乾のりの変質におよぼす水分,温度の影響

抄録

The influences of moisture content and storage temperature on the degradation of chlorophyll and biliprotein in dried laver, Phorphyra yezoensis, were studied. Moisture content was adjusted to the desired levels by holding samples over saturated salt solutions. The BET (Brunauer-Emmett-Teller) monolayer values of the laver were 5.5%, 5.6% and 5.7% at 40°C, 30°C and 20°C, respectively. Better quality retention of the laver was obtained at lower moisture content. At moisture content lower than 4.8% at 40°C, the rate of chlorophyll degradation was very low, but, at more than 6.5% moisture, the rate increased much. The critical moisture levels to the degradation rate were 5.7-7.3% at 30°C and 7.2-8.9% at 20°C, respectively. The rate of biliprotein degradation was lower than that of chlorophyll, while the critical moisture levels were almost the same. The optimum moisture content for the stability of the laver was defined to be 4-5%, leaving a safety margin of 1-2% moisture.