{"id":458,"date":"2019-03-11T19:16:46","date_gmt":"2019-03-11T19:16:46","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/sunyltnutrition\/?post_type=chapter&p=458"},"modified":"2019-04-15T13:51:42","modified_gmt":"2019-04-15T13:51:42","slug":"11-6-food-preservation","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-mcc-ltnutrition\/chapter\/11-6-food-preservation\/","title":{"raw":"11.6: Food Preservation","rendered":"11.6: Food Preservation"},"content":{"raw":"Food preservation\u00a0involves preventing the growth of\u00a0bacteria,\u00a0fungi\u00a0(such as\u00a0yeasts), or other\u00a0micro-organisms\u00a0(although some methods work by introducing benign\u00a0bacteria\u00a0or fungi to the food), as well as slowing the\u00a0oxidation\u00a0of\u00a0fats\u00a0that cause\u00a0rancidity. Food preservation may also include processes that inhibit visual deterioration, such as the\u00a0enzymatic browning\u00a0reaction in apples after they are cut during food preparation.\r\n\r\nMany 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\u2019s moisture content and to kill bacteria, etc.), sugaring (to prevent their re-growth) and sealing within an airtight jar (to prevent recontamination). Some traditional methods of preserving food have been shown to have a lower\u00a0energy input\u00a0and\u00a0carbon footprint, when compared to modern methods.\r\n\r\nMaintaining or creating nutritional value,\u00a0texture\u00a0and\u00a0flavor\u00a0is 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 \u2013\u00a0cheese,\u00a0yogurt\u00a0and pickled onions being common examples.\r\n
\r\n

Traditional techniques<\/h2>\r\nNew techniques of food preservation became available to the home chef from the dawn of\u00a0agriculture\u00a0until the\u00a0Industrial Revolution.\r\n\r\n<\/div>\r\n
\r\n

Drying<\/h3>\r\nDrying is one of the oldest techniques used to hamper the decomposition of food products. As early as 12,000 B.C., Middle Eastern and Oriental cultures were drying foods using the power of the sun. Vegetables and fruits are naturally dried by the sun and wind, but \"still houses\" were built in areas that did not have enough sunlight to dry things. A fire would be built inside the building to provide the heat to dry the various fruits, vegetables, and herbs.\r\n\r\n<\/div>\r\n
\r\n

Cooling<\/h3>\r\nCooling\u00a0preserves food 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\u00a0Western world\u00a0by allowing foods such as fresh fruit, salads and dairy products to be stored safely for longer periods, particularly during warm weather.\r\n\r\n<\/div>\r\n
\r\n

Freezing<\/h3>\r\nFreezing\u00a0is also one of the most commonly used processes, both commercially and domestically, for preserving a very wide range of foods, including prepared foods that would not have required freezing in their unprepared state. For example, potato waffles are stored in the freezer, but potatoes themselves require only a cool dark place to ensure many months' storage. Cold stores provide large-volume, long-term storage for strategic food stocks held in case of national emergency in many countries.\r\n\r\n<\/div>\r\n
\r\n

Boiling<\/h3>\r\nBoiling liquid food items can kill any existing microbes. Milk and water are often boiled to kill any harmful microbes that may be present in them.\r\n\r\n<\/div>\r\n
\r\n

Heating<\/h3>\r\nHeating to temperatures which are sufficient to kill microorganisms inside the food is a method used with\u00a0perpetual stews. Milk is also boiled before storing to kill many microorganisms.\r\n\r\n<\/div>\r\n
\r\n

Salting<\/h3>\r\nBag of Prague powder #1, also known as \"curing salt\" or \"pink salt\". It is typically a combination of salt and sodium nitrite, with the pink color added to distinguish it from ordinary salt. Salting or curing draws moisture from a substance through a process of osmosis. substances are\u00a0cured\u00a0with salt or sugar, or a combination of the two. Nitrates and nitrites are also often used to cure meat and contribute the characteristic pink colour. It was a main method of preservation in medieval times and around the 1700s.\r\n\r\n<\/div>\r\n
\r\n

