Abstract: 
Consumer demand of austerely processed foods without artificial preservatives has led to a growing attention in their substitution for new natural alternatives. The pressing issue to feed the escalating world population has twisted a demand to augment food production, which has to be cheaper, but at the same time must meet towering quality standards. Taste, appearance, texture, and microbiological safety are required to be preserved within a foodstuff for the longest period of time. Although substantial improvements have been met in terms of food additives, some are still enveloped in controversy. The lacks of uniformity in worldwide laws regarding additives, along with contradictory outcome of many studies help foster this controversy. In this report, the most important preservatives, nutritional additives, coloring, flavoring, texturizing, and miscellaneous agents are analyzed in terms of safety and toxicity. Natural additives and extracts, which are gaining interest due to changes in consumer habits are also evaluated in terms of their benefits to health and combined effects. Technologies, like edible coatings and films, which have helped overcome some drawbacks of additives, but still pose some disadvantages, are briefly addressed. Food preservative is a class of food additive that help to prevent food spoilage by preventing the growth and proliferation of pathogenic microorganisms like Clostridium spp, Bacillus cereus and Staphylococcus aureus. This can be achieved by bringing down the pH of the food so as to make the environment unfavorable for these microbes. Onion is widely used as a food ingredient and it is known as a good source of bioactive compounds, such as sulphur-containing compounds and flavonoids with well known health beneficial effects, antioxidant and antimicrobial capacities. Preservatives, whether natural or artificial, work as in three different ways: Antimicrobial, Antioxidants and Act on enzymes. In antimicrobial, the growth of microbes like bacteria and fungi is inhibited. In antioxidants the process of oxidation is either delayed or stopped. And the one that acts on enzymes stops the ripening or aging of food product. Preservation is important part in many industries, such as the cosmetic and pharmaceutical industries, as the shelf life of many cosmetic and pharmaceutical products is important. The present review is an extensive compilation of various preservatives obtained from plants, animal and microbial source.

Keywords: Additives, Preservatives, Microbiological Safety, Technologies, Food.