Food preservation using chemicals pdf

Preservation using chemicals and microbes presents comprehensive preservation methods. Food chemistry or chemistry is the study of chemical. This lecture talks about chemical method of food preservation. Chemical preservatives the purpose of using a chemical agent as a preservative is to retard food spoilage. This is not to imply that any and all chemotherapeutic compounds can or should be used as food preservatives. Preservation using chemicals and microbes presents comprehensive preservation methods based on additives of chemical or microbiological nature, including fermentation, antimicrobials, antioxidants, phlowering agents, and nitrides. They are only added as a precaution to extend the shelf life of products by inhibiting microbial spoilage. Food preservatives and their harmful effects ijsrp. Chemical preservatives cannot be used to cover up for poor quality raw materials. Shelflife may be defined as the time it takes a product to decline to an unacceptable level. Food preservation consists of the application of sciencebased knowledge through a variety of available technologies and procedures, to prevent deterioration and spoilage of food products and extend their shelflife, while assuring consumers a product free of pathogenic microorganisms. Chemicals useful as food preservatives role of antioxidants.

Salting can be done by rubbing adequate quantities of dry salt into foods, or by immersion, where the food item is soaked in a concentrated salt solution i. Chemical added to a food or material to prevent for a reasonable time the growth of microorganisms, or occurrence of undesirable chemical reactions such as oxidation, that spoil it. Questions on drying, canning, salting and freezing will help cover the most. Food chemistry is the study of chemical processes and interactions of all. The indian pickle already contains salts, sugar, oil and spices as basic ingredients. Food preservation an overview sciencedirect topics. Food preservation involves different food processing steps to maintain food quality at a.

The use of chemicals to prevent or delay the spoilage of foods derives in part from the fact that such compounds are used with great success in the treatment of diseases of humans, animals, and plants. Microbial spoilage of food products is also controlled by using chemical preservatives. Chemical food preservatives have also been used for quite some time now. Lecture 5 chemical preservation of food slideshare. Main categories of food additives are food colours, flavours and sweeteners, antioxidants, fat emulsifiers, stabilizing agents, flour improvers, food preservatives, nutritional supplements like minerals, vitamins, amino acids. Some chemical preservatives can taint the flavour of fruit juices if the recommended level is exceeded. Preservatives are substances which, under certain conditions, either delay the growth of microorganisms without necessarily destroying them or prevent deterioration of quality during manufacture and distribution. Preservation by using chemicals a preservative is defined as only substance which is capable of inhibiting, retarding or arresting the growth of microorganisms. This chemical compound enters in each cell and balances the ph of the food and effectively increases the acidity of the food and helps in preserving the food. Chemicals used as food preservatives sodium benzoate is used as food preservative as it has antifungal properties. Chemical preservation food and agriculture organization of the. To increase shelf life and to make food attractive various chemicals are added to food.

These ingredients act as preservatives itself, there is no need for the extra preservatives. Application of pulsed electric field as a food preservation method has a high potential for preservation of high quality, nutritious and heat. They are the most effective for a longer shelf life and stop or delay the growth of bacteria, suppress the reaction when food comes in. The use of chemical preservatives is regulated by maximum permitted levels. Use the following quiz and worksheet to check your understanding of the major methods and effects of food preservation. The use of chemicals to prevent or delay the spoilage of foods derives in part from the fact that such compounds are used. Artificial way of food preservation can be done by nuclear radiation 6, vacuum packing and hypobaric packingnowadays certain synthetic chemical are used as food preservatives. The use of chemicals to prevent or delay the spoilage of foods derives in part from the fact that such compounds are used with great success in the treatment of. Each chapter covers the mode of preservation actions and their.