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'''Tom Lehmann''' has been an [[economist]], [[programmer]], [[boardgame]] [[publisher]], [[game designer]], and [[technical writer]].
[[Image:Konservering.jpg|thumb|300px|Various preserved foods]]
'''Food preservation''' is the process of treating and handling [[food]] in such a way as to stop or greatly slow down spoilage to prevent [[foodborne illness]] while maintaining [[nutrition]]al value, texture and [[flavor]].
==Published Games==
== Preservation Processes ==
*''[[1846 (board game)|1846]]'' - an [[18XX]] game (2005, [[Deep Thought Games, LLC]])
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*''[[2038 (board game)|2038]]'' - co-designed with [[Jim Hlavaty (game designer)|Jim Hlavaty]] (1995, [[Prism Games]])
! Method
*''[[Age of Exploration (board game)|Age of Exploration]]'' (1994, [[Prism Games]])
! Effect on microbial growth or survival
*''[[Fast Food Franchise (board game)|Fast Food Franchise]]'' (1992, [[Prism Games]])
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*''[[Magellan (board game)|Magellan]]/[[Pizarro and Co. (board game)|Pizarro & Co.]]'' (2002, [[Hans im Glück]]/[[Rio Grande Games]])
| [[Refrigeration]] or chilling
*''[[Meine Wuerful, Deine Wuerful]]'' (''My Dice, Your Dice'') - a freebie [[dice game]] included with 55 (2005, Abacus)
| Low temperature to retard growth
*''[[Outpost Expert Game (board game)|Outpost Expert Game]]'' - co-developer (1994, [[Prism Games]]/[[TimJim Games]])
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*''[[Suzerain (board game)|Suzerain]]'' (1993, [[Prism Games]])
| [[Freezing]]
*''[[Throneworld (board game)|Throneworld]]'' (1997, [[Prism Games]])
| Low temperature and reduction of water activity to prevent growth
*''[[Time Agent (board game)|Time Agent]]'' (1992, [[Prism Games]])
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*''[[To Court the King]]'' - A dice-based game (2006, [[Amigo Spiele]] and [[Rio Grande Games]])
| [[Drying (food)|Drying]], [[curing]] and conserving
| Reduction in [[water activity]] sufficient to delay or prevent growth
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| [[Vacuum]] and [[oxygen]] free [[modified atmosphere]] packaging
| Low [[oxygen]] tension inhibits strict [[aerobe]]s and delay growth of facultative [[Anaerobic organism|anaerobe]]s
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| Carbon dioxide enriched modified atmosphere packaging
| Specific inhibition of some micro-organisms by [[carbon dioxide]]
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| Addition of [[weak acid]]s
| Reduction of the intracellular [[pH]] of micro-organisms
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| [[Lactic acid|Lactic]] [[fermentation]]
| Reduction of pH value ''in situ'' by microbial action and sometimes additional inhibition by the lactic and [[acetic acid]]s formed and by other microbial products. (e.g. [[ethanol]], [[bacteriocin]]s)
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| [[Sugar]] preservation
| Cooking in high sucrose concentration creating too high osmotic pressure for most microbial survival.
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| [[Ethanol]] preservation
| Steeping or cooking in [[Ethanol]] produces toxic inhibition of microbes. Can be combined with [[sugar]] preservation
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| [[Emulsion|Emulsification]]
| Compartmentalisation and [[nutrient limitation]] within the [[aqueous]] droplets in water-in-oil emulsion foods
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| Addition of [[preservative]]s such as [[nitrite]] or [[sulphite]] ions
| Inhibition of specific groups of micro-organisms
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| [[Pasteurization]] and [[appertization]]
| Delivery of [[heat]] sufficient to inactivate target micro-organisms to the desired extent
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| [[Food irradiation]] ([[Radurization]], [[radicidation]] and [[radappertization]])
| Delivery of [[ionising radiation]]
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| Application of high hydrostatic pressure (Pascalization)
| Pressure-inactivation of vegetative bacteria, yeasts and moulds
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In addition to these, he typically has 15-20 new games available for publication{{fact}}. Several are to be published in 2006, including ''[[Royal Advancement (board game)|Royal Advancement]]'' (a [http://www.amigo-spiele.de/Amigo_kopfkarton_Start.Amigo?ActiveID=1002 German article] chronicling its passage from prototype to publishing is available) and ''[[1834 (board game)|1834]]''.
