## 3 Results and Discussion
### Effect of Chitosan-Licorice Edible Coatings on Strawberries' Quality
#### 3.4.1 Physicochemical Effects
Figure 6: Fungal decay of uncoated and licorice-chitosan-coated strawberries stored for 10 days at 4 °C: (\(\odot\)) Ch (Chitosan); (\(\blacksquare\)) C (uncoated). effect exerted by the coatings could be observed, since all coatings reduced the loss of fruit weight in comparison with uncoated samples, with the coatings containing Ch + LE-1 and Ch + LE-5 being more efficient than the one containing solely chitosan. For these coatings, weight losses of samples are lower than 2% after 10 days of storing. Similar weight loss values were obtained by [PERSON] et al. [15] using chitosan coatings combined with _Thymus capitatus_ essential oil. Furthermore, these loss weight values were lower than those observed by [PERSON] et al. [72] when studying different species of strawberry coated with 2% chitosan (weight losses of 7-9%) or [PERSON] [73] using an edible film of chitosan combined with a _Roselle calyces_ extract (weight loss of 6%). The effect of the different coatings in comparison with uncoated samples on the pH and titratable acidity (TA) of strawberries were also examined, since these properties are a measure of ripening effect. Fruit maturation produces the enzymatic reaction of sugars and the amounts of acids tend to decrease and the pH increases. The initial pH values of coated strawberries were slightly higher than uncoated samples (Figure 8a). Although there were some differences on day 1, pH values of coated samples did not change significantly during storage and no significant differences were observed between coated samples on day 10 (mean pH value is \(4.05\pm 0.10\)), while a significantly higher pH value was obtained for the uncoated fruit (\(4.5\pm 0.20\)). Figure 8: Effect of different coatings based on chitosan and licorice extracts on (**a**) pH and (**b**) titratable acidity (TA) expressed as citric acid percentage of strawberries stored for 10 days at 4 °C. C = uncoated; Ch = chitosan; Ch + LE-1 = Chitosan + 1% of licorice extract; Ch + LE-5 = Chitosan + 5% of licorice extract. Means values and intervals of [PERSON]’s test at 95% according to the analysis of variance (ANOVA) test. Figure 7: Effect of different licorice-chitosan coatings on the weight loss of strawberries stored for 10 days at 4 °C: (\(\Circinus\)) Ch (chitosan) (\(\blacktriangle\)) Ch + LE-1 (Chitosan + 1% of licorice extract); (\(\overline{\bigtriangledown}\)) Ch + LE- 5 (Chitosan + 5% of licorice extract; (\(\blacksquare\)) C = uncoated. Furthermore, the TA values were significantly reduced (\(p<0.05\)) both in coated and uncoated strawberries, but due to the nature of fruit organic acids, these usual decreases in fruit acidity during maturity did not induce a notable change in the pH value. As can be observed in Figure 8b, a significant decrease of TA values (\(p<0.05\)) with storing time was observed in all cases, but differences between control and the different coatings were not significant. These results are in agreement with similar research conducted by [PERSON] et al. [74], who studied the extension of shelf life of strawberries using a coating formed with chitosan and whey protein isolate.