大豆乳清粉对小鼠肠道菌群及其产生短链脂肪酸的影响

大豆乳清是制备大豆分离蛋白时产生的副产物,带来的环境污染问题十分严重。为了利用这一废弃物资源并促进传统产业升级,本研究进一步探索了大豆乳清的营养功能。利用喷雾干燥方法得到大豆乳清粉,检测其蛋白质、膳食纤维、低聚糖、灰分及氨基酸组成等主要成分指标。将大豆乳清分别按0. 5%、1. 0%和2. 0%的添加量加入小鼠饮食,饲喂28 d后分析其对动物肠道菌群及其产生短链脂肪酸(SCFAs)的影响。结果表明:大豆乳清粉主要成分如下:灰分含量20. 9%,蛋白质含量20. 1%,低聚糖含量9. 68%,总膳食纤维含量5. 01%,脂肪含量3. 8%。与对照组相比,大豆乳清粉饲喂小鼠的肠道中厚壁菌门与拟杆菌门菌群比值显著降低,比值为0. 71～1. 20;另枝菌相对丰度增加,毛螺菌、拟普雷沃菌、拟杆菌、普雷沃菌相对丰度降低。不同剂量大豆乳清粉饲喂小鼠的肠道中总SCFAs含量显著提高,且SCFAs结构有明显不同。本研究结果可以为大豆乳清的高附加值利用提供理论依据和基础数据。     

乳清浓缩蛋白和大豆分离蛋白的营养价值评价

采用国际上通用的营养价值评价方法,分别测定了蛋白粉中乳清浓缩蛋白(WPC)和大豆分离蛋白(SPI)粗蛋白含量和氨基酸组成,对它们的营养价值进行全面评价.分析结果显示,乳清浓缩蛋白和大豆分离蛋白必需氨基酸含量较高,分别占其氨基酸总量的40.8%和38.5%,蛋白质的氨基酸评分(AAS)、化学评分(CS)、必需氨基酸指数(EAAI)、生物价(BV)、营养指数(NI)和氨基酸比值系数分(SRCAA)分别为66.3、61.4、69.5、64.1、56.0、82.0和48.3、44.6、62.3、56.2、51.1、76.6.结果表明乳清浓缩蛋白和大豆分离蛋白是良好的蛋白质来源.     

树脂及活性碳吸附技术回收大豆乳清中的异黄酮和低聚糖

对用树脂及活性碳吸附方法回收大豆乳清废水中的大豆异黄酮和低聚糖进行了研究。测定了树脂及活性碳吸附饱和曲线，研究了异黄酮和低聚糖的洗脱条件，建立了该法处理大豆乳清废水回收大豆异黄酮和精制大豆低聚糖的工艺。结果表明：处理1t废水，约可回收40%的大豆异黄酮130g，精制大豆低聚糖浆9kg，并将乳清废水的COD和BOD分别由13600和7800降至960和340。本法处理乳清废水可创造良好的经济效益。     

利用大豆废水提取功能性因子工艺技术

以大豆分离蛋白生产中的乳清废水为原料,利用膜分离设备分别对乳清蛋白、异黄酮、低聚糖进行回收利用,对生产工艺进行了探讨,对所生产的产品进行了分析。     

影响大豆乳清蛋白起泡性因素研究

大豆乳清蛋白是一种天然两亲物质,具有界面性质,是一种天然的表面活性剂.易消化吸收、具有很高的代谢效率和生物学价值.以蛋白质溶液的浓度、温度、离子强度、震荡时间等作为影响因素,通过实验得出结论大豆乳清蛋白起泡性效果最佳条件是:浓度1.0%,温度60℃,pH值5,钙离子强度0.1 mol/L.     

蒽酮比色法测定大豆乳清废水中总糖含量

本文研究了用蒽酮比色法测定大豆乳清废水中可溶性总糖含量,本法可溶性总糖测定的回收率为98%~105%,标准偏差1.032×10-3,本法灵敏度高,可靠性强,误差小,而且设备简便、迅速、准确。     

大豆乳清蛋白的热促凝聚及其对分离蛋白功能性的影响

分别在pH8.0和pH4.5对"碱提酸沉"法制备大豆分离蛋白过程中所得提取液进行热处理,研究了大豆乳清蛋白的热促凝聚效果及其对所制备分离蛋白功能性的影响。结果表明:加热处理可降低大豆乳清中乳清蛋白的含量,在pH8.0和pH4.5时提取液经70℃加热10 min分别使25.7%和40%乳清蛋白转移到分离蛋白产品中。以普通分离蛋白为对照,对3种分离蛋白产品进行功能性分析,发现3种产品均在pH4.5~4.8的范围内溶解度最小,70℃加热10 min所制备分离蛋白的持水性明显高于普通分离蛋白,但其持油性、起泡性、泡沫稳定性和乳化性均低于普通分离蛋白,而乳化稳定性无显著差异。     

超滤/纳滤在大豆乳清资源化处理中的应用研究

研究了超滤和纳滤在大豆乳清资源化处理中的应用效果,结果表明采用MWCO5kDa的PS亲水UF膜切向流过滤大豆乳清时,膜通量随乳清浓缩比(VCR)的增大而迅速衰减,当VCR大于8以后,膜通量衰减速率减缓;该超滤膜对蛋白质、盐类、糖份和异黄酮的平均截留率分别为90%、3%、7.2%和6.1%.采用聚酰胺NF-1812(MWCO360Da)切向流过滤UF透过液时,当VCR小于3时,膜通量基本上随VCR增大而线性衰减,其后变化相对缓慢;该NF膜对盐份截留率小于20%,对糖份和异黄酮的平均截留率分别为95%和85%左右.     

