# Shellfish Chitosan Potential in Wine Clarification
## 3 Results and Discussion
### Wine Clarification Performance
No correlation between the calculated molecular weight and the clarification capacity was found, as the two MCs with the best clarifying capacity (F2 and F3) were those with the highest (84 kDa) and the lowest (30 kDa) molecular weight, respectively. Animal chitosan allowed a greater clarification than MC at all of the time points (Figure 6). Figure 8 shows the comparison of SC behavior after 2 h of treatment because after that point the chitosan clarification rate decreased. As expressed before, in animal CTS the manufacturing process varies in several steps, such as demineralization and deproteinization, besides deacetylation. [PERSON] and colleagues [30] demonstrated that the alkaline deproteinization performed for 2 h could induce CTS backbone breaking even at 65 \({}^{\circ}\)C, or less for longer treatment, while the comparison of the deacetylations revealed a less clear effect on CTS, confirming that the \"pre-treatment\" participates to define CTS molecular mass. However, even in this case, no correlation between the molecular masses and the clarification capacity was evidenced. This indicates that other factors are more relevant for determining the CTS clarification property. Based on the literature, two main parameters seem to strongly affect the colloids-CTS interaction, namely the chitosan DDA  
Figure 6: Clarification of Glera wine. Turbidities of treated and untreated wine are compared. Category mean and standard deviations of fungal and animal chitosans dissolved in four acids (three replications for each chitosan sample) are expressed. Capital letters represent statistically significant differences among dissolving acids, and stars express statistical differences between successive time points (\(p\) < 0.05). AA: acetic acid, MA: malic acid, SA: succinic acid, HCl: hydrochloric acid. Figure 7: Fungal-derived chitosan clarification after 4 h. Mean and standard deviations of three replications are expressed. Capital letters represent statistically significant differences among samples dissolved into the same acid (\(p\) < 0.05, no letter means the absence of significance), numbers represent statistically different sample groups. AA: acetic acid, MA: malic acid, SA: succinic acid, HCl: hydrochloric acid. and the pH of the reaction [35]. However, A8 demonstrated a degree of deacetylation similar to A7 (Figure 2), while its clarification power was considerably lower. Concerning pH, this factor should be excluded because the experiment was carried out at the same pH value for all of the chitosan, as only one wine was used. The shellfish chitosan comparison registered a statistically significant effect of the dissolving acid (showed in Figure 8 by different capital letters), together with a significant interaction between the sample and the acid (sample x acid, F (15, 48) = 15.092, \(p<0.01\)). This is demonstrated by the fact that in five out of six cases (namely A5, A6, A7, A9, and A10) the dissolving acid had an effect on CTS clarifying capacity (expressed as lowercase letters in Figure 8), while this influence was not confirmed in the A8, which demonstrated a sensible reduction in clarification capability in comparison to the others. However, with the exception of A6 and A10, the degree of that effect was negligible. The nature of this interaction could probably be attributed to the specific charge distribution on the chitosan surface.