The preservative effects of propionic acid for bread and sponge cake stored at 25°C was investigated.
The results obtained were as follows:
1) Addition of 0.25% propionic acid in sponge cake and bread prolonged their shelflife for two days as compared with the non-addition of propionic acid as revealed by sensory test.
The sponge cake and bread with added propionic acid at the level of 0.25% maintained their quality for four to five days as shown by the bacterial, molds, yeasts counts.
2) In the inoculated studies using Bacillus subtilis results showed that in the nonaddition of propionic acid it exhibited Rope in bread, four days after inoculation. On the other hand, the bread with added propionic acid at the level of 0.25% could be preserved for seven days at about 25°C.
While the sponge cake with added 0.25% propionic acid could be preserved for three weeks without the appearance of rope.
3) In the inoculated groups of molds, Aspergillus niger and Penicillium expansum which were allowed to grow in the sponge cake and bread which treated with 0.25% propionic acid, but Mucor sp. was not allowed to grow on it.