South Korean scientists have developed a portable molecular sensor that can quickly detect biogenic amines by changing color. This helps prevent people from consuming spoiled meat, ensures food quality, and contributes to building a more effective environment for food storage and distribution in the logistics chain. The relevant research was published in the latest issue of the journal *Food Chemistry*. When foods such as fish, meat, and cheese decay, they release various organic nitrogen compounds called biogenic amines (BAs). Although the human body uses small amounts of BAs in processes like hormone synthesis, ingesting large quantities of BAs from spoiled food can cause serious health problems. Therefore, detecting BAs during food storage and distribution is crucial. In the latest study, scientists from Pusan National University utilized the unique property of polydiacetylene (PDA)-based hydrogel beads, which change color when bound to BAs. They combined these hydrogel beads with an alginate solution to form a three-dimensional porous structure with a large surface area, thereby creating this new sensor. Test results showed that the sensor can easily detect BAs such as cadaverine and propylamine in solutions and in vapor form through distinct color changes from blue to red. It can also effectively track the gradual spoilage of pork through obvious color changes. Made of lightweight beads, the sensor does not require technical personnel or complex analytical equipment. The seamless and rapid visual detection can be achieved through the color change of the beads from blue to red. Seongbaek Seo (transliterated), associate professor of biomaterial science at Pusan National University and leader of the latest research, pointed out that this PDA-based portable color-changing sensor can quickly monitor BAs released from spoiled food in a simple way, preventing people from eating spoiled meat and helping to build a more effective environment for food storage and distribution. Food Safety Testing Equipment Market Reaches Hundreds of Billions in Scale Food safety is related to the safety of people's lives and health. However, due to insufficient domestic food safety supervision and irregular production by some bad enterprises, food safety problems in China occur frequently. To strengthen food supervision, food safety testing will be one of the important links in implementing food safety. As an important tool for food safety testing, the market demand for food safety testing instruments is constantly increasing. According to the *2023-2028 Food Safety Tester Industry Market In-depth Research and Investment Prospect Forecast Analysis Report* released by the New Think Tank Industry Research Center, the market size of China's food safety testing instruments was close to 100 billion yuan in 2022, and the industry has a good development prospect. At the same time, as the state pays increasing attention to food safety testing, the demand growth space for domestic food safety testing instruments will continue to expand. For example, in October 2022, the state issued the *Interim Measures for the Supervision and Administration of the Quality and Safety of Food-Related Products*, which stipulates that producers of food-related products shall inspect their products either by themselves or by entrusting qualified inspection institutions, form and keep corresponding records, and the products can leave the factory or be sold only after passing the inspection. In the future, against the background of people's growing health awareness and increasing attention to food safety, the market penetration rate of domestic food safety testing instruments will continue to rise, and families are expected to become a new scenario for the demand of food safety testing instruments. In this context, food safety testing instruments need to be continuously upgraded towards portability, miniaturization, intelligence, and specialization, so as to adapt to more scenarios and create broad development space for the industry. Analysts from the New Think Tank industry stated that food safety testing instruments are a type of equipment used to detect toxic and harmful substances in food. Currently, with the increasing attention paid by the state to food safety and the strengthening of food safety supervision, their market potential is constantly emerging. Rapid Microbial Detection Technologies Food safety problems caused by microorganisms are very common and pose a serious threat to people's health, such as diseases like diarrhea caused by pathogenic microorganisms, which seriously endanger people's physical and mental health. At present, food safety issues have received widespread attention. China has introduced many policies and regulations, and actively implemented them to strictly control microbial contamination in food. For food inspection institutions, microbial detection technology is a commonly used technical means, which can effectively detect harmful microorganisms in food and ensure food quality. So what are the common rapid microbial detection technologies? And which foods are they suitable for? 1. Biosensor Technology Biosensor technology is a rapid detection technology that uses biosensors for detection. The main components of a biosensor include recognition elements and transduction elements. Its advantage lies in the effective integration of biological reaction technology and biological characteristics, which can be effectively identified and analyzed in the recognition system of the biosensor, and then the types of components and the content of harmful substances in food can be obtained by converting the measured signals. This technology has the advantages of convenient operation, high sensitivity, strong accuracy, rapid screening, portability, online monitoring, and low cost. As a new interdisciplinary technology, it has now become a major means of food detection. Biosensor technology can detect harmful microorganisms, viruses, pesticides, and illegal additives in food. For example, in the rapid detection of bacteria in food samples, the reaction between ATP in bacterial cells and luciferin-enzyme reagents can produce light, and the signal is converted into an electrical signal. Finally, the number of bacteria is detected by a photometer. However, there are many shortcomings in practical applications, such as poor stability and short service life. At present, biosensor technology is mostly used for the detection of pathogenic bacteria and pesticide residues in food, and its practical application has certain limitations, so there is still a need to continuously improve the technical level. 