch and fibre content, reinforced packaging materials made from cassava pomace predominate. In the present manuscript, many possible uses of cassava pomace in packaging materials are discussed.  Furthermore, the performance attributes of packing materials assume a crucial role in the evaluation of the quality of the respective materials. The manuscript discusses various performance characteristics of packaging materials derived from cassava pomace. The features discussed include water vapour permeability, moisture content, solubility, thickness, colour, light barrier properties, mechanical properties, FT-IR analysis, thermal stability, biodegradation, contact angle, and the presence of plasticizers. Though cassava starch film has become a favourable substitute for conventional packaging materials, commercialization is limited due to having drawbacks, and the current solutions are also catalogued in this review.

Fabricating a visibly colorimetric film via self-releasing of anthocyanins from distributed mulberry pomace particles in hydrophilic sodium carboxymethyl starch-based matrix to monitor meat freshness

A highly distinguishable indicator film was developed based on sodium carboxymethyl starch, κ-carrageenan, carboxylated cellulose nanocrystals and mulberry pomace particles (MPPs). As the content of MPPs increased from 0 % to 6 %, the tensile strength decreased from 11.71 MPa to 5.20 MPa, the elongation at break increased from 26.84 % to 43.76 %, respectively, and the haze increased from 34.12 % to 52.10 %. The films accurately exhibit a color change from purple to blue-green under alkaline conditions. The enhanced haze improved the visible resolution of the films during the color-changing process. The films with the size of 7.50 mm × 7.50 mm and 10.0 mm × 10.0 mm exhibited obvious color changes when the total volatile basic nitrogen reached 14.60 mg/100 g and 19.04 mg/100 g, respectively, which accurately indicated the quality of pork and fish. This study will offer a simplified path to improve both accurate sensitivity and distinguishability for smart films.

Biodegradable Active Packaging Material Containing Grape Seed Ethanol Extract and Corn Starch/κ-Carrageenan Composite Film

An active film composed of corn starch/κ-carrageenan and ethanolic grape seed extract (0, 1, 3, and 5 wt% of GSE on corn starch basis) were successfully prepared using the solvent casting technique. The effects of the different concentrations of ethanolic grape seed extract (GSE) on the physicochemical properties, antioxidant properties, and antibacterial properties of CS/κC films were analyzed. The results showed that the addition of GSE inhibited the recrystallization of starch in the composite film. The glass transition temperature of composite film is 121.65 °C. With the addition of GSE, the surface roughness of the composite film increased, and the cross-section displayed a stratification phenomenon. Meanwhile, when GSE was added to the composite film, the tensile strength of the composite film decreased (3.50 ± 0.27 MPa), the elongation at break increased (36.87 ± 2.08%), and the WVP increased (1.58 ± 0.03 g mm/m2·d· kPa). With the increase of the concentration of GSE in the composite film, the a* value and b* value of the composite film increase, the L* value decreases, and the opacity increases. The lipid oxidation test proved that the composite films containing 1% GSE has a significant inhibitory effect on the oxidation of lard (p < 0.05). The above results indicate that the GSE can be used as a food-grade packaging material and has a good application prospect in the food industry.

Preparation and characterization of an intelligent film based on fish gelatin and Coleus scutellarioides anthocyanin to monitor the freshness of rainbow trout fish fillet

In this study, a pH-sensitive indicator based on fish gelatin and Coleus scutellarioides anthocyanin extract (CSAE) was prepared and characterized. Films were prepared using the solvent casting method and different levels of CSAE, including 10 ml (CSG1), 20 ml (CSG2), and 30 ml (CSG3), and 0 ml (CSG0) as a control sample. The mechanical, optical, and pH sensing of active films and the release of anthocyanins from the films were investigated. The relationship between the total volatile basic nitrogen (TVB-N) of fish fillets and a* color index of films was studied. By incorporation of CSAE, the flexibility of films increased, while the tensile strength and UV-Vis light transmittance through the films decreased (p < .05). The films containing the CSAE had a darker, yellowish, and reddish color than the control film. There was a significant relationship between the pH variation and the film color. The films had a purple color at acidic pH, and their color changed to green at an alkaline pH, indicating the sensitivity of the produced films to pH changes. There was a significant relationship between the TVB-N value of fish fillets and the a* index of the film during the 16 h storage time. The results showed that by increasing TVB-N values of the fillets, the a* color index decreased, and the films' color changed from purple to colorless. In summary, the active films prepared with fish gelatin and CSAE could be used as pH-sensitive intelligent packaging to display the freshness of fishery products.

