## 2 Materials and Methods  
### Sample Description  
The investigated samples, collected during the year 2020, were divided into four groups (G#, # = 1, 2, 3, 4), according to what is reported in Table 1. The five samples in each group belong to Italian brands and different batches.  
_Homogenized fruit_ and _meat_ are early childhood foods with a mixed consistency between solid and liquid, frequently used for infant weaning. They do not require chewing, and therefore they are very useful in the case of an incomplete dental structure and represent transition foods between the liquid feeding of the infant and the solid one of the weaned infant [21]. The nutritional composition of homogenized foods varies significantly depending on their typology. In theory, they should be produced from raw materials and water alone, without adding anything else; however, several simple sugars are added to various fruit ones [22]. Those based on meat, on the other hand, are rich in proteins with a high biological value.  
As for the non-energetic nutrients, the homogenized foods fully satisfy the needs of mineral salts and vitamins. In addition, they also show low levels of cholesterol and saturated fat, and provide a few grams of dietary fiber [23].  
_Childhood biscuits_, commonly used for weaning children under one year of life, are not much different from a common dry biscuit in terms of nutritional composition, neither in sugar content nor in saturated fat content. They are a source of complex carbohydrates, which provide slow-release energy that can therefore be used over time, and of simple carbohydrates, which immediately enter into the circulation and are burned [24]. They are also enriched with protein, both of animal and vegetable origin, which are fundamental elements for the growth of the cells and tissues of the child's body [25]. _Childhood biscuits_ are also integrated with vitamins, i.e., those of group B, essential for calcium absorption and cell renewal, and vitamin C, which stimulates the body's natural defenses and promotes iron absorption. In addition, they also contain minerals, such as calcium and phosphorus (for the development of the skeletal system and teeth), copper (for the nervous system), iron (for the formation of red blood cells) and zinc (to strengthen bones and muscles in addition to the immune system) [26].  
_Baby pasta_ should be given to the children at the beginning of weaning, taking into account that it has very specific characteristics [27]. First of all, it is gluten-free, so it can be given even before six months of age. Then, it is prepared with soft wheat, more digestible and easily chewable than that used for pasta commonly consumed by adults. Finally, it is obtained with diastased flour, which is subjected to a specific procedure following which the starch is broken down into simpler elements making it easier for the early children to digest, while still maintaining the right nutritional values [28]. After one year of age, durum wheat pasta in a larger format can be given to children, even combined with legumes in order to constitute a complete meal from the point of view of protein [29].  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Group ID** & **Typology** & **Number of Samples** \\ \hline G1 & _Homogenized fruit_ & 5 \\ G2 & _Homogenized meat_ & 5 \\ G3 & _Childhood biscuits_ & 5 \\ G4 & _Baby pasta_ & 5 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Group identification code (ID), typology and number of samples for each group.