细微玉米粉的低温酶解

    Enzymatic hydrolysis of micronized corn flour at low temperatures

    • 摘要: 为了开发玉米粉低温酶解新工艺,采用双酶法对粒度不同的市售玉米粉(中位粒径273.6 μm)和细微玉米粉(中位粒径17.1 μm)进行液化、糖化处理,调查了30~70℃范围内的液化温度对液化速度和葡萄糖收率的影响。试验结果表明,市售玉米粉在40~70℃的温度范围内,细微玉米粉在30~70℃的温度范围内,液化速率常数与温度的关系可用Arrhenius方程式表示。细微粉碎使液化反应活化能从市售玉米粉的4.63×104 J/mol降低到2.15×104 J/mol。40℃时,细微玉米粉的液化速度大约是市售玉米粉的2.5倍。液化温度对细微玉米粉的葡萄糖收率没有显著影响。细微玉米粉的葡萄糖收率可达95.4%,大大高于市售玉米粉的79.2%。由此可见,通过细微粉碎可以降低玉米粉的液化温度,同时提高液化速度和葡萄糖收率。

       

      Abstract: In order to develop a new technology for enzymatic hydrolysis of corn flour at low temperatures, two-step enzymatic hydrolysis was performed for commercial corn flour(with median particle size of 273.6 μm) and micronized corn flour(with median particle size of 17.1 μm), and the effects of liquefaction temperature on the liquefaction rate and glucose yield were studied at the temperature range of 30~70℃. Experimental results showed that the relationship between the liquefaction rate and the liquefaction temperature could be expressed by an Arrhenius equation at the temperature range of 40~70℃ for commercial corn flour and at the range of 30~70℃ for micronized corn flour. The activation energy of liquefaction for commercial corn flour was 4.63×104 J/mol. It was decreased to 2.15×104 J/mol for micronized corn flour. At 40℃, the liquefaction rate of micronized corn flour was 2.5 times higher than that of commercial corn flour. In the enzymatic hydrolysis of micronized corn flour, the effect of liquefaction temperature on glucose yield was not significant. A glucose yield of 95.4% was obtained for micronized corn flour, which was considerably higher than 79.2% for commercial corn flour. It was found that liquefaction temperature could be decreased, and liquefaction rate and glucose yield could be increased by the micronizing of corn flour.

       

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