【作者】 宋彩霞；

【导师】 陈美珍；

【作者基本信息】 汕头大学 ， 生物化学与分子生物学， 2010， 硕士

【摘要】 本文首次对种植于广东省汕头南澳岛的海水蔬菜海蓬子进行了研究,分析了海蓬子嫩茎和种子的营养成分,优化了嫩茎多糖提取工艺,并对提取的多糖进行了分离纯化和红外光谱分析,研究了嫩茎的体外抗氧化作用、减肥降血脂作用等生理活性及其食用安全性。营养成分分析结果表明:新鲜海蓬子嫩茎粗蛋白、粗脂肪、粗纤维、总糖、多糖、灰分含量（%）分别为:1.34、0.28、0.76、1.28、0.39、3.42,维生素C、β-胡萝卜素和矿物元素等含量高于普通蔬菜,且富含人体八种必需氨基酸和鲜味氨基酸,叶绿素含量高达44.29mg/100g,其营养价值高且味道鲜美;海蓬子种子蛋白质（34.01%）和油脂（23.79%）含量都很高;种子蛋白质氨基酸种类齐全,含有八种必需氨基酸,籽油富含不饱和脂肪酸,尤其是亚油酸含量高达70.62%,并含有丰富的维生素E,其营养价值相当高。海蓬子嫩茎重金属镉、汞、铅和砷的含量分别为:0.072、<0.01、0.0279、0.0099（mg/kg）,均低于国家相关标准,符合食品卫生要求。急性毒性试验结果表明:海蓬子嫩茎LD50>464g/kg,属实际无毒类（LD50>10g/kg）蔬菜,其食用安全。海蓬子嫩茎多糖提取工艺条件优化结果为:水料比48:1,提取时间4.0h,提取温度90℃,在该条件下最大提取得率预测值为2.01%。采用DEAE-52阴离子交换层析和Sephadex G-25柱层析对多糖进行分离纯化得到两个单一的多糖组分apex-Ⅰ与apex-Ⅱ,apex-Ⅰ为双蒸水洗脱组分,apex-Ⅱ为1mol/L NaCl溶液梯度洗脱组分。经红外光谱图分析,初步推测apex-Ⅰ是具有β-D-吡喃葡萄糖与α-D-吡喃木糖结构的中性多糖,apex-Ⅱ是含有硫酸基与α-D-吡喃半乳糖结构的酸性多糖。海蓬子嫩茎提取物体外抗氧化实验结果显示:海蓬子水提物、醇提物及水提多糖都具有一定的还原能力和抗氧化作用,作用效果均低于对照物维生素C,其中水提物的还原能力和清除·OH能力都比醇提物强,但未显示清除O₂^-·的活性;海蓬子粗多糖和精多糖均有清除·OH的作用,一定浓度范围内,粗多糖活性比精多糖强,但均无清除O₂^-·的活性。以营养肥胖模型小鼠进行减肥实验,结果显示:海蓬子嫩茎能显著抑制肥胖小鼠体重的增加,减轻体内脂肪质量,减小脂肪细胞的体积,具有较好的减肥效果。分别采用海蓬子茎汁、茎渣和全茎对高脂血症肥胖模型大鼠进行减肥降脂实验,结果表明:与模型组相比,全茎的减肥作用最强,能极显著地抑制大鼠体重增长（p<0.01）、降低肥胖指数（p<0.01）、降低脂肪指数（p<0.01）和减小脂肪细胞体积;此外,全茎的降血脂效果也是最好,可显著降低TG （p<0.05）、TC（p<0.01）含量和升高HDL-C的水平（p<0.01）。可见,海蓬子嫩茎具有较好的减肥和降血脂功效,以全茎作用效果最好。更多还原

【Abstract】 In this paper, sea vegetable Salicornia cultivated in Nanao Island, Shantou, Guangdong Province, was studied for the first time。The main nutritional composition of the stem and seeds from Salicornia was analyzed, the extraction technology of polysaccharides from Salicornia stem was optimized, the polysaccharide was purified, and the purified polysaccharides were analysed preliminarily with FTIR, the function on in-vitro anti-oxidative, anti-obesity and reducing blood lipid were also investigated.Nutritional analysis showed that: the content of the crude protein, crude fat, crude fiber, total sugar, polysaccharides and ash from fresh Salicornia stem were 1.34, 0.28, 0.76, 1.28, 0.39, 3.42% respectively, the fresh stem was also rich in vitamin C,β-carotene, minerals and other nutrients, and was rich in eight essential amino acids and delicious amino acids, the content of Chlorophyll was up to 44.29mg/100g; the protein （34.01%） and oil （23.79%） contents from the seeds were rich, the protein was included kinds of amino acids, containing eight essential amino acids, the oil was rich in unsaturated fatty acids（UFA）, especially in linoleic acid （70.62%）, and was rich in vitamin E, the nutritional value was rather high.The content of cadmium, mercury, lead and arsenic of Salicornia stem were: 0.072, <0.01, 0.0279, 0.0099 （mg/kg） respectively, which were lower than national standards, complied with food hygiene requirements. Acute toxicity test results showed that: Salicornia stem （LD50>464g/kg） was one kind of nontoxic （LD50>10g/kg） vegetable, it is safe to eat.The optimum extraction conditions were obtained as ratio of water to material of 48:1, extraction time of 4.0h, extraction temperature of 90℃, under which the theoretically predicted yield of polysaccharides was 2.01%. Two single polysaccharides apex-Ⅰand apex-Ⅱwere isolated and purified by DEAE-52 and Sephadex G-25 column chromatography, apex-Ⅰwere double-distilled water washed fractions, apex-Ⅱwere NaCl gradient washed fractions. By Fourier Transform infrared spectroscopy （FTIR）, apex-Ⅰwere speculated one kind of neutral polysaccharides withβ-D-glucopyranose andα-D-xylopyranosyl, apex-Ⅱwere speculated one kind of acidic polysaccharides contained sulfate andα-D-Galactosidase.The In-vitro anti-oxidative function of the extracts from Salicornia stem were showed that: the water extract, ethanol extract and water extracted polysaccharide had a certain reducing capacity and anti-oxidative effect, which were lower than the capacity of the control, vitamin C, the reducing power and the ability to Scavenging hydroxyl free radical （?OH） of the aqueous extract were stronger than the alcohol extract, but the aqueous extract did not show Scavenging superoxide anion free radical (O₂^-·) activity; The crude polysaccharides and purified polysaccharide also showed reducing capacity and the ability to Scavenging ?OH to some extent, while the activity of the crude polysaccharides was stronger than the purified polysaccharides, but both of them didn’t show some scavenging O₂^-· activity.The result of the salicornia stem’s anti-obesity function on the nutritive obses mice experiment showed that: Salicornia stem significantly inhibited the increase in obses mice body weight, reduced body fat mass, reduced fat cell size, had a good anti-obesity function. The stem juice, stem residue and the whole stem were used for anti-obesity and lipid-lowering experiments on obese rats, the results showed that: Compared with model group,the whole stem group had the best anti-obesity activity, could significantly inhibit body weight gain （p<0.01）, lowering body mass index （BMI） （p<0.01）, lowering body mass index （p<0.01） and decreased the fat cell volume; In addition, compared with the model group, the lipid-lowering effect of the whole stem was the best, it could significantly reduce the TG （p<0.05）, TC （p<0.01） levels and increased HDL-C levels （p<0.01）. These results indicated that Salicornia stem had a good anti-obesity and lipid-lowering effect, the whole stem could gat a best effect.更多还原