Sugaring<\/h3>\r\nThe earliest cultures have used sugar as a preservative, and it was commonplace to store fruit in honey. Similar to pickled foods, sugar cane was brought to Europe through the trade routes. In northern climates without sufficient sun to dry foods, preserves are made by heating the fruit with sugar.\u00a0\"Sugar tends to draw water from the microbes (plasmolysis). This process leaves the microbial cells dehydrated, thus killing them. In this way, the food will remain safe from microbial spoilage.\"Sugar is used to preserve fruits, either in an\u00a0anti-microbial\u00a0syrup with fruit such as\u00a0apples,\u00a0pears,\u00a0peaches,\u00a0apricots\u00a0and\u00a0plums, or in crystallized form where the preserved material is cooked in sugar to the point of crystallization and the resultant product is then stored dry. This method is used for the skins of\u00a0citrus\u00a0fruit (candied peel),\u00a0angelica\u00a0and\u00a0ginger. Also sugaring can be used in\u00a0jam\u00a0jellies.\r\n\r\n<\/div>\r\n
\r\n

Smoking<\/h3>\r\nSmoking is used to lengthen the\u00a0shelf life\u00a0of\u00a0perishable\u00a0food items. This effect is achieved by exposing the food to\u00a0smoke\u00a0from burning plant materials such as\u00a0wood. Smoke deposits a number of pyrolysis products onto the food, including the\u00a0phenols\u00a0syringol,\u00a0guaiacol\u00a0and\u00a0catechol.\u00a0These compounds aid in the drying and preservation of meats and other foods. Most commonly subjected to this method of food preservation are\u00a0meats and\u00a0fish\u00a0that have undergone\u00a0curing.\u00a0Fruits\u00a0and\u00a0vegetables\u00a0like\u00a0paprika,\u00a0cheeses,\u00a0spices, and ingredients for making\u00a0drinks\u00a0such as\u00a0malt\u00a0and\u00a0tealeaves are also smoked, but mainly for\u00a0cooking\u00a0or\u00a0flavoring\u00a0them. It is one of the oldest food preservation methods, which probably arose after the development of\u00a0cooking\u00a0with\u00a0fire.\r\n\r\n<\/div>\r\n
\r\n

Pickling<\/h3>\r\nPickling is a method of preserving food in an edible\u00a0anti-microbial\u00a0liquid. Pickling can be broadly classified into two categories: chemical pickling and fermentation pickling. In chemical pickling, the food is placed in an edible liquid that inhibits or kills bacteria and other micro-organisms. Typical pickling agents include\u00a0brine\u00a0(high in\u00a0salt),\u00a0vinegar,\u00a0alcohol, and\u00a0vegetable oil, especially\u00a0olive oil\u00a0but also many other oils. Many chemical pickling processes also involve heating or boiling so that the food being preserved becomes saturated with the pickling agent. Common chemically pickled foods include\u00a0cucumbers,\u00a0peppers,\u00a0corned beef,\u00a0herring, and\u00a0eggs, as well as mixed vegetables such as\u00a0piccalilli.\r\n\r\nIn fermentation pickling, the food itself produces the preservation agent, typically by a process that produces\u00a0lactic acid. Fermented pickles include\u00a0sauerkraut,\u00a0nukazuke,\u00a0kimchi,\u00a0surstr\u00f6mming,\r\n\r\n<\/div>\r\n
\r\n

Lye<\/h3>\r\nSodium hydroxide\u00a0(lye) makes food too\u00a0alkaline\u00a0for bacterial growth. Lye will\u00a0saponify\u00a0fats in the food, which will change its flavor and texture.\u00a0Lutefisk\u00a0uses lye in its preparation, as do some olive recipes. Modern recipes for\u00a0century eggs\u00a0also call for lye.\r\n\r\n<\/div>\r\n
\r\n

