Propylene Glycol Alginate
<p><b >Propylene glycol alginate</b> (<b >PGA</b>) is an emulsifier, stabilizer, and thickener used in food products. </p>
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It is a <a href="http://en.wikipedia.org/wiki/Food_additive" title="Food additive" >food additive</a> with <a href="http://en.wikipedia.org/wiki/E_number" title="E number" >E number</a> E405. Chemically, propylene glycol alginate is an <a href="http://en.wikipedia.org/wiki/Ester" title="Ester" >ester</a> of <a href="http://en.wikipedia.org/wiki/Alginic_acid" title="Alginic acid" >alginic acid</a>, which is derived from <a href="http://en.wikipedia.org/wiki/Kelp" title="Kelp" >kelp</a>. </p>
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Some of the<a href="http://en.wikipedia.org/wiki/Carboxyl_group" title="Carboxyl group" class="mw-redirect" >carboxyl groups</a> are esterified with <a href="http://en.wikipedia.org/wiki/Propylene_glycol" title="Propylene glycol" >propylene glycol</a>, some are neutralized with an appropriate <a href="http://en.wikipedia.org/wiki/Alkali" title="Alkali" >alkali</a>, and some remain free.<sup id="cite_ref-fao_0-1" class="reference" ><a href="http://en.wikipedia.org/wiki/Propylene_glycol_alginate#cite_note-fao-0" >[1]</a></sup></p>