# Electronic Sensing Technologies in Food Quality Assessment: A Comprehensive Literature Review
## 2 Methodology
Standard instrumental testing techniques have problems with cost and their time-consuming nature [43; 44; 45; 46; 47]. These analyses are performed by trained or specialized personnel in a laboratory infrastructure. Sensory evaluation methods can pose problems such as the length of the training cycles of professionals and personal subjectivity, which makes it difficult to formulate objective assessments [48; 49]. Some examples of such problems include microbiological problems that take at least several days to assess; chemical and chromatographic methods that require continuous expenditure of gases, consumables, and expensive equipment; and sensory analysis that involves multiple panelists to evaluate selected attributes. Another key aspect of these methods is the destruction of samples, which makes further analysis difficult [50; 51]. Traditional methods are often characterized by complex, time-consuming, and limited detection capabilities. Furthermore, these methods usually address only one aspect of food quality. As a result, there has been an increase in research aimed at developing efficient and accurate quality detection techniques [2; 12; 13]. The ability to perform rapid, non-destructive analyses is particularly important in today's food market, characterized by increased international trade in fresh produce, as well as the need to have an environmentally efficient product. As a result, the use of more quality control technologies has become a key question that stakeholders in science and industry must answer [52]. In contrast to traditional methods, electronic sensing techniques aim to provide information in real time, thus overcoming the costs and time associated with laboratory methods or with human intervention, as in the case of traditional sensory analysis methods [42]. Compared to traditional analytical methods, electronic systems have special features: they are fast, objective, versatile, and potentially useful for at-line or on-line applications. In addition, these techniques are considered environmentally friendly, as they require little or no chemical reagent for sample preparation [53]. Sensors are generally distinguished by the type of electrochemical, thermometric, piezoelectric, magnetic, or optical transducers used. Their main function is to report physicochemical changes of bioactive materials interacting with the sample under study. Detectors can measure one or more sample variants, enzymatic reaction products, substrate consumption, cofactor consumption, microbial respiration or growth, specific metabolites, antigen binding, etc. [54; 55]. Electronic sensors have recently attracted much attention from scientists and many industries, who see their advantages as alternatives to traditional sensory testing. These electronic sensors can solve the problems associated with the use of panelists in sensory methods, such as subjectivity, sensory fatigue, and the high cost and time consumption of the methods [56]. Electronic sensors are used in the food industry to monitor product quality in quality assurance and control departments. The e-tongue and e-nose are expected to be more widely used in on-line work to detect unpleasant odors and tastes in industrial applications. The integration of electronic sensors with product processing and production enables their use for timely control and quality assurance. The development of biological sensors and the increase in the number of identified compounds give these sensory instruments great potential in fruit/vegetable harvesting, post-harvest, and horticultural applications. For example, they could facilitate the prediction of the harvest season of fruits and vegetables using deep learning or machine learning algorithms and advanced regression analysis models [57]. Of note, e-eyes, e-noses, and e-tongues, designed to mimic human senses, can be useful for real evaluation of fresh food products, thus enabling reductions in food waste. These approaches aim to assess quality parameters based on sensory characteristics or quantify specific analytes [6].