Preservation usually involves preventing the growth of [[bacterium|bacteria]], [[fungus|fungi]] and other [[microorganism|micro-organisms]], as well as retarding the [[redox|oxidation]] of [[fat]]s which cause [[Rancidification|rancidity]]. It also includes processes to inhibit natural aging and discolouration that can occur during food preparation such as the [[polyphenoloxidase]] reaction in [[apple]]s which causes browning when apples are cut. Some preservation methods require the food to be sealed after treatment to prevent re-contamination with microbes; others, such as drying, allow food to be stored without any special containment for long periods.
Tom has also contributed design ideas to other published games, including ''[[San Juan (game)|San Juan]]''.
Preservation processes include:
* Heating to kill or denature organisms (e.g. boiling)
* Oxidation (e.g use of sulphur dioxide)
* Toxic inhibition (e.g. smoking, use of carbon dioxide, vinegar, alcohol etc)
* Dehydration (drying)
* Osmotic inhibition ( e.g use of syrups)
* Low temperature inactivation (e.g. freezing)
* Many combinations of these methods
* [[Chelation]]
==Methods==
Common methods of applying these processes include [[drying (food)|drying]], [[freeze drying]], [[freezing]], [[vacuum-packing]], [[canning]], preserving in syrup, sugar crystalisation, [[food irradiation]], adding [[preservative]]s or inert [[gas]]es such as [[carbon dioxide]].
Other methods that not only help to preserve food, but also add flavor, include [[pickling]], [[salting (food)|salting]], [[smoking (food)|smoking]] , preserving in [[syrup]] or [[ethanol|alcohol ]], [[sugar]] crystalisation and [[curing]].
===Drying===
One of the oldest methods of food preservation is by drying (food)|drying, which reduces water activity sufficient to delay or prevent bacterium|bacterial growth.
Most types of meat can be dried and this is especially valuable in the case of pig meat since this is difficult to keep without preservation. Many fruits can also be dried and the process is often applied to apples, pears, bananas, mangos, papaya, coconut etc. Zante currant|Currants, sultanas and raisins are all forms of dried Grapes. Drying is also the normal means of preservation for cereal grains such as wheat, maize, oats, barley, rice, millet and rye.
===Freezing===
Freezing is also one of the most commonly used processes commercially and domestically for preserving a very wide range of food stuffs including prepared food stuffs which 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.
===Vacuum Packing===
[[Vacuum-packing]] stores food in a [[vacuum]] environment, usually in an air-tight bag or bottle. The [[vacuum]] environment strips [[bacteria]] of oxygen needed for survival, hence preventing the food from spoiling. Vacuum-packing is commonly used for storing [[nut (fruit)|nuts]].
===Curing===
Curing draws moisture from the meat through a process of osmosis. Meat is [[curing|cured]] with [[edible salt|salt]] or sugar, or a combination of the two. Nitrates and nitrites are also often used to cure meat.
===Sugar===
[[Sugar]] is used to preserve fruits, either in syrup with fruit such as [[apple]]s, [[pear]]s, [[peach]]es, [[apricot]]s, [[plum]]s or in crystalised form where the preserved material is cooked in sugar to the point of crystralisation and the resultant product is then stored dry. This method is used for the skins of [[citrus]] fruit (candied peel), [[angelica]] and [[ginger]]. A modification of this process produces glacé fruit such as glacé [[cherry|cherries]] where the fruit is preserved in sugar but is then extracted from the syrup and sold, the preservation being maintained by the sugar content of the fruit and the superficial coating of syrup.
The use of sugar is often combined with [[ethanol|alcohol]] for preservation of luxury products such as fruit in [[brandy]] or other spirits. These should not be confused with fruit flavoured spirits such as [[Cherry Brandy]] or [[Sloe gin]]
===Pickling===
[[Pickling]] is a method of preserving food by placing it or cooking it in a substance that inhibits or kills bacteria and other micro-organisms. This material must also be fit for human consumption. Typical pickling agents include [[brine]] (high in [[edible salt|salt]]), [[vinegar]], [[ethanol]], and [[vegetable oil]], especially [[olive oil]] but also many other oils. Most pickling processes also involve heating or boiling so that the food being preserved becomes saturated with the pickling agent.
Frequently pickled items include [[vegetables]] such as [[cabbage]] (to make [[sauerkraut]] and [[curtido]]), [[capsicum|pepper]]s, and some animal products such as [[corned beef]] and [[egg (food)|eggs]].
A less-common form of pickling uses [[sodium hydroxide]] ([[lye]]) to make the food too [[alkaline]] for bacterial growth. Lye will [[saponification|saponify]] fats in the food, which will change its flavor and texture. [[Lutefisk]] and [[hominy]] use lye in their preparation, as do some olive recipes.
