采用FCF染色法测定粮食破碎率

Biochemical method for evaluation of grain damage with fast green FCF dye

根据染色剂快绿FCF与粮粒破碎部分能够形成蓝色复合物,该复合物溶于稀Na OH溶液,本研究采用比色方法定量了OD_(610)与粮食破碎率之间的关系。建立了FCF染色法测定玉米、小麦及糙米破碎率方法,对5~20 g样品用体积为样品质量克数2倍的0.1%FCF染料染色20 min后,用蒸馏水冲洗直到水显示无色,再用体积为样品质量克数2倍的0.01 mol·L^(-1)Na OH溶液洗脱样品30 min,对洗脱液采用紫外分光光度计测定OD_(610)。整个操作在1 h内完成。该方法检测玉米、小麦及糙米破碎率范围分别在40%、20%及60%以上,但是不适合大米和大豆破碎率检测。OD_(610)(y)与破碎率(x)之间的线性方程对玉米、小麦及糙米代表品种分别为y=0.034x+0.316、y=0.071x+0.204、y=0.049x+0.206,相关系数高于0.998。

The complexes between Fast Green FCF dye and the damaged part of a grain were vivid,and were soluble in sodium hydroxide solution. The study established a biochemical method for evaluation of grain damage by FCF dye. Five to twenty grams of samples were soaked for 20 min by 10 to 40 m L of 0.1% FCF dye dissolved in 0.01 mol·L-1Na OH solution,then the samples were rinsed off by distilled water till no blue color in washed water,finally the samples were bleached in 10 to 40 m L of 0.01 mol·L-1Na OH for 30 min in order to recover the complexes formed between FCF dye and the damaged part of grain. The bleaching solution was used to determine absorbency in 610 nm. This protocol was carried out within 1 hour for determination of grain damage. The damaged rates for shelled corn,brown rice,and wheat were respectively detected by this method over the range of 40%,60% and 20%,but it can’t be used to detect the breakage percent of milled rice and soybean. The linear equations of between OD610（y） and sample breakage percent（x） for shelled corn,wheat,and brown rice were y=0.034x＋0.316,y=0.071x＋0.204,y=0.049x＋0.206 and,respectively,with determined coefficient higher than 0.998.