Influence of modified atmosphere packaging and potassium sorbate on microbiological characteristics of sliced bread

Effects of modified atmosphere packaging (MAP) and potassium sorbate (PS) on total viable count (TVC) and yeast and mould counts (YMC) in sliced bread during storage were investigated. Gas combinations of air (control), 100% N2 (A), 70% N2:30% CO2 (B), 50% N2:50% CO2 (C), 30% N2:70% CO2 (D) and 100% CO2 (E) and PS concentrations of 0, 0.15 and 0.30% were tested during 21 days of storage at ambient conditions (20 ± 2 °C and 60 ± 2% RH). At the end of 21 days in all samples both with and without PS, the lowest YMC were in E. In air packed control without PS and with 0.15% PS, mould developed after 14 days storage. In addition to this, none of samples in all MAP treatments presented signs of mold at the end of the storage period (21 days). Similarly, E was the most effective treatment for the inhibition of bacteria. Also, it is concluded that 100 CO2 atmospheres in MAP treatments and 0.15% PS addition to bread dough were sufficient for YM growth inhibition in sliced bread, in terms of human health. However, TVC was under 3 log cfu/g in only sample packaged with E and containing 0.30% PS until day 14.