Starch/Polyaniline Biopolymer Film as Potential Intelligent Food Packaging with Colourimetric Ammonia Sensor

The latest research progress on polysaccharides-based biosensors for food packaging: A review

In recent years, polysaccharide-based biosensors have emerged as promising technologies for intelligent food packaging, offering innovative solutions to enhance food quality and safety. This review highlights advancements in designing, developing, and applying these biosensors, particularly those utilizing polysaccharides such as chitosan, cellulose and alginate. Engineered with nanomaterials like ZnO, silver, and carbon nano-tubes demonstrated high sensitivity in real-time monitoring of food spoilage indicators, including pH changes, volatile nitrogen compounds and microbial activity. We discuss the electrochemical properties of these biosensors, highlighting how the integration of electrochemical methods significantly improves their detection capabilities within packaging environments, leading to sensor sensitivity enhancement, greater accuracy, and spoilage detection, ultimately extending the shelf life of perishable food products. Additionally, the review addresses the practical challenges of industrial implementation and explores future research directions for optimizing sensor functionality and scalability. The findings underscore the potential of polysaccharide-based intelligent packaging as a sustainable and effective alternative to conventional methods, paving the way for broader commercial adoption.

Biopolymer-based solutions for enhanced safety and quality assurance: A review

The improper disposal of petroleum-based plastics has been associated with detrimental environmental consequences, such as the proliferation of microplastic pollution and increased emissions of greenhouse gases (GHGs). Consequently, biopolymers have emerged as a highly regarded alternative due to their environmental-friendly attributes and versatile range of applications. In response to consumer demands for safer food options, sustainable packaging, and escalating environmental concerns, the food sector is increasingly adopting biopolymers. Further, in the recent decade, the usage of active or functional biopolymers has evolved into smart biopolymers that can transmit real-time data to consumers. This review covers key topics such as antimicrobial and biodegradable packaging, edible coatings and films, incorporation of scavengers and bioactive substances that prolong the shelf life and guard against moisture and microbial contamination. The paper also discusses the development of edible cutlery as a sustainable substitute for plastic, the encapsulation of bioactive substances within biopolymers, 3-D food printing for regulated nutrition delivery and thickening and gelling agents that improve food texture and stability. It also discusses the integration of smart polymer functions, demonstrating their importance in guaranteeing food safety and quality, such as biosensing, pH and gas detection, antibacterial characteristics, and time-temperature monitoring. By shedding light on market trends, future scope, and potentialities, this review aims to elucidate the prospects of utilizing biopolymers to address sustainability and quality concerns within the food industry effectively.

Sustainable strategies for using natural extracts in smart food packaging

The growing demand for sustainable and eco-friendly food packaging has prompted research on innovative solutions to environmental and consumer health issues. To enhance the properties of smart packaging, the incorporation of bioactive compounds derived from various natural sources has attracted considerable interest because of their functional properties, including antioxidant and antimicrobial effects. However, extracting these compounds from natural sources poses challenges because of their complex chemical structures and low concentrations. Traditional extraction methods are often environmentally harmful, expensive and time-consuming. Thus, green extraction techniques have emerged as promising alternatives, offering sustainable and eco-friendly approaches that minimise the use of hazardous solvents and reduce environmental impact. This review explores cutting-edge research on the green extraction of bioactive compounds and their incorporation into smart packaging systems in the last 10 years. Then, an overview of bioactive compounds, green extraction techniques, integrated techniques, green extraction solvents and their application in smart packaging was provided, and the impact of bioactive compounds incorporated in smart packaging on the shelf lives of food products was explored. Furthermore, it highlights the challenges and opportunities within this field and presents recommendations for future research, aiming to contribute to the advancement of sustainable and efficient smart packaging solutions.

