# Textural Properties of Bakery Products: A Review of Instrumental and Sensory Evaluation Studies
## 4 Discussion  
This review showed that bread, cake and cookies were the most studied product types. These products also represent those with the highest relevance in the bakery sector globally. According to the Observatory of Economic Complexity [31], which refers to bread, pastry, cakes, biscuits and other similar products, in 2020, the world trade in the bakery sector accounted for 37.3 billion dollars, corresponding to a growth of 0.6% in relation to the previous year. The leading exporter being Germany and top importer being the United States (4.3 and 6.2 billion dollars, respectively in 2020). Freshness perception is a key factor in consumer choice and acceptability of bakery products that interrelates with texture, among other characteristics. Loss of freshness in bakery and pastry foods causes a decrease in quality along shelf life and is related to how the texture parameters evolve over time. The organoleptic properties are related and will be influenced by the product's ingredients and the manufacturing processes utilized in their production. On the other hand, the mechanical properties of foods depend on how food ingredients are mixed and processed during manufacture and influence their texture as well as how stable that texture is [32]. According to [PERSON] et al. [33], the main sensory attributes for bread relate to the dough's resistance to deformation, the balance between elasticity and viscosity, and the rate of dough growth (raising). The consumer acceptance of bread may be related to its moisture level, which, in turn, is associated with freshness [33]. Given the commercial competition and consumer demand, the industry seeks to improve products to satisfy consumer needs and increase profit. Understanding the product's key attributes allows the industry to minimize the risk of failure when launching new products on the market [33; 34]. In the food industry, measuring the textural properties of bakery and pastry products is very important, for example, in quality control and for the development of new products [33; 34; 35]. Instrumental texture analysis, particularly the TPA, represents an important breakthrough, being presently widely used by the food industry and the scientific community. TPA is an objective method; the textural attributes it estimates can correlate with the sensory textural attributes. Hence, this method is fast enough and needs easy sample preparation to be used in quality control in the processing line [36]. Most studies in this review used instrumental texture measurement, from which nearly half also included sensorial tests. A smaller number of studies focused exclusively on the sensorial assessment of texture. The instrumental methods for texture determination can be divided into three tests: fundamental, imitative and empirical. The first measure defines rheological properties, and the second imitates the conditions to which the food is submitted in real circumstances. The last measure mechanical properties of the sample in empirical units of the instrument, therefore not being able to be extrapolated outside the test conditions and specific sample or even compared with other products. The imitative tests have the most potential and adaptability for research and industry. However, the empirical tests also have advantages for quick determinations on the production line [37]. Imitative instruments simulate the chewing process. The problem with this type of measurement is the insufficient definition of what is measured and the arbitrariness of the test, which are effective only with a limited number of foods, despite being widely used in the food industries [37; 38; 39]. The TPA is a set of measures developed based on the imitation of the compression of a bite on a piece of food, representing twice the movement of the jaws in chewing. The test is based on the sample's response to the applied force. Strain levels between 20-50% are generally applied to semi-solid products.