*2.4. Mechanical Properties*

The mechanical behaviour of the freeze-dried puree was registered using a texture analyser (TA-XT2i, Stable Micro Systems, Godalming, UK). Portions of 20 × 20 mm of the freeze-dried puree were compressed using a cylindrical probe of 10 mm diameter, applying a strain of 80% with a test speed of 1 mms<sup>−</sup>1. Six replicates were performed per sample. The parameters analysed in the test were the force required to fracture the sample (Fracture force, Ff), expressed in Newtons, and the slope

(S, N/mm) of the curve in the linear zone prior to fracture point, related to the sample resistance to deformation (rigidity) [28].

## *2.5. Colour Measurements*

The CIE L\*a\*b colorimetric space was considered to characterize the colour [29]. A colorimeter (Minolta, CM 3600D, Japan) was used to measure the colour of the surface of the freeze-dried puree, taking the system observer 10◦ and illuminant D65 as reference. Colour coordinates, L\*, a\*, b\*, were obtained for each freeze-dried puree. From them, the hue angle (h\*, Equation (1)) and chroma or saturation (C\*, Equation (2)) were obtained. When total colour differences (ΔE\*) were calculated, Equation (3) was used. Measurements were carried out with the specular component excluded. Six replicates were performed per sample.

$$\mathbf{h}^\* = \arctan(\mathbf{b}^\*/\mathbf{a}^\*) \tag{1}$$

$$\mathbf{C}^\* = (\mathbf{a}^{\*2} + \mathbf{b}^{\*2})^{0.5} \tag{2}$$

$$
\Delta \mathbf{E}^\* = ((\Delta \mathbf{L}^\*)^2 + (\Delta \mathbf{a}^\*)^2 + (\Delta \mathbf{b}^\*)^2)^{1/2} \tag{3}
$$
