Separation Of Total Flavonoids From Phyllostachys Pubescens Leaves And Design Of Product Chain For Phyllostachys Pubescens Based On Circular Economy

Phyllostachys pubescens Mazel. (P. pubescens) is a local bamboo with prominent economic value in China. And the industry of P. pubescens has been of high-consumption and low-efficiency. So far, a product chain is proposed based on the strategy of circular economy to promote the sustainable development of P. pubescens industry. The total flavonoids extracted from P. pubescens leaves have remarkable bioactivity, such as anti-free radical, anti-oxidation, etc, and the correlative research has just been in the starting phase. In order to make use of the abundant leave resource more effectively, a process for extracting and separating total flavonoids from P. pubescens leaves is studied. The main contents are as follows:1. Imitating material flows and energy flows of ecosystem, a product chain of P. pubescens is proposed based on the three principles of circular economy, i.e. reducing, reusing and recycling. The chain covers bamboo forest cultivation, utilization of shoot and the whole-bamboo use, and forms a multi-level product structure. The chain is composed of seven sections, namely the bamboo stand, the shoot plant, the flavonoids plant, the panel board plant, the charcoal plant, the handwork plant and the feed-processing plant. In the chain, special attention is paid to heat integration and water integration, and the closed cycles of resource and energy are approximately carried out.2. To determine the content of total flavonoids in the extracts from P. pubescens more accurately, three colorimetric methods (NaNO₂-Al(NO₃)₃-NaOH colorimetry ultraviolet spectrophotometry, and AlCl₃-(HAc-NaAc) colorimetry) are compared. And a simple AlCl₃-(HAc-NaAc) colorimetry is proposed.3. The influences of solvent and mass of leaves to volume of solvent on the leaching of total flavonoids from P. pubescens leaves are studied, and the suitable conditions are obtained. The crude leaching product is purified by the batch solvent extraction. In order to optimize the batch extraction process, the suitable extractant is chosen and the effects of feed concentration, ratio of solvent volume to feed volume and extraction times on the extraction yield and purity are investigated, respectively. 4. To solve the problem of poor seal existed in the traditional pulser, a new-style pulser is developed. With a magnetic drive rotary valve instead of the conventional mechanical rotary valve, and two pulsed pots instead of four in the traditional pulser, the new one is better sealed and simpler. Based on this new pulser, a pulsed packed extraction column (PPEC) is developed.5. The PPEC with a diameter of 25mm and an effective packing height of 700mm is applied to implement the continuous extraction of the total flavonoids from the crude leaching products. The flooding characteristic of n-butanol-water system is studied, and the influences of pulsation intensity and ratio of solvent volume to feed volume on extraction performances are investigated.