基于响应面法的豆粕挤压系统参数优化

为了考察挤压膨化生产大豆组织蛋白过程中相关参数对系统参数的影响,以豆粕为原料,利用响应面模型,以豆粕含水率、膨化机螺杆转速和机筒温度为输入变量,以扭矩为响应变量,探索豆粕挤压膨化系统的相关参数对扭矩影响规律和挤压膨化系统最佳参数。结果表明:豆粕含水率、膨化机螺杆转速和机筒温度对扭矩具有显著的影响;膨化机转速是影响扭矩的主要因素。采用优化方法对试验参数进行了优化计算,当豆粕含水率为17.2%、膨化机转速为202.5 r.min-1、机筒温度为110℃时,膨化机工作性能指标达到最优。     

大豆粕结团的原因及对策

大豆制油生产过程中,蒸脱机出口处的豆粕水份偏高,结团较多,溶剂消耗较高,通过对蒸脱机的改造,改变了脱溶层和烘干层的相对高度,改善直接蒸汽的质量,使湿粕在接触直接蒸汽之前达到100℃以上.并且改进和增加了一些附属设备,解决了豆粕结团的问题,豆粕的外观颜色呈金黄色,溶剂消耗3 kg/t料以下.     

响应面优化豆粕生物肽的生产工艺研究

以高温豆粕为原料,枯草芽孢杆菌为试验菌株,在单因素试验基础上,以发酵液a-N含量为响应值,对摇瓶发酵制备大豆肽工艺条件进行响应面优化.确定最佳工艺条件为:豆粕粒度40目,初始pH 6.8,种子培养时间16.25 h,碳源用量1.75％,豆粕用量10.75％,接种量6.25％,发酵时间48 h.在此条件下,发酵液α-N含...     

黑龙江省豆粕深加工增值新途径——豆粕单细胞蛋白饲料

黑龙江省豆粕深加工增值新途径──豆粕单细胞蛋白饲料黑龙江省杜尔伯特县种子公司倪树田黑龙江省每年用于浸油的大豆约８０万吨，其主要副产品是脱脂豆粕占原料的７０－８０％，即产豆粕５５－６２万吨。因此，如何科学开发利用豆粕资源，具有重要价值。这些豆粕除本省留...     

应用大孔树脂纯化大豆异黄酮的工艺研究

先用聚醚砜有机膜对豆粕乙醇提取液进行超滤,然后用D101大孔树脂纯化,研究大豆异黄酮的精制工艺.结果表明:用孔径5000D的有机膜超滤处理豆粕乙醇提取液,能够去除其中56.1％的杂质.用D101大孔树脂纯化,采用上样液浓度为0.750 mg·mL -1大豆异黄酮溶液,流速为1.0 BV·h-1,依次用去离子水、1.0 ...     

纳豆菌发酵对豆粕脲酶活性的影响

微生物发酵可一定程度降低豆粕抗营养因子活性，提高豆粕作为蛋白源的利用率。采用2株纳豆菌发酵研究豆粕中脲酶的失活情况。首先测定了其生长曲线，用以指导其发酵条件的优化研究。研究了水／豆粕比例、培养温度、pH、接种量等发酵参数对脲酶活性的影响，结果表明：降低脲酶活性的最优发酵条件为：彬豆粕比例为5：1，pH4．5、温度30℃、接种量5％、种龄为8h，发酵60h，豆粕脲酶活性降低93％。     

芽孢菌固态发酵降解豆粕工艺研究

以工业副产物脱脂豆粕粉为原料,通过芽孢菌发酵将其水解得到大豆肽是对资源的有效利用.以水解度为指标,筛选到降解豆粕能力较强的芽孢菌4株,编号CHDl2、CHDl6、CHD21和CHD27;以大豆肽含量作为固态发酵产物的评价指标,从4株芽孢菌出发,得到适宜固态发酵降解豆粕的菌株组合(CHDl6 CHD27);通过两个(L934)正交试验对该组合的固态发酵工艺进行优化,结果为其产物的大豆肽含量达23.9%,比优化前所得产物的大豆肽含量(14.1%)提高69.5%,比未经发酵处理的培养基中大豆肽含量(4.14%)提高约4.8倍,大豆肽得率达60%.     

我国近年豆粕进口贸易与下年度趋势浅析

一、近年我国由豆粕出口国逆转为豆粕进口国我国是世界四大豆粕主产国之一，１９９４／１９９５年以前，在国际的豆粕贸易中一直处于出口国地位，年净出口豆粕逾１００万吨。１９９５／１９９６年开始逆转，由出口国转化为进口国，至１９９７／１９９８年，三年间分别净进...     

中国豆粕价格看跌

中国豆粕价格看跌王自铭（中国粮食贸易公司）路透社香港站报告《中国豆粕价格看跌》，笔者将其译后整理如下，供读者参阅。大量豆粕源源不断抵达中国口岸，将导致中国国内豆粕价格下跌。预计今后两个月内每吨豆粕将从目前２７５０元跌到２５５０元。北京一家贸易商估计，...     

