1Department of Food Science and Technology, Faculty of Marine Science, Tokyo University of Marine Science and Technology, Minato, Tokyo 108-8477, 2Iwate Fisheries Technology Center, Kamaishi, Iwate 026-0001, Japan.
There was a negative correlation between water activity (aw) and NaCl content/moisture of boiled and salted Uudaria pinnatifida and Laminaria religiosa. Boiled and salted Uudaria pinnatifida processed by the recommended method to prolong the shelf life showed aw of 0.76 and NaCl content of 18.0%. It should be possible to evaluate sodium chloride content and water content by aw analysis. To shorten the processing time and to obtain uniform quality of seaweed products, the salting method in saturated solution was performed in this study. It took 48 hours and 18 hours to obtain sufficiently low aw of salted U. pinnatifida and L. religiosa by soaking in saturated NaCl solution. With mechanical stirring of the saturated NaCl solution for treating the seaweeds, only 1 hour was required to reach aw of 0.75. This salting method with stirring will shorten the salting time, and enable safe products to be provided.