REB A (purified stevia extract)

<p><b >Steviol glycosides</b> are responsible for the sweet taste of the leaves of the <a href="http://en.wikipedia.org/wiki/Stevia" title="Stevia" >stevia</a> plant (<i >Stevia rebaudiana</i> Bertoni). These compounds range in <a href="http://en.wikipedia.org/wiki/Sweetness" title="Sweetness" >sweetness</a> from 40 to 300 times sweeter than <a href="http://en.wikipedia.org/wiki/Sucrose" title="Sucrose" >sucrose</a>.<sup id="cite_ref-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-0" >[1]</a></sup> They are heat-stable, pH-stable, and do not ferment.<sup id="cite_ref-faq_1-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-faq-1" >[2]</a></sup> </p>

<p>

They also do not induce a <a href="http://en.wikipedia.org/wiki/Blood_sugar" title="Blood sugar" >glycemic response</a> when ingested, making them attractive as natural <a href="http://en.wikipedia.org/wiki/Sugar_substitute" title="Sugar substitute" >sweeteners</a> to <a href="http://en.wikipedia.org/wiki/Diabetics" title="Diabetics" class="mw-redirect" >diabetics</a> and others on <a href="http://en.wikipedia.org/wiki/Carbohydrate" title="Carbohydrate" >carbohydrate</a>-controlled diets.

 </p>

<h2 >Structure</h2>

Steviol</div>

</div>

Stevioside is formed by attaching glucose molecules to the steviol structure.</div>

</div>

<p >The <a href="http://en.wikipedia.org/wiki/Diterpene" title="Diterpene" >diterpene</a> known as <a href="http://en.wikipedia.org/wiki/Steviol" title="Steviol" >steviol</a> is the <a href="http://en.wikipedia.org/wiki/Aglycone" title="Aglycone" >aglycone</a> of <a href="http://en.wikipedia.org/wiki/Stevia" title="Stevia" >stevia</a>'s sweet <a href="http://en.wikipedia.org/wiki/Glycoside" title="Glycoside" >glycosides</a>, which are constructed by replacing steviol's carboxyl <a href="http://en.wikipedia.org/wiki/Hydrogen" title="Hydrogen" >hydrogen</a> <a href="http://en.wikipedia.org/wiki/Atom" title="Atom" >atom</a> (at the bottom left of the figure) with <a href="http://en.wikipedia.org/wiki/Glucose" title="Glucose" >glucose</a> to form an <a href="http://en.wikipedia.org/wiki/Ester" title="Ester" >ester</a>, and replacing the hydroxyl hydrogen (at the top of the figure) with combinations of glucose and <a href="http://en.wikipedia.org/wiki/Rhamnose" title="Rhamnose" >rhamnose</a> to form an <a href="http://en.wikipedia.org/wiki/Ether" title="Ether" >ether</a>. The two primary compounds, stevioside and rebaudioside A, use only glucose: Stevioside has two linked glucose molecules at the hydroxyl site, whereas rebaudioside A has three, with the middle glucose of the triplet connected to the central steviol structure.</p>

<p>

In terms of weight fraction, the four major steviol glycosides found in the stevia plant tissue are:</p>

<ul >

<li >5–10% stevioside (250–300X of sugar)</li>

<li >2–4% rebaudioside A — most sweet (350–450X of sugar) and least bitter</li>

<li >1–2% rebaudioside C</li>

<li >½–1% dulcoside A.</li>

</ul>

<p>

Rebaudioside B, D, and E may also be present in minute quantities; however, it is suspected that rebaudioside B is a byproduct of the isolation technique.<sup id="cite_ref-faq_1-1" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-faq-1" >[2]</a></sup> The two majority compounds stevioside and rebaudioside, primarily responsible for the sweet taste of stevia leaves, were first isolated by two French chemists, Bridel and Lavielle (1931).<sup id="cite_ref-2" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-2" >[3]</a></sup></p>

<h2 >[<a href="http://en.wikipedia.org/w/index.php?title=Steviol_glycoside&action=edit&section=2" title="Edit section: Availability" >edit</a>]Availability</h2>

<div class="rellink relarticle mainarticle" >Main article: <a href="http://en.wikipedia.org/wiki/Stevia#Availability" title="Stevia" >Stevia#Availability</a></div>

<p >Steviol glycosides were first commercialized as a sweetener in 1971 by the Japanese firm Morita Kagaku Kogyo Co., Ltd., a leading stevia extract producer in Japan.</p>

