末水残次坛紫菜的营养成分及多糖组成分析

摘要

Porphyra haitanensis is an important food resource containing abundant dietary fiber,protein,active substances and trace elements essential for the human body.P.haitanensis is always be harvested for several times during its life cycle.P.haitanensis at the sixth harvest is known as low-value P.haitanensis due to inferior sensory quality,poor palatability and low commercial value.Here,the main nutritional composition and polysaccharide composition of low-value P.haitanensis were analyzed by chemical methods and spectroscopic methods.Compared with high-yield P.haitanensis at the third harvest,low-value P.haitanensis showed a remarkable increase in the contents of crude protein（35.30%）,crude fat（0.51%） and crude fiber（5.11%）,a dramatic decrease in the contents of total sugar（34.57%） and polysaccharides（20.67%）,a similar ash content（10.37%） and a K/Na ratio of 6.3.Hot-water polysaccharide extract from low-value P.haitanensis consisted of a single component with a 28.54 kD molecular weight,which was mainly constituted by galactose（83.12%）,3,6-anhydrogalactose（15.71%） and sulfate group（10.61%）.In summary,the results obtained show that low-value P.haitanensis is a high-protein,high-natural dietary fiber,low-fat,low-calory nourishing healthcare food resource.%为有效利用残次（即末水）坛紫菜资源,采用化学和光谱分析等方法对残次坛紫菜的主要营养成分及多糖组成进行分析。结果表明：与盛产的三水坛紫菜比较,残次坛紫菜粗蛋白（35.30%）、粗脂肪（0.51%）和粗纤维（5.11%）的含量明显增加,而总糖（34.57%）和多糖（20.67%）含量均显著减少,灰分（10.37%）含量变化不大,矿物元素K/Na值为6.3;残次坛紫菜热水提取多糖为单一组分（分子质量28.54kD）,其主要由半乳糖（83.12%）、3,6-内醚半乳糖（15.71%）和硫酸基（10.61%）组成。残次坛紫菜是一种高蛋白、高膳食纤维、低脂肪、低热能天然营养保健食品。