Preservatives

A preservative is a <a href="http://en.wikipedia.org/wiki/Natural" title="Natural" class="mw-redirect" >naturally</a> occurring or <a href="http://en.wikipedia.org/w/index.php?title=Synthetic_organic_compounds&action=edit&redlink=1" class="new" title="Synthetic organic compounds (page does not exist)" >synthetically</a> produced substance that is added to products such as foods, <a href="http://en.wikipedia.org/wiki/Pharmaceuticals" title="Pharmaceuticals" class="mw-redirect" >pharmaceuticals</a>, paints, biological samples, wood, etc. to prevent <a href="http://en.wikipedia.org/wiki/Decomposition" title="Decomposition" >decomposition</a> by <a href="http://en.wikipedia.org/wiki/Microbial" title="Microbial" class="mw-redirect" >microbial</a> growth or by undesirable <a href="http://en.wikipedia.org/wiki/Chemical" title="Chemical" class="mw-redirect" >chemical</a> changes.

Preservative <a href="http://en.wikipedia.org/wiki/Food_additive" title="Food additive" >food additives</a> can be used alone or in conjunction with other methods of <a href="http://en.wikipedia.org/wiki/Food_preservation" title="Food preservation" >food preservation</a>.

Preservatives may be antimicrobial preservatives, which inhibit the growth of <a href="http://en.wikipedia.org/wiki/Bacteria" title="Bacteria" >bacteria</a> or <a href="http://en.wikipedia.org/wiki/Fungi" title="Fungi" class="mw-redirect" >fungi</a>, including <a href="http://en.wikipedia.org/wiki/Mold" title="Mold" >mold</a>, <a href="http://en.wikipedia.org/wiki/Antioxidant" title="Antioxidant" >antioxidants</a> such as <a href="http://en.wikipedia.org/wiki/Oxygen_absorber" title="Oxygen absorber" >oxygen absorbers</a>, which inhibit the <a href="http://en.wikipedia.org/wiki/Oxidation" title="Oxidation" class="mw-redirect" >oxidation</a> of food constituents.

Common antimicrobial preservatives include <a href="http://en.wikipedia.org/wiki/Sorbic_acid" title="Sorbic acid" >sorbic acid</a> and its salts, <a href="http://en.wikipedia.org/wiki/Benzoic_acid" title="Benzoic acid" >benzoic acid</a> and its salts, <a href="http://en.wikipedia.org/wiki/Calcium_propionate" title="Calcium propionate" class="mw-redirect" >calcium propionate</a>,

<a href="http://en.wikipedia.org/wiki/Sodium_nitrite" title="Sodium nitrite" >sodium nitrite</a> (and <a href="http://en.wikipedia.org/wiki/Sodium_nitrate" title="Sodium nitrate" >sodium nitrate</a> which converts to sodium nitrite "in situ"), <a href="http://en.wikipedia.org/wiki/Sulfite" title="Sulfite" >sulfites</a> (<a href="http://en.wikipedia.org/wiki/Sulfur_dioxide" title="Sulfur dioxide" >sulfur dioxide</a>, <a href="http://en.wikipedia.org/wiki/Sodium_bisulfite" title="Sodium bisulfite" >sodium bisulfite</a>,

<a href="http://en.wikipedia.org/wiki/Potassium_hydrogen_sulfite" title="Potassium hydrogen sulfite" class="mw-redirect" >potassium hydrogen sulfite</a>, etc.) and <a href="http://en.wikipedia.org/wiki/EDTA" title="EDTA" class="mw-redirect" >disodium EDTA</a><a href="http://en.wikipedia.org/wiki/Preservative#cite_note-CEN-1-0" >[1]</a><a href="http://en.wikipedia.org/wiki/Preservative#cite_note-1" >[2]</a>.

<a href="http://en.wikipedia.org/wiki/Antioxidant" title="Antioxidant" >Antioxidants</a> include <a href="http://en.wikipedia.org/wiki/Butylated_hydroxyanisole" title="Butylated hydroxyanisole" >BHA</a>, <a href="http://en.wikipedia.org/wiki/Butylated_hydroxytoluene" title="Butylated hydroxytoluene" >BHT</a>, <a href="http://en.wikipedia.org/w/index.php?title=%27%27tert%27%27-Butyl_hydroquinone&action=edit&redlink=1" class="new" title="''tert''-Butyl hydroquinone (page does not exist)" >TBHQ</a> and <a href="http://en.wikipedia.org/wiki/Propyl_gallate" title="Propyl gallate" >propyl gallate</a><a href="http://en.wikipedia.org/wiki/Preservative#cite_note-CEN-1-0" >[1]</a>. Other preservatives include <a href="http://en.wikipedia.org/wiki/Ethanol" title="Ethanol" >ethanol</a> and <a href="http://en.wikipedia.org/wiki/Methylchloroisothiazolinone" title="Methylchloroisothiazolinone" >methylchloroisothiazolinone</a>.

