Shrimp Quality Index

The guidelines for the assessment of quality or freshness of shrimp associated with the changes in the sensory based quality attributes such as shell appearance, shell meat adherence, meat appearance, meat texture, meat colour and odour; and brief description on the instructions to be followed while evaluating or assessing the quality or freshness of shrimp with respect to the quality attributes are given below. Care must be taken to evaluate physically undamaged shrimp and to avoid physically damaged shrimp while evaluating the quality or freshness of shrimp.

The developed Shrimp Quality Index (SQI) ranges from 0 to 1, where 0 represents shrimp with excellent/ best quality and 1 represents shrimp with bad/ worst quality.

1	SHELL APPEARANCE	Fresh shrimp is bright and shiny but the gloss of its shell drops as the meat spoils, effecting in blackening and discoloration on the surface. Accordingly, examine the surface of the shrimp and give appropriate score based on the appearance of shell surface.
2	SHELL MEAT ADHERENCE	Initially, meat of fresh shrimp maintains a firm adherence. But as freshness or quality of shrimp drops, the meat slowly loosens and detaches from the shell, eventually resulting in weak adhesion, and the meat gets separated from the shell easily. Correspondingly examine the shell meat adherence of shrimp and give suitable score based on degree of adherence of the meat to the shell.
3	MEAT APPEARANCE	Shrimp meat in its fresh state is opaque initially, but the opacity of the meat diminishes and exhibits translucent or bleached nature over time. Based on this, examine the appearance of shrimp meat and give the appropriate score depending on the level of opacity of shrimp meat.
4	MEAT TEXTURE	Fresh shrimp exhibits strong elasticity and is rigid and firm. But, the elasticity of meat falls and softens relative to freshness. So, examine the texture of shrimp meat and give appropriate score by gently checking the rigidness or firmness of the shrimp meat.
5	MEAT COLOUR	First sensory changes that occur in fresh shrimp is related to its appearance. Initially, fresh shrimp shows white/ light grey/ pinkish colour without black spots. But as quality changes shrimp exhibits discolourations and black spots. Correspondingly, examine the colour of shrimp meat and give appropriate score.
6	ODOUR	Fresh shrimp exhibits fresh seaweedy odour. Gradually, owing to freshness change, shrimp exhibits slightly seaweedy, neutral or fishy odour. Accordingly, smell the shrimp and give an appropriate score based on the odour.