Smart labels for fruit and vegetable quality detection: A review of recent?progress

In the field of food storage and transportation, smart labels have emerged as an innovative tool for monitoring and communicating changes in food quality. These labels use visual effects or digital forms to convey information about food quality. Three types of smart labels are currently available: indicator, sensor, and integrated. Indicator smart labels rely on a colorant and a film-forming substrate to change color, making them an ideal tool for tracking freshness. As time passes and the quality of the food changes, the color of the label will also change, providing a clear sign of how fresh the food is. Sensor smart labels, on the other hand, take a more digital approach. They can measure changes in moisture, aroma compounds and amine concentration, allowing for more accurate monitoring of food quality. However, sensor labels can only assess the quality of the product at one time. Overall, smart labels have revolutionized the way we track food quality during storage and transportation. Whether you?re looking to track freshness or quantify changes in food quality, these labels provide an effective and convenient solution. Smart labels have a wide variety of applications and can be classified in many ways. A study by Jiangnan University in China proposes smart labels suitable for fruit and vegetable quality inspection based on factors such as ethylene content, color, temperature, and pesticide residues. Below is a summary of this review. Ethylene-sensitive smart labels are essential for monitoring and controlling the ripeness of produce in the supply chain. Ethylene-sensitive sensors consist of a network unit, a server unit and an interaction unit. They collect data via a sensor node, send the data via 4G network communication, and present it to the user via an application or graphical display. Various sensors based on materials such as palladium-loaded tin oxide, metal ion molybdenum, and gold-plated electrodes have been developed to detect ethylene concentration. An integrated system based on a pulsed quantum cascade laser and off-axis integrated cavity output spectroscopy has also been developed to detect ethylene. The detection limit is an important indicator for the selection of ethylene sensors. Color-sensitive smart labels can assess the ripeness of fruits and vegetables by detecting changes in pigments through optical analysis. Researchers have used color recognition systems and radio frequency identification RFID-optical sensor coupling to develop smart labeling systems for fruits such as tomatoes, mangoes, and bananas. Temperature-sensitive smart labels are the most used and measure real-time temperature to assess the freshness of produce. Three types of temperature-sensitive smart labels are microbial-based, enzyme-reactive, and photochemical-based. There are several available smart labels, including OnVuTM, eO?, and Timestrip?, as well as RFID smart labels that watch quality from farm to fork. Gas-sensitive smart labels are also used to check the quality of fruits and vegetables. Oxygen and carbon dioxide levels affect the quality of fruits and vegetables in a variety of ways, including oxidation, respiratory metabolism, and carbon dioxide concentration effects. Pesticide residue monitoring smart labels (or biosensors) detect pesticide residues in fruits and vegetables that can affect quality and human health. Nanomaterials have improved detection accuracy, and combining biosensors with acetylcholinesterase and nanocomposites can improve detection. A wearable smart label has been developed to quantify residues on fruit and vegetable surfaces. In conclusion, while smart labels are useful for real-time quality detection of fruits and vegetables, their implementation is limited by high production costs, safety concerns, and consumer and producer factors. In addition, the specific characteristics of different types of products make it difficult to develop this type of label. The full development of smart labels requires further research. Source: Bing Chen, Min Zhang, Huizhi Chen, Arun S. Mujumdar, Zhimei Guo. Progress in smart labels for rapid quality detection of fruit and vegetables: A review. Postharvest Biology and Technology, Volume 198, 2023. Author:?Jorge Luis?Alonso G. (with ChatGPT)?Maximizing Agribusiness Profits with Expert Postharvest Storage Strategies | Horticultural Writing Specialist.?This article was written exclusively for the business platform Postharvest. Cover photo:?Wikipedia.