**1. Introduction**

The quality term has undergone variations over time. In the last century, the food quality was expressed only by the intrinsic and extrinsic characteristics of different individual units of a product which would determine its acceptability [1]. Currently, the term quality has already a broader aspect: it is related to the ability to plan and develop continuous actions during all stages of processing, aiming at maintaining the product characteristics and performance to reach the requirements that satisfy the needs and expectations of the consumer [2]. Thus, food companies seek to achieve more and more the quality standard of their products that will be delivered to the final consumer. In turn, the perception of quality by consumers is closely linked to the attributes they most value: nutrition and food safety.

Food safety practices aim to ensure the appropriate physical, chemical, and microbiological conditions for product quality. For food industries, the safety aspect is always a determining factor about quality, since any problem can compromise the consumer health, culminating in serious financial losses and diminishing the reliability of their products. Thus, the industry advocates the application of food safety management system in the entire food production chain, as a preventative approach toward identifying, preventing, and reducing foodborne hazards, to ensure the food is safe for consumption and with nutritional value. Only then, the total quality of food can be reached [3–5].

One of the main parameters that determine the food quality is its microbiological characteristic, since microbial contamination is responsible for most foodborne disease (FBD) outbreaks in worldwide, affecting individuals of all ages, particularly children under 5 years of age and persons living in low-income regions of the world [6]. The microbiological evaluation is performed with the objective of establishing the absence of pathogens or their toxins and to enumerate total or indicator microorganisms that provide information about the conditions of processing, storage, distribution, shelf life, and the health risk of the population [7]. As such examples, we can cite the increased numbers of *Staphylococcus aureus* when detected in a food processing step might imply in contamination by handling, the increased numbers of *Escherichia coli* might suggest fecal contamination, and the detection of *Salmonella* spp. might indicate that the processing has not been able to eliminate pathogenic microorganisms [8].

The microbiological quality should be effectively focused on traceability, with emphasis on the "farm-to-fork" approach, reaching the entire food chain. For this, rapid diagnostic methods are highly recommended so that early interventions of control strategies can be applied, ensuring the consumer's health and reducing the financial losses of the industry, as well as the costs with public health in cases of FBD outbreaks. In addition, these methods are essential for assessment of food safety objectives (maximum levels of hazards at the point of consumption) in food safety management, which require results in a shorter time than those obtained by culture cultivation [9]. Among rapid methods, real-time quantitative polymerase chain reaction (qPCR) has been shown to be a good tool for monitoring microbiological quality of food, since this technique is evolving to improve the sensitivity and specificity in detection and quantification of pathogens. According to "MIQE guidelines" [10], we chose to use the abbreviation qPCR for real-time quantitative PCR in entire chapter, avoiding confusion with other abbreviations that designate reverse transcription-qPCR (RT-qPCR).
