Variation of native agar gel strength in light deprived Gracilaria chilensis Bird, McLachlan et Oliveira

摘要

Wild-grown Gracilaria chilensis subjected to a post-harvest period of light-deprived culture prior to extraction gave native agar with greatly improved gel strength. Two quite different sets of post-harvest seawater nutrient and motion conditions gave the greatest improvements in gel strength. Gel strengths of dialysis/freeze-thaw purified native agars (711-912 g cm(-2) for a 1.5 % w/w gel) compared favourably with those of a commercial bacteriological agar (645 g cm(-2) for a 1.5 % w/w gel). Such a post-harvest light deprivation regime might be a practical, environmentally friendly alternative to the chemical processing (alkali treatment) currently necessary for the production of food grade agar from Gracilaria chilensis.