Eggshell membrane as a novel and green platform for the preparation of highly efficient and reversible curcumin-based colorimetric sensor for the monitoring of chicken freshness

Herein, for the very first time, we report a paper-like biomass, eggshell membrane (ESM), as a suitable platform for the fabrication of a colorimetric sensor (E-Cot). Green ethanolic extract, curcumin (CUR), was used as a sensing material to coat with the ESM. The present E-Cot effectively changed its color (yellow to red) in the real-time monitoring for chicken spoilage. The E-Cot exhibits barrier properties due to its inherent semi-permeability characteristics. Interestingly, the E-Cot showed a significant change in total color difference value (ΔE, 0 days - 0.0-39.6, after 1 day - 39.6-42.1, after 2 days - 42.1-53.6, after 3 days- 53.6-60.1, and after 4 days - 60.1-66.3, detectable by the naked eye) in the real-time monitoring for chicken freshness. In addition, the present E-Cot smart colorimetric sensor is reversible with a change in pH, and the sensor can be reused. Further, the hydrophobic nature of the E-Cot was confirmed by water contact angle analysis (WCA, contact angle of 101.21 ± 8.39). Good antibacterial, barrier, and optical properties of the present E-Cot were also found. Owing to the advantages such as green, efficient, cost-effective, biodegradable, reusable, sustainable, and simple preparation, we believe that the present E-Cot would be a more attractive candidate.

Improved electrochemical performance of bio-derived plasticized starch/ reduced graphene oxide/ molybdenum disulfide ternary nanocomposite for flexible energy storage applications

A ternary nanocomposite of plasticized starch (PS), reduced graphene oxide (rGO), and molybdenum disulfide (MoS2) was prepared via a solution casting process, with MoS2 concentrations ranging from 0.25 to 1.00 wt%. The structural, surface morphological, optical, and electrochemical properties of the nanocomposites were studied. FTIR analysis reveals the formation of new chemical bonds between PS, rGO, and MoS2, indicating strong interactions among them. The XRD analysis showed a reduction in the crystallinity of the nanocomposite from 40 to 21% due to the incorporation of nanofiller. FESEM micrograph showed an increment of the surface roughness due to the incorporation of rGO-MoS2 layers. UV-vis spectroscopy demonstrated a reduction of optical bandgap from 4.71 to 2.90 eV, resulting from enhanced charge transfer between the layers and defect states due to the addition of nanofillers. The incorporation of MoS2 increase the specific capacitance of the PS from 2.78 to 124.98 F g-1 at a current density of 0.10 mA g-1. The EIS analysis revealed that the nanofiller significantly reduces the charge transfer resistance from 4574 to 0 Ω, facilitating the ion transportation between the layers. The PS/rGO/MoS2 nanocomposite also exhibited excellent stability, retaining about 85% of its capacitance up to 10,000 charging-discharging cycles. These biocompatible polymer-based nanocomposites with improved electrochemical performance synthesized from an easy and economical route may offer a promising direction to fabricate a nature-friendly electrode material for energy storage applications.

Effect of Lithium Salts on the Properties of Cassava Starch Solid Biopolymer Electrolytes

This study evaluates the effect of lithium salts on the structural, electrochemical, and thermal properties of cassava starch solid biopolymer electrolytes (SBPEs). Films of SBPEs were synthesized using plasticizing agents and lithium salts (LiCl, Li2SO4, and CF3LiSO3) via thermochemical method. The SBPEs with lithium salts exhibited characteristic FTIR bands starch, with slight variations in the vibration oxygen-related functional groups compared to salt-free biopolymer spectra. The RCOH/COC index (short-range crystallinity) was higher in the films synthesized without lithium salt and the lowest value was established in the films synthesized with Li2SO4. Thermal degradation involved dehydration between 40 to 110 °C and molecular decomposition between 245 to 335 °C. Degradation temperatures were close when synthesized with salts but differed in films without lithium salt. DSC revealed two endothermic processes: one around 65 °C linked to crystalline structure changes and the second at approximately 271 °C associated with glucose ring decomposition. The electrochemical behavior of the SBPEs varied with the salts used, resulting in differences in the potential and current of peaks from the redox processes and its conductivity, presenting the lowest value (8.42 × 10-5 S cm-1) in the SBPE films without salt and highest value (9.54 × 10-3 S cm-1) in the films with Li2SO4. It was concluded that the type of lithium salt used in SBPEs synthesis affected their properties. SBPEs with lithium triflate showed higher molecular ordering, thermal stability, and lower redox potentials in electrochemical processes.

