挤压膨化对紫糯全麦粉理化性质及抗氧化活性的影响

通过改变挤压膨化的工艺条件,分析了不同膨化条件下紫糯全麦粉的主要理化指标变化情况。结果表明:随着膨化温度、螺杆转速的升高,紫糯全麦粉的膨化度、水溶性指数、总膳食纤维、可溶性膳食纤维以及总酚含量均有所升高,而吸水性指数则有所下降。挤压膨化可使紫糯全麦粉的可溶性膳食纤维含量增加约6%~26%,总酚含量在膨化温度160℃、物料含水量13%时,达到最高1.03mg/g。膨化紫麦粉的WSI和WAI分别比原料提高70%和37%;物料含水量的增加则使水溶性指数和总酚含量下降,吸水性指数及其他指标均有所升高;膨化产品的总抗氧化能力随着膨化温度、物料含水量以及螺杆转速的增加均有所降低。      

鲜食玉米冻结过程传热分析及冻结时间的研究

采用数值方法,将鲜食玉米模拟为具有同轴的双层圆柱,建立数学模型,并用改进的焓法进行求解,对鲜食玉米的冻结过程进行传热分析和冻结时间的预测。研究结果表明,该模型可以用来预测具有同轴双层圆柱特征尺寸的食品的冻结时间,最大相对误差为5．6％。冻结过程中玉米轴部分相变界面的移动速度明显小于玉米粒部分。而且鲜食玉米冻结时间随着送风速度的不同有很大的变化。     

双酶混合水解玉米皮渣制备阿魏酰低聚糖研究

以玉米皮渣为原料,采用酶解方法制备阿魏酰低聚糖(Feruloyl oligosaccharides,FOs),通过比较不同酶解条件下阿魏酰低聚糖产量的差异及不同酶解方式下玉米皮渣细胞壁结构的变化,确定酶解阿魏酰低聚糖生成的方法,并优化获得玉米皮渣中阿魏酰低聚糖的最佳酶解条件。结果表明:纤维素酶和木聚糖酶混合酶解可使玉米皮渣细胞壁出现溶洞,可有效提高阿魏酰低聚糖产量;经单因素和响应面实验确定双酶混合酶解的最佳条件为混合酶的添加量为15.7 g/L,混合酶中纤维素酶添加比例为70%,酶解1 h,玉米皮渣底物添加量为100 g/L,在此条件下FOs产量最高,为1008.43μmol/L。本研究为双酶混合酶解制备玉米皮渣FOs提供理论依据。      

The Anthocyanin Accumulation Related ZmBZ1, Facilitates Seedling Salinity Stress Tolerance via ROS Scavenging

Anthocyanins are a class of antioxidants that scavenge free radicals in cells and play an important role in promoting human health and preventing many diseases. Here, we characterized a maize Bronze gene (BZ1) from the purple colored W22 introgression line, which encodes an anthocyanin 3-O-glucosyltransferase, a key enzyme in the anthocyanin synthesis pathway. Mutation of ZmBZ1 showed bronze-colored seeds and reduced anthocyanins in seeds aleurone layer, seedlings coleoptile, and stem of mature plants by comparison with purple colored W22 (WT). Furthermore, we proved that maize BZ1 is an aleurone layer-specific expressed protein and sub-located in cell nucleus. Real-time tracing of the anthocyanins in developing seeds demonstrated that the pigment was visible from 16 DAP (day after pollination) in field condition, and first deposited in the crown part then spread all over the seed. Additionally, it was transferred along with the embryo cell activity during seed germination, from aleurone layer to cotyledon and coleoptile, as confirmed by microscopy and real-time qRT-PCR. Finally, we demonstrated that the ZmBZ1 contributes to stress tolerance, especially salinity. Further study proved that ZmBZ1 participates in reactive oxygen scavenging (ROS) by accumulating anthocyanins, thereby enhancing the tolerance to abiotic stress.     

A comparison of commercial enzymes for the aqueous enzymatic extraction of corn oil from corn germ

An aqueous enzymatic method was developed to extract corn oil from corn germ. The basic steps in the method involved “churning” the corn germ with various enzymes and buffer for 4 h at 50°C, and an additional 16 h at 65°C, followed by centrifugation and removal of the oil layer from the surface. No hexane or other organic solvents are used in this process. By using oven-dried corn germ samples (6 g) from a commercial corn wet mill, corn oil yields of about 80% were achieved using three different commercial cellulases. A fourfold scale-up of the method (to 24 g of germ) resulted in oil yields of about 90%. Nine other commercial enzymes were evaluated and resulted in significant but lower oil yields. In the absence of enzymes, oil yields of 27 to 37% were achieved. The chemical compositions of hexane-extracted vs. aqueous enzymatic-extracted corn oils were very similar.     

山东省夏玉米田杂草发生及其化学防除

本文就山东省夏玉米田杂草的发生种类,发生特点以及化学防除概况作了总结。     

基于机器视觉技术预测玉米质量等级的方法研究

国家标准规定玉米的质量定等指标为容重,为了实现利用机器视觉快速预测玉米等级,采用自行构建的基于机器视觉技术的玉米检测系统获取4种不同等级的玉米籽粒图像,通过均值滤波、最大类间方差法和形态学运算对玉米籽粒和背景进行处理、分割和特征参数的选取,并采用主成分分析法确定图像特征信息的最佳主成分因子数,建立以玉米容重为基础的8-21-4三层BP神经网络质量等级识别模型。结果表明:利用BP神经网络对基于完整籽粒图像和籽粒横切面图像的玉米等级的总体识别率均在90%以上,因此利用该模型对玉米等级的检测识别具有较高的可行性。