Development of curcumin/rice starch films for sensitive detection of hypoxanthine in chicken and fish meat

Development of curcumin integrated smart pH indicator, antibacterial, and antioxidant waste derived Artocarpus lakoocha starch-based packaging film

Monitoring of food freshness is considered one of the crucial challenges for both customers/consumers and the food industries. In this study, we developed a curcumin-based starch film (F1) for pH-sensitive intelligent food packaging application. The starch was obtained from waste seeds of Artocarpus lakoocha (NS-MJF). The native starch underwent various physical and chemical modifications to yield modified starches (S1 [Autoclave heat treated], S2 [osmotic-pressure treated], S3 [citric acid treated]). The native starch was then used further for the formation of curcumin (2.5 % w/w)-based film (F1). We had analyzed these starches for solubility, colour analysis, biodegradability, oil absorption capacity, and moisture content, etc. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed favourable microstructures. The addition of curcumin to the starch enhanced the contact angle and elongation at the break of the resulting films. Antioxidant and antimicrobial assays, along with real-time freshness monitoring of chicken fillets, were also conducted. Thus, our findings may contribute to the optimization of pH-responsive biopolymer-based films for intelligent poultry packaging, promising advancements in food preservation and safety.

A review on improving the sensitivity and color stability of naturally sourced pH-sensitive indicator films

Naturally sourced pH-sensitive indicator films are of interest for real-time monitoring of food freshness through color changes because of their safety. Therefore, natural pigments for indicator films are required. However, pigment stability is affected by environmental factors, which can in turn affect the sensitivity and color stability of the pH-sensitive indicator film. First, natural pigments (anthocyanin, betalain, curcumin, alizarin, and shikonin) commonly used in pH-sensitive indicator films are presented. Subsequently, the mechanisms behind the change in pigment color under different pH environments and their applications in monitoring food freshness are also described. Third, influence factors, such as the sources, types, and pH sensitivity of pigments, as well as environmental parameters (light, temperature, humidity, and oxygen) of sensitivity and color stability, are analyzed. Finally, methods for improving the pH-sensitive indicator film are explored, encapsulation of natural pigments, incorporation of a hydrophobic film-forming matrix or function material, and protective layer have been shown to enhance the color stability of indicator films, the addition of copigments or mental ions, blending of different natural pigments, and the utilization of electrospinning have been proved to increase the color sensitivity of indicator films. This review could provide theoretical support for the development of naturally sourced pH-sensitive indicator films with high stability and sensitivity and facilitate the development in the field of monitoring food freshness.

Recent advances on natural colorants-based intelligent colorimetric food freshness indicators: fabrication, multifunctional applications and optimization strategies

With the increasing concerns of food safety and public health, tremendous efforts have been concentrated on the development of effective, reliable, nondestructive methods to evaluate the freshness level of different kinds of food. Natural colorants-based intelligent colorimetric indicators which are typically constructed with natural colorants and polymer matrices has been regarded as an innovative approach to notify the customers and retailers of the food quality during the storage and transportation procedure in real-time. This review briefly elucidates the mechanism of natural colorants used for intelligent colorimetric indicators and fabrication methodologies of natural colorants-based food freshness indicators. Subsequently, their multifunctional applications in intelligent food packaging systems like antioxidant packaging, antimicrobial packaging, biodegradable packaging, UV-blocking packaging and inkless packaging are well introduced. This paper also summarizes several optimizing strategies for the practical application of this advanced technology from different perspectives. Strategies like adopting a hydrophobic matrix, constructing double-layer film and encapsulation have been developed to improve the stability of the indicators. Co-pigmentation, metal ion complexation, pigment-mixing and using substrates with high surface area are proved to be effective to enhance the sensitivity of the indicators. Approaches include multi-index evaluation, machine learning and smartphone-assisted evaluation have been proven to improve the accuracy of the intelligent food freshness indicators. Finally, future research opportunities and challenges are proposed. Based on the fundamental understanding of natural colorants-based intelligent colorimetric food freshness indicators, and the latest research and findings from literature, this review article will help to develop better, lower cost and more reliable food freshness evaluation technique for modern food industry.

