Biomass Measuration And Analysis Of Nutrient Components Of Leaf-Oriented Tree Model Of Bronssonetia Papyrifera

This article is concerned with biomass measuration for Bronssonetia Papyrifera and analysised the nutrition ingredient of the leaves, and studied extraction technology for leaf polysaccharides and leaf protein and evaluated the nutritive value of this leaf protein. In order to provide theory basis for the comprehensive exploitation and utilization of the Bronssonetia Papyrifera leaves resources. This thesis will summarize several main conclusions as follows:(1) The investigation results showed that the aboveground biomass was the32869.32kg/hm2, biomass of stem、bark、leaves was24737.36kg/hm2、5748.62kg/hm2、2383.33kg/hm2, respectively, and the stem biomass was the highest. The breast diameter、 ground diameter tree high and under branch high were normal distribution, showed a tidy of forest. Breast diameter ground diameter and tree high were showed linear correlation, and the biomass of every component of Broussonetia(W) to the square of breast diameter(D2) and tree height (H) product (D2H) related to normal distribution. The analysis of the nutrition ingredient of the leaf, the result showed that nutrition contents, mineral elements, vitamin is various and high. Leaf polysaccharide and leaf protein content were7.02%and16.9%.(2) To extract polysaccharide from Broussonetia leaves, by the single factor experiments, effects of extraction time, extraction temperature and ratio of material to water on the yield of polysaccharides were studied. Next, on the basis of this and according to the Box-Benhnken design principles, the method of response surface analysis with3factors and3levels was adopted. The results showed that the optimum conditions of Broussonetia leaves polysaccharide extraction were:ratio of material to water of1:29.13,extraction time of1.58h, and the extraction temperature of79.65℃, and on these conditions the leaves polysaccharide extraction rate was up to6.914%. The polysaccharide product analysised by gas chromatography after being hydrolysised, the result showed that the leaf polysaccharide contained monosaccharide composition includes the rhamnose, the arabinose, the mannitose, the glucose, the galactose in the percentage of4.05:2.62:1.74:1:1.43.(3) By the single factor experiments and the Box-Benhnken center-united experimental design principles. The optimum extracting conditions were determined by means of regression analysis. Response surface and contour were finally graphed with the extraction rate of leaves protein as the response value. The results showed that the optimum conditions of Broussonetia leaves protein extraction were as follows:pH is4.0, extraction time of1.70hour, ratio of material to water of1:31.54g/ml, extraction temperature54.15℃, sodium chloride of0.2mol/l. Under these conditions, the extraction rate was up to36.93%. The effects of different decolorization factor were studied in this article, such as activated carbon, macroporous resin and organic solvents. The result of decolorization tests showed that the absolute ethyl alcohol on Broussonetia leaf protein decolorization was more useful. So used IE-salting to precipitae leaves protein, with the absolute ethyl alcohol in decoloring, dialysis in addition to salt, and finally got shallow gray protein products.(4) Using amino acids automatic analyzer analysised the amino acid contents of the leaf protein and others the nutrition ingredient. Based on the analyses of the protein and amino acid contents of Broussonetia leaf protein, The total ratio of Amino acid was41.32%, The ratio of essential amino acids contents to total amino acid contents was37%, The ratio of essential amino acids contents to non-essential amino acids contents was0.59, nearly the WHO/FAO stander40%and0.6respectively. According to the theory of amino acid balance which was a new one designed to evaluate nutritional value of protein, the SCR was83.36of this leaf protein. The amino acids proportion of the Broussonetia leaf protein was considered to be fine, and might have a certain nutritional value.