Konjac glucomannan-based hydrogels with health-promoting effects for potential edible electronics applications: A mini-review

Konjac glucomannan (KGM), a dietary fiber hydrocolloid polysaccharide isolated from Amorphophallus konjac tubers, has potential applications in various fields. However, the use of KGM-based hydrogels has mainly focused on the food, biomedical, and water treatment industries. KGM possesses several health benefits and could be a promising candidate for use in edible electronics. This paper presents the first review of KGM-based hydrogels as edible electronics and their potential health benefits. The paper initially focuses on the health-promoting effects of KGM-based hydrogels, such as prebiotic effects, antiobesity, antioxidant, and antibacterial properties. Then, it discusses the feasible design strategies for KGM-based hydrogels as edible electronics, considering their flexibility, mechanical properties, response to stimuli, degradability aspects, their role as electronic device components, and the retention period of the devices. Finally, this review outlines future directions for developing KGM-based hydrogels for use in edible electronics.

Recent Advances in Halal Bioactive Materials for Intelligent Food Packaging Indicator

Food safety and security are top priorities for consumers and the food industry alike. Despite strict standards and criteria for food production processes, the potential for food-borne diseases due to improper handling and processing is always present. This has led to an urgent need for solutions that can ensure the safety of packaged foods. Therefore, this paper reviews intelligent packaging, which employs non-toxic and environmentally friendly packaging with superior bioactive materials that has emerged as a promising solution. This review was prepared based on several online libraries and databases from 2008 to 2022. By incorporating halal bioactive materials into the packaging system, it becomes possible to interact with the contents and surrounding environment of halal food products, helping preserve them for longer periods. One particularly promising avenue of research is the use of natural colourants as halal bioactive materials. These colourants possess excellent chemical, thermal, and physical stabilities, along with antioxidant and antimicrobial properties, making them ideal candidates for use in intelligent indicators that can detect food blemishes and prevent pathogenic spoilage. However, despite the potential of this technology, further research and development are needed to promote commercial applications and market development. With continued efforts to explore the full potential of natural colourants as halal bioactive materials, we can meet the increasing demand for food safety and security, helping to ensure that consumers have access to high-quality, safe, and nutritious foods.

Recent advancements in natural colorants and their application as coloring in food and in intelligent food packaging

Colorants are widely employed in the food industry as an essential ingredient in many products since color is one of the most valued attributes by consumers. Furthermore, the utilization of colorants is currently being extended to the food packaging technologies. The objective of this review was to compile recent information about the main families of natural coloring compounds, and to describe their real implications in food coloring. In addition, their technological use in different food systems (namely, bakery products, beverages, meat and meat products, and dairy products) and their utilization in intelligent packaging to monitor the freshness of foodstuffs with the aim of extending food shelf life and improving food properties was discussed. The potential of using natural colorant in different food to improve their color has been demonstrated, although color stability is still a challenging task. More interestingly, the application of intelligent colorimetric indicators to exhibit color changes with variations in pH can enable real-time monitoring of food quality.

Triple-function chitosan-based film for pork and shrimp packaging

A film simultaneously with colorimetric, fluorescent and active functions was engineered using chitosan (CS) and polyvinyl alcohol (PVA) as the film matrix and curcumin-β-cyclodextrin complex (Cur-β-CD) as the indicator for freshness monitoring and maintaining of pork and shrimp. In addition to the efficacy of prolonging shelf life, the film's color could change from yellow to orange with ΔE > 5 and its fluorescence intensity could decrease during storage. The incorporation of PVA significantly enhanced the mechanical properties of CS film with tensile strength of 31.80 MPa and elongation at break of 127.22 %. The Cur-β-CD improved the antioxidant and antibacterial properties, water contact angle (from 86.3° to 111.2°), water vapor permeability (from 3.28 × 10^-10 g (m s Pa)^-1 to 0.42 × 10^-10 g (m s Pa)^-1) and mechanical properties of CS/PVA film. These results show the potential of the film as promising alternatives for intelligent and active food packaging.

Emerging Applications of Versatile Polyaniline-Based Polymers in the Food Industry

Intrinsically conducting polymers (ICPs) have been widely studied in various applications, such as sensors, tissue engineering, drug delivery, and semiconductors. Specifically, polyaniline (PANI) stands out in food industry applications due to its advantageous reversible redox properties, electrical conductivity, and simple modification. The rising concerns about food safety and security have encouraged the development of PANI as an antioxidant, antimicrobial agent, food freshness indicator, and electronic nose. At the same time, it plays an important role in food safety control to ensure the quality of food. This study reviews the emerging applications of PANI in the food industry. It has been found that the versatile applications of PANI allow the advancement of modern active and intelligent food packaging and better food quality monitoring systems.