A critical review on biodegradable food packaging for meat: Materials, sustainability, regulations, and perspectives in the EU

The development of biodegradable packaging is a challenge, as conventional plastics have many advantages in terms of high flexibility, transparency, low cost, strong mechanical characteristics, and high resistance to heat compared with most biodegradable plastics. The quality of biodegradable materials and the research needed for their improvement for meat packaging were critically evaluated in this study. In terms of sustainability, biodegradable packagings are more sustainable than conventional plastics; however, most of them contain unsustainable chemical additives. Cellulose showed a high potential for meat preservation due to high moisture control. Polyhydroxyalkanoates and polylactic acid (PLA) are renewable materials that have been recently introduced to the market, but their application in meat products is still limited. To be classified as an edible film, the mechanical properties and acceptable control over gas and moisture exchange need to be improved. PLA and cellulose-based films possess the advantage of protection against oxygen and water permeation; however, the addition of functional substances plays an important role in their effects on the foods. Furthermore, the use of packaging materials is increasing due to consumer demand for natural high-quality food packaging that serves functions such as extended shelf-life and contamination protection. To support the importance moving toward biodegradable packaging for meat, this review presented novel perspectives regarding ecological impacts, commercial status, and consumer perspectives. Those aspects are then evaluated with the specific consideration of regulations and perspective in the European Union (EU) for employing renewable and ecological meat packaging materials. This review also helps to highlight the situation regarding biodegradable food packaging for meat in the EU specifically.

Assessing Meat Freshness via Nanotechnology Biosensors: Is the World Prepared for Lightning-Fast Pace Methods?

In the rapidly evolving field of food science, nanotechnology-based biosensors are one of the most intriguing techniques for tracking meat freshness. Purine derivatives, especially hypoxanthine and xanthine, are important signs of food going bad, especially in meat and meat products. This article compares the analytical performance parameters of traditional biosensor techniques and nanotechnology-based biosensor techniques that can be used to find purine derivatives in meat samples. In the introduction, we discussed the significance of purine metabolisms as analytes in the field of food science. Traditional methods of analysis and biosensors based on nanotechnology were also briefly explained. A comprehensive section of conventional and nanotechnology-based biosensing techniques is covered in detail, along with their analytical performance parameters (selectivity, sensitivity, linearity, and detection limit) in meat samples. Furthermore, the comparison of the methods above was thoroughly explained. In the last part, the pros and cons of the methods and the future of the nanotechnology-based biosensors that have been created are discussed.

Molecularly Imprinted Polymer-Based Electrochemical Sensor for Rapid and Selective Detection of Hypoxanthine

In this paper, we report on the coupling of an electrochemical transducer with a specifically designed biomimetic and synthetic polymeric layer that serves as a recognition surface that demonstrates the molecular memory necessary to facilitate the stable and selective identification of the meat-freshness indicator hypoxanthine. Consumer preferences and the food safety of meat products are largely influenced by their freshness, so it is crucial to monitor it so as to quickly identify when it deteriorates. The sensor consists of a glassy-carbon electrode, which can be regenerated in situ continuously, functionalized with molecularly imprinted polymers (MIPs) and a nanocomposite of curcumin-coated iron oxide magnetic nanospheres (C-IO-MNSs) and multiwalled carbon nanotubes (MWCNTs) that enhance the surface area as well as the electroactive characteristics. The electrochemical behavior of the fabricated sensor was analyzed by both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Differential pulse voltammetric studies revealed the rapid response of the proposed sol-gel-MIP/MWCNT/C-IO-MNS/GCE sensor to hypoxanthine in a concentration range of 2-50 µg/mL with a lower limit of detection at 0.165 μg/mL. Application of the newly fabricated sensor demonstrated acceptable recoveries and satisfactory accuracy when used to measure hypoxanthine in different meat samples.

The Emergence of Edible and Food-Application Coatings for Food Packaging: A Review

Food packaging was not as important in the past as it is now, because the world has more people but fewer food resources. Food packaging will become more prevalent and go from being a nice-to-have to an essential feature of modern life. Food packaging has grown to be an important industry sector in today's world of more people and more food. Food packaging innovation faces significant challenges in extending perishable food products' shelf life and contributing to meeting daily nutrient requirements as people nowadays are searching for foods that offer additional health advantages. Modern food preservation techniques have two objectives: process viability and safe, environmentally friendly end products. Long-term storage techniques can include the use of edible coatings and films. This article gives a succinct overview of the supplies and procedures used to coat food products with conventional packaging films and coatings. The key findings summarizing the biodegradable packaging materials are emphasized for their ability to prolong the freshness and flavor of a wide range of food items; films and edible coatings are highlighted as viable alternatives to traditional packaging methods. We discuss the safety concerns and opportunities presented by applying edible films and coatings, allowing it to be used as quality indicators for time-sensitive foods.