Canning<\/h3>\r\nCanning\u00a0involves cooking food, sealing it in sterile cans or jars, and\u00a0boiling\u00a0the containers to kill or weaken any remaining bacteria as a form of\u00a0sterilization. It was invented by the French confectioner\u00a0Nicolas Appert.\u00a0By 1806, this process was used by the French Navy to preserve meat, fruit, vegetables, and even milk. Although Appert had discovered a new way of preservation, it wasn't understood until 1864 when Louis Pasteur found the relationship between microorganisms, food spoilage, and illness.\r\n\r\nFoods have varying degrees of natural protection against spoilage and may require that the final step occur in a\u00a0pressure cooker. High-acid fruits like\u00a0strawberries\u00a0require no preservatives to can and only a short boiling cycle, whereas marginal vegetables such as\u00a0carrots\u00a0require longer boiling and addition of other acidic elements. Low-acid foods, such as vegetables and meats, require pressure canning. Food preserved by canning or bottling is at immediate risk of spoilage once the can or bottle has been opened.\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"411\"]\"\" Figure\u00a011.6.1:\u00a0Preserved food.\u00a0Unidentified stacks of home-canned food. Image used with permission (public domain).\u00a0<\/em>[\/caption]\r\n\r\nLack of quality control in the canning process may allow ingress of water or micro-organisms. Most such failures are rapidly detected as decomposition within the can causes gas production and the can will swell or burst. However, there have been examples of poor manufacture (underprocessing) and poor\u00a0hygiene\u00a0allowing contamination of canned food by the obligate\u00a0anaerobe\u00a0Clostridium botulinum, which produces an acute toxin within the food, leading to severe illness or death. This organism produces no gas or obvious taste and remains undetected by taste or smell. Its toxin is denatured by cooking, however. Cooked mushrooms, handled poorly and then canned, can support the growth of\u00a0Staphylococcus aureus<\/em>, which produces a toxin that is not destroyed by canning or subsequent reheating.\r\n\r\n<\/div>\r\n
\r\n

Jellying<\/h3>\r\nFood may be preserved by cooking in a material that solidifies to form a gel. Such materials include\u00a0gelatin,\u00a0agar,\u00a0maize\u00a0flour, and\u00a0arrowrootflour. Some foods naturally form a\u00a0protein\u00a0gel when cooked, such as\u00a0eels and elvers, and\u00a0sipunculid\u00a0worms, which are a delicacy in\u00a0Xiamen, in the Fujian province of the\u00a0People's Republic of China.\u00a0Jellied eels\u00a0are a delicacy in the East End of\u00a0London, where they are eaten with mashed potatoes. Potted meats in\u00a0aspic\u00a0(a gel made from gelatine and clarified meat broth) were a common way of serving meat off-cuts in the UK until the 1950s. Many jugged meats are also jellied.\r\n\r\n<\/div>\r\n
\r\n

Jugging<\/h3>\r\nMeat can be preserved by jugging. Jugging is the process of\u00a0stewing\u00a0the meat (commonly\u00a0game\u00a0or\u00a0fish) in a covered\u00a0earthenware\u00a0jug or\u00a0casserole. The animal to be jugged is usually cut into pieces, placed into a tightly-sealed jug with brine or\u00a0gravy, and stewed.\u00a0Red wine and\/or the animal's own blood is sometimes added to the cooking liquid. Jugging was a popular method of preserving meat up until the middle of the 20th century.\r\n\r\n<\/div>\r\n
\r\n

Burial<\/h3>\r\nBurial of food can preserve it due to a variety of factors: lack of light, lack of oxygen, cool temperatures, pH level, or\u00a0desiccants\u00a0in the soil. Burial may be combined with other methods such as salting or fermentation. Most foods can be preserved in soil that is very dry and salty (thus a desiccant) such as sand, or soil that is frozen. Many root vegetables are very resistant to spoilage and require no other preservation than storage in cool dark conditions, for example by burial in the ground, such as in a\u00a0storage clamp.\u00a0Century eggs\u00a0are created by placing eggs in alkaline mud (or other alkaline substance), resulting in their \"inorganic\" fermentation through raised pH instead of spoiling. The fermentation preserves them and breaks down some of the complex, less flavorful proteins and fats into simpler, more flavorful ones.\u00a0Cabbage\u00a0was traditionally buried in the fall in northern farms in the U.S. for preservation. Some methods keep it crispy while other methods produce\u00a0sauerkraut. A similar process is used in the traditional production of\u00a0kimchi. Sometimes meat is buried under conditions that cause preservation. If buried on hot coals or ashes, the heat can kill pathogens, the dry ash can desiccate, and the earth can block oxygen and further contamination. If buried where the earth is very cold, the earth acts like a refrigerator.\r\n\r\n<\/div>\r\n
\r\n