酶制剂体外酶解豆粕中抗营养因子的研究

为了评价几种单一酶、复合酶以及钙离子对豆粕中的相关抗营养因子的水解效果,进行了体外酶解试验。共有4种单一酶制剂（植酸酶、果胶酶、纤维素酶和木聚糖酶）和3种复合酶制剂被采用,其中复合酶SB由α-半乳糖苷酶和木聚糖酶组成,复合酶C3由植酸酶、果胶酶、纤维素酶组成,复合酶C5由植酸酶、果胶酶、纤维素酶、木聚糖酶和α-半乳糖苷酶组成。预试验显示上述酶有基本相似的最适水解反应参数：水分50％、pH4．8-5．0、温度50℃和时间45min。在此参数下,添加10．5U g^-1豆粕的植酸酶,豆粕中植酸的降解率达到69．63％;添加果胶酶16U·g^-1豆粕,豆粕中果胶的降解率达到45．93％;添加纤维素酶50U·g^-1豆粕,纤维素降解率达到66．21％;分别添加木聚糖酶80U·g^-1豆粕和α-半乳糖苷酶0．7U·g^-1豆粕,豆粕中还原糖的释放量增加率分别达到84．77％和65．19％。在豆粕中添加0．2％CaCl2,植酸的降解率与对照组相比微增至71．09％,还原糖的释放量分别增加到88．68％和65．23％。但果胶和纤维素的降解率分别显著地增加到90．01％和70．43％。研究发现复合酶C3和C5对相关的抗营养因子均呈现出不同程度的协同效应。说明使用复合酶制剂并适量添加CaCl2,体外水解豆粕中的相关抗营养因子是可行的。     

大豆品种表现型与配合力的相关分析

大豆植株的表现型与配合力的相互关系分析结果表明，植株形态性状的亲本均值与Ｆ１、Ｆ２的一般配合力效应值里呈著或极显著正相关。Ｆ１、Ｆ２的主要产量性状的均值与相应世代的特殊配合力效应值呈显著或极显著正相关。植株形态性状和品质性状的Ｆ１育种值与Ｆ２均值呈显著或极显著正相关。植株形态性状、产量性状及品质性状总配合力效应值世代间相关显著。     

THE MACHAIR GRASSLANDS OF THE HEBRIDES

The utilization of Scottish hill-land potential is severely limited by inadequate wintering facilities resulting from a low proportion of inbye land to hill-land. The machair lands of the Uists, in the Outer Hebrides, however, provide a more suitable ratio, which is not commonly found in the Highlands of Scotland.
Investigations into the grassland problems of the Hebrides were intensified in 1955; and some of the data obtained from trials are given here, as are suggestions for improving the production and utilization of grass in these areas. The climate, soil, and agricultural system all interact to provide conditions which are rarely seen elsewhere.     

THE USE OF THE FORAGE HARVESTER IN THE IMPROVEMENT OF ROUGH GRAZING

Considerable improvement has been achieved in rough grazings by fairly frequent close mowing with the forage harvester or flail mower, particularly when combined with manuring and surface seeding.
The implement has proved capable of tackling very tough vegetation and converting it into grazing swards of fair value and good botanical composition. Undesirable species have been largely eliminated by treatment over two growing seasons.
The method is believed to compare favourably in cost with sward renovation by cultivation or by herbicides.     

THE ROLE OF GREEN SOILING IN THE ECONOMY OF THE DAIRY FARM

With modern machinery and modem techniques of grass production, mechanical-or zero-grazing offers a means of utilizing the crop to perfection. Whether this results in enhanced profits depends largely upon the farm and the specific circumstances. It may, it may not. What is evident is that the health of the cows is not affected by an unnatural manner of summer feeding; the sward, per se, may be improved by the regular and uniform defoliation; and under conditions of intensive production and the vital need to use profitably every blade of grass, as for instance on small, highly-rented farms, the practice of zero-grazing merits the most careful consideration. It cannot lightly be dismissed as merely a new fad.     

THE USE OF THE IN VITRO TECHNIQUE IN THE DETERMINATION OF THE DIGESTIBILITY OF GRASS/LEGUME MIXTURES

The in vitro dry-matter digestibility was determined of two samples of Digitaria decumbens , one sample of Medicago sativa , and one sample of Trifolium repens and nine mixtures prepared from these samples.
When the results were compared with in vivo digestibilities the standard errors of the regressions for the three combinations of legume, grass and legume/grass mixtures were ±0.6, ±0.6 and ±1.5 percentage units, respectively.
It is considered that in vivo digestibility of mixtures of grasses and legumes can be estimated by the in vitro technique, provided that suitable grass and legume standards are included.     

THE EFFECT OF TEMPERATURE IN THE MASS ON THE CHEMICAL COMPOSITION OF SILAGE

The effect of temperature on silage quality was investigated in a series of trials over a period of three years.
The results indicated that when conditions in the silage were favourable for the formation of lactic acid, either through treatment or because of the herbage itself, low temperatures in the mass had no adverse effect on silage quality.
Some results suggest that, with chopped or lacerated silage, low maximum temperatures are associated with better quality silage. The results, however, were not entirely consistent.
There appeared to be little or no advantage in allowing unchopped silage to heat to 100°F.     

THE EFFECT ON THE SOIL OF THE COMPONENTS AND MANAGEMENT OF A LEY

The effect of four grasses, and four methods of utilizing the herbage, on the root weight, the proportion of organic matter in the soil and the water-stability of the soil aggregates was measured over a period of three years. The grass species in the sward had a greater effect upon the measurements than had the methods of management. Of the grass species, Lolium perenne produced the greatest root weight and highest percentage of organic matter in the soil.