大豆乳清废水超滤条件研究

就超滤溶液pH、操作压力、操作温度等操作参数对大豆乳清蛋白超滤过程的影响进行了研究,通过单因素试验和3因素3水平正交试验,确定了比较合适的超滤条件:超滤压力选择0.025MPa,超滤pH选择8.0,超滤温度选择30℃。在此条件下,蛋白质的截留率为80.44%。     

利用大豆浓缩蛋白乳清制备水苏糖的发酵条件

利用酵母对大豆浓缩蛋白乳清进行发酵处理制备水苏糖.在确定最佳起始发酵液的糖度为31.8Brix后,对温度、pH、接种量、装液量等工艺条件进行了单因素试验及正交试验,结果表明最佳发酵条件为:温度32°C,pH5.5,接种量8%,在此发酵条件下利用酵母对大豆浓缩蛋白乳清进行发酵处理48 h,水苏糖的纯度达到了90%,保留率为68%.     

黑龙江省大豆区域试验品种品质现状分析

为了解黑龙江省大豆新品种化学品质发展变化的概况及趋势,对黑龙江省2005～2008年参加区域试验的360份大豆品种(品系)进行品质分析,对照美国2号大豆期货标准,评价了近年来黑龙江省大豆品种品质改良的效果.结果表明:在360份材料中,蛋白质(干基)含量达到该标准的有151份,占全部材料的41.9%;脂肪(干基)含量达到该标准的有104份,占全部材料的28.9%;蛋白质加脂肪(干基)含量达到标准的有87份,占全部材料的24.2%.黑龙江省大豆区域试验品种的整体品质与美国2号大豆质量标准还有较大差距.     

添加大豆蛋白对乳清干酪产品品质的影响

向乳清中分别添加0.2%、0.3%、0.4%、0.5%和0.6%大豆蛋白,研究了大豆蛋白添加量对乳清干酪产品品质的影响.结果表明:添加大豆蛋白可以提高乳清干酪的硬度、弹性、胶着性和咀嚼性,改善乳清干酪的质构特性.当大豆蛋白添加量为0.3%(w/w)时,乳清干酪产品品质最佳.     

Elevated methionine content in soybean seed by overexpressing maize β-zein protein

Soybean provides superior and readily available protein for human and livestock. However, nutritional value of soybean is limited due to the deficiency of an essential amino acid, methionine. To improve total methionine content of soybean, a methionine-rich seed storage protein, β-zein, was introduced into soybean cultivar ’Jack’ under the control of legumin B4 promoter or CaMV 35S promoter. Totally 4 T₃ transgenic lines exhibited higher expression levels of foreign genes, and legumin B4 promoter directed a stronger accumulation of β-zein protein than CaMV 35S promoter. Compared to wild type plant, total methionine content in transgenic soybean seeds significantly increased by up to approximately 15%. Although the introduction of β-zein gene improved total methionine content, the level was negligible compared to native soybean storage proteins, implying that the inadequate soluble methionine is the limiting factor. Based on these observations, a new strategy for simultaneously increasing the “source” and “sink” of methionine metabolism is proposed to further improvement of total methionine content in soybean seed.     

导入外源总DNA获得优质高蛋白和双高大豆新品系

本文报道了利用大豆自花受粉后形成的花粉管通道，将外源野生大豆总ＤＮＡ直接导入受体栽培大品种中，其中一组合（Ｄ８７０１）获得的导入后代Ｄ８９－９８２，蛋白南含量比受体提高了近２个百分点，球蛋白总量提高近１０个百分点，并使其与大豆加工品质密切相关的１１Ｓ球蛋白组分所占比例超过了７０％该品系经品比和异地鉴定，产量比标准品种提高１１％，于１９９５年进入省区域试验；另一组合（Ｄ８７０５）的导入后代Ｄ９０－１     

不同大豆品种豆乳的凝聚特性研究

以全国不同地区的67个大豆品种为原料,研究了不同品种豆乳的凝聚特性,并分析了大豆理化成分与豆乳的凝聚特性之间的关系.结果表明:豆乳的氯化钙凝聚特性受大豆中多种化学组分的影响.可溶性蛋白、P、豆乳总固形物含量越高的品种,凝固速度越慢,凝乳所需要的Ca2+浓度也越高;蛋白质组成中11 S/7S比值越大,豆乳凝固越早,凝乳也...     

