Font Size: a A A

The Preparation Of Di-esterified Corn Starch And The Application Of Di-esterified Corn Starch In Pumpkin-Noodles

Posted on:2013-02-16Degree:MasterType:Thesis
Country:ChinaCandidate:T T XiaoFull Text:PDF
GTID:2231330374978756Subject:Agricultural products processing and storage
Abstract/Summary:PDF Full Text Request
In the process of ultrasonic pretreatment and microwave response of dry phosphate, the phosphoryl degree of substitution (DS1) is used as an indicator to test the effect on corn starch phosphate when ultrasonic time, ultrasonic power, reaction time of microwave,. the microwave reaction power, the amount of water content and esterification agent are changed.(1) Then determined by orthogonal experiments, the optimal reaction conditions for corn starch phosphate is the microwave power400W, reaction time5min, the reaction to add water content of20%, esterification dosage of7%. By using the different phosphoryl degree of substitution of starch to test their transmittance, and freeze-thaw stability, gelatinization temperature, and rheological properties, it has been found that the transmittance increase to48.3%, compared with the original corn starch, it increase of about30%; freeze-thaw stability increased with the degree of substitution rise; pasting temperature decreased with the rise of the degree of substitution, a maximum temperature decreased by5℃, the lowest pasting temperature is64.2℃; And significantly improve the stability of the starch paste viscosity, starch gel strength has increased.(2) The IR spectra indicate that the P-O-C, a kind of phosphorus esters key, is exist in the sample, and the microwave semidry can make an effective response between the starch and esterification agent. XRD experiment results show that the crystallinity of corn starch is59.15%,after ultrasonic treatment, the crystallinity is50.61%,indicating that the ultrasonic treatment can reduce corn starch crystallinity.(3) In the process of further acetic acid esterification wet reaction to the preparation of Di-esterified starch, the acetyl degree of substitution (DS2) is used as an indicator to test the effect on the process when temperature, time, effect of pH and the amount of esterification agent are changed.Then determined by orthogonal experiments, the optimum reaction conditions for acetic acid esterification step25℃reaction temperature, reaction time60min,25%of the amount of esterification agent, pH value of8, and the best Di-esterified corn starch acetyl degree of substitution is0.3098.(4) Through using different acetyl degree of substitution of starch to test their transmittance, freeze-thaw stability, gelatinization temperature, and rheological properties, it has been found that Di-esterified corn starch transmittance with acetyl degree of substitution increased with the increase, the maximum light transmission rate of53.2%.Freeze-thaw stability increased with the rise of the acetyl degree of substitution, gelatinization temperature with acetyl degree of substitution of the rise anddecline, the lowest gelatinization temperature of59.8℃.(5) The range of20~60℃warming, low-acetyl degree of substitution of the diester starch have a stable viscosity performance, high acetyl degree of substitution of Di-esterified starches with a higher viscosity.100~20℃in the cooling process, high-acetyl degree of substitution of Di-esterified starch gel strength is better, acetyl degree of substitution on the stability of the starch gel has little effect. Di-esterified starch-IR spectra of hydroxyl absorption peaks move12cm-1to lower wavenumber.(6) Di-esterified starch can effectively improve the quality of the pumpkin noodles, its improvement is better than corn native starch, oxidized starch, phosphate starch and starch acetate. The noodle sensory evaluation scores increased by10.67%, which has been added Di-esterified starch, and it shorten the cooking time of2min, the dissolution rate decreased by4.1%. Texture test data show that of the cooked pumpkin noodles, which have been added Di-esterified starch, the hardness decreased by10.8%,62.3%increase flexibility chewing increased17.1%, recovery23.0%. Di-esterified starch was4%in the pumpkin noodles production is the best. The sensory score of85, the best cooking time for180s, and dissolution rate of8.0%, cooked noodle the hard1209.94g, elastic1.581chewiness,870.615g,recovery0.651.
Keywords/Search Tags:Corn starch, Ultrasonic wave, Microwave, Phosphorylate starch, Acetate starch, Di-esterified corn starch, Pumpkin noodle
PDF Full Text Request
Related items