Rays, belonging to the class Elasmobranchii, constitute a major fishery in many states in India
like Tamil Nadu, Gujarat, Andhra Pradesh, Kerala and Maharashtra. The estimated landings are
21,700 tonnes per annum. Even though the meat of rays is nutritious and free from bones and spines,
there is little demand for fresh meat due to the presence of a high urea content. The landings are
mainly used for salt curing which fetches only very low prices for the producers.
Urea nitrogen constituted the major component (50.8%) of the non-protein nitrogen of the
meat. An attempt has been made to standat-dize the processing steps to reduce the urea levels in the
meat before freezing by using different simple techniques like dipping the fillets in stagnant chilled
water, dipping in chilled running water and dipping in stirred chilled running water. It was found
that meat dipped in stirred running water for two hours reduced the urea level of the meat by 62%.
The yield of the lateral fin fillets and caudal fin fillets vary with the size of the ray. The drip loss
during frozen storage is found to be more in the case of samples frozen stored after the treatment for
urea removal by the method of stirring in running water. The samples treated in stagnant chilled
water had the lowest drip loss. The total nitrogen was higher in samples treated in stagnant chilled
water and lowest in the samples treated in stirred running water. The overall acceptability was high
in the case of samples treated with stirred running water and frozen stored