三种大豆分离蛋白的比较研究和物化特性相关性分析

对3种不同大豆分离蛋白的基本化学组成、游离巯基、二硫键和表面疏水性进行了测定;对3种不同大豆分离蛋白的粘度、乳化性和凝胶性进行了分析;采用SPSS软件对物化特性与大豆分离蛋白的基本化学组成、游离巯基、二硫键和表面疏水性的相关性进行了分析,确定了大豆分离蛋白的粘度、乳化性和凝胶性与蛋白质含量、二硫键、游离巯基含量的相关性。     

Comparative Protein Digestibility in Growing Rats of Cooked Rice and Protein Properties of Indica and Japonica Milled Rices

College,Laguna, Philippines.Received 1 ABSTRACT Eight indica and japonica milled rices with low amylose content and low starch gelatinisation temperature were analysed for cooked rice energy and N balance in growing rats and for protein properties. Digestible energy values were similar. Japonica rices Koshihikari and Sasanishiki had higher true digestibility (TD) and net protein utilisation in rats than indica rices IR24 and PR23383-15. Similar results were obtained from in vitro proteolysis. High TD of cooked rices was not significantly correlated with low prolamin content in raw rice and with low waxy gene product (protein bound to starch granule) but was significantly correlated with low cysteine content in protein and with low denatured prolamin content in cooked rice. In two pairs of cooked waxy milled rices, which are devoid of waxy gene product, japonica rice still tended to show higher rat TD and in vitro protein digestibility than indica rice, consistent with lower cysteine content in japonica protein.     

大豆配方施肥的研究与应用

根据几年田间大豆配方施肥试验获得的资料,确定沈阳市所属县区大豆配方施肥应用的方法为目标产量法和肥料效应函数法.     

大豆分离蛋白与低浓度尿素相互作用的红外光谱分析

大豆蛋白在食品工业中有很重要的应用,随着地球可再生资源的日益匮乏,大豆蛋白在非食品工业中的应用也越来越受到人们的关注,尿素是常用的化学变性剂,在蛋白质变性中有广泛的应用.为研究尿素变性对大豆蛋白结构的影响,对大豆分离蛋白(SPI)与低浓度尿素溶液相互作用的红外光谱进行了酰胺Ⅲ带研究.结果表明,溶解在不同浓度尿素溶液中的大豆分离蛋白的二级结构与大豆分离蛋白的水溶液相比发生了很大的变化,在0.1mol L-1尿素溶液中大豆分离蛋白中的β-折叠的含量最小,随着尿素浓度的增加,β-折叠的含量增加,无规卷曲的含量在0.1 mol L-1尿素溶液中达到最大,之后随尿素浓度增加而降低,α-螺旋和β-转角随着尿素浓度的增加,其含量都是呈现先增加后下降的趋势,在1 mol L-1尿素溶液中两者的含量与大豆分离蛋白水溶液中的含量相比变化不大.因此,低浓度尿素可以明显影响大豆分离蛋白的二级结构.     

高温高湿对大豆分离蛋白二级结构及乳化性的影响

被广泛应用于食品工业的大豆分离蛋白在贮运过程中,其功能特性可能会发生变化。研究采用不同包装形式(100%氮气铝箔包装、80%氮气:20%二氧化碳铝箔包装、60%氮气:40%二氧化碳铝箔包装、真空铝箔包装、实际工厂包装:白板纸塑/HDPE和PE包装)将大豆分离蛋白(SPI)包装后在高温高湿环境(RH 80%、30℃)条件下贮藏12个月。研究贮藏环境、时间、包装条件对SPI的二级结构及乳化性的影响。通过对酰胺Ⅰ带1 600～1 700 cm-1波段的图谱进行分析发现,PE包装中SPI的β-折叠与对照样相比显著下降(p0.05),通过对各包装中SPI功能特性的比较得出包装材质对温湿度的阻隔性:铝箔包装工厂包装PE。通过相关性分析得出,大豆分离蛋白的乳化性与β-折叠含量呈负相关(-0.675)。     

Effect of Grain Structure and Cooking on Sorghum and Maize in vitro Protein Digestibility

