CAJ | 학술논문

为了提高胡萝卜微粉加工效率，改善粉碎过程中粉体团聚问题。该文通过对胡萝卜干式高速剪切粉碎试验，研究粉碎过程中胡萝卜粉体粒径、温度、含水率以及类胡萝卜素含量的变化情况。结果表明，随着粉体粒径的减小，其比表面积增大、温度升高、含水率增加，颗粒间范德华力、静电力、液桥力作用增强导致粉体颗粒团聚，产生了“逆粉碎”现象。高压电场能够克服粉体颗粒间的作用力，使粉体具有抗团聚，相互分散的性能。研究中利用针板电极原理，设计出高压电场粉体处理装置。以处理电压和处理时间为试验因素，以粒径<125μm 粉体质量百分比为评价指标，通过正交试验建立回归方程，优化求解并验证，得到胡萝卜粉体抗团聚分散处理的最优工艺参数为：处理电压45 kV，处理时间60 min，此时粉体颗粒分散效果明显，粒径<125μm粉体质量百分比由未处理时的61.75%提升到77.38%。研究结论为实现胡萝卜微粉高效加工提供理论参考。
위료제고호라복미분가공효솔，개선분쇄과정중분체단취문제。해문통과대호라복간식고속전절분쇄시험，연구분쇄과정중호라복분체립경、온도、함수솔이급류호라복소함량적변화정황。결과표명，수착분체립경적감소，기비표면적증대、온도승고、함수솔증가，과립간범덕화력、정전력、액교력작용증강도치분체과립단취，산생료“역분쇄”현상。고압전장능구극복분체과립간적작용력，사분체구유항단취，상호분산적성능。연구중이용침판전겁원리，설계출고압전장분체처리장치。이처리전압화처리시간위시험인소，이립경<125μm 분체질량백분비위평개지표，통과정교시험건립회귀방정，우화구해병험증，득도호라복분체항단취분산처리적최우공예삼수위：처리전압45 kV，처리시간60 min，차시분체과립분산효과명현，립경<125μm분체질량백분비유미처리시적61.75%제승도77.38%。연구결론위실현호라복미분고효가공제공이론삼고。
Carrot is a kind of familiar vegetable, and it has abundant carotenoid content. Carrot grinding is a common processing method. In this paper, the changes of the influencing factors including the powder particle size, the temperature, the moisture content and the carotenoid content in the grinding process were researched through the carrot shearing and crushing tests. The evaluation index of powder particle size was the percentage of particle size which was less than 125μm, screened by standard sieve whose mesh number was 120. Through the single factor test, the result showed that the percentage of particle size less 125μm decreased first, then increased and later decreased once again during the crush time of from 1 to 5 min. According to the references and the analysis results, the main reason of percentage decreasing was powder reunion. When the crush time changed from 1 to 4 min, the average temperature increased by 40.2℃, measured by Testo 890-1 infrared thermal imager, and the moisture content increased by 1.658%, tested by drying oven. The percentage of particle size which was less than 125μm decreased by 7.17%, as crush time changed from 4 to 5 min. Otherwise, the carotenoid content of carrot powder decreased by 228 mg/kg due to the high temperature produced in crushing process. It was found that the main reason of powder reunion was that the surface forces among particles increased with the rise of the particle specific surface area, the temperature and the moisture content. The main surface forces among particles included: Van der Waals force, which increases with the growing smaller of particle size, electrostatic force, which is a result of friction, and hydrogen bonding force, which is made by moisture in powder. In consequence, the most effective method to solve the reunion of powder was to reduce the surface forces among particles. High voltage electrical field can overcome the surface forces among particles so that the powders have capability of resisting reunion. In this study, according to “Asakawa effect” and the principle of needle-plate electrode, the test device of high voltage electrical field was designed. The test device of high voltage electrical field could form a non-uniform electric field that was used to treat carrot powder. The treating voltage and the treating time were the test factors, and the percentage of particle size less than 125μm was the evaluation index in the single factor test and the orthogonal experiment. Then, the regression equation was established and optimized. The test factors’ significant order for the evaluation index was: treating voltage> treating time> treating voltage× treating time> treating time2. Based on the linear programming theory, the optimal processing parameters were determined. The appropriate treating voltage was 45 kV, and the best treating time was 60 min. Through the verification test, the percentage of particle size less than 125μm was increased from 61.75% to 77.38%. The conclusions of this study provide a theoretical reference for the efficient processing of carrot powders.