Studies On Extraction Of Nutrients From Bashan Boletus Edulis

Boletus edulis, an mycorrhizal fungi, also called"dajaogu"; it is popular with people all the world for heavy flavor and delicious testing; it is a kind of fungus with high edible value. Taking the edible fungi Bashan Boletus edulis as material, this research established the methods for the quantitative determination of Boletus edulis Polysaccharides , and its components analysis was conducted firstly. Secondly, the optimum technological parameters of extracting conditions for nutrient composition were investigated. Finally, the methods for the quantitative determination of Boletus edulis volatile flavor were established, and extracting conditions for volatile flavor and its components were studied. The conclusions of this research were as follows:1. The methods for the quantitative determination of active components poly-saccharide in Boletus edulis were established. Phenol-sulfuric acid method is a commonly used method for measuring polysaccharides. However, many factors affect the colored conditions and different types of polysaccharides have different colored conditions. In this test, color metric method for the determination of polysaccharides in boletus was developed by the use of phenol-sulfuric acid and optimized by orthogonal experimentations. The results showed that under the optimal conditions were as follows: time 25min, temperature 70℃, phenol 0.2ml and sulfuric acid 8.0ml. This method was rapid and accurate with good reproduci-bility, and the average recovery and the relative standard deviation were 99.0% and 3.70% respectively.2. Components analysis of Boletus edulis. Among the extract of Boletus edulis, the protein, crude fat, ash, polysaccharide, carbohydrate accounted for 31.81%, 4.30%, 7.37%, 3.52%, 47.13% of dry weight, respectively. In addition, the extract of Boletus edulis was rich in metal elements, including calcium(382.5 mg/100g) , magnesium(221.6 mg/100g) , zincum (12.4mg/100g) , iron(21.3mg/100g). They were poor in deleterious heavy metals, for example, plumbum (0.082mg/100g). Consequently, Boletus edulis was a high protein, low fat edible fungus which contained many kinds of volatile sweet matters, mineral substances and active polysaccharide.3. Studying of extracting conditions for nutrient compositions from Boletus edulis. The optimal processes of water extraction, alkaline extraction and enzymatic extraction were discussed. Compared with water extraction, alkaline extraction and enzymatic extraction had an increase the extraction rate of soluble solids more than doubled. Solution of enzymatic extraction had no less soluble protein than alkaline extraction's, and other indicators were greater than alkaline extraction's; in addition, solution of alkaline extraction had darker color and greater impact on the flavor, therefore, enzymatic extraction was selected finally.4. The methods for the relative content determination of volatile flavor in Boletus edulis were established. Selected in the 540nm wavelength, there was a good linear relationship between the relative content of volatile flavor distillate and ab-sorbance, so this method was simple and had a certain reference.5. Studying of extracting conditions for volatile flavor from Boletus edulis. The optimum extracting conditions were as follows: 50g of raw materials was crushed to 100 head, solid-liquid ratio was 1:15, and it was extracted for 2 hours in 2L flask by steam distillation. Under these conditions, 60mL of volatile flavor distillate volumed to 100mL, and then its OD value which was 0.293 was measured.6. GC/MS analysis of volatile flavor from Boletus edulis. 40 kinds of volatile components from Boletus edulis were separated and detected, the main components were 1-Octen-3-ol (21.39%) and 1-Octen-3-one (13.85%), (E) -2-Octen-1-ol (7.61%) and acetophenone (6.86%) were followed.7. Comparing the result of using different extraction programs which were plan I was to extract nutrients first and then recover the volatile flavor and plan II was to extract the volatile flavor first and then nutrients from Boletus edulis, we can founded, compared with plan I , not only the extraction rate of soluble solids of plan II was higher and contents of other indicators were no less than plan I , but also can effectively extract volatile flavor from Boletus edulis. If we chose plan I , there would be greater loss and more difficult recovery of flavor components and there would be cost much. Therefore, plan II was selected finally , which can extract not only nutrients but also volatile flavor from Boletus edulis.