玉米半湿法提胚关键工艺与设备研究综述

对玉米半湿法提胚关键工艺与设备进行综述,阐述了玉米半湿法提胚原理;指出充分调质、高效脱胚和合理提胚是玉米半湿法提胚的三个关键工艺环节,水汽调节机、玉米脱胚机和玉米提胚机是玉米半湿法提胚的关键设备,并对各设备的优缺点进行了分析;最后指出必须研制具有自主知识产权且具有较高科技含量的玉米提胚关键设备,才能提高我国玉米深加工与综合利用的水平与质量。     

浅谈如何提高湿法线胚芽提取率

采用传统的湿法工艺,通过悬浮和筛分可以从玉米加工工艺中回收价值很高的玉米胚芽,针对国内玉米湿法深加工线的玉米胚芽提取率相对偏低的情况,研究分析了技术路线、工艺控制和生产管理对提取率的影响,提出了提高湿法线胚芽提取率的一些措施.     

玉米浸泡在酒精生产中应用及影响因素

在湿法玉米酒精及半湿法玉米酒精工艺中,玉米浸泡的作用非常关键,玉米浸泡质量和浸泡周期都将对酒精、饲料、玉米油这些产品产率和质量及生产成本产生巨大的影响,所以玉米浸泡始终被认为是湿法(包括半湿法)酒精生产工艺的关键性第一步,通过玉米浸泡,可以充分软化玉米,使胚芽和纤维得充分分离,获得最大的淀粉得率,提高发酵过程中酒精的产量。     

不同来源和不同方法提取玉米胚的品质对比研究

从不同玉米深加工企业采集不同提胚工艺生产的玉米胚样品,同时在实验室以优质玉米为原料采用不同工艺提取玉米胚,对玉米胚的主要组分含量、真菌毒素含量、挥发性风味成分及其中油脂品质进行检测分析,对比研究不同来源和不同方法提取玉米胚的品质。结果显示：从玉米淀粉厂所采集玉米胚的纯胚率(60.29%~88.92%)高于从玉米酒精厂所采集玉米胚(42.29%~57.25%),通过风选和筛分可将玉米胚的纯胚率提高至84.11%~97.85%。半干法玉米胚水分含量(9.09%~14.48%)高于湿法玉米胚(3.51%~5.51%),粗脂肪含量(23.63%-26.94%)明显低于湿法玉米胚(53.42%-54.77%),粗蛋白含量(13.75%-18.46%)高于湿法玉米胚(10.10%-12.35%),总氨基酸含量和必须氨基酸含量均高于湿法玉米胚。不同玉米胚毛油的脂肪酸组成和甾醇含量无明显差别,但干法玉米胚毛油中维生素E含量更高。半干法玉米胚中挥发性风味成分(38~46种)明显多于湿法玉米胚(11~36种),感官呈青草味和甜香味,颜色浅且有色泽,湿法玉米胚有哈喇味和刺激味,色泽偏黄且较为暗淡,但湿法玉米胚中玉米赤霉烯酮和呕吐毒素含量更低。以优质玉米为原料采用半干法提取的玉米胚适合做为食用玉米胚的产品开发。     

冲击式胶体磨在乙醇工业中的应用

简述了湿法制作玉米酒精的优点及湿法玉米酒精制粉浆的工艺流程。详细介绍了冲击式胶体磨的工作原理、优点及其在各行业的应用和发展     

冲击式胶体磨在乙醇工业中的应用

简述了湿法制作玉米酒精的优点及湿法玉米酒精制粉浆的工艺流程。详细介绍了冲击式胶体磨的工作原理、优点及其在各行业的应用和发展。     

玉米湿法研磨膜技术的应用前景

主要介绍国外玉米湿法研磨中膜技术的应用，着重讨论了膜的类型和使用特性，以及在玉米湿法研磨中使用的效果和生产工艺过程等。     

玉米湿法工艺提取淀粉的研究进展

湿法加工是一种常见的农产品加工工艺,可以分离出农产品中的不同组分,该文主要从玉米的自身性质及贮藏条件介绍湿法提取玉米淀粉的影响因素,论述传统湿法提取的弊端及局限性,介绍近年来诸如酶法、超声法、挤压法等一些新型高效、绿色的玉米淀粉提取方法,以期为加工中降低能源消耗和二氧化碳排放量提供参考。     

