We did a shelf life study for a mix of cheese sandwich. We did both sensory & micro evaluation. A fresh batch of sandwiches were made each day & test was carried out on the 4th day, meaning starting sun-72hrs,mon-48hrs, tues-24hrs,wed-fresh batch.
For micro - the Total coliform count below (duplicates) & E.Coli - at 48 hrs-10,21 (cfu/g)1100-Fresh 950-Fresh 2200-24hr 2700-24hr 1700-48hr 2800-48hr 1200-72hr 630-72hr
Why is there a fluctuation of the readings, particularly at 72hrs coliform is less & E.coli is <10? Can a competing flora dormant these species? We did APC, Total coliform, E.coli, B.cereus, Staph. aureus and salmonella.
Will be great if anyone has possible explanations or what different we could to repeat the tests to get more coherent results.