**2. Materials and Methods**

### *2.1. Food Materials and Sample Preparation*

Colombian fresh lulo fruits (*Solanum quitoense* Lam.) were purchased at the Central Market of Valencia (Spain) and stored at 4 ◦C until processing.

The whole fruits were processed as follows for their analysis: after removing the peduncle, they were washed and cut into pieces, which were crushed in a mortar. This whole crushed fruit is hereafter called "fruit".

The procedure for obtaining the lulo juice was as follows: after removing the peduncle, the whole fresh fruit was washed and blended (Phillips Advance Collection Standmixer, 800 W, 2 L) for 10 min. Then, the blend was filtered and sieved with a 500 μm stainless-steel mesh sift (200/50, CISA). The filtered liquid thus obtained is hereafter called "juice".

The sample preparation for VI experiments was as follows: the fruit was washed and cut transversally into 5 mm thickness and 64 mm diameter slices (FAGOR CF-150 slicer). The fruit skin was not removed, so as to prevent any absorption of materials through the lateral surface of the slices, which allowed assuming unidirectional matter flow. The

impregnation experiments were carried out on three lulo fruit batches at a very similar ripeness stage, and three samples per batch were characterized.

Figure 1 summarizes in a flow chart the sample preparation and treatments.

**Figure 1.** Flow chart summarizing sample preparation and treatments.