Current Trends in the Utilization of Essential Oils for Polysaccharide- and Protein-Derived Food Packaging Materials

Essential oils (EOs) have received attention in the food industry for developing biopolymer-derived food packaging materials. EOs are an excellent choice to replace petroleum-derived additives in food packaging materials due to their abundance in nature, eco-friendliness, and superior antimicrobial and antioxidant attributes. Thus far, EOs have been used in cellulose-, starch-, chitosan-, and protein-based food packaging materials. Biopolymer-based materials have lower antioxidant and antibacterial properties in comparison with their counterparts, and are not suitable for food packaging applications. Various synthetic-based compounds are being used to improve the antimicrobial and antioxidant properties of biopolymers. However, natural essential oils are sustainable and non-harmful alternatives to synthetic antimicrobial and antioxidant agents for use in biopolymer-derived food packaging materials. The incorporation of EOs into the polymeric matrix affects their physicochemical properties, particularly improving their antimicrobial and antioxidant properties. EOs in the food packaging materials increase the shelf life of the packaged food, inhibit the growth of microorganisms, and provide protection against oxidation. Essential oils also influence other properties, such as tensile, barrier, and optical properties of the biopolymers. This review article gives a detailed overview of the use of EOs in biopolymer-derived food packaging materials. The innovative ways of incorporating of EOs into food packaging materials are also highlighted, and future perspectives are discussed.

A starch-based pH-sensing and ammonia detector film containing betacyanin of paperflower for application in intelligent packaging of fish

An easy-to-use food packaging label with pH and ammonia sensitivity was developed by adding betacyanin (5, 10 and 15 mg per g of starch) from flowers of paperflower (Bougainvillea glabra) to potato starch film made using the solvent casting method. The betacyanin was well dispersed into the starch matrix and formed new interactions with it as revealed by FTIR. The film containing 15 mg/g of betacyanin showed a color change from light pink to yellow as a response to pH adjustment of between 2 to 13. It was also able to detect the presence of ammonia in a range of 0.1 and 0.01 mg of ammonia per ml of water. Surface hydrophobicity and water vapor barrier capacity of the starch film increased by addition of the betacyanin, yet their mechanical strength decreased in the presence of the betacyanin. The ability of the film in the real-time indication of fish quality as a label was also evaluated during the storage of Caspian sprat at 4 °C. A visual change in the color of the packaging label from pink to yellow in parallel with the increase in the total volatile basic nitrogen (TVB-N), microbial count of the fish samples was detected. The starch/betacyanin film could be a novel intelligent label for application in food packaging.

Antioxidant capacity, total phenolic content and phenolic compounds of pulp and bagasse of four Peruvian berries

Revaluing agri-food waste to offer consumers bioactive compounds for a healthy diet is an important issue. In the present work, the antioxidant capacity (AC), total phenolic content (TPC) and phenolic compounds of pulp and bagasse of four Peruvian berries with UHPLC-DAD was determined. Elderberry (Sambucus peruviana Kunth) bagasse had a greater amount of TPC (4.87 ± 0.02 mg GAE/100 gfw) and AC (7.66 ± 0.04 and 7.51 ± 0.24 μmol TE/gfw in DPPH and ABTS, respectively) than the bagasse of the other berries, with a strong positive correlation between TPC and AC. Blueberry (Vaccinium floribundum Kunth) bagasse contains the highest amount of gallic acid (103.26 ± 1.59 μg/gfw), chlorogenic acid (1276.55 ± 1.86 μg/gfw), caffeic acid (144.46 ± 1.78 μg/gfw), epicatechin (1113.88 ± 1.82 μg/gfw) and p-coumaric acid (77.82 ± 1.92 μg/gfw). Elderberry (Sambucus peruviana Kunth) bagasse contains the highest amount of catechin (153.32 ± 0.79 μg/gfw). No significant differences were found in the content of chlorogenic acid and epicatechin of blackberry (Rubus roseus Poir). It was shown that the wastes of the four Amazonian berries have higher values of bioactive properties than their pulp, being the elderberry bagasse the one with the best properties.

Sustainable blueberry waste recycling towards biorefinery strategy and circular bioeconomy: A review

Waste valorization using biological methods for value addition as well as environmental management is becoming popular approach for sustainable development. The present review addresses the availability of blueberry crop residues (BCR), applications of this feedstock in bioprocess for obtaining range of value-added products, to offer economic viability, business development and market potential, challenges and future perspectives. To the best of our knowledge, this is the first article addressing the blueberry waste valorization for a sustainable circular bioeconomy. Furthermore, it covers the information on the alternative BCR valorization methods and production of biochar for environmental management through removal or mitigation of organic and inorganic pollutants from contaminated sites. The review also discusses the ample opportunities of strategic utilization of BCR to offer solutions for environmental sustenance, covers the emerging trends to produce multi-products and techno-economic prospective for sustainable agronomy.

Green Design of Novel Starch-Based Packaging Materials Sustaining Human and Environmental Health

A critical overview of current approaches to the development of starch-containing packaging, integrating the principles of green chemistry (GC), green technology (GT) and green nanotechnology (GN) with those of green packaging (GP) to produce materials important for both us and the planet is given. First, as a relationship between GP and GC, the benefits of natural bioactive compounds are analyzed and the state-of-the-art is updated in terms of the starch packaging incorporating green chemicals that normally help us to maintain health, are environmentally friendly and are obtained via GC. Newer approaches are identified, such as the incorporation of vitamins or minerals into films and coatings. Second, the relationship between GP and GT is assessed by analyzing the influence on starch films of green physical treatments such as UV, electron beam or gamma irradiation, and plasma; emerging research areas are proposed, such as the use of cold atmospheric plasma for the production of films. Thirdly, the approaches on how GN can be used successfully to improve the mechanical properties and bioactivity of packaging are summarized; current trends are identified, such as a green synthesis of bionanocomposites containing phytosynthesized metal nanoparticles. Last but not least, bioinspiration ideas for the design of the future green packaging containing starch are presented.

