Effects of Sodium Chloride and Ethanol Concentrations on Ripening of Salted Sea Urchin Gonads

Abstract

The effects of sodium chloride (4-10%) and ethanol (8-12%) concentrations on ripening of salted sea urchin gonads were investigated. The viable cell count of salted gonads decreased to a level of below 10³ per g from 4.9×10⁴ of fresh gonads during 1 month of ripening and did not change during storage of 12 months. It was suggested that the changes in components of salted gonads during ripening may be attributable to enzymes of sea urchin gonads rather than to those of microorganisms. The salted gonads softened gradually with ripening. The pH of salted gonads was in the range of 6.0 to 6.5 throughout ripening. The changes in the firmness of salted gonads and pH were independent of sodium chloride and ethanol concentrations. The total and reducing sugars in the extracts increased with lowering of the concentrations of sodium chloride and ethanol added throughout ripening. The total and amino nitrogen contents in the extracts increased slowly during 12 months of ripening. The amount of volatile base nitrogen (VBN) in the extracts increased with lowering of the sodium chloride and ethanol concentrations. The VBN of good-tasting salted gonads was determined to be in the range of 20 to 50 mg/100g.