**4.4 Natural antimicrobials**

Since ancient times, spices and herbs have been used for preventing food spoilage and deterioration, and also for extending food shelf life. The antimicrobial effect of these components is a result of an increase in the permeability of the cytoplasmic membrane which leads to the loss of cellular constituents. At the same time, plant secondary metabolites such as essential oils and natural plant extracts have also been reported to have antibacterial, antifungal and anti-insecticidal properties. Extracts from capsicum, seaweeds and green tea have been found to inhibit the growth of *Salmonella* spp. in-vitro. Studies are also available wherein inhibitory effect of plant extracts was evaluated against *Salmonella* inoculated in minced beef, salad vegetables, fresh cut apples and minced sheep meat.
