## 3 Results and Discussion
According to the one-way ANOVA and Multiple Range Test of Tukey applied in vitamin D values, it was found that there were no significant differences (\(p>0.05\)) between the PIF and the RIF (Table 2). PIF reported values between 9.02 and 9.14 mcg D\({}_{3}\)/100 g. [PERSON] et al. [36] developed a simple and robust liquid chromatography-mass spectrometry method with a 2D ion trap (LC-MSn) to determine the levels of vitamin D\({}_{3}\) in infant formulas, obtaining values of 7.80 \(\pm\) 0.200 ug/100 g, which are like those obtained in our study. Meanwhile, for the RIF \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Type of Microorganisms**} & \multicolumn{2}{c}{**Example Type**} \\ \cline{2-3}  & **Powdered Infant Formulas** & **Reconstituted Infant Formulas** \\ \hline Mesophilic aerobic count & & \\ (cfu/g) & \textless{}10.0 & \textless{}10.0 \\ \hline Total coliforms (MPN/g) & \textless{}3.00 & Not required * \\ \hline _Staphylococcus aureus_ (cfu/g) & \textless{}10.0 & \textless{}10.0 \\ \hline _Salmonella_ in 25 g (P/A) & Absence & Absence \\ \hline _Bacillus cereus_ (cfu/g) & \textless{}10.0 & \textless{}10.0 \\ \hline _Cronobacter_ spp. (P/A) & Absence & Absence \\ \hline _Escherichia coli_ (MPN/g) & \textless{}3.00 & \textless{}3.00 \\ \hline _Clostriidium perfingens_ (cfu/g) & \textless{}10.0 & Not required * \\ \hline \hline \end{tabular}  
* Not required by the Chilean Food Sanitary Regulations (RSAs).  
\end{table} 
Table 1: Microorganisms evaluated in powdered (PIF) and reconstituted (RIF) infant formula according to the requirements of the Chilean Food Sanitary Regulations (RSAs). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Samples**} & \multicolumn{2}{c}{**Powdered Infant Formula**} & \multicolumn{2}{c}{**Reconstituted Infant Formula**} \\  & \multicolumn{2}{c}{**[mcg D\({}_{3}\)/100 g]**} & \multicolumn{2}{c}{**[mcg D\({}_{3}\)/100 mL]**} \\ \cline{2-5}  & **PIF Sample** & **PIF Reference** & **Sample RIF** & **RIF Reference** \\ \hline Vitamin D content & 9.08 \({}^{\pm}\) 0.080 & 9.00 \({}^{\pm}\) 0.020 & 1.89 \({}^{\text{a}}\)\(\pm\) 0.100 & 1.80 \({}^{\text{a}}\)\(\pm\) 0.020 \\ \hline PIF (powdered infant formula) and RIF (reconstituted infant formula). Values are shown as mean [mcg D\({}_{3}\)/100 gl] and [mcg D\({}_{3}\)/100 mL] of two duplicate experiments \(\pm\) SD (standard deviation). The same lowercase superscripts between columns of the same sample category indicate that there is no significant difference (\(p>0.050\)) between sample and reference. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Type of Microorganisms**} & \multicolumn{2}{c}{**Example Type**} \\ \cline{2-3}  & **Powdered Infant Formulas** & **Reconstituted Infant Formulas** \\ \hline Mesophilic aerobic count & & \\ (cfu/g) & \textless{}10.0 & \textless{}10.0 \\ \hline Total coliforms (MPN/g) & \textless{}3.00 & Not required * \\ \hline _Staphylococcus aureus_ (cfu/g) & \textless{}10.0 & \textless{}10.0 \\ \hline _Salmonella_ in 25 g (P/A) & Absence & Absence \\ \hline _Bacillus cereus_ (cfu/g) & \textless{}10.0 & \textless{}10.0 \\ \hline _Cronobacter_ spp. (P/A) & Absence & Absence \\ \hline _Escherichia coli_ (MPN/g) & \textless{}3.00 & \textless{}3.00 \\ \hline _Clostriidium perfingens_ (cfu/g) & \textless{}10.0 & Not required * \\ \hline \hline \end{tabular}  
* Not required by the Chilean Food Sanitary Regulations (RSAs).  
\end{table} 
Table 2: Effect of infant formula preparation on vitamin D content. values between 1.82 and 1.96 mcg, D\({}_{3}\)/100 mL were obtained. [PERSON] et al. [37] reported similar values (1.13 \(\pm\) 0.120 \(\upmu\)g/100 mL) when they developed and validated a sensitive liquid chromatography method for determining vitamin D in infant formulas. Our data were not only like other studies but also like those reported on the nutritional labels of PIFs and RIFs, with values of 9.00 \(\upmu\)g/100 mL and 1.80 \(\upmu\)g/100 mL, respectively.