*3.5. Differential Scanning Calorimetry (DSC)*

The down peak in the graph represents an endothermic reaction, and the up peak represents an exothermic reaction (Figure 3). In mancozeb-loaded chitosan–gum acacia NPs, a sharp endothermic peak is observed at 190.95 ◦C with an enthalpy change (ΔH) of 99.406 J/g, which may be attributed to the melting of mancozeb [33]. Commercial mancozeb around 180 ◦C has a ΔH of 159.8806 J/g (Figure 3e). In contrast, blank and drug-loaded polymeric NPs have lower ΔH of 33.3051 J/g and 99.406 J/g, respectively (Figure 3c,d), which may be due to the glass transition of CSGA nanocomposites [34]. The lower ΔH, as compared to commercial mancozeb, makes both nanoformulations (blank and mancozeb-loaded NPs) more thermally stable than commercial mancozeb [29].

**Figure 3.** DSC thermograms of raw biopolymeric materials, (**a**) chitosan, (**b**) gum acacia and test samples, (**c**) CSGA blank, NPs (**d**) CSGA-1.0 NPs, (**e**) mancozeb.