Contributors<\/h2>\r\n
    \r\n \t
  • Wikipedia<\/li>\r\n<\/ul>\r\n<\/div>","rendered":"

    Food preservation\u00a0involves preventing the growth of\u00a0bacteria,\u00a0fungi\u00a0(such as\u00a0yeasts), or other\u00a0micro-organisms\u00a0(although some methods work by introducing benign\u00a0bacteria\u00a0or fungi to the food), as well as slowing the\u00a0oxidation\u00a0of\u00a0fats\u00a0that cause\u00a0rancidity. Food preservation may also include processes that inhibit visual deterioration, such as the\u00a0enzymatic browning\u00a0reaction in apples after they are cut during food preparation.<\/p>\n

    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\u2019s moisture content and to kill bacteria, etc.), sugaring (to prevent their re-growth) and sealing within an airtight jar (to prevent recontamination). Some traditional methods of preserving food have been shown to have a lower\u00a0energy input\u00a0and\u00a0carbon footprint, when compared to modern methods.<\/p>\n

    Maintaining or creating nutritional value,\u00a0texture\u00a0and\u00a0flavor\u00a0is 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 \u2013\u00a0cheese,\u00a0yogurt\u00a0and pickled onions being common examples.<\/p>\n

    \n

    Traditional techniques<\/h2>\n

    New techniques of food preservation became available to the home chef from the dawn of\u00a0agriculture\u00a0until the\u00a0Industrial Revolution.<\/p>\n<\/div>\n

    \n

    Drying<\/h3>\n

    Drying is one of the oldest techniques used to hamper the decomposition of food products. As early as 12,000 B.C., Middle Eastern and Oriental cultures were drying foods using the power of the sun. Vegetables and fruits are naturally dried by the sun and wind, but “still houses” were built in areas that did not have enough sunlight to dry things. A fire would be built inside the building to provide the heat to dry the various fruits, vegetables, and herbs.<\/p>\n<\/div>\n

    \n

    Cooling<\/h3>\n

    Cooling\u00a0preserves food 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\u00a0Western world\u00a0by allowing foods such as fresh fruit, salads and dairy products to be stored safely for longer periods, particularly during warm weather.<\/p>\n<\/div>\n

    \n

    Freezing<\/h3>\n

    Freezing\u00a0is also one of the most commonly used processes, both commercially and domestically, for preserving a very wide range of foods, including prepared foods that would not have required freezing in their unprepared state. For example, potato waffles are stored in the freezer, but potatoes themselves require only a cool dark place to ensure many months’ storage. Cold stores provide large-volume, long-term storage for strategic food stocks held in case of national emergency in many countries.<\/p>\n<\/div>\n

    \n

    Boiling<\/h3>\n

    Boiling liquid food items can kill any existing microbes. Milk and water are often boiled to kill any harmful microbes that may be present in them.<\/p>\n<\/div>\n

    \n

    Heating<\/h3>\n

    Heating to temperatures which are sufficient to kill microorganisms inside the food is a method used with\u00a0perpetual stews. Milk is also boiled before storing to kill many microorganisms.<\/p>\n<\/div>\n

    \n

    Salting<\/h3>\n

    Bag of Prague powder #1, also known as “curing salt” or “pink salt”. It is typically a combination of salt and sodium nitrite, with the pink color added to distinguish it from ordinary salt. Salting or curing draws moisture from a substance through a process of osmosis. substances are\u00a0cured\u00a0with salt or sugar, or a combination of the two. Nitrates and nitrites are also often used to cure meat and contribute the characteristic pink colour. It was a main method of preservation in medieval times and around the 1700s.<\/p>\n<\/div>\n

