Study on biochemical divergences of the meat and egg of freshwater prawns (Macrobrachium rosenbergii)

Abstract

Aquaculture of freshwater prawn (Macrobrachium rosenbergii) is an important fishery sector in Asian countries. The biochemical characteristics including proximate compositions and taste components of cultured freshwater prawns were analyzed for different gender and their egg. Freshwater prawns contained moisture ranging from 77.51% to 78.37%, protein with 19.56 to 19.91%, and low levels of lipid and ash around 0.2 and 1%, respectively. The moisture and protein contents of egg samples (72.82 and 15.61%, respectively) were lower than meat samples, whereas for the lipid content, it was otherwise significantly higher than the meat samples. The male and female meat samples of freshwater prawns were rich in free amino acids (FAAs), namely 1756 to 1725 mg/100 g with arginine, proline, glycine, glutamic acid, lysine, alanine, and taurine being the predominant compounds. On the contrary, the FAA amount of egg (590 mg/100 g) was remarkably lower than meat samples. The ATP-related compounds in freshwater prawn meat ranged from 8.26 to 8.80 mu mole/g, majorly composed of adenosine diphosphate (ADP), adenosine triphosphate (ATP), adenosine monophosphate (AMP), and inosine 5'-monophosphate (IMP). The ATP-related values in egg sample (28.33 mu mole/g) were significantly higher with IMP (18.48 mu mole/g) and AMP (5.44 mu mole/g) being the predominant compounds. The pH values of male and female meats were neutral, whereas this value in egg sample was acidic (6.5). Urea content in egg sample was detected at huge value (58.35 mu mole/g), whereas it was not detected in meat samples. These findings have established useful information for product developers to utilize the meat and eggs of freshwater prawns. In addition, the assessment of FAAs, ATP-related compounds, and quality index (pH and urea content) was also established to give fundamental criteria to evaluate the quality of fresh M. rosenbergii.