几种红藻琼脂的组分结构及理化性质的比较

以我国3种经济红藻龙须菜、石花菜、坛紫菜为原料，对高温稀碱法、常温浓碱法和无碱法提取的琼脂进行理化性质和化学组分结构方面的横向比较。结果表明，所提取琼脂的主要组分均为无取代的琼脂糖；凝固温度与甲氧基的取代位置及含量有关；我国3种琼脂海藻均为优质的琼脂原料；提取琼脂时，石花菜不用碱处理，龙须菜和坛紫菜则必须经过碱处理；从灰分和硫酸基含量角度分析，石花菜琼脂优于坛紫菜琼脂后，后者又优于龙须菜琼脂。

COMPARATIVE RESEARCH ON THE STRUCTURES AND PHYSICAL-CHEMICAL PROPERTIES OF AGARS FROM SEVERAL AGAROPHYTA

Agars were extracted from Gracilaria lemaneiformis, Gelidium amansii, Porphyra haitanensis and Ahnfeltia sp. by different methods. In order to provide some theoretic guidance for preparing high quality agars suitable for different usages, comparative studies on their structures and physico chemical properties are carried out.The results show that the main constituent of each sample is unsubstituted agarose. Gelling temperature is affected by the location and quantity of OCH 3 substituent. The three economic agarophyta in China are all high quality resources of agar. Before extraction, the alkali pretreatment is unnecessary for Gelidium amansii , but it is essential for Porphyra haitanensis and Gracilaria lemaneiformis . In terms of the ash and sulfate content, agar from Gelidium amansii is better than from Porphyra haitanensis , with the latter being is better than from Gracilaria lemaneiformis .