玉米蛋白粉对大豆根际环境的影响

通过施用不同数量玉米蛋白粉对大豆根际环境影响变化的初步研究表明,玉米蛋白粉有增加土壤中细菌、真菌和放线菌的数量及改善土壤物理性质的作用,施入80 kg/667m2玉米蛋白粉后,土壤容重降低了0.3 g/cm3,总空隙度提高了2.1个百分点,毛管空隙度提高了2.8个百分点,非毛管空隙度提高了1.9个百分点,田间持水量提高了3.1个百分点。玉米蛋白粉对大豆增产效果明显,蛋白粉60 kg/667m2处理产量最高为177.4kg/667m2,增产25.6%,产量差异达到极显著水平。     

挤压膨化碱处理豆渣制备水溶性膳食纤维工艺的研究

以豆渣为原料,并在碱液处理后直接挤压膨化制备豆渣水溶性膳食纤维.以水溶性膳食纤维得率为指标,对物料水分、挤压温度、螺杆转速及氢氧化钠浓度进行了单因素试验.采用响应面分析方法,对挤压膨化提高碱处理豆渣水溶性膳食纤维的工艺条件进行了优化,并建立了物料水分、挤压温度、螺杆转速三因素的回归模型.确定了挤压膨化碱处理豆渣制备水溶...     

Nutritional evaluation of the soy-whey milk analogLa colina

The milk analogLa colina is a product which contains mainly whey, soy protein isolate and vegetable oil, designed for infants since one year, children, adolescents and adults of all ages. The concept behind this product is to offer an alternative to milk consumption which during the last decade has decreased dramatically in Venezuela mainly due to its high price and low availability. Accordingly, the purpose of this study was to evaluate nutritionally this new product in order to determine if from a nutritional stand point it could represent a valid alternative to milk consumption. The results showed thatLa Colina offers the same amount of protein, energy, vitamin A, calcium, phosphorus and potassium as whole milk powder and more sodium, iron and zinc. In addition, a rat assay showed that the energy in these two products is equally available and even though the proteins inLa colina are 3.9% less digestible, their quality determined by growth, PER or the nitrogen retained are excellent and identical to the quality of the proteins in milk. These results agreed with the theoretical chemical score of the proteins of this new product, which indicated that the amino acid profile of the mixture can fulfill the amino acid requirements of children, adolescents an adults. Both milk andLa colina are products with a high fat content. The fat in this new product however, is vegetable oil and therefore it has a more convenient fatty acid profile than whole milk and about one third of its cholesterol. In short, these results showed thatLa Colina from a nutritional point of view is an excellent alternative to milk consumption.     

Contribution of low molecular weight antioxidants to the antioxidant screen of germinated soybean seeds

Soybean seed of the Mazovia variety (Glycine max) were germinated in the dark at a constant temperature of 25°C up to 168 h (24 h × 7). Changes in content of low molecular weight antioxidants (LMWA) in the course of germination were studied. The analyzed compounds were: total phenolics, soluble proteins, tocopherols (-T, -T, -T, -T), reduced and oxidized glutathione, L-ascorbic acid and L-dehydroascorbic acid. The changes in total antioxidant status (TAS) and the peroxyl radical-trapping capacity (PRTC) of the processed seeds were measured and compared to those of the raw seeds. On the basis of data obtained, the contribution of LMWA to the TAS of raw and germinated soybean seeds was calculated. The results showed a very high molar percentage contribution of phenolic compounds (49.7%) in opposition to glutathione (7.0%), tocopherols (4.0%) and soluble protein (5.7%) to the total TAS of raw soybean seeds. The germination process led to the increased contribution of phenolic compounds (67.7%), soluble proteins (9.3%) and ascorbic acid (4.4%) to the total TAS of germinated seeds and as a result, a decrease in the antioxidant gap was observed compared to the total TAS of raw soybean seeds. This study showed that the contribution of experimentally obtained total PRTC to the total TAS of raw and germinated soybean seeds after seven days ofthe process was 48% and 25.2%, respectively. The PRTC results were comparable to those obtained in TAS only when calculation was done by multiple mean values for content of investigated compounds and their relative potency with respect to Trolox. The PRTC values obtained in this manner were higher than those obtained experimentally indicating that high molecular weight antioxidants as well as are able to quench peroxyl radicals as well as low molecular weight antioxidants. Therefore, calculation of PRTC is a more accurate method that eliminates the puzzling question of unidentified antioxidants shown as the antioxidant gap in the TAS assay.     

不同生态条件重迎茬对大豆化学品质的影响

本文通过不同生态条件下大豆不同轮作方式的定位试验，研究了重迎茬对大豆的蛋白质含量，脂肪含量和二者总量的影响，结果表明，在不同试验点，迎茬对蛋白质含量及蛋白脂肪总量的影响没有规律性，迎茬大豆的脂肪含量略有增加，并且不同迎茬轮作方式的影响幅度不同，重茬大豆的蛋白质含量有所增加，并且增加幅度随着重茬年限增长而加大，在短期内（重茬2年），重茬对脂肪含量的影响没有规律性，在重茬3年以后，重茬使脂肪含量降低，并且降低幅度随重茬年份增长而加大，重茬使蛋白质与脂肪总量增加，增加幅度随重茬年份增长而加大（重茬2年以后）。