World Aquaculture Singapore 2022

November 29 - December 2, 2022

Singapore

GRADING STRATEGIES FOR MANGROVE CRABS

Mark Richards1

 

School of Chemical & Life Sciences, Nanyang Polytechnic1

180 Ang Mo Kio Ave 8

Singapore 569830

Mark_Richards@NYP.EDU.SG

 



 Crustacean  farmers, wholesalers, restaurant owners, and consumers can all benefit from a data-driven method to ascertain the meat quality of crustaceans. In South-East Asia’s context, the mangrove crab, Scylla serrata is an important commercial seafood species. Mangrove crab is the basic ingredient of one of Singapore’s most iconic dishes: the Chili Crab. In recent years, the supply of adult mangrove crabs has been adversely affected, both in terms of price and in quality. Soaring prices and the lack of good-quality crabs is causing supply to fall behind demand. These disruptions have placed a serious dampener on the business. It is important to be able to distinguish meaty crabs from lean crabs. The meat yield of individual crabs can vary from filled high-quality crabs to empty water-filled crabs. Only a portion of the catches, depending on season and geographical area, are of good quality. Crabs with high meat content have a higher value and can be sold live or cooked whole at restaurants. Medium quality crabs are generally limited to being used as raw material by the processing industry. A correct quality sorting of live crabs is essential to optimize this logistics. The current methods adopted by the industry to assess crabs such as “pressing carapace”, “looking at shell color ”, “checking if claws are worn out” and “looking at moon phase to plan harvest time” are inadequate as they are very empirical. These methods often lead to errors in ascertaining whether a crab is suitable for the restaurant. A practical, portable, simple, rapid, and non-invasive technique to analyze crustacean nutritional condition has enormous potential to assist with the management of wild stocks, improve post-harvest survival and quality control, and manage brood stock as the aquaculture industry continues to expand to meet growing consumer demand.

 We evaluated several grading approaches for sorting Mangrove Crabs in this study. Particularly, the use of a  portable Near Infrared Spectroscopy

 (NIRS) approach for grading mangrove crabs proved to be easy-to-use, rapid, and reliable.