    \n

    Sugaring<\/h3>\n

    The earliest cultures have used sugar as a preservative, and it was commonplace to store fruit in honey. Similar to pickled foods, sugar cane was brought to Europe through the trade routes. In northern climates without sufficient sun to dry foods, preserves are made by heating the fruit with sugar.\u00a0“Sugar tends to draw water from the microbes (plasmolysis). This process leaves the microbial cells dehydrated, thus killing them. In this way, the food will remain safe from microbial spoilage.”Sugar is used to preserve fruits, either in an\u00a0anti-microbial\u00a0syrup with fruit such as\u00a0apples,\u00a0pears,\u00a0peaches,\u00a0apricots\u00a0and\u00a0plums, or in crystallized form where the preserved material is cooked in sugar to the point of crystallization and the resultant product is then stored dry. This method is used for the skins of\u00a0citrus\u00a0fruit (candied peel),\u00a0angelica\u00a0and\u00a0ginger. Also sugaring can be used in\u00a0jam\u00a0jellies.<\/p>\n<\/div>\n

    \n

    Smoking<\/h3>\n

    Smoking is used to lengthen the\u00a0shelf life\u00a0of\u00a0perishable\u00a0food items. This effect is achieved by exposing the food to\u00a0smoke\u00a0from burning plant materials such as\u00a0wood. Smoke deposits a number of pyrolysis products onto the food, including the\u00a0phenols\u00a0syringol,\u00a0guaiacol\u00a0and\u00a0catechol.\u00a0These compounds aid in the drying and preservation of meats and other foods. Most commonly subjected to this method of food preservation are\u00a0meats and\u00a0fish\u00a0that have undergone\u00a0curing.\u00a0Fruits\u00a0and\u00a0vegetables\u00a0like\u00a0paprika,\u00a0cheeses,\u00a0spices, and ingredients for making\u00a0drinks\u00a0such as\u00a0malt\u00a0and\u00a0tealeaves are also smoked, but mainly for\u00a0cooking\u00a0or\u00a0flavoring\u00a0them. It is one of the oldest food preservation methods, which probably arose after the development of\u00a0cooking\u00a0with\u00a0fire.<\/p>\n<\/div>\n

    \n

    Pickling<\/h3>\n

    Pickling is a method of preserving food in an edible\u00a0anti-microbial\u00a0liquid. Pickling can be broadly classified into two categories: chemical pickling and fermentation pickling. In chemical pickling, the food is placed in an edible liquid that inhibits or kills bacteria and other micro-organisms. Typical pickling agents include\u00a0brine\u00a0(high in\u00a0salt),\u00a0vinegar,\u00a0alcohol, and\u00a0vegetable oil, especially\u00a0olive oil\u00a0but also many other oils. Many chemical pickling processes also involve heating or boiling so that the food being preserved becomes saturated with the pickling agent. Common chemically pickled foods include\u00a0cucumbers,\u00a0peppers,\u00a0corned beef,\u00a0herring, and\u00a0eggs, as well as mixed vegetables such as\u00a0piccalilli.<\/p>\n

    In fermentation pickling, the food itself produces the preservation agent, typically by a process that produces\u00a0lactic acid. Fermented pickles include\u00a0sauerkraut,\u00a0nukazuke,\u00a0kimchi,\u00a0surstr\u00f6mming,<\/p>\n<\/div>\n

    \n

    Lye<\/h3>\n

    Sodium hydroxide\u00a0(lye) makes food too\u00a0alkaline\u00a0for bacterial growth. Lye will\u00a0saponify\u00a0fats in the food, which will change its flavor and texture.\u00a0Lutefisk\u00a0uses lye in its preparation, as do some olive recipes. Modern recipes for\u00a0century eggs\u00a0also call for lye.<\/p>\n<\/div>\n

    \n

    Canning<\/h3>\n

    Canning\u00a0involves cooking food, sealing it in sterile cans or jars, and\u00a0boiling\u00a0the containers to kill or weaken any remaining bacteria as a form of\u00a0sterilization. It was invented by the French confectioner\u00a0Nicolas Appert.\u00a0By 1806, this process was used by the French Navy to preserve meat, fruit, vegetables, and even milk. Although Appert had discovered a new way of preservation, it wasn’t understood until 1864 when Louis Pasteur found the relationship between microorganisms, food spoilage, and illness.<\/p>\n

