H170 ph meter

On each day of sampling, pH was measured using a probe style-pH meter (H170 Hach pH meter, Hach, Loveland, CO, USA), calibrated each day using a standard 4.0 and 7.0 buffer solution prior to collecting microbial and instrumental color samples. Chicken tenders (n = 2) were removed from their respective package and a stainless-steel probe was inserted into the geometric center of each tender. The average reading of three readings from each tender within each treatment across all sampling days was recorded.

Fermented and unfermented feed were collected and dried at 65 °C for 48 h. Feed samples (n = 3) were tested to determine their crude fiber (CF; AOAC #978.10), crude protein (CP; AOAC #984.13) and ether extract (EE; AOAC #2003.05) contents according to AOAC International guidelines [20 ]. Phytic acid levels were determined as in a previous study [21 (link)]. Trypsin inhibitor and β-glucan in fermented and unfermented mixture were tested using a commercial kit (Jianglai Bio Company, Shanghai, China). To determine pH, 5 g of fermented and unfermented mixed feed were dissolved in 50 mL distilled water. After centrifuging at 4000× g for 5 min, the supernatant pH was tested using a probe style-pH meter (H170 Hach pH meter, Hach, Loveland, CO, USA). Protein extraction and SDS-polyacrylamide gel electrophoresis (PAGE) of the feed samples were performed according to the method described in reference [22 (link)].