## 2 Materials and Methods
### Raw Milk and Fermented Milk Analysis  
2.5.1. Determination of Culture Viability and pH  
For microbiological counts of fermented milks serial dilutions were prepared in sterile peptone water and de Man Rososa Sharpe (MRS) and M17 agar (Merck KGaA, Darmstadt, Germany) were used for enumeration of _Lactobacillus_ spp. and _Streptococcus_ spp./_Lactococcus_ spp. respectively. Milks fermented with YO-MIXTM300 were analyzed for lactobacillus in MRS (incubated under microaerophilic conditions at 37 \({}^{\circ}\)C for 48 h) and streptococci in M17 (aerobic conditions at 37 \({}^{\circ}\)C for 24 h). Milk cultured with MA400 was analyzed for streptocci/lactococci counts on M17 under the same conditions.  
pH was determined at 25 \({}^{\circ}\)C using a pH Basic 20 instrument (Crison, Barcelona, Spain). Three replicates were run for pH and microbial counts.  
2.5.2. Milk, Fermented Milk and Whey Compositional Analysis  
The chemical composition (fat, protein, lactose and total solids) of milk was determined by means of a near-infrared spectrophotometer (FOSS, Milko-Scan FT120; Foss Electric, HillerOd, Denmark) using the base calibration of the equipment (Foss Electric validated according to ISO 21543:2006 (ISO, 2006). The equipment software contains different modules with calibrations for precise determinations of milk components (Improved Milk Calibration, Foss Electric, 1999), fermented mills (Application Note N\({}^{\circ}\) 94, P/N 492264, Foss Electric, 1999) and whey (pH Independent Whey Calibration, Application Note No. 91, P/N 491928, Foss Electric, 1999). The determination in raw milk was made directly on the sample. Fermented milk samples, in order to reduce their viscosity were diluted 1/3 with zero-liquid (Cero S-6060, HillerOd, Denmark) before analysis. Whey samples were obtained by centrifuging the curd using the methodology previously described [6; 30] that allowed syneresis determination and whey separation for its compositional analysis. Synneresis (% drained whey) was expressed as whey/milk ratio mass [14]. Analysis were performed in duplicate in samples warmed at 40 \({}^{\circ}\)C.  
2.5.3. Sugar Profile and Lactic Acid  
The individual analysis of sugars and lactic acid in raw milk took 5 mL of milk and the methodology previously described was used [31]. However, in fermented mills, the methodology described by [PERSON] et al., 2018 [32] was used with some modifications, 5 g of sample were weighed and 10 mL of ultrapure water were added. In both cases, the sample was homogenized for approximately 1 min and centrifuged at 11,000 rpm for 20 min at a temperature of 4 \({}^{\circ}\)C. In both cases, prior to chromatographic analysis, the supernatant was filtered through a 0.45 micron nylon filter (Merck KGaA, Darmstadt, Germany) and injected into a high performance liquid chromatograph Hewlett-Packard HP-1100, Woldbronn, Germany). Chromatographic analysis was performed in isocratic gradient with a flow of 0.5 mL/min and a mobile phase consisting of ultrapure water acidified with 0.1% phosphoric acid. The column used was a Supelcogel C-610H, 30 cm \(\times\) 7.8 mm (SupelcoPark, Bellefonte, PA, USA). Sugars were detected with a refractive index detector and lactic acid with a diode array (DAD) at a wavelength of 210 nm. The quantification was carried out using external calibration curves prepared with pure standards of sugars and lactic acid (Merck KGaA, Darmstadt, Germany). Analysis were performed in duplicate.