42results about How to "High degree of esterification" patented technology

The invention belongs to the field of cellulose modification, and more specifically relates to a cellulose higher fatty acid ester and a preparation method thereof. The weight ratio of cellulose, an esterifying agent and a coreactant, which are the principle raw materials of the cellulose higher fatty acid ester, is 100g:50g-300g:100g-600g. The preparation method comprises steps of pre-reaction and esterification reaction, wherein the esterifying agent and the coreactant are mixed uniformly firstly; the mixture is subjected to pre-reaction for 10 to 30min at a temperature of 50 to 90 DEG C; cellulose is mixed with the mixture uniformly after the pre-reaction, and the mixture is delivered into a ball grinder and is subjected to esterification reaction for 20 to 90min at the temperature of 40 to 90 DEGC with a stirring speed of 100 to 500rmp; and then obtained reaction product is washed and dried so as to obtain the cellulose higher fatty acid ester. Mechanical activation technology is employed so as to increase esterification efficiency of cellulose, shorten reaction time and simplify the processing steps.

Provided is a defoamer for fermentation which has excellent dispersibility in water and forms neither a precipitate nor oil droplets when the dispersion is heated, and which is highly effective in defoaming fermentation media. This defoamer contains a reaction product obtained by mixing a fat or oil having an iodine value of 40 to 130 with glycerin or like in a molar ratio of from 3 / 2 to 1 / 2 to obtain a mixture, causing 4 to 17 mol of propylene oxide to add to 1 mol of the mixture, and then causing 20 to 40 mol of ethylene oxide and 70 to 110 mol of propylene oxide to block-wise add thereto in this order, the reaction product having an ethylene oxide / propylene oxide molar ratio of from 1 / 4 to 2 / 5.

The invention discloses honey vinegar and a preparation method thereof. The honey vinegar contains the following raw materials: honey, water, ammonium sulfate, dipotassium phosphate, bran, rice husk,yeast and acetic acid bacteria. The prepared honey vinegar is reddish brown, glossy, uniform in liquid, mellow, sour and palatable, has no sediment and peculiar smell, has the specific fragrance of honey vinegar and the fragrance of foods such as bran and rice hull and is rich in multiple nutritive values of honey, bran and rice husk and rich in nutrients, the total acid content is 4.5-5.0g / 100mL,the sourness is relatively strong, and the honey vinegar can meet the standard requirements of GB 18187-2000 Brewed Table Vinegar. According to the preparation method, the sugar degree, pH value andnutrients of the honey are adjusted, and the honey vinegar produced sequentially through alcohol liquid fermentation and acetic acid solid fermentation contains rich organic acid, amino acid, vitaminsand mineral substances and is gentle in sourness; and the preparation method is simple and convenient and easy to operate.

Provided is a defoamer for fermentation which has excellent dispersibility in water and forms neither a precipitate nor oil droplets when the dispersion is heated, and which is highly effective in defoaming fermentation media. This defoamer contains a reaction product obtained by mixing a fat or oil having an iodine value of 40 to 130 with glycerin or like in a molar ratio of from 3 / 2 to 1 / 2 to obtain a mixture, causing 4 to 17 mol of propylene oxide to add to 1 mol of the mixture, and then causing 20 to 40 mol of ethylene oxide and 70 to 110 mol of propylene oxide to block-wise add thereto in this order, the reaction product having an ethylene oxide / propylene oxide molar ratio of from 1 / 4 to 2 / 5.

The invention relates to a method for preparing adipic acid dimaltitol ester, which belongs to the field of plasticizers and auxiliary heat stabilizers for polyvinyl chloride processing. Adipic acid and maltitol are mixed with each other to be subjected to esterificated reaction under the action of a catalyst at 140-165 DEG C. Cyclohexane, benzene and toluene are takes as water-carrying agents to separate water out during the reaction process, so that the esterification rate is increased. Concentrated sulphuric acid and p-toluenesulfonic acid are taken as the catalysts, and the usage amount of the catalysts accounts for 20-30% of the mass of the adipic acid. The easterification reaction time is between 4 and 5 hours, and the faint yellow oily adipic acid dimaltitol ester is obtained after the reaction is completed. The prepared adipic acid dimaltitol ester has high esterification degree, the preparation method is simple, the catalysts and unreacted adipic acid and maltitol do not need to be separated out after the esterification is completed, and the product can be directly used as a polyvinyl chloride (PVC) processing agent. Through adding CaO, a powdery product can also be obtained, and the use of adipic acid dimaltitol ester is benefited.

The invention relates to a preparation method of oxidation-esterification composite modified starch. There are many starch modification methods, and the composite modification can combine the advantages of the two modified starches. Adding nanocellulose in the starch modification process can promote starch modification. It improves the performance and application range of starch, and performs oxidation-esterification modification of starch. It has the advantages of both oxidized starch and esterified starch, and is more widely used in various fields of production and life.

The invention discloses a method for preparing rice starch acetate catalyzed by a solid-carrying heteropolyacid. The method mainly includes the following steps: preparation of activated carbon immobilized heteropolyacid catalyst; using glacial acetic acid as solvent and acetic anhydride as esterification agent, under the catalysis of immobilized heteropolyacid, at a temperature of 70-80°C and react for 2 to 3 hours; the first suction filtration recovers the immobilized heteropolyacid; the filtrate is poured into a large amount of distilled water for washing, and the second suction filtration obtains the product, which is then dried in a vacuum environment, ground, and filtered Sieve to obtain rice starch acetate with a degree of substitution of more than 2.5 and a high degree of substitution up to 2.7. The method of the invention has the characteristics of high reaction efficiency, recyclable and reusable catalyst, green safety and the like.

The invention discloses a method for preparing a low ash sucrose fatty acid ester, and the method comprises the following steps: A, esterification of fatty acid methyl ester and part of sucrose powder is performed in the presence of an alkaline catalyst, after the reaction is completed, water with the volume equivalent to 0.4-1 time of the volume of the product after the reaction is added for dilution, metal ions in the diluted solution are removed by ion exchange in an ion exchange column, and the alkaline catalyst is an alkaline metal salt or a metal hydroxide; and B, after the ion exchange is completed, water in the ion-exchanged material is removed, and after the removal of the water, sucrose powder is supplemented for continuous reaction. The method has the advantages of low cost and convenient operation, and can solve the problems of low esterification degree, low purity of the sucrose fatty acid ester and high ash content of the product in the prior art.

The invention relates to a method for preparing rice starch phosphate monoester by virtue of pneumatic premixing and belongs to the field of starch deep processing. The method is used for preparing the product from rice starch as the raw material in the presence of an orthophosphate as an esterifying agent and urea as a catalyst, and mainly comprises the steps of regulating the pH of the mixed solution of the orthophosphate, the urea and water to an appropriate value and then mixing the mixed solution thoroughly by use of a pneumatic conveying mixer, next, conveying the mixture to a fluidized bed reactor for esterification reaction, and finally washing and drying the product to obtain the rice starch phosphate monoester. The method for preparing the rice starch phosphate monoester by virtue of pneumatic premixing is simple in process, low in cost and suitable for industrial large-scale production, and the prepared rice starch phosphate monoester in a paste form is transparent, resistant to aging and excellent in water holding capacity, and can be used as an emulsifier, a stabilizer and a thickening agent in the field of food.