## 3 Results and Discussion
### Effect of Biosurfactant Extract on the Grape Morphology
As well, the Sq parameter showed similar behavior for the non-coated grapes, with the lower percentiles ranging between 5580 and 6947 nm and with the upper percentiles ranging between 10,558-11,487 nm. Regarding coated grapes, a progressive increase in roughness was observed, for both Sa and Sq parameters, with a progressive increase in the upper percentiles although less strong than in non-coated grapes. The dispersion of the results was higher in the non-coated grapes than in the coated grapes, with interquartile ranges for non-coated grapes oscillating between 3771-4277 and 4540-5015 nm, for the Sa and Sq parameters, respectively. In contrast, in the coated grapes, the interquartile ranges were considerably smaller, with values between 443-2044 and 518-2435 nm for the Sa and Sq variables, respectively. On other hand, Figure 4 shows the boxplot graphs for grape roughness, considering only fine structure. It was observed that non-coated grapes increased Sa and Sq values progressively from day 1 to day 5, where the upper percentile values of each day were always lower than the lower percentiles of the following day, for both Sa and Sq parameters (Figure 4a,b). However, on days 9 and 11 a stagnation in the increase of roughness was observed, with Sa and Sq values being quite similar between days 5 and 11. In fact, for days 5 to 11, the lower percentile values for the variable Sa were always between 690-785 nm and for the upper percentile between 900-1417 nm. In parallel, for the Sq parameter, the lower percentile for day 5 to 11 ranged between 874-989 nm and the upper percentile was between 1158-1799 nm, which showed a great similarity between the results compared. In relation to the coated grapes, on the first three days (1, 3, and 5), a very insignificant increase in roughness was observed, considering Sa and Sq values. Hence, the lower percentile for Sa ranged between 128-162 nm and that of the Sq variable between 164-206 nm, whereas the upper percentile being between 156-217 nm for the Sa and between 203-274 nm for Sq. However, a significant increase in roughness was detected from day 5, where the upper percentile values of each day were always lower than the lower percentiles of the next day. Similarly, to the results shown in Figure 3, where it was considered fine structure and shape, a greater dispersion of Sa and Sq values was observed for non-coated grapes, where it was considered only fine structure (Figure 4), being more prominent between days 5 and 11. In fact, when considering only the fine structure (Figure 4), the interquartile ranges of the variable Sa oscillated between 210-631 for the non-coated grapes, whereas coated grapes gave an interquartile range between 51-105 nm. The same behavior was noticed for the Sq parameter, since the interquartile range of the non-coated grapes was considerably higher (283-810 nm) than that of the coated grapes (68-124 nm). In overall terms, it can be said that the biosurfactant extract under evaluation protects grape skin against roughness, showing a significant positive effect. Additionally, Figure 5a,b show the images obtained for non-coated and coated grapes, respectively, considering only fine texture at different storage times. The blue or dark zones represent fissures and cavities (right). The greater the proportion of these cavities, more are the changes in height and, therefore, the roughness parameters. It can be noticed that non-coated grapes presented zones with more fissures and cavities, which is in agreement with the data reported in Tables 1 and 2. Also, in the real images (left), more bumps and wrinkles were observed on the surface of the non-coated grapes. The heights in the non-coated grapes were between 4 and \(-3\) um, whereas in the coated grapes, they were between 2.5 and \(-3.5\) um, which indicates that non-coated grapes possess higher numbers of cavities than coated grapes.