2. Resistance and Conductance Detection Technology Resistance and conductance technology is a rapid detection technology that detects the content of microorganisms in food samples by measuring changes in the electrical properties of the culture medium caused by microbial metabolism. When culturing microorganisms, due to physiological metabolism, electrically inert substances in the culture medium can be converted into active substances, such as fat metabolized into heavy phosphate, and macromolecular substances metabolized into small molecular substances. In the process of continuous microbial growth, the electrically inert molecules in the culture medium are gradually replaced by active molecules and ions, resulting in increased conductivity and decreased impedance. The initial number of microorganisms varies, and the time of their exponential growth phase is also different. By establishing a relationship between the two, this technology can be used to measure the original number of microorganisms. In addition, this technology can also be used to judge the shelf life of food. The use of this technology usually requires equipment such as microbial counters and automatic microbial detectors, which calculate the specific number of microorganisms based on parameters such as resistance and capacitance, and generate data with reference value to provide a basis for inspectors to judge whether food meets the standards. 3. Mass Spectrometry Technology The application of mass spectrometry technology covers many theoretical knowledge, such as biological genetics and metabolomics, and has high application value in the inspection of seafood, fermented food, and other food types. In specific detection, this technology can separate Gram-positive bacteria in food and generate a list of spectral fingerprints, and detect bacteria by combining indicators such as genus-specific peaks and quantities. For example, when detecting fermented food, it can effectively determine the type of animal-derived Bifidobacterium subspecies. The use of this technology can make up for the shortcomings of molecular biology detection and meet the requirements of rapid inspection. In the specific inspection process, staff can efficiently detect bacterial contamination in food by using liquid chromatography separation technology and mass spectrometry technology. 4. Gas Chromatography Technology Gas chromatography technology is a commonly used rapid detection technology at present. It mainly uses inert gas as a carrier, introduces the tested sample into the instrument for comparative analysis, and comprehensively analyzes gases, liquids, and solids through a gas chromatograph. This technology has obvious application advantages in gas mixtures, solids, and volatile liquids, and the separation time is very short even when detecting complex mixtures that are difficult to separate. The components of the mixture will flow to the stationary phase (another solid or liquid) driven by the gas mobile phase. The stationary phase has different dissolution and adsorption capacities for different components, so the actual residence time of the mixture components in it is different, and thus they can be separated into multiple components. After separation, relevant instruments can perform non-electrical conversion in the corresponding order and display electrical signals corresponding to the concentration of each component, facilitating staff to record and analyze. 5. Nucleic Acid Probe Technology Nucleic acid probe technology mainly includes nucleic acid molecular hybridization technology and gene probe technology, whose function is to detect different gene chains in food and clarify the microbial situation in food on this basis. Different nucleic acid chains come from different sources, and their complementary base sequences can form molecular hybrid chains under the action of specific binding. Therefore, labeling probes on known DNA or RNA fragments can effectively detect microorganisms, that is, detect whether the same sequence exists in food. At present, this detection technology is frequently used in food microbial detection and is suitable for the detection of toxins and pathogenic bacteria. 6. Low-Field Nuclear Magnetic Resonance (LF-NMR) Technology Low-field nuclear magnetic resonance technology mainly refers to the interaction between magnetic atomic nuclei and a magnetic field. When low-energy nuclear magnetic moments absorb energy from an alternating field and reach a high-energy state, this phenomenon is called nuclear magnetic resonance, and corresponding nuclear magnetic resonance signals are generated. According to the strength of the magnetic field, high-field nuclear magnetic resonance refers to a constant magnetic field strength > 1.0T; medium-field nuclear magnetic resonance refers to a constant magnetic field strength of 0.5-1.0T; and low-field nuclear magnetic resonance refers to a constant magnetic field strength < 0.5T. This technology uses physical principles to effectively detect the characteristic parameters of spectral lines, thereby analyzing the internal structure of food molecules. The magnetic field strength is very low, so it is also a non-destructive testing method, which can maintain the original structure of substances to the greatest extent. Compared with traditional detection technologies, this technology can meet the requirements of rapid detection and has the advantages of being green and environmentally friendly. In the detection of food quality, different foods have significant differences in moisture content and water retention. Using this technology to test the water quality in food can accurately analyze food quality, with the advantages of non-destructiveness and repeatability. For example, in the detection of moisture and quality of dried shrimp, based on the analysis of the relationship between nuclear magnetic resonance parameters, structure, and moisture, the changes in the content and diffusion direction of free water and bound water in food can be detected, meeting the requirements of efficient and non-destructive detection. In addition, this technology can also analyze the level of food additives and moisture content, effectively detect their physical and chemical properties, and ensure food quality. Sources: *Science and Technology Daily*, New Think Tank Network, Xiaojiu Views the World