Wearable Natural Rubber Latex Gloves with Curcumin for Torn Glove Detection in Clinical Settings

Glove tear or perforation is a common occurrence during various activities that require gloves to be worn, posing a significant risk to the wearer and possibly others. This is vitally important in a clinical environment and particularly during surgical procedures. When a glove perforation occurs (and is noticed), the glove must be replaced as soon as possible; however, it is not always noticeable. The present article is focused on the design and development of a novel fluorescence-based sensing mechanism, which is integrated within the glove topology, to help alert the wearer of a perforation in situ. We hypothesized that natural rubber gloves with curcumin infused would yield fluorescence when the glove is damaged, particularly when torn or punctured. The glove design is based on double-dipping between Natural Rubber Latex (NRL) and an inner layer of latex mixed with curcumin, which results in a notable bright yellow-green emission when exposed to UV light. Curcumin (Cur) is a phenolic chemical found primarily in turmeric that fluoresces yellowish-green at 525 nm. The tear region on the glove will glow, indicating the presence of a Cur coating/dipping layer beneath. NRL film is modified by dipping it in a Cur dispersion solution mixed with NRL for the second dipping layer. Using Cur as a filler in NRL also has the distinct advantage of allowing the glove to be made stronger by evenly distributing it throughout the rubber phase. Herein, the optimized design is fully characterized, including physicochemical (fluorescence emission) and mechanical (tensile and tear tests) properties, highlighting the clear potential of this novel and low-cost approach for in situ torn glove detection.

Green Tea Extract Enrichment: Mechanical and Physicochemical Properties Improvement of Rice Starch-Pectin Composite Film

The effects of green tea extract (GTE) at varying concentrations (0.000, 0.125, 0.250, 0.500, and 1.000%, w/v) on the properties of rice-starch-pectin (RS-P) blend films were investigated. The results showed that GTE addition enhanced (p < 0.05) the antioxidation properties (i.e., total phenolic content, DPPH radical scavenging activity, and ferric reducing antioxidant power) and thickness of the RS-P composite film. The darker appearance of the RS-T-GTE blend films was obtained in correspondence to the lower L* values. However, the a* and b* values were higher toward red and yellow as GTE increased. Though GTE did not significantly alter the film solubility, the moisture content and the water vapor permeability (WVP) of the resulting films were reduced. In addition, the GTE enrichment diminished the light transmission in the UV-Visible region (200−800 nm) and the transparency of the developed films. The inclusion of GTE also significantly (p < 0.05) lowered the tensile strength (TS) and elongation at break (EAB) of the developed film. The FT-IR spectra revealed the interactions between RS-P films and GTE with no changes in functional groups. The antimicrobial activity against Staphylococcus aureus (TISTR 764) was observed in the RS-P biocomposite film with 1% (w/v) GTE. These results suggested that the RS-P-GTE composite film has considerable potential for application as active food packaging.

Development of Aloe Vera-Green Banana Saba-Curcumin Composite Film for Colorimetric Detection of Ferrum (II)

This study was performed to develop and characterize a bio-film composed of Aloe vera (Aloe barbadensis), green banana Saba (Musa acuminata x balbisiana), and curcumin for the detection of Fe²⁺ ions. Cross-linking interaction between banana starch-aloe vera gel and banana starch-curcumin enhanced l the sensing performance of the composite film towards divalent metal ions of Fe²⁺. The morphological structure of the Aloe vera-banana starch-curcumin composite revealed a smooth and compact surface without cracks and some heterogeneity when observed under Scanning Electron Microscopy (SEM). The thickness, density, color property, opacity, biodegradation, moisture content, water-solubility, water absorption, swelling degree, and water vapor permeability of bio-films were measured. The incorporation of aloe vera gel and curcumin particles onto the banana starch film has successfully improved the film properties. The formation of the curcumin-ferrum (II) complex has triggered the film to transform color from yellow to greenish-brown after interaction with Fe²⁺ ions that exhibit an accuracy of 101.11% within a swift reaction time. Good linearity (R² = 0.9845) of response on colorimetric analysis was also obtained in Fe²⁺ ions concentration that ranges from 0 to 100 ppm, with a limit of detection and quantification found at 27.84 ppm and 92.81 ppm, respectively. In this context, the film was highly selective towards Fe²⁺ ions because no changes of color occur through naked eye observation when films interact with other metal ions, including Fe³⁺, Pb²⁺, Ni²⁺, Cd²⁺, and Cu^2+. Thus, these findings encourage curcumin-based starch films as sensing materials to detect Fe²⁺ ions in the field of food and agriculture.

Recent Advancements of Polysaccharides to Enhance Quality and Delay Ripening of Fresh Produce: A Review

The freshness of fruits and vegetables plays a significant role in consumers' decision to purchase a product at the supermarket. Fresh-cut products are the latest trend in fulfilling society's restless needs, and the food industry is faced with the challenge of maintaining the quality of fresh produce. The food industry is concerned with the natural maturation and degradation of fruits and vegetables, primarily due to enzymatic reactions. It has been demonstrated that polysaccharide coatings effectively preserve the freshness of these products, extending their shelf life depending on the preservation method used. This review informs readers about the different types of polysaccharides and their novel applications as natural food preservatives in the past five years (2018-2022). The key findings summarized the properties of the antimicrobial agent, the molecular mechanism of action, coating methods, and formulation for the preservation approach. Additionally, we discuss the scientific factors influencing polysaccharide processing and preservation efficacy, allowing it to be used in post-harvest management.