2.2.3. Microbiological, Chemico-Physical and Sensorial Analyses

For microbiological analyses, mini-cheeses (25 g) were diluted with 225 mL of 0.1% peptone water with salt (0.9% NaCl) in a Stomacher bag (Seward, London, England) and homogenized for 1 min in a Stomacher Lab Blender 400 (Seward). Serial dilutions of cheese homogenates were plated on the surface of the appropriate media in Petri dishes. The media and the conditions used were: *Listeria* selective agar base (Oxoid) plus *Listeria* selective supplement-Oxoid formulation, incubated at 37 ◦C for 48 h, for *L. monocytogenes*; *Pseudomonas* Agar Base (Oxoid) plus *Pseudomonas* CFC Supplement, incubated at 25 ◦C for 48 h, for *Ps. fluorescens*; MRS agar (Oxoid), incubated at 30 ◦C for 4 days under anaerobiosis, for mesophilic lactobacilli.

For each batch, the measurement of pH was performed twice on the first homogenized dilution of the cheese samples during storage with a Crison pH meter model micro pH 2001 (Crison). *aw* was measured by a hygrometer AQUALAB CX-2 (Decagon Device, Pullman, WA, USA).

During the storage at 4 and 15 ◦C, a sensory evaluation was also performed: the panel consisted of 15 panelists aged between 22 and 38 years (students and researchers of the Department of the Science of Agriculture, Food and Environment (SAFE), University of Foggia). Using a scale ranging from 0 to 10 (where 10 stands for the most attractive attributes and 0 for the absolutely unpleasant attributes), the sensorial overall quality of the samples was determined by evaluating colour, odour, texture and overall acceptability. During the test sessions, cheese samples were coded by a letter and presented individually to each panelist in plastic cups covered with a lid in random order. Sensory evaluation was conducted in individual booths under controlled conditions of light (white light), temperature (20 ± 2 ◦C), and humidity (70% to 85%).