湿法提取玉米淀粉的工艺优化

通过单因素和二次通用旋转试验研究浸泡时间、温度、NaHSO_3添加量、乳酸添加量对玉米淀粉提取率的影响,并比较了湿法提取的玉米淀粉与市售淀粉的理化指标、透明度、凝沉性、水吸收指数等性质。试验得出玉米淀粉最佳提取条件为:浸泡时间42h、浸泡温度55℃、NaHSO_3质量分数为0.5%、乳酸质量分数0.6%,淀粉提取率为63.07%。湿法提取玉米淀粉与市售玉米淀粉的理化性质接近;与市售玉米淀粉相比,湿法提取玉米淀粉的直链淀粉含量、透明度、水吸收指数、膨润力有所提高,但两者之间的性质差异均不显著。     

玉米淀粉基质乳粉中锡的检测

目的建立检测含有玉米淀粉基质乳粉中锡的测试方法,为此类乳粉中锡的检测提供依据。方法选择基质含玉米淀粉的乳粉作为研究对象,通过加标回收的方式,结合不含玉米基质乳粉作为对比实验,分别研究3种不同的样品制备流程。运用干法消化、湿法消化、酶解后湿法消化3种方法进行含玉米淀粉基质乳粉中锡的检测。结果加标样品经干法消化,回收率62.8%;经湿法消化,回收率0%;经酶解后湿法消化,回收率86.0%。酶解后湿法消化回收率结果,显著优于干法消化和湿法消化的测试结果,与不含由淀粉基质的乳粉加标测试回收率88.9%结果相当。结论对于含有玉米淀粉基质的乳粉中锡的检测,酶解后湿法消化的方式操作简单,最为适用,也说明引入淀粉酶能够保证锡测试结果的准确性。     

Sonication Enhanced Cornstarch Separation

Yellow dent corn soaked in deionized water at 52°C for 24 h without addition of SO₂ was wet‐milled using a modified 100‐g laboratory procedure employing ultrasound treatment at different points in the milling process and compared to conventional wet milling and milling‐only corn. Starch yields from ultrasound treatments varied from 66.93 to 68.72% and were comparable to conventional wet milling (68.92%). The ultrasound treated samples produced 6.35 to 7.02 more percentage point starch compared to the milling‐only corn. Compared to the starch from milling‐only corn, the ultrasound‐produced starches showed a significant increase in whiteness and decrease in yellowness that are comparable to starches produced by conventional wet milling. Ultrasound treatment after the second grinding produced the highest starch yield and the lowest protein content in the resulting starch. The ultrasound‐treated starches exhibited different pasting properties as evidenced by higher paste viscosities.     

蜡质玉米粉的糊化特性研究

为了解蜡质玉米粉及其不同制粉方法对糊化特性的影响,测定了干磨、湿磨、挤压制蜡质玉米粉以及蜡质玉米淀粉、糯米粉的溶胀度和RVA参数。结果表明:蜡质玉米粉糊化进程中溶胀度高,水合能力强,具有较高的糊化参数。不同品种蜡质玉米粉的破损值、谷值、峰值和终黏度的变异程度较大,蜡质玉米粉的峰值与谷值、终粘度和回生值、谷值与回生值、谷值与终粘度、终粘度与回生值均呈极显著正相关。湿法制粉糊化进程中水合能力强,主要RVA参数显著高于干法制粉和挤压制粉,具备很强的成糊能力和黏滞性,干法制粉成糊后稳定较好,抗老化性较强,挤压制粉的糊化进程不明显。     

实时荧光定性聚合酶链式反应标准方法检测转基因产品的验证及应用

目的验证实验室大豆、玉米和水稻及其制品转基因检测方法,并应用于实际样品检测。方法根据GB 19495.4-2018《转基因产品检测实时荧光定性聚合酶链式反应(PCR)检测方法》要求对无转基因标识的样品进行转基因成分检测。结果方法验证满意。40批次样品(大豆、玉米和水稻及其制品)中发现1批次的转基因成分检出,检出率为2.5%。结论市场中绝大部分未标示转基因成分的大豆、玉米和水稻及其制品确实未检出转基因成分,仅有极少数产品含有转基因成分,但未进行有效标识。     

Effects of corn grain conservation method on ruminal digestion kinetics for lactating dairy cows at two dietary starch concentrations

