Thakur Sheetal, Kaur Amritpal, Singh Narpinder, Virdi Amardeep Singh
Dept. of Food Science and Technology, Guru Nanak Dev Univ., Amritsar, Punjab, India.
J Food Sci. 2015 Jun;80(6):C1144-55. doi: 10.1111/1750-3841.12895. Epub 2015 May 5.
Dry milling of different corn types resulted in varied proportions of germ, pericarp, grit and flour. Grit and flour produced during different reduction stages varied in particle size and chemical constituents, hence applications in food industry. In this study, recovery of different fractions and variation in physicochemical and pasting properties of grit and flour fractions obtained during 3 successive reduction dry millings of 2 normal (African tall, HQPM1) and 1 waxy corn (IC 550353) were evaluated. Waxy corn grains had the highest L*, a*, b*, ash, fat, and protein content and the lowest weight. Waxy and African tall gave the highest recovery of germ and pericarp, respectively. Waxy corn showed lower grit and flour recovery as compared to normal corn. Flour fractions showed higher L* and lower a* and b* values than grit fractions. Particle size of grit and flour fractions ranged from 840 to 982 μm and 330 to 409 μm, respectively. Fractions with larger particle size showed lower L* value. The b* value showed positive correlation with yellow pigment content. Grit and flour from the 1st reduction stage showed higher ash and fat content. Protein content was correlated positively with ash content and negatively with L* value. Grit and flour fractions with higher protein content had lower pasting viscosities. Pasting viscosities were higher for flours than their corresponding grits. Protein profiling of grit and flour fractions from different stages showed quantitative and qualitative differences in medium (22, 28, and 35 kDa) and low molecular weight (16, 17, and 19 kDa) polypeptides and were related to grit and flour yield.
对不同类型的玉米进行干法研磨会得到不同比例的胚芽、果皮、粗粉和细粉。在不同的粉碎阶段产生的粗粉和细粉在粒度和化学成分上存在差异，因此在食品工业中有不同的应用。在本研究中，对2种常规玉米（非洲高秆玉米、HQPM1）和1种糯玉米（IC 550353）连续进行3次干法研磨还原过程中得到的不同组分的回收率以及粗粉和细粉组分的物理化学性质和糊化特性的变化进行了评估。糯玉米籽粒的L值、a值、b值、灰分、脂肪和蛋白质含量最高，重量最低。糯玉米和非洲高秆玉米分别具有最高的胚芽和果皮回收率。与常规玉米相比，糯玉米的粗粉和细粉回收率较低。细粉组分的L值较高，a值和b值较低。粗粉和细粉组分的粒度分别为840至982μm和330至409μm。粒度较大的组分L值较低。b值与黄色素含量呈正相关。第一次还原阶段的粗粉和细粉灰分和脂肪含量较高。蛋白质含量与灰分含量呈正相关，与L*值呈负相关。蛋白质含量较高的粗粉和细粉组分糊化粘度较低。细粉的糊化粘度高于相应的粗粉。不同阶段粗粉和细粉组分的蛋白质谱分析表明，中等分子量（22、28和35 kDa）和低分子量（16、17和19 kDa）多肽在数量和质量上存在差异，且与粗粉和细粉产量有关。