<ul >

<li ><b>Rebiana</b> is the trade name<sup id="cite_ref-3" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-3" >[4]</a></sup> for a zero-calorie sweetener containing mainly rebaudioside A (also called Reb A).<sup id="cite_ref-4" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-4" >[5]</a></sup></li>

<li ><b>Truvia</b> is the consumer brand for Rebiana marketed by <a href="http://en.wikipedia.org/wiki/Cargill" title="Cargill" >Cargill</a> and developed jointly with <a href="http://en.wikipedia.org/wiki/The_Coca-Cola_Company" title="The Coca-Cola Company" >The Coca-Cola Company</a>.<sup id="cite_ref-nyt_5-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-nyt-5" >[6]</a></sup></li>

<li ><b>PureVia</b> is <a href="http://en.wikipedia.org/wiki/PepsiCo" title="PepsiCo" >PepsiCo</a>'s <a href="http://en.wikipedia.org/wiki/Brand" title="Brand" >brand</a> of Reb A sweetener and developed jointly with <a href="http://en.wikipedia.org/wiki/Whole_Earth_Sweetener_Company" title="Whole Earth Sweetener Company" class="mw-redirect" >Whole Earth Sweetener Company</a>.</li>

<li ><b>Enliten</b> is <a href="http://en.wikipedia.org/wiki/Corn_Products_International" title="Corn Products International" class="mw-redirect" >Corn Products International</a>'s <a href="http://en.wikipedia.org/wiki/Brand" title="Brand" >brand</a> of Reb A sweetener.</li>

</ul>

<p>

A 1985 study reporting that steviol may be a <a href="http://en.wikipedia.org/wiki/Mutagen" title="Mutagen" >mutagen</a><sup id="cite_ref-6" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-6" >[7]</a></sup> has been criticized on procedural grounds that the data were mishandled in such a way that even <a href="http://en.wikipedia.org/wiki/Distilled_water" title="Distilled water" >distilled water</a> would appear mutagenic.<sup id="cite_ref-7" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-7" >[8]</a></sup> More recent studies appear to establish the safety of steviol and its glycosides. In 2006, the <a href="http://en.wikipedia.org/wiki/World_Health_Organization" title="World Health Organization" >World Health Organization</a> (WHO) performed a thorough evaluation of recent experimental studies of stevia extracts conducted on animals and humans, and concluded that “<i>stevioside and rebaudioside A are not genotoxic <a href="http://en.wikipedia.org/wiki/In_vitro" title="In vitro" >in vitro</a> or <a href="http://en.wikipedia.org/wiki/In_vivo" title="In vivo" >in vivo</a> and that the genotoxicity of steviol and some of its oxidative derivatives in vitro is not expressed in vivo.</i>”<sup id="cite_ref-WHO_8-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-WHO-8" >[9]</a></sup> The report also found no evidence of carcinogenic activity. The report also suggested the possibility of health benefits, in that “<i>stevioside has shown some evidence of pharmacological effects in patients with hypertension or with type-2 diabetes</i>”,<sup id="cite_ref-WHO_8-1" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-WHO-8" >[9]</a></sup> but concluded that further study was required to determine proper dosage.

The <a href="http://en.wikipedia.org/wiki/European_Food_Safety_Authority" title="European Food Safety Authority" >European Food Safety Authority</a> evaluated the safety of steviol glycosides, extracted from the leaves of the Stevia rebaudiana Bertoni plant, as sweetener and expressed its opinion on 10 March 2010. The authority concluded an <a href="http://en.wikipedia.org/wiki/Acceptable_Daily_Intake" title="Acceptable Daily Intake" class="mw-redirect" >Acceptable Daily Intake</a> (ADI) for steviol glycosides, expressed as steviol equivalents, of 4 mg/kg bodyweight/day.<sup id="cite_ref-ce1131A_9-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Reb_A#cite_note-ce1131A-9" >[10]</a></sup>

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<ul >

<li ><a href="http://en.wikipedia.org/wiki/Glycoside" title="Glycoside" >Glycoside</a></li>

<li ><a href="http://en.wikipedia.org/wiki/Stevia" title="Stevia" >Stevia</a></li>

<li ><a href="http://en.wikipedia.org/wiki/Sugar_substitute" title="Sugar substitute" >Sugar substitute</a></li>

</ul>

REB A (purified stevia extract)

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