Effects of conservation method of corn grain and dietary starch concentration on ruminal digestion kinetics were evaluated. Eight ruminally and duodenally cannulated Holstein cows (55 +/- 15.9 days in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Experimental diets contained either ground high moisture corn (HM) or dry ground corn (DG) at two dietary starch concentrations (32 vs. 21%). Mean particle size and dry-matter concentration of corn grain were 1,863 microm and 63.2%, and 885 microm and 89.7%, for HM and DG, respectively. Starch digestibility in the rumen was greater for HM treatments compared with DG treatments, but starch digestibility in the total tract was not affected by conservation method of corn grain because of compensatory digestion in the intestines. The difference in ruminal starch digestibility between HM and DG treatment was greater for high-starch diets (71.1 vs. 46.9%) compared with low-starch diets (58.5 vs. 45.9%). This interaction is attributed to a greater difference in first-order digestion rate of starch between HM and DG treatment in high-starch diets (28.2 vs. 14.6%/h) compared with low-starch diets (16.8 vs. 12.2%/h). This suggests that ruminal starch digestion is a second-order reaction limited by enzyme activities as well as substrate availability; ruminal contents of cows fed low-starch diets may have insufficient amylolytic activity for maximal starch digestion when readily fermentable starch is available. Rate of neutral detergent fiber digestion in the rumen was slower for high-starch diets and HM treatments compared with low-starch diets and DG treatments, respectively. Effects of corn grain conservation method on ruminal digestion kinetics are greatly altered by starch concentration of diets.     

Rapid wetting method to reduce cyanogen content of cassava flour

In 2005 a simple wetting method was developed that reduced total cyanide content of cassava flour 3–6-fold. The method involved spreading wet flour in a thin layer and standing in the shade for five hours to allow evolution of HCN gas. We found that breakdown of linamarin catalysed by linamarase to acetone cyanohydrin, followed by its spontaneous decomposition to HCN and acetone was greatly increased by standing the wet flour in the sun. Treatment for two hours in the sun gave the same amount of total cyanide remaining as five hours in the shade. This rapid treatment in the sun may be more acceptable to rural women in Democratic Republic of Congo, than five hours in the shade. The two methods are offered as alternatives for use in rural Africa. With adequate linamarase present the residual cyanogen remaining after the wetting treatment was acetone cyanohydrin.     

高压蒸煮法在玉米胚芽蛋白提取中的作用

以提油后的玉米胚芽粕为原料,用高压蒸煮法处理原料后,再利用纤维素酶进行酶解处理,通过测定离心液中的糖量,残渣中纤维素水解率及浓缩后蛋白质含量等指标,考察采用高压蒸煮法后对蛋白提取效果的影响。结果表明,经高压蒸煮处理后,蛋白质提取效果与浸泡48h再酶解的效果相当。处理后蛋白质含量均可达到42%。而高压蒸煮法处理大大缩短了处理时间,优于浸泡法处理原料。     

湿法制备高黏度玉米变性淀粉的工艺研究

应用湿法,以普通玉米淀粉为原料,在交联变性之后,进行阳离子醚化反应。以峰值黏度为评价指标,应用单因素实验法和正交实验法筛选和优化了工艺条件,并对其黏度特性进行了比较研究。制得的淀粉峰值黏度可达2 433 BU,约是原淀粉黏度的8倍,且糊液的黏度稳定性也有很大的提升。优化的制备工艺参数为:阳离子醚化剂用量为淀粉干基质量的10%,反应温度41℃,反应时间12 h,反应pH值11.3,NaOH与醚化剂摩尔比为1.2∶1。     

玉米淀粉酸度与pH值相关性及质量快速筛查方法研究

借助酸度计,对玉米淀粉酸度检测前调配的淀粉乳液进行pH检测,同时,为消除人员视觉误差,结合酚酞变色原理及变色点等因素,在滴定接近终点,以酸度计显示结果为参考进行终点判定,寻求滴定前pH和玉米淀粉酸度值间关系。结合淀粉糖生产工艺,研究湿基淀粉以及不同婆美度对淀粉乳液pH值影响及相关性研究,实验结果表明,采用酸度计对玉米淀粉酸度指标快速评估方法可行,且检测周期由原始方法 2.5 h缩短为10 min,达到快速、高效,及时为生产中控提供参考的目的。