    Foods have varying degrees of natural protection against spoilage and may require that the final step occur in a\u00a0pressure cooker. High-acid fruits like\u00a0strawberries\u00a0require no preservatives to can and only a short boiling cycle, whereas marginal vegetables such as\u00a0carrots\u00a0require longer boiling and addition of other acidic elements. Low-acid foods, such as vegetables and meats, require pressure canning. Food preserved by canning or bottling is at immediate risk of spoilage once the can or bottle has been opened.<\/p>\n

    \"\"<\/p>\n

    Figure\u00a011.6.1:\u00a0Preserved food.\u00a0Unidentified stacks of home-canned food. Image used with permission (public domain).\u00a0<\/em><\/p>\n<\/div>\n

    Lack of quality control in the canning process may allow ingress of water or micro-organisms. Most such failures are rapidly detected as decomposition within the can causes gas production and the can will swell or burst. However, there have been examples of poor manufacture (underprocessing) and poor\u00a0hygiene\u00a0allowing contamination of canned food by the obligate\u00a0anaerobe\u00a0Clostridium botulinum, which produces an acute toxin within the food, leading to severe illness or death. This organism produces no gas or obvious taste and remains undetected by taste or smell. Its toxin is denatured by cooking, however. Cooked mushrooms, handled poorly and then canned, can support the growth of\u00a0Staphylococcus aureus<\/em>, which produces a toxin that is not destroyed by canning or subsequent reheating.<\/p>\n<\/div>\n

    \n

    Jellying<\/h3>\n

    Food may be preserved by cooking in a material that solidifies to form a gel. Such materials include\u00a0gelatin,\u00a0agar,\u00a0maize\u00a0flour, and\u00a0arrowrootflour. Some foods naturally form a\u00a0protein\u00a0gel when cooked, such as\u00a0eels and elvers, and\u00a0sipunculid\u00a0worms, which are a delicacy in\u00a0Xiamen, in the Fujian province of the\u00a0People’s Republic of China.\u00a0Jellied eels\u00a0are a delicacy in the East End of\u00a0London, where they are eaten with mashed potatoes. Potted meats in\u00a0aspic\u00a0(a gel made from gelatine and clarified meat broth) were a common way of serving meat off-cuts in the UK until the 1950s. Many jugged meats are also jellied.<\/p>\n<\/div>\n

    \n

    Jugging<\/h3>\n

    Meat can be preserved by jugging. Jugging is the process of\u00a0stewing\u00a0the meat (commonly\u00a0game\u00a0or\u00a0fish) in a covered\u00a0earthenware\u00a0jug or\u00a0casserole. The animal to be jugged is usually cut into pieces, placed into a tightly-sealed jug with brine or\u00a0gravy, and stewed.\u00a0Red wine and\/or the animal’s own blood is sometimes added to the cooking liquid. Jugging was a popular method of preserving meat up until the middle of the 20th century.<\/p>\n<\/div>\n

    \n

    Burial<\/h3>\n

    Burial of food can preserve it due to a variety of factors: lack of light, lack of oxygen, cool temperatures, pH level, or\u00a0desiccants\u00a0in the soil. Burial may be combined with other methods such as salting or fermentation. Most foods can be preserved in soil that is very dry and salty (thus a desiccant) such as sand, or soil that is frozen. Many root vegetables are very resistant to spoilage and require no other preservation than storage in cool dark conditions, for example by burial in the ground, such as in a\u00a0storage clamp.\u00a0Century eggs\u00a0are created by placing eggs in alkaline mud (or other alkaline substance), resulting in their “inorganic” fermentation through raised pH instead of spoiling. The fermentation preserves them and breaks down some of the complex, less flavorful proteins and fats into simpler, more flavorful ones.\u00a0Cabbage\u00a0was traditionally buried in the fall in northern farms in the U.S. for preservation. Some methods keep it crispy while other methods produce\u00a0sauerkraut. A similar process is used in the traditional production of\u00a0kimchi. Sometimes meat is buried under conditions that cause preservation. If buried on hot coals or ashes, the heat can kill pathogens, the dry ash can desiccate, and the earth can block oxygen and further contamination. If buried where the earth is very cold, the earth acts like a refrigerator.<\/p>\n<\/div>\n

    \n

    Contributors<\/h2>\n