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Research—DNA Test Identifies Four Species of Shrimp

 

Restaurants and processors that mislabel shrimp species—beware!  Fisheries scientists in India have developed a technique for detecting mislabeled shrimp.  Researchers led by Geevaretnam Jeyasekaran at the Fisheries College and Research Institute (FCRI) in Thoothukkudi, Tamil Nadu, have developed a sophisticated, lab-based PCR test that is capable of identifying four commercially important shrimp species:  tiger shrimp (Penaeus monodon), Indian white shrimp (P. indicus), flower shrimp (P. semisulcatus) and Pacific white shrimp (P. vannamei).

 

“When you go to a restaurant and order a pan-cooked tiger shrimp curry, there is a possibility that what you get may not have tiger shrimp, but contains a cheaper cousin, like Pacific white shrimp,” said Jeyasekaran, the FCRI scientist, who led the development of the test.  “This is because once the head and tail are removed, different species of shrimp look similar and their distinct odor and taste are often masked by pungent spices.  Those who are out there to make a quick buck mix cheaper varieties with prized ones and sell them as the much-sought-after varieties,” Jeyasekaran said.

 

According to Jeyasekaran, in developed countries, nearly 50 percent of the shrimp sold are processed, and often do not bear an appropriate label regarding the species.

 

The technique that Jeyasekaran and his team developed, however, can bring an end to the mislabeling problem because it is capable of identifying the shrimp species from cooked, fried, canned or raw shrimp in eight hours using a single enzyme.

 

In 2014, DNA testing by the USA-based non-profit organization Oceana found that 30 per cent of 143 shrimp products from 111 grocery shops and restaurants were misrepresented.  For the rebuttal on this study click on the following links:

 

Missouri—GAA’s Comments on Shrimp Mislabeling Issue

Daniel Gruenberg on Mislabeling

Washington DC—Rebuttal to Oceana’s Shrimp Mislabeling Report

 

Sources: 1. The Hindu/Business Line.  Now, A Tool to Check Shrimp Mislabeling T.J. Jayan.  July 5, 2017.   2. Food Chemistry.  A Single Enzyme PCR-RFLP Protocol Targeting 16S rRNA/tRNAval Region to Authenticate Four Commercially Important Shrimp Species in India.  Lidiya Wilwet, Geevaretnam Jeyasekaran (Email jeyasekarang@gmail.com, Department of Fish Quality Assurance and Management, Fisheries College and Research Institute, Tamil Nadu Fisheries University, Thoothukkudi 628 008, India), Robinson Jeya Shakila, Balasubramanian Sivaraman and Pandurengan Padmavathy.  Prepublication!  Volume 239, Pages 369-376, January 15, 2018.