Shikonin Functionalized Packaging Film for Monitoring the Freshness of Shrimp

Abstract

A shikonin embedded smart and active food packaging film was produced using a binary mixture of gelatin and cellulose nanofiber (CNF). Shikonin is an alcohol-soluble natural pigment extracted from Lithospermum erythrorhizon root. The fabricated film showed good pH-responsive color changes and volatile gas sensing properties. Moreover, the film exhibited excellent antioxidant and antibacterial activity against foodborne pathogens. The shikonin incorporated gelatin/CNF-based film showed excellent UV-light barrier properties (>95%) and high tensile strength (>80 MPa), which is useful for food packaging. The hydrodynamic properties of the film were also slightly changed in the presence of shikonin, but the thermal stability and water vapor permeability remained unaffected. Thus, the inclusion of shikonin in the gelatin/CNF-based film improves not only the physical properties but also the functional properties. The film’s color indicator properties also clearly show shrimp’s freshness and spoilage during storage for 48 h. The shikonin-based functional film is expected to be a promising tool for multi-purpose smart and active food packaging applications.

Biobased Intelligent Food-Packaging Materials with Sustained-Release Antibacterial and Real-Time Monitoring Ability

“…After 48 h at room temperature, shrimp packaged using the composite film with AAEO decays significantly slower (pH from 6.2 to 6.6) than that of the film without AAEO (pH from 6.2 to 7.1), with smaller changes in HSV (hue, saturation, value) values. Compared with the related reported studies, as shown in Figure e and Table S1, the developed intelligent food packaging materials can better monitor the freshness with significant color response (higher Δ S , Δ H , and Δ V values). − …”

Preparation of Maleic Anhydride–Polystyrene Microsphere Cross-Linking Shikonin and Oxidized Nanocellulose Film for Freshness Monitoring

“…When ΔE > 5, the color change was visible to the naked eye; when ΔE > 12, the color change difference value was defined as large. 6 Due to the high pH sensitivity of SKN pigment, the SMA-SKN/oxidized CNF film could be used to monitor the freshness of pork and shrimp. Figure 6 shows the color change of the SMA-SKN/oxidized CNF film in detecting the freshness of pork and shrimp.…”

“…5 Intelligent packaging materials can monitor the freshness change of packaged food in real time and transmit this information to customers. 6 Food spoilage is usually accompanied by the release of acidic or alkaline gases. These kinds of gases could change the pH of the food environment, an intelligent packaging's pigment with pH responsiveness could exhibit a color change instantly with a change in the pH, and consumers could identify the food freshness by the characteristic color of intelligent packaging.…”

“…Due to the continuous improvement of people’s living conditions, the freshness and safety of food have attracted more and more attention from packaging material researchers and consumers. − It is worth noting that the quality of food may not be fully reflected by the shelf life, especially for meat products with high protein content . Intelligent packaging materials can monitor the freshness change of packaged food in real time and transmit this information to customers . Food spoilage is usually accompanied by the release of acidic or alkaline gases.…”

Reflections on food security and smart packaging

“…In the presence of shikonin, the film's hydrodynamic properties slightly altered, but its thermal stability and WVP remained unaffected. The shrimp's freshness and spoilage after 48 h of storage are also clearly visible [ 72 ] Sensor D-π-A luminogen Food spoilage Fish 8 days in refrigerator temperature at 3.5 °C The present D-π-A compound was made into a cellulose film with a colorimetric and fluorometric dual-channel as a response to amine vapors from fish samples. It is simple to transform into smart labels and encase it in food bags, resulting in an intelligent food package [ 73 ] Polypropylene (PP) film Two composite films (Polypropylene/Octadecane and Polypropylene/Octadecane/Zeolite) Food quality Cherry tomatoes 10 days and 23 °C It showed significantly higher temperature dependence.…”