FDA standards do not currently require fruit and vegetable product labels to reflect the type of chemical preservative(s) used on the produce.[<a href="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" >citation needed</a>] The benefits and safety of many artificial food additives (including preservatives) are the subject of debate among academics and regulators specializing in <a href="http://en.wikipedia.org/wiki/Food_science" title="Food science" >food science</a>, <a href="http://en.wikipedia.org/wiki/Toxicology" title="Toxicology" >toxicology</a>, and <a href="http://en.wikipedia.org/wiki/Biology" title="Biology" >biology</a>.

<h3 >Natural food preservation</h3>

Naturally occurring substances such as <a href="http://en.wikipedia.org/wiki/Rosemary" title="Rosemary" >rosemary</a> extract, <a href="http://en.wikipedia.org/wiki/Hops" title="Hops" >hops</a>, <a href="http://en.wikipedia.org/wiki/Salt" title="Salt" >salt</a>, <a href="http://en.wikipedia.org/wiki/Sugar" title="Sugar" >sugar</a>, <a href="http://en.wikipedia.org/wiki/Vinegar" title="Vinegar" >vinegar</a>, <a href="http://en.wikipedia.org/wiki/Ethanol" title="Ethanol" >alcohol</a>, <a href="http://en.wikipedia.org/wiki/Diatomaceous_earth" title="Diatomaceous earth" >diatomaceous earth</a> and <a href="http://en.wikipedia.org/wiki/Castor_oil" title="Castor oil" >castor oil</a> are also used as traditional preservatives. Certain processes such as <a href="http://en.wikipedia.org/wiki/Frozen_food" title="Frozen food" >freezing</a>, <a href="http://en.wikipedia.org/wiki/Pickling" title="Pickling" >pickling</a>, <a href="http://en.wikipedia.org/wiki/Smoking(cooking)" title="Smoking (cooking)" >smoking</a> and <a href="http://en.wikipedia.org/wiki/Salting(food)" title="Salting (food)" >salting</a> can also be used to preserve food.

Another group of preservatives targets <a href="http://en.wikipedia.org/wiki/Enzymes" title="Enzymes" class="mw-redirect" >enzymes</a> in fruits and vegetables that start to metabolize after they are cut. For instance, the naturally occurring <a href="http://en.wikipedia.org/wiki/Citric_acid" title="Citric acid" >citric</a> and <a href="http://en.wikipedia.org/wiki/Ascorbic_acid" title="Ascorbic acid" >ascorbic acids</a> in lemon or other <a href="http://en.wikipedia.org/wiki/Citrus" title="Citrus" >citrus</a> juice can inhibit the action of the enzyme <a href="http://en.wikipedia.org/wiki/Phenolase" title="Phenolase" class="mw-redirect" >phenolase</a> which turns surfaces of cut apples and potatoes brown if a small amount of the juice is applied to the freshly cut produce. <a href="http://en.wikipedia.org/wiki/Vitamin_C" title="Vitamin C" >Vitamin C</a> and <a href="http://en.wikipedia.org/wiki/Vitamin_E" title="Vitamin E" >Vitamin E</a> are also sometimes used as preservatives.

<h3 >Health concerns</h3>

Some modern synthetic preservatives have been shown to cause <a href="http://en.wikipedia.org/wiki/Respiratory" title="Respiratory" class="mw-redirect" >respiratory</a> or other health problems.[<a href="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" >citation needed</a>] For example <a href="http://en.wikipedia.org/wiki/Sulfite" title="Sulfite" >sulfites</a> are commonly used in wines and some dried fruits or vegetables and are known as possible irritants to people with <a href="http://en.wikipedia.org/wiki/Asthma" title="Asthma" >asthma</a>. In one study, children exhibited increased hyperactivity after consuming drinks containing sodium benzoate or artificial food color and additives.<a href="http://en.wikipedia.org/wiki/Preservative#cite_note-2" >[3]</a> Prior studies were however inconclusive.[<a href="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" >citation needed</a>]