Biochemical evaluation with reference to nutritional aspects of edible species of crabs collected from the coastal waters of Pakistan.

• Nutritional composition of edible crab species from coasts of Pakistan analyzed. • Vitamins, minerals and amino acids were quantified in these crabs. • Protein contents were higher in S. serrata than other crab species. • These crab species are rich in nutrients (amino acids, vitamins and minerals). The commercially important edible crab species from Pakistani waters are Portunus pelagicus, Portunus sanguinolentus, Scylla serrata and Charybdis feriatus. The present study has been designed to investigate the nutritional composition of edible crab species including proximate composition, vitamins, minerals and amino acids content. Among all the species, fat content were found at low levels (0.25 %–1.86 %), however, the protein content was higher in hard shell crab (S. serrata), i.e. 23.3 %, than those in soft shell crabs (P. pelagicus, P. sanguinolentus and C. feriatus), 16.4 %, 14.2 % and 15.1 %, respectively. Energy value was high in S. serrata (107 kcals/100 g) whereas C. feriatus recorded the lowest value (65.5 kcals/100 g). In terms of amino acid profiling a total of eighteen amino acids were detected from which arginine (19.0 mg/100 g in S. serrata and 9.98 mg/100 g in P. sanguinolentus) and lysine (0.15–6.53 mg/100 g) have shown the highest values with variations in all crab samples. Of the seven minerals examined, calcium was the highest ranging between 292 ppm and 513 ppm followed by zinc (15.7 ppm–47.4 ppm) in all four crab species. Among the vitamins, niacin (Vit B3) recorded the highest value ranging between 16.9 mg/100 g and 49.2 mg/100 g followed by thiamine (Vit B1) and ascorbic acid (Vit C) in all crab samples. The results showed that the crabs contained appreciable amounts of nutrients. The present study findings revealed that the mud crab S. serrata has higher values of nutrients in terms of protein, amino acids, vitamins and minerals than other species. [ABSTRACT FROM AUTHOR]