*5.1.1 Determination of biocompound contents by ultraviolet spectrophotometry (UV: Vis)*

Pre-formulation studies are of fundamental importance in relation to quality control tests, which are based on analyzes that allow the characterization of the raw material for the evaluation of its potential to be used as a finished product asset [27]. The characterization of an extract implies the definition of the contents of its main chemical constituents, as well as moisture, color, particle size distribution, viscosity, and technological properties, ensuring the safety, efficacy and quality of a product. When formulating products containing natural actives, the standard identification of markers or the development of methods that allow the quantification of purified chemical groups before, during, and after the obtaining process is essential [38].

There are many qualitative analytical methods used to identify total polyphenol levels (**Table 3**) such as UV–vis spectrophotometry, where one of the main colorimetric methods used is the Folin–Ciocalteu reagent. For the analysis, in a 25 mL volumetric flask, 4.8 ml of deionized water, 0.2 ml of sample, and 0.5 ml of Folin–Ciocalteu reagent are added. To this mixture is added 1.0 mL of 20% sodium carbonate solution, and then deionized water should be added to complete the volume of 10 mL and homogenize. The reaction system should be kept for 1 hour at room temperature and protected from light. After time, aliquots were collected and analyzed by UV–vis spectrophotometer (Perkin Elmer, Wellesley, MA, USA) at a wavelength of 725 nm. TP was standardized against gallic acid and expressed as micrograms of gallic acid equivalents per gram of dried extract (mgGAE/g) [39].

The total flavonoid contents (**Table 3**) can be determined by spectrophotometric analysis using aluminum chloride and for the extracts as described by [39, 40] for the analysis of CA, CP, PX, and TM, the UV–vis spectrophotometer was used (Perkin Elmer, Wellesley, MA, USA) to a wavelength of 510 nm.
