摘要
本文分析了10种22份中国产江蓠样品碱处理前后所得琼胶的产率、凝胶强度、凝固点,融点、粘度及其硫酸基、半乳糖和3.6-内醚半乳糖的含量,为筛选适宜的种类作制造琼胶的原料提供依据。未经碱处理看,凝胶强度都很低,达不到商品要求。碱处理后,真江蓠、龙须菜和细基江蓠三种的凝胶强度大幅度上升,产率亦高,是极好的制造琼胶的原料。
The purpose of this experiment is to study the effect of the alkali treat-ment on the yield and properties of agar extracted from Chinese Gracilaria and toselect the suitable species of Gracilaria as raw materials for the production of agar.Specimens of Gracilaria were treated with 32% NaOH at room temperature for 5 days.Using this cold concentrated alkali method, 10 species of Gracilaria which were collectedin China were studied. The agar yield, properties and chemical composition before andafter alkali treatment are shown in table 1, and the infrared spectra are shown in figs1,2 and 3. The main results obtained are summarized as follows: 1) Agars extracted with sodium hexametaphsphate afterr alkali treatment were muchbetter than those extracted with water. The agar yield from G. asitica was 27.6-31.3%, G. tenuistipitata was 14.0-39.5%, G. sjoestedtii 22.4-27.8%, G. haina-nensis 8.6%, G. articulata 19.1% G. chorda 15.4% G, textorii 21.6%, G.euche-umoides 31.7%, G. blodgettii 27.6% and G. sp.42.6%, respectively. 2) The Gel strength of agar extracted with (NaPO_?)_? after alkali treatment were:G. asiatica 234-1025g/cm^2, G. tenuistipitata 329-1035g/cm^2, G. sjoestedtii 375-855 g/cm^2, G. hainanensis 130 g/cm^2, G. articulata 87g/cm^2, G. chorda 376g/cm^2,G. textorii 10g/cm^2, G. eucheumoides 38 g/cm^2, G. blodgettii 323 g/cm^2 and G. sp.923 g/cm^2. 3) According to the results of agar yield and gel strength, G. asiatica, G. tenuistipitata and G. sjoestedtii are considered to be the better raw materials for agarproduction to other species of Gracilaria ever studied. 4) The gelation and melting temperature of agar after being treated by alkaliwere increased while the viscosity decreased. 5) The 3,6-AG content of agar isolated. from alkali-treated Gracilaria was higherthan those without alkali treatment, and the reverse relation was observed about thesulfate and galactose content. The increase of gel strength lay in the extent of thesulfate decreased and the 3,6-AG increased. 6) The effect of the alkali treatment on t
出处
《水产学报》
CAS
1988年第2期145-155,共11页
Journal of Fisheries of China