Sustainable Use of Fruit and Vegetable By-Products to Enhance Food Packaging Performance

Fruit and vegetable by-products are the most abundant food waste. Industrial processes such as oil, juice, wine or sugar production greatly contribute to this amount. These kinds of residues are generally thrown away in form of leftover and used as feed or composted, but they are a great source of bioactive compounds like polyphenols, vitamins or minerals. The amount of residue with potential utilization after processing has been estimated in millions of tons every year. For this reason, many researchers all around the world are making great efforts to valorize and reuse these valuable resources. Of greatest importance is the by-product potential to enhance the properties of packaging intended for food applications. Therefore, this overview collects the most recent researches dealing with fruit and vegetable by-products used to enhance physical, mechanical, antioxidant and antimicrobial properties of packaging systems. Recent advances on synthetic or bio-based films enriched with by-product components are extensively reviewed, with an emphasis on the role that by-product extracts can play in food packaging materials.

Preparation and characterization of starch/enteromorpha/nano-clay hybrid composites

Environmentally friendly and biodegradable hybrid composites of starch/enteromorpha/nano-clay were developed. Enteromorpha was used as cheaper filler since it is a waste from marine pollution, while nano-clay acted as a reinforcing agent. The microstructures and performance of these composites were investigated by SEM, DMA, XRD, TGA and tensile testing. Enteromorpha has a hollow tubular thallus structure with very weak mechanical properties, so it is not expected to have the ability to reinforce the starch matrix even though they have very a good interface. However, the granulated fine particles of enteromorpha can mix well with the starch matrix and reduce weak points. Furthermore, the delaminated clay by water and ultrasonic treatment reinforced the mechanical properties of the starch-based materials. The results showed that the hybrid composite containing up to 40% enteromorpha reinforced with nano-clay still has similar or even slightly better mechanical properties compared with pure starch-based materials. Since all components are hydrophilic natural materials, the interfaces between them are very good, and the composites are environmentally friendly and biodegradable.

Development of Polylactic Acid Films with Selenium Microparticles and Its Application for Food Packaging

Selenium is a natural element which exists in the human body and plays an important role in metabolism. Along with this, selenium also possesses antibacterial and antioxidant properties. Using selenium microparticles (SeMPs) in food packaging films is exceptional. In this experiment, a solution casting method was used to make film. For this purpose, we used polylactic acid (PLA) as a substrate for the formation of a film membrane while SeMPs were added with certain ratios to attain antibacterial and antioxidant properties. The effects of SeMPs on the PLA film and the value of SeMPs in food packaging film production were investigated. The effects of the SeMPs contents on the features of the film, such as its mechanical property, solubility, swelling capacity, water vapor permeability, antioxidant activity, and the antibacterial activity of the composite membrane against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) strains, were studied. The results manifest that the PLA/SeMPs films showed higher water resistance, UV resistance, antioxidant activity, and antibacterial activity than pure PLA film. When the concentration of SeMPs was 1.5 wt%, the composite membrane showed the best comprehensive performance. Although the tensile strength and elongation at break of the membrane were slightly reduced by the addition of SeMPs, the results show that PLA/SeMPs films are still suitable for food packaging and would be a very promising material for food packaging.

Development of active and intelligent films based on cassava starch and Chinese bayberry (Myrica rubra Sieb. et Zucc.) anthocyanins

Chinese bayberry (Myrica rubra Sieb. et Zucc.) fruit is a functional food rich in anthocyanins. In this study, anthocyanin-rich bayberry extract (BBE) was added into cassava starch to develop food packaging films with antioxidant and pH-sensitive properties. Results showed the main anthocyanin in BBE was cyanidin-3-O-glucoside (95.6%). The addition of 1 wt% of BBE into the film matrix resulted in a dense and compact internal microstructure, which greatly improved the water vapor permeability and tensile strength of the film. However, the addition of 2, 3 and 4 wt% of BBE into film matrix produced heterogeneous inner microstructures due to the formation of agglomerated BBE. The intermolecular interactions between BBE and the starch film matrix were through hydrogen binding. As compared with the starch film, starch–BBE films exhibited higher thicknesses, tensile strength, UV-vis light barrier and antioxidant properties. Moreover, starch–BBE films presented significant color changes when exposed to hydrogen chloride and ammonia gases. The pH-sensitive starch–BBE films were able to monitor the freshness of pork. Our results suggested that starch–BBE films could be used as smart and active packaging materials in the food industry.

In this study, anthocyanin-rich Chinese bayberry extract (BBE) was added into cassava starch to develop food packaging films with antioxidant and pH-sensitive properties.