Proximate composition, pH and water activity Moisture, fat and protein contents of 1-day stored samples were analyzed using the method of the Association of Official Analytical Chemists (A.O.A.C, 2000).
The pH values of samples were determined using a pH meter
(Model 340, Mettler-Toledo GmbH, Schwerzenbach, Switzerland) that was calibrated with 3 different standard pH solutions (4.0, 7.0 and 9.25). Water activity (aw) was determined at 25 C with a Novasina measuring instrument; model AW SPRINT-TH 300 (Pfaffikon, Switzerland).