Effects of Water Activity on Pigments in Dried Laver (Porphyra) during Storage

Abstract

Degradation of chlorophyll, carotenoids, and phycobilins in dried laver (Porphyra) was studied during storage at water activities (Aw) of 0.112, 0.316, 0.484, 0.747, or 0.890 in the dark at 40 degrees C for 15 days. The chlorophyll, carotenoid, and phycobilin contents were determined using HPLC and spectrophotometry. The chorophyll a, carotenoid, and phycobilin contents in dried laver decreased with storage time in the dark, and degradation was increased and accelerated as the Aw value increased. Among pigments, chlorophyll a was degraded at the highest rate, and differences in degradation rates among pigments became greater as the Aw value increased. Phycoerythrin was more stable than phycocyanin. Changes in the Aw value affected degradation of phycocyarrin and chlorophyll more than phycoerythrin or carotenoids. Control of the Aw value can improve the color stability of dried laver in the dark.