Nutrient analysis and value addition of underutilized fish

Abstract

Fish contains the best proteins and other superior nutritional constituents that place them in a specially important category of food. It has very poor shelf life. Hence, the present study on nutrient analysis and value addition of under utilized fish was aimed at evaluating the nutrients and developing products from three under utilized fish varieties namely netholi (Stoliphorus heterolobus), flat fish (Cynoglossus macrostorus) and veluri (Kovala kova/). This will help in meeting the increasing demand for fish; to avoid wastage of small fish and to provide income to the fisher women. The fresh and dried fish varieties were analysed for chemical constituents like moisture, fat, protein, calcium, phosphorus, iron, vitamin A and peroxide value. Fish was found to be rich sources of protein, calcium and phosphorus. Chemical constituents varied significantly between the varieties. The dried fish was packed in polythene covers and was stored for a period of three months. The peroxide value increased during the storage but the increase was not significant. Dried netholi had the highest peroxide value throughout the storage period. The organoleptic qualities decreased during storage. The change of organoleptic scores was not significant; veluri had the highest acceptability throughout the storage period. Microbial enumeration revealed that bacterial population increased I slightly during storage and fungus was found only in second and third month of storage. No traces of yeast were found throughout the storage period. The pickle prepared from fresh and dried fish was stored in glass bottle and polyester laminated HDPE film for a period of six months. The peroxide value of the pickle increased during the storage but the increase was insignificant. The acidity of the pickle increased significantly. The pickle stored in flexible packaging material had higher peroxide value and acidity than pickle stored in glass bottle. Dried fish pickle had higher peroxide value and acidity than fresh fish pickle.

The organoleptic evaluation of pickle revealed that appearance and colour decreased during storage. The flavour texture, taste and overall acceptability of pickle increased during storage. Changes in organoleptic scores except appearance were insignificant. Appearance decreased significantly. The pickle stored in glass bottle had better acceptability than pickle stored in polyester laminated IIDPE film, but the variation was insignificant. The fresh fish pickle had better acceptability and among them veluri pickle was found to be the best. A gradual increase in the bacterial and fungal load with storage of pickle was observed but yeast was not found during the storage. The benefit cost analysis showed that all products had BC ratio above one hence, all are economically beneficial.