Advances and opportunities of hydrogel-based artificial olfactory colorimetric systems for food safety detection: A review

Food safety has attracted increasing attention in recent years. Harmful gases often produced during food storage have devastating effects on human health and ecosystems, and identifying and detecting them is essential. To date, many traditional methods have been used to monitor the freshness of food products. These methods have high precision and sensitivity, but their application to daily life is limited because they are time-consuming and require complex instruments. Therefore, the development of simple, rapid, and low-cost methods for evaluating food freshness is essential. Hydrogel-based colorimetric artificial olfactory systems have attracted a great deal of attention and have been widely applied in the field of food safety testing in recent years. The system has the advantages of a low detection limit, portability, onsite monitoring, high precision and rapid detection. This superiority makes the colorimetric hydrogel gas sensor a strong contender for improving food safety detection. This paper reviews the application of a hydrogel-based colorimetric artificial olfactory system for detecting hazardous gases for food safety purposes. The main sections of this review succinctly discuss the construction principles and operational mechanisms of the colorimetric artificial olfactory system. Additionally, it delves into the selection and preparation methodologies of hydrogel materials. This paper focuses on advancements in hydrogel-based colorimetric artificial olfactory systems for detecting gases, such as ammonia, biogenic amines, and H2S that are relevant to food safety. Furthermore, this work outlines the challenges encountered by this artificial olfactory system and proposes potential solutions to overcome them. The study presented in this paper demonstrates the potential application of a hydrogel-based colorimetric artificial olfactory system for food safety detection, and complements the previous review of colorimetric hydrogel gas sensors for the detection of spoilage gases in food products and serves as a reference for further advanced research and applications in this field. [Display omitted] •Recent advances in colorimetric hydrogel gas sensors for food safety detection are reviewed.•Potential trends in colorimetric hydrogel gas sensors for food safety detection are highlighted.•The food safety detection can be effectively simplified by colorimetric hydrogel gas sensors.