Uncooked and cooked sorghum showed improvement in in vitro protein digestibility as the structural complexity of the sample reduced from whole grain flour through endosperm flour to protein body-enriched samples. This was not the case for maize. Cooking reduced protein digestibility of sorghum but not maize. Treating cooked sorghum and maize whole grain and endosperm flours with alpha -amylase to reduce sample complexity before in vitro pepsin digestion slightly improved protein digestibility. The reduction in sorghum protein digestibility on cooking was not related to the total polyphenol content of samples. Pericarp components, germ, endosperm cell walls, and gelatinised starch were identified as possible factors limiting sorghum protein digestibility. Electrophoresis of uncooked and cooked protein-body-enriched samples of sorghum and maize, and prolamin fractions of sorghum under non-reducing conditions showed oligomeric proteins with molecular weights (M_r) 45, 66 and >66 kDa and monomeric kafirins and zeins. Protein-body-enriched samples of sorghum had more 45–50 kDa oligomers than those of maize. In cooked sorghum, some of these were resistant to reduction. Pepsin-indigestible residues from protein-body-enriched samples consisted mainly of α-zein (uncooked and cooked maize) or α-kafirin (uncooked sorghum), whilst cooked sorghum had in addition, β- and γ-kafirin and reduction-resistant 45–50 kDa oligomers. Cooking appears to lead to formation of disulphide-bonded oligomeric proteins that occurs to a greater extent in sorghum than in maize. This may explain the poorer protein digestibility of cooked sorghum.     

保护性耕作对土壤部分物理特性及大豆产量的影响

研究了免耕和少耕对松嫩平原地区农田土壤温度、土壤水分、土壤紧实性等物理特性和大豆产量的影响。结果表明:在春季大豆播种期,免耕处理(NT)土壤含水量高于少耕(RT)和传统耕作(CT)。在大豆生长前期,免耕条件下的土壤平均温度低于传统耕作和少耕,传统耕作和少耕接近,免耕模式的土壤温度日较差低于少耕和传统耕作。5~20 cm深度内,免耕条件下的土壤容重高于传统耕作,在10~20 cm深度内,免耕和少耕接近。不同模式间的土壤机械阻力表现出差异,在0~20 cm深度内,免耕高于少耕和传统耕作。不同耕作模式间的大豆产量差异不显著。短期保护性耕作试验结果表明:在当地气候和土壤条件下应用少免耕模式,能够减少春季播种期间土壤水分损失和沙尘暴侵袭造成的危害,同时对大豆产量并没有造成不利影响。     

糖基化大豆分离蛋白制备工艺优化及对其性质的影响

以大豆分离蛋白为试验材料,优化糖基化大豆分离蛋白制备工艺并研究经过葡萄糖处理对大豆分离蛋白溶解度、凝胶强度、乳化性以及热稳定方面的影响。结果表明:糖基化大豆分离蛋白最佳制备工艺为反应温度69.49℃、反应时间46.64 min、糖的添加量10.64%,凝胶强度最高为76.03;在相同p H下,经葡萄糖处理后的大豆分离蛋白溶解度较大,沉淀较少,而未糖基化的大豆分离蛋白沉淀量增加。糖基化处理的大豆分离蛋白乳化稳定性(emulsifying stability,ES)和热稳定性均有所增强。糖基化改性过程可显著提高大豆分离蛋白的溶解性和乳化性能,这为拓宽其在食品工业中的应用提供了理论基础。     

两种大豆同名品种鉴别方法的对比研究

针对作物种质资源保存工作中存在的库存材料同名问题,以国家种质库中10份不同来源的大豆同名品种满仓金种子为试验材料,使用电子鼻对其挥发物进行检测,通过主成分分析(PCA)及线性判别分析(LDA)对其进行区分鉴别,并对其目录性状进行分析。目录性状聚类分析结果表明:利用13个目录性状,只能将10个品种中的6个品种区分开来,其遗传距离较远;ZDD604和ZDD607,ZDD605和ZDD606则聚在一起,无法有效区分,其目录性状中分别有8个和10个性状完全一致,因此单纯依据目录性状进行品种鉴别存在一定的局限性。对电子鼻采集到的信号,利用LDA分析方法只能将10个品种区分成6类;而利用PCA分析,则能够将10个品种很好地区分开来。为验证该技术对大豆品种鉴别的有效性,使用电子鼻-PCA分析随机选取其中的2份种子进行回判,其回判准确率较高,表明电子鼻-PCA分析技术对同名大豆品种的鉴别效果是可靠的。     

荷正电大豆蛋白和丙烯酸的复合体系研究

通过酶解大豆蛋白获得荷正电大豆蛋白,采用HPLC、Zeta电位、TEM对其酶解行为进行了追踪,进一步将酶解得到的大豆蛋白与丙烯酸复合,对复合物的溶液行为和微结构进行考察研究。结果显示:酶解大豆蛋白后得到荷正电的球形粒子,其能够与丙烯酸通过静电作用形成球形的复合物SPI-AA纳米粒子,该球形粒子在加入引发剂引发聚合反应后粒径变小,在加入交联剂交联后粒径也随之变小。该纳米颗粒在药物负载、生物传感、水处理等领域有较好的应用前景。     

Impact of Feed Moisture on Microstructure,Crystallinity, Pasting,Physico-Functional Properties and In Vitro Digestibility of Twin-Screw Extruded Corn and Potato Starches

Plant Foods for Human Nutrition - The effect of extrusion feed moisture (FM) on the microstructure, pasting, physico-functional properties and in vitro starch digestibility (IVSD) of corn and...     

