You're about to create your best presentation ever

Food Preservation Powerpoint Template

Create your presentation by reusing a template from our community or transition your PowerPoint deck into a visually compelling Prezi presentation.

Food Preservation

Transcript: Basic Principles of Food Preservation Foods with a high water content Lettuce, tomatoes, cucumber Mayonnaise Bananas, strawberries Types of Home Freezing Change in temperature from extreme heat to cold Dehydration Using chemicals Fermentation Irradiation Foods can be preserved by: Slow Freezing Quick Freezing Same principles apply as for home freezing Preparation Packaging Freezing Storing Thawing Principles Very quick Expensive Food is sprayed with liquid nitrogen -200oC Strawberries and prawns methods of treating food to prevent food spoilage Disadvantages of Home Freezing Similar to blast freezing Used to freeze smaller food products Temp -30oC Used to preserve vegetables vegetables are prepared and blanched Hot air circulated around the food - dehydrating it Food is continuously moved around - prevents from sticking Types of Commercial Freezing Blast Freezing: Food passed through tunnel on conveyor belt and cold air (-30ºC) is blown over it. Suitable for most food. Prevent microbial growth Inhibit enzyme activity Maintain colour, taste, texture and nutritional value Sealed containers prevent food being recontaminated 1. Air blast freezing 2. Plate/contact freezing 3. Fluidised bed freezing 4. Cryogenic freezing Commercial Freezing Unsuitable Foods Food is pressed between 2 cold metal surfaces. Used for thin foods e.g. burgers, fish fillets or fingers, chops. Most fruit and veg Meat, fish, poultry (raw and cooked) Convenience foods Breads and Pastries Advantages of Home Freezing Suitable packaging can be expensive Bulk cooking and freezing - time consuming and labour intensive. Cost of actual freezer - expensive Availability of frozen foods could lead to unhealthy dietary options Water present in food - converted to ice Freezing removes warmth and moisture (conditions for microbial growth) Micro-organisms can't utilize frozen water molecules - can't multiple Freezing creates a hostile environment - microbes and enzymes become inactivated. If foods, e.g. vegetables, are blanched - enzymes are inactivated Plate or Contact Freezing P. 135 Textbook Write three points on each Suitable Foods Prevents waste - increased shelf- life Preserved food - economical, convenient and easy to use Wide variety available throughout the year What is food preservation? Principles of Home Freezing Guidelines for Freezing Foods Suitable for a variety of food Simple and safe method of preservation Maintains nutritional value, colour, flavour and texture of food Prevents waste - leftovers frozen Foods bulk frozen - save time and energy Foods out of season available all year Advantages of Home Preservation Cryogenic Freezing Fluidised Bed Freezing

Food Preservation

Transcript: Advantages of Preservation: PRESERVING BY HOT PICKLING,JARRING OR CANNING. ONE METHOD OF CONTROLLING BACTERIA GROWTH IS BY CANNING THE FOOD TO EXTEND THEIR SHELF LIFE. Historically, the human race has preserved foods in jars, pots,tubs,barrels, and bottles longer than archeologists have been uncovering shards of pots. Today, in the modern kitchen , it makes sense to try to capture the same freshness and quality and preservation has become a very important part of the kitchen. Adding an acid ingredient to a piece of food not only extends its shelf life but also improves its flavor dramatically. In order to understand how to apply the acids to foods, the garde manger chef must first understand how to measure its effectiveness and which acids are the most effective. The acidity of a food is indicated by its PH VALUE . The pH value can range from 0 to 14, with pH7 being neutral Preservation captures the food at its very best quality. Seasonal foods are less expensive to purchase,saving on food cost. The food can be marked as having been made -in house. Add more flavor of the food. Food Preservation Using Acid to Preserve EXAMPLES OF PRESERVE AS AN EXAMPLE OF OF PRESERVE CEVICHE IS A METHOD WERE ACID IS USED TO COOK THE FISH AND PRESERVE IT FOR LATER USE. EXAMPLES OF PRESERVE The Advantages of Food Preservation in the Kitchen. Discovering new methods of preservation and techniques . DRYING FOOD IS ALSO ANOTHER METHOD OF PRESERVATION AS IN THIS CASE SUN DRIED TOMATOES WERE USED BUT OTHER VEGETABLES AND FRUIT CAN BE DRIED Food Preservation EXAMPLES OF PRESERVE

