| Phyllostachys pracecox shoots is a low-fat high-protein food,and is rich in soluble sugar,fiber and protein,is very suitable for the extraction of dietary fiber raw materials.On the basis of this,the feasibility of extracting dietary fiber from Phyllostachys praecox shoots by chemical method,hot water extraction method and enzymatic hydrolysis method was studied.The suitable extraction conditions of each method were explored,and then the three methods the water-soluble dietary fiber was studied from the point of view of physicochemical,physiological and application.The texture analysis and Fourier transform infrared spectroscopy(FTIR)were used to analyze the SDF components of Phyllostachys praecox shoots.The effects of different extraction methods on water-effects of fiber on bacteria(Staphylococcus aureus,Escherichia coli,Enterococcus faecalis).In addition,the preparation technology of fermented yogurt prepared by co-fermentation of bamboo shoots and milk was studied.The effects of different extraction methods on the fermentation and storage of yoghurt were also studied.In this paper,the effects of different extraction methods on water-soluble dietary fiber extracted from bamboo shoots were analyzed from several perspectives.The main results of this paper are as follows:(1)The effect of different extraction conditions on the extraction rate was analyzed by single factor experiment.The results showed that the method with the highest extraction efficiency was chemical extraction,followed by chemical extraction.The extraction rate was 31.25%,15.09%and 12.45%,respectively.The extraction rate was 31.25%,9.18%and 2.6%,respectively.The extraction conditions were as follows:2%sodium hexametaphosphate solution,the ratio of material to liquid was 1:20,the pH value was 6.5,the extraction temperature was 60 ?,the extraction time was 3h,the second extraction was water extraction,The extraction conditions were as follows:the ratio of material to liquid was 1:20,the pH was natural pH,the extraction temperature was 90 ? and the extraction time was 5h.The optimum extraction conditions were as follows:the ratio of material to liquid 1:20,the addition of cellulase was 0.8%,Extraction time 25h.(2)The results showed that the spectra of the four extracts were similar,indicating that they were similar in composition and content,and the characteristic peaks of the four extracts were respectively analyzed by Fourier transform infrared extraction of water-soluble dietary fiber At 500,700,900,1000,1100,1300,1600 cm-1,mainly containing P-D-mannose,cellulose and uronic acid are not galactose.The SDF structure of Phyllostachys praecox shoots was more porous than that observed by chemical method,and the SDF structure of the Phyllostachys pracecox shoots extracted by the water extraction method and the enzymatic method was similar.The solubility of water-soluble dietary fiber extracted from three different methods was studied.It was found that the solubility of water-soluble dietary fiber extracted from the three methods was almost the same,which was 4.3g/100mL at 20 ?.High solubility,SDF1>SDF2>SDF3,solubility at 100 ?,44 g/100 mL,41.9 g/100 mL and 40.1 g/100 mL,respectively.(3)The effects of water-soluble dietary fiber extracted from different extraction methods on the three bacteria of Escherichia coli,Staphylococcus aureus and Enterococcus faecium were analyzed.The results showed that when the chemical extraction,water extraction and enzymatic hydrolysis When the extracted amount of SDF was more than 0.12 g/ml,the three kinds of harmful bacteria had some inhibitory effect,and all of them had better inhibitory effect with the increase of the addition amount.(4)The IDF of Phyllostachys praecox shoots prepared by different methods was prepared by adding the method of SDF and Chen Wanying and others to the reconstituted milk.The main factors affecting the fermentation of Phyllostachys pracecox shoots were studied by single factor experiment and orthogonal test.The suitable formula of bamboo shoots was 1.5%IDF,1%of SDF 1%,15%of skim milk powder,,Sucrose 7%,gelatin 0.2%,agar 0.1%,suitable fermentation temperature 42± 1 ?,fermentation time 6h(acidity 71T°).(5)The effects of water-soluble dietary fiber extracted from three different methods on the rheological properties of DF-1 bamboo shoots were studied.The results showed that the effects of SDF extracted from different extraction methods on the rheological properties of SDF were studied Large,which added SDF1 yogurt viscosity is much larger than do not add water-soluble dietary fiber or add SDF2,SDF3 yogurt,and the elasticity is due to the addition of SDF bamboo shoots to reduce the SDF3 to bamboo shoots bamboo shoots reduced The degree is greater than SDF2 and SDF1.The effect of SDF on the thixotropy of bamboo leaves was studied by three different methods.The shear stress was changed from SDF1>SDF3>CK>SDF2,These phenomena may be because SDF1 has better adsorption,making the ingredients in the yogurt more closely together,so that it has a stronger thixotropy.(6)In the storage environment of 7 days and 4 ?,three kinds of extraction methods were used to extract the water-soluble dietary fiber of the bamboo shoots and the bamboo leaves of the bamboo shoots without adding the bamboo shoots.The pH value of the lactic acid bacteria was Down trend.Leech bamboo shoots CK yogurt during storage pH:add SDF1>add SDF2>add SDF3>CK.When the water-soluble dietary fiber of Phyllostachys edulis was added,the pH of the yoghurt decreased,and the pH value of the SDF1 or SDF3 was significantly slowed down from the fourth day of storage,which may be the polysaccharide Lactic acid bacteria have a certain inhibitory effect,and thus make the bamboo shoot bamboo shoots pH value maintained at 6.0 or so,to promote the proliferation of lactic acid bacteria. |
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