Study On Beet Pulp For Compound Package Film

Because of the high water holding and colloid formation characteristics, dietary fiber has been widely used in the area of food industry and medicine. Research about the extraction of beet dietary fiber are few now and mainly concentrated on the extraction of dietary fiber from wet beet pulp by alkali or acid. The result was that soluble dietary fiber content is low and there is no report about the comprehensive use of beet dry pulp. Therefore, this experiment designed to develop packaging film by modified beet fiber, so that enhance its comprehensive utilization and increase economic value, also it has some significance in promote economic development, solve "white pollution" and ameliorate health status of people. Microwave and enzymolysis assisted extraction of beet dietary fiber, its carboxymethylation so as to improve its solubility were studied in this experiment. Furthermore, by comparison with traditional chemical extraction method and optimization put forward the comprehensive utilization parameters and procedure of beet pulp. Also, study the making procedure and characteristics of edible film and non-edible film from modified beet fiber.1. Results showed that the optimum condition of microwave assisted extraction were as follows: pH2.0 vitriolic acid solvent, power of microwave 856.80w, extraction time 68.40s/time, liquid-to-solid ratio 14.87mL/g, pectin extraction rate 20.01%. The optimum salt precipitation condition are precipitator Al₂（SO₄）₃ , pH5.0, salt 5%, temperature 60℃, time60min. According to the desalination single factor experiment and orthogonal test, the optimum desalination conditions are pH1.0, liquid-to-solid ratio15:1（mL/g）, time 65min, ethanol 60%, the pectin extraction rate is 93.07%. The sample acquired from this experiment is gray, its water content 4.65%, pH2.6, pectin content 82.05%, viscosity 48mp.s, its main index reaches the national standard.2. Considering the deproteinization effect and residue in the sample, the results of deproteinization by enzyme are pH6.6, temperature 65℃, amount of enzyme 0.20%, liquid-to-solid ratio 13:1mL/g, time 80min. 51.36% and 98.56% protein was eliminated in the first and second time respectively, extracted non-soluble dietary fiber ratio among the dry pulp is 64.23%3. After eliminated hemi-cellulose from the enzymolysis residue, carboxymethylation experiment was conducted and the results showed that NaOH addition amount, ClCH₂COOH addition amount, liquid-to-solid ratio, ethanol concentration, etherification time have impact on the synthesis of high degree substituted carboxymethylcellulose, among them, NaOH addition amount, ClCH₂COOH addition amount, liquid-to-solid ratio are highly significant factors, ethanol concentration, etherification time has significant effect and temperature has no significant effect. The optimum results of high viscosity cellulose synthesis are n（NaOH）/n（AGU）=2.5, n（ClCH₂COOH）/n（AGU） =1.5, ethanol concentration 75%, temperature 35℃, etherification temperature35℃, etherification time 3h, liquid-to-solid ratio 8:1 mL/g, CMC substitution is 0.86.4. From the results of the composite filming orthogonal tests, the optimum condition of the forming composite films is: A₂B₁C₃D₁, namely CMC/WG=7:3, alcohol concentration i45%, glycerin concentration 2% and desiccation temperature 60℃. Results and analyses of orthogonal tests showed that the blend proportion of CMC and WG is the biggest influence to the film capability, the next influence is the desiccation temperature, the influences of the glycerin consumption and the ethyl alcohol concentration are fairly small. Moreover, from the results of the parallel tests of the composite films can be known that the optimum filming condition is reliable, all indexes of the composite film that forms under the optimum condition are higher, and therefore, the filming condition will have the guidance effect to the research on the edible composite packaging films in the future.5. In the experiment of making carboxymethylcellulose （CMC）/ poval （PVA）/ amylum composite packaging film under different material ratio, tensile strength , tearing elongation rate, oxygen permeability, water vapor permeability, oil permeability, light transmition rate , film thickness are determined through single factor experiment and orthogonal experiment, so that study the optimum procedure of carboxymethylcellulose （CMC）/ poval （PVA）/ amylum compsite film. In order to get composite film with good properties, seven items of composite film were determined and integrated evaluation principle was established to evaluate the different properties of the composite film. Eight main filming factors, such as CMC/ PVA concentration and ratio, amyl dialdehyde concentration, pH, plasticizer, ammonia amount, desiccation temperature, filming medium were studied to determine the optimum material ratio.CMC/ PVA /amylum composite film orthogonal experiment results showed that the optimum filming condition are CMC/PVA/ amylum =3:3:4, amyl dialdehyde 6%, filming liquid concentration 5%, ammonia 0.75%, pH11, glycerin 2%, desiccation temperature 80℃. It was known from the composite film orthogonal experiment that the properties of composite film have high correlation with the making condition. Variance analysis showed that the PVA/CMC ratio has significant effect on tensile strength and elongation and amyl dialdehyde, ammonia amount in turn and the effect of filming liquid concentration is least.