{"id":6615,"date":"2012-07-17T10:43:17","date_gmt":"2012-07-17T00:43:17","guid":{"rendered":"https:\/\/scienceillustrated.com.au\/blog\/?p=6615"},"modified":"2012-07-17T10:47:32","modified_gmt":"2012-07-17T00:47:32","slug":"why-do-shellfish-change-colour-when-cooked","status":"publish","type":"post","link":"https:\/\/scienceillustrated.com.au\/blog\/nature\/why-do-shellfish-change-colour-when-cooked\/","title":{"rendered":"Why do shellfish change colour when cooked?"},"content":{"rendered":"<p>&nbsp;<\/p>\n<div id=\"attachment_6616\" class=\"wp-caption aligncenter\" style=\"width: 605px\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-6616\" title=\"Astaxanthin is the pigment that gives prawns that bright red colouring. Image: Shutterstock\" src=\"https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2012\/07\/prawns.gif\" alt=\"\" width=\"605\" height=\"375\" srcset=\"https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2012\/07\/prawns.gif 605w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2012\/07\/prawns-300x185.gif 300w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2012\/07\/prawns-250x154.gif 250w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2012\/07\/prawns-119x74.gif 119w\" sizes=\"(max-width: 605px) 100vw, 605px\" \/><\/p>\n<p class=\"wp-caption-text\">Astaxanthin is the pigment that gives prawns that bright red colouring. Image: Shutterstock<\/p>\n<\/div>\n<p><strong>The answer to this question lies in the breaking of specific chemical bonds by heat.<\/strong><strong><!--more--><\/strong><\/p>\n<p>When a prawn, lobster or crab is alive and well, scurrying around in its normal habitat, their shell is a dull grey or green colour, which helps them blend in with their surroundings.<\/p>\n<p>But when these creatures are exposed to heat \u2014 say, during the cooking process \u2014 all the pigments in their shell break down, apart from the one responsible for providing a red colour called <a href=\"http:\/\/en.wikipedia.org\/wiki\/Astaxanthin\">astaxanthin<\/a>. This pigment is stable in heat and is usually bound to proteins in the shell. But as these proteins denature and unwind, it\u00a0becomes free.<\/p>\n<p>Astaxanthin also gives salmon, krill, plankton and some algae species their reddish colour.\u00a0It is produced synthetically for commercial use in animal and fish foods (in tiny quantities) to impart colour on those that eat it. Some research suggests that astaxanthin may also have health benefits, and it can be used as a food supplement.<\/p>\n<div id=\"attachment_6620\" class=\"wp-caption aligncenter\" style=\"width: 605px\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-6620\" title=\"Astaxanthin is a type of carotenoid, which belongs to a class of phytochemicals known as tarpenes. Image: Wikipedia\" src=\"https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2012\/07\/Astaxanthin.jpg\" alt=\"\" width=\"605\" height=\"200\" srcset=\"https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2012\/07\/Astaxanthin.jpg 605w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2012\/07\/Astaxanthin-300x99.jpg 300w, https:\/\/scienceillustrated.com.au\/blog\/wp-content\/uploads\/2012\/07\/Astaxanthin-250x82.jpg 250w\" sizes=\"(max-width: 605px) 100vw, 605px\" \/><\/p>\n<p class=\"wp-caption-text\">Astaxanthin is a type of carotenoid, which belongs to a class of phytochemicals known as tarpenes. Image: Wikipedia<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; The answer to this question lies in the breaking of specific chemical bonds by heat.<\/p>\n","protected":false},"author":8,"featured_media":6616,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[52,58,32,6,8],"tags":[489,491,490,74,488],"class_list":["post-6615","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ask-us","category-chemistry","category-marine-biology","category-nature","category-science","tag-astaxanthin","tag-cooking","tag-pigment","tag-science-2","tag-shellfish"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/posts\/6615"}],"collection":[{"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/comments?post=6615"}],"version-history":[{"count":7,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/posts\/6615\/revisions"}],"predecessor-version":[{"id":6650,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/posts\/6615\/revisions\/6650"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/media\/6616"}],"wp:attachment":[{"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/media?parent=6615"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/categories?post=6615"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/scienceillustrated.com.au\/blog\/wp-json\/wp\/v2\/tags?post=6615"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}