Antibacterial Effect of Ethanolic Extract Shallot (Allium Hirtifolium) on the Clostridium botulinum & Staphylococcus aureus and Orgoanoleptic Propertise of Liquid Curd

Liquid curd is one of the milk byproducts and a rich source of protein among the food products. So it is a suitable environment for the growth and reproduction of different microorganisms. According to the harmful effects of chemical preservatives, the need for studies on antimicrobial effects of natural preservatives on the growth of microorganisms in food and laboratory models are growing.
This study includes extraction and determination of chemical composition of shallot (Allium Hirtifolium) and evaluation of their antibacterial effects against Staphylococcus aureus and Clostridium botulinum. First liquid curds containing 0.5%, 0.75%, 1% and 2% shallots extract were prepared. Then each sample was contaminated individually with Staphylococcus aureus (107 cfu/ml) and Clostridium botulinum (107 cfu/ml) and stored at 4ºC refrigerator for 21 days. Sampling of curd took place on day zero, seven, fourteen and twenty-one.
The results of this study showed that the pH of liquid curd was considerably reduced during the storage time. Also the population of Staphylococcus aureus decreased more quickly than Clostridium botulinum. After 21 days of storage, there was no sign of survival of Staphylococcus aureus.
The sample containing 1% shallot (Allium Hirtifolium) extract was preferred in both terms of reducing microbial growth and suitable sensory properties.
as the sample with 25% triticale flour 0.6% tragacanth gum.
Replacing 25% of wheat flour with triticale flour, (Sanabad varieties) is recommended as the first edible cultivars in bread production in Iran with gum tragacanth at 0.6 % for strengthening and improvements of the gluten network in bread.