• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.5
• /
• pp.489-494
• /
• 2014

This study determined the effect of packaging and electron beam irradiation on the quality of dried Undaria pinnatifida. Samples were air or vacuum packaged and irradiated at 7 kGy. The dried Undaria pinnatifida had total viable cells and coliform counts of 5.51 and 4.40 log CFU/g in total, respectively, and counts of 5.56 and 4.19 log CFU/g in surface. These counts were reduced by 2-4 log cycles after irradiation. Irradiation increased the lightness and yellowness of the dried Undaria pinnatifida, but not the redness. In the sensory evaluation, there were no significant differences among samples. Therefore, electron beam irradiation improves the microbial safety and quality of dried Undaria pinnatifida.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.14 no.3
• /
• pp.165-170
• /
• 1981

Recently an unknown microbial desease and some parasitic crustaceans are prevailing in the sea-weed farms of Uudaria pinnatifida along the south-eastern coast of Korea.(1) Green spots probably caused by the microbial pathogens were found on the fronds of Undaira Pinnatifide. Particularly they were densely distributed on the distal half of the fronds. The tissues of the green spot area rot off, and small holes with green colored margin are formed. The holes at the distal part of the fronds are enlarged and they finally coalesced each other. Then this process accelerates decaying of the distal ends of the fronds.. The fronds growing in the central part of the farms are usually severely damaged, whereas in the marginal area of the farm toward the open sea side the damage is less serious. An examination revealed that the deseased fronds bore a number of viable bacteria, $6.8\times10^5\;to\;1.2\times10^6$ per gram at $15^{\circ}C$, whereas the healthy fronds $1.1\times10^4$. Twenty-six kinds of colonies, 247 strains of bacteria, were isolated from deseased fronds, belonging to Moraxella, Achromobacter, Vibrio, Flavobacterium, Acinetobacter, Pseudomonas, etc. (2) Pinholes occurred in one series on the frond. They were probably caused by a harpacticoid copepod, Thalestris sp. Seven years ago when the disease was first found to occur the copepod was observed on the fronds from March of the year. Recently, however, they have been found as early as December of the previous year. (3) A gammarid amphipod, Ceinina iaponica, invades the pith of the midrib through holdfast of thalli. This rarely causes the longitudinal seperation of the entire frond through the midrib as they bore a tunnel in the pith. Sometimes holdfasts of tile heavy damaged thalli make the frond departed from the substrate.