Food Preservation

Transcript: Food Preservation Refrigeration is a process in which work is done to move heat from one location to another. Refrigerating Freezing How to can your food 1. Review procedure and equipment needs before buying produce. Choose a time when you can work with few or no interruptions. 2. Wash canning jars in hot sudsy water; rinse. Cover with boiling water until ready to fill. Jars used in recipes in which food is processed for less than 10 minutes must be sterilized by immersion in boiling water for 10 minutes. Prepare lids and screw bands according to manufacturer's directions. 3. Fill canner with water; start heating. 4. Prepare only as much food as needed to fill the maximum number of jars your canner will hold at one time. Work quickly, keeping work area clean. 5. Place hot jars on cloth towels to prevent slippage while filling. 6. Fill jars 7. Add boiling liquid to jar, keeping specified headspace. 8. Release trapped air bubbles in jar by gently working a nonmetallic utensil around the jar's sides. Add liquid if needed to maintain headspace. 9. Set each jar into the canner as it is filled; jars should not touch. 10. Cover canner; process as directed. 11. Remove jars; set on towels or rack, leaving at least 1 inch between jars. 12. After jars are completely cooled (12 to 24 hours), press center of each lid. Refrigerating Refrigeration preserve foods by slowing down the growth and reproduction of micro-organisms and the action of enzymes that cause food to rot. The introduction of commercial and domestic refrigerators drastically improved the diets of many in the Western world by allowing foods such as fresh fruit, salads, and dairy products to be stored safely for longer periods, particularly during warm weather. Canning Canning Processes in Freezing Method 1 of 4: Freezer Storage Methods 1. Seal food destined for the freezer tightly. If the food is exposed to air in its container, plastic bag, or other packaging, it will cause the food to dry out and experience freezer burn. o Place your food in quality freezer bags or plastic containers; alternatively, wrap your food with freezer wrap or aluminum foil. o Squeeze any extra air out of the plastic bags and containers before sealing them. o Leave enough space for your food to expand in the bag or container if you are storing a liquid or a food that contains a lot of juice or gravy. o Be sure to label and date all frozen food. 2. Let warm or hot, freshly cooked foods cool before freezing. This will prevent your food from retaining moisture during the freezing process if you place it into the freezer while it is still warm. Importantly, ensure that this food cools quickly; cool on the kitchen bench until the steam stops escaping. Then, place into the container and freeze. 3. Label and date every container and bag of frozen food. This will help you identify the foods after they have become frozen, and will also help you keep track of the dates on which they were originally placed in the freezer. Place sticker labels on each container or use a permanent marker to label each plastic bag 4. Store your food so that it freezes at a fast pace. The faster your food becomes frozen, the better it will retain its flavor and freshness upon defrosting it. This means avoiding freezing large amounts of food at a time; rather, split the food up. • Package your food in small portions so that it freezes faster, especially if you are freezing large dishes such as casseroles. This also means that it defrosts more quickly and it's easier to add packages together to make enough food than to undo a large package and leave waste. • Place your food in the freezer with space around each item. This will allow the cold air to circulate around your food efficiently and cause it to freeze a fast pace. Thank you for listening :) :) :) Freezing is a common method of food preservation that slows both food decay and the growth of micro-organisms. Besides the effect of lower temperatures on reaction rates, freezing makes water less available for bacterial growth. Freezing, in food processing, method of preserving food by lowering the temperature to inhibit microorganism growth. The method has been used for centuries in cold regions, and a patent was issued in Britain as early as 1842 for freezing food by immersion in an ice and salt brine. It was not, however, until the advent of mechanical refrigeration that the process became widely applicable commercially. In 1880 a cargo of meat shipped from Australia to Britain under refrigeration accidentally froze, with such good results that the process was at once adopted for long-distance shipments and other storage. Canning is a method of preserving food in which the food contents are processed and sealed in an airtight container. Canning provides a shelf life typically ranging from one to five years, although under specific circumstances it can be much longer. Freezing

