Gelatin-Based Film as a Color Indicator in Food-Spoilage Observation: A Review

Abstract

The color indicator can monitor the quality and safety of food products due to its sensitive nature toward various pH levels. A color indicator helps consumers monitor the freshness of food products since it is difficult for them to depend solely on their appearance. Thus, this review could provide alternative suggestions to solve the food-spoilage determination, especially for perishable food. Usually, food spoilage happens due to protein and lipid oxidation, enzymatic reaction, and microbial activity that will cause an alteration of the pH level. Due to their broad-spectrum properties, natural sources such as anthocyanin, curcumin, and betacyanin are commonly used in developing color indicators. They can also improve the gelatin-based film’s morphology and significant drawbacks. Incorporating natural colorants into the gelatin-based film can improve the film’s strength, gas-barrier properties, and water-vapor permeability and provide antioxidant and antimicrobial properties. Hence, the color indicator can be utilized as an effective tool to monitor and control the shelf life of packaged foods. Nevertheless, future studies should consider the determination of food-spoilage observation using natural colorants from betacyanin, chlorophyll, and carotenoids, as well as the determination of gas levels in food spoilage, especially carbon dioxide gas.

Recent advances in the design of SERS substrates and sensing systems for (bio)sensing applications: Systems from single cell to single molecule detection

“…Paper-based substrates are gaining attention owing to their customizable, biodegradable, and biocompatible properties, and their scalable use in the development of consumer-oriented products. Most paper-based substrates are made of cellulose polymer, which is composed of a linear structure of a few to hundred 1 of 4-linked D-glucose monomers (Shaik et al, 2022). Other common polymers in paper include hemicellulosic paper (Kaushik & Moores, 2016;Xiang et al, 2022), lignin-based paper (Klemm et al, 2005;Mahmoud & Zourob, 2013), and bacterial cellulose-based paper (Basta & El-Saied, 2009;Xiao et al, 2023).…”

Integrated Smart Gas Tracking Device with Artificially Tailored Selectivity for Real-Time Monitoring Food Freshness

“…Up to date, methods that have been frequently reported for food freshness monitoring include but are not limited to microbiological testing, visual recognition, capillary electrochromatography, volatile compounds analysis, etc. [6][7][8][9][10][11]. Among them, discriminating food freshness by tracking volatile compounds receives extensive attention due to its attractive characteristics of rapid and non-invasive, which are suitable for alarming food spoilage at an early stage [12][13][14].…”

“…Until present, high-performance silicon transistor arrays for trace-level, multi-gas sensing have effectively assessed food freshness in complex gaseous environments for practical applications [13]. However, in consideration of the ambient environment of low temperature (normally below 4 • C) and high humidity (90% R.H.) in refrigerators, it is highly desired to develop high-performance chemical gas sensors when tacking target volatile gas species [7,9,14,[22][23][24].…”

Preparation, Characterization, and Application of pH-Response Color-Changeable Films Based on Pullulan, Cooked Amaranth (Amaranthus tricolor L.) Juice, and Bergamot Essential Oil

“…In recent years, natural pigments with pH-response color-changeable properties have attracted attention in the field of smart packaging [8][9][10]. Betacyanins, one kind of natural pigment, are distributed in the flowers, leaves, fruits, and rhizomes of plant order Caryophyllales [11].…”