===Canning and Bottling===
[[Image:PreservedFood1.jpg|thumb|right|225px|Preserved food]]
[[Canning]] involves cooking [[fruit]]s or [[vegetable]]s, sealing them in sterile cans or jars, and [[boiling]] the containers to kill or weaken any remaining bacteria. Various foods have varying degrees of natural protection against spoilage and may require that the final step occur in a [[pressure cooker]]. High-acid fruits like [[strawberry|strawberries]] require no preservatives to can and only a short boiling cycle, whereas marginal fruits such as [[tomato]]es require longer boiling and addition of other acidic elements. Many vegetables require pressure canning. Food preserved by canning or bottling is at immediate risk of spoilage once the can or bottle has been opened.
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 and poor [[hygiene]] allowing contanmination of canned food by the obligate [[Anaerobic organism|anaerobe]], ''[[Clostridium 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. Food contaminated in this way has included [[Corned beef]] and [[Tuna]].
===Jellying===
Food may be preserved by cooking in a material that solidifies to form a gel. Such materials include [[gelatine]], [[agar]], [[maize]] flour and [[arrowroot]] flour. Some foods naturally form a [[protein]] gel when cooked such as [[Eel|eels and elvers]], and [[Sipuncula|sipunculid]] worms which are a delicacy in the town of [[Xiamen]] in Fujian province of [[China]]. [[Jellied eels]] are a delicacy in the East End of [[London]] where they are eaten with mashed [[potato]]es.
Potted meats in [[aspic]], (the gel made from arrowroot flour) were a common way of serving meat off-cuts in the UK until the [[1950]]s
===Irradiation===
A [[1950s]] issue of [[Popular Mechanics]] details the impending arrival of "[[food irradiation]]". But the implications of irradiation are not fully understood, and the use of the technology is limited. Irradiation of [[potato]]es, strawberries, and meat is common in many countries where refrigerated facilities and trucks are not. In [[2002]], the [[Food and Drug Administration]] permitted irradiation of meat and poultry to reduce the spread of [[E. coli]] and [[salmonella]].
In the US and most of Europe, irradiation of spices is common, as the only alternative (treatment with gas) is potentially carcinogenic. The process is called "cold pasteurization" because it is feared that the label "irradiation" would hurt sales. Foods may also carry labels saying "Picowaved For Your Protection" as food processors may not want to openly label their foods as being irradiated.
It should be noted that although irradiation is effective at killing [[bacteria]], [[fungi]] and other [[pathogens]], there is still a danger that the food may contain some of their toxins.
===Modified atmosphere===
[[Modified atmosphere]] is a way to preserve food operating on the atmosphere around it. Salad crops which are notoriously difficult to preserve are now being packaged in sealed bags with an atmosphere modified to reduce the [[oxygen]] concentration and increase the [[carbon dioxide]] concentration. There is concern that although salad vegetables retain their appearance and texture in such conditions, this method of preservation may not retain nutrients, especially [[vitamin]]s.
Grains may be preserved using [[carbon dioxide]]. A block of [[dry ice]] is placed in the bottom and the can is filled with grain. The can is then "burped" of excess gas. The [[carbon dioxide]] from the sublimation of the dry ice prevents insects, [[mold]], and [[oxidation]] from damaging the grain. Grain stored in this way can remain edible for five years.
===Clamps===
Many root vegetables are very resistant to spoilage and require no other preservation other than storage in cool dark conditions, usually in field [[Storage clamp|clamp]]s.
===Biological processes===
Some foods, such as many traditional [[cheese]]s, will keep for a long time without use of any special procedures. The preservation occurs because of the presence in very high numbers of beneficial bacteria or fungi which use their own biological defences to prevent other organisms gaining a foot-hold.
==See also==
* [[Food engineering]]
* [[Canning]]
* [[Chutney]]
* [[Food processing]]
* [[Jam]]
* [[Marmalade]]
* [[Pickle]]
==External links==
*{{bgg designer|150}}
{{Commons|Category:Food preservation}}
* [http://www.uga.edu/nchfp National Center for Home Food Preservation]
* [[BBC News Online]] - [http://news.bbc.co.uk/1/hi/world/americas/3915659.stm US army food... just add urine]
* [http://www.rense.com/general10/topten.htm Ten Top Reasons For Opposing Food Irradiation]
[[Category:Food preservation| ]]
[[Category:Living people|Lehmann, Thomas]]
[[da:Konservering (madvarer)]]
[[Category:Board game designers|Lehmann, Thomas]]
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[[fr:Conservation des aliments]]
[[he:שימור מזון]]
[[nl:Conserveren]]
[[ja:保存食]]
[[pl:Konserwacja żywności]]
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[[zh:食物保鲜法]]
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