Food preservation

Transcript: INTRDUCTION Food preservation Food preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), or any other micro-organisms (although some methods work by introducing benign bacteria or fungi to the food), as well as retarding the oxidation of fats that cause rancidity. Food preservation can also include processes that inhibit visual deterioration, such as the enzymatic browning reaction in apples after they are cut, which can occur during food preparation. Many processes designed to preserve food will involve a number of food preservation methods. Preserving fruit by turning it into jam, for example, involves boiling (to reduce the fruit’s moisture content and to kill bacteria, yeasts, etc.), sugaring (to prevent their re-growth) and sealing within an airtight jar (to prevent recontamination). There are many traditional methods of preserving food that limit the energy inputs and reduce carbon footprint.[1] Maintaining or creating nutritional value, texture and flavour is an important aspect of food preservation, although, historically, some methods drastically altered the character of the food being preserved. In many cases these changes have come to be seen as desirable qualities – cheese, yoghurt and pickled onions being common examples. Food preservative technologies are accepted differently by consumers. In general, traditional technologies like pasteurisation are better accepted than nanotechnology for example.


Transcript: Freezing 10, 000 B.C. Napoleon Appert used wide-mouthed glass jars into which he put the food, and heated them to drive out the air which he thought was the cause of food deterioration. Finally, he closed the jars with tight-fitting corks to keep the contents fresh. 1790s-1800s Curing Canning Fermentation was not invented, but rather discovered. No doubt that the first beer was discovered when a few grains of barley were left in the rain. Opportunistic microorganisms fermented the starch-derived sugars into alcohols. So too can be said about fruits fermented into wine, cabbage into Kim chi or sauerkraut, and so on. The skill of ancient peoples to observe, harness, and encourage these fermentations are admirable. Some anthropologists believe that mankind settled down from nomadic wanderers into farmers to grow barley to make beer in roughly 10,000 BC. Beer was nutritious and the alcohol was divine. It was treated as a gift from the gods. Fermentation was a valuable food preservation method. It not only could preserve foods, but it also created more nutritious foods and was used to create more palatable foods from less than desirable ingredients. Microorganisms responsible for fermentations can produce vitamins as they ferment. This produces a more nutritious end product from the ingredients. In the 1800’s mechanical refrigeration was invented and was quickly put to use. Also in the late 1800’s Clarence Birdseye discovered that quick freezing at very low temperatures made for better tasting meats and vegetables. After some time he perfected his “quick freeze” process and revolutionized this method of food preservation. In the 1800’s it was discovered that certain sources of salt gave meat a red color instead of the usual unappetizing grey. Consumers overwhelmingly preferred the red colored meat. In this mixture of salts were nitrites (saltpeter). As the microbiology of Clostridium botulinum was elucidated in the 1920’s it was realized that nitrites inhibited this organism. Drying 1800s 12,000 B.C Fermenting In ancient times the sun and wind would have naturally dried foods. Evidence shows that Middle East and oriental cultures actively dried foods as early as 12,000 B.C. in the hot sun. Later cultures left more evidence and each would have methods and materials to reflect their food supplies—fish, wild game, domestic animals, etc. Vegetables and fruits were also dried from the earliest times. The Romans were particularly fond of any dried fruit they could make. In the Middle Ages purposely built “still houses” were created to dry fruits, vegetables and herbs in areas that did not have enough strong sunlight for drying. A fire was used to create the heat needed to dry foods and in some cases smoking them as well. Canning is the newest of the food preservations methods being pioneered in the 1790s when a French confectioner, Nicolas Appert, discovered that the application of heat to food in sealed glass bottles preserved the food from deterioration. He theorized “if it works for wine, why not foods?” In about 1806 Appert's principles were successfully trialed by the French Navy on a wide range of foods including meat, vegetables, fruit and even milk. Based on Appert's methods Englishman, Peter Durand, used tin cans in 1810. Appert had found a new and successful method to preserve foods, but he did not fully understand it. It was thought that the exclusion of air was responsible for the preservations. It was not until 1864 when Louis Pasteur discovered the relationship between microorganisms and food spoilage/illness did it become clearer. Just prior to Pasteur’s discovery Raymond Chevalier-Appert patented the pressure retort (canner) in 1851 to can at temperatures higher than 212ºF. However, not until the 1920’s was the significance of this method known in relation to Clostridium botulinum. Describing the methods FOOD PRESERVATION

Now you can make any subject more engaging and memorable