Feeding Value and In situ Digestibility of Edible Canna for Silage

Abstract

To assess the potentiality of edible canna (Canna edulis Ker-Gawl.) as economically and environmentally sound animal feed, the feeding value of silage prepared from aboveground parts was examined, in parallel with studies on in situ digestion in the rumen among three local varieties. Contents of crude protein, acid and neutral detergent fibers and crude ash in canna silage were significantly higher, and that of nonstructural carbohydrate was significantly lower than in corn silage. The pH of corn and ‘yellow flower’ canna silages were significantly lower (3.8~3.9) than either ‘green stem’ or ‘red stem’ canna silage (4.4~4.9). The contents of lactic acid, acetic acid, total organic acid and the Flieg’s score of ‘yellow flower’ canna silage were equivalent or superior to those of corn silage. The rate of disappearance of dry matter in the rumen was significantly higher for corn silage than for canna silage, while the disappearance of neutral detergent fiber in canna silage was more rapid during the first 12 hours of incubation, but less rapid thereafter. The effective degradability of dry matter and organic matter of canna silage in the rumen was significantly higher than that of corn. Silage made from edible canna has a potential as a feed for ruminants.     

不同粒径鹧鸪茶粉体表征与理化特性的比较研究

本研究以海南植物鹧鸪茶为研究对象,比较了鹧鸪粗粉（D₅₀为120.45 mm）、细粉（D₅₀为65.86 mm）、超微粉Ⅰ、超微粉Ⅱ和超微粉Ⅲ5种粉体的表征与理化特性。通过色度测定、粒径测定、电镜扫描分析、红外光谱分析,探究5种不同粒径鹧鸪粉体的加工特性、流动性,以及5种粉体茶多糖和皂苷含量的变化规律。结果表明:随着粉体粒径逐渐减小,其溶解度、润湿性、流动性均增大,膨胀度、持水力减小;鹧鸪茶超微粉的茶多糖、皂苷含量明显高于粗粉、细粉;随着超微粉碎时间的延长,茶多糖含量逐渐增大,皂苷含量各不相同。不同粒径鹧鸪茶粉体的特性各不相同,综合比较得出,超微粉的溶解度、茶多糖、皂苷含量较高,更容易被人体吸收,生物利用度高,加工方便。因此,鹧鸪茶超微粉具有较好的开发前景。     

生物炭对盐碱土理化性质及大豆产量的影响

为改良松嫩平原盐碱地土壤地力,提高作物产量,对生物炭改良盐碱土的技术理论进行完善,用随机区组设计,研究了不同生物炭用量对盐碱土水分渗透性及大豆产量的影响。结果表明,生物炭增加了盐碱土水分渗透性能,生物炭处理Y3初始渗透速率、平均渗透速率、稳定渗透速率、累积入渗量和饱和渗透系数分别为CK的23.75,28.46,23.69,24.42和24.79倍。生物炭增加了盐碱地的有机质、速效磷、速效钾、全氮、全磷和全钾含量。生物炭处理Y3的大豆产量最高,单株产量达3.17 g,为CK的2.22倍。     

发芽黑豆乳的制备及其稳定剂配方优化研究

为全面提升发芽黑豆乳的营养特性及口感,将发芽48 h的黑豆芽经过磨浆分离、煮浆灭酶、果胶酶和纤维素酶水解后得到发芽黑豆原浆,并以此为主要原料,添加牛奶、白砂糖和柠檬酸调配成发芽黑豆乳.以感官评价和可溶性固形物含量为指标进行单因素试验,在此基础上通过正交试验优化发芽黑豆乳的配方;在发芽黑豆乳优化配方条件下,进一步以稳定系...     

Digestibility and Structural Properties of Thermal and High Hydrostatic Pressure Treated Sweet Potato (Ipomoea batatas L.) Protein

This study assessed the effects of thermal (40, 60, 80, 100 and 127 °C) and high hydrostatic pressure (HHP, 200, 400 and 600 MPa) treatments on the in vitro digestibility and structural properties of sweet potato protein (SPP). The results showed that the in vitro digestibility of SPP increased significantly with increasing heating temperature and heating time (0–60 min), while HHP treatment had little or no effect. Native SPP denaturation temperature (T _d ) and enthalpy change (ΔH) were 89.0 °C and 9.6 J/g, respectively. Thermal and HHP treated SPP had T _d of 84.6–88.9 °C and 86.4–87.6 °C, respectively. ΔH of thermal treated SPP was 3.6–6.4 J/g, while that of HHP treated SPP was 5.9–7.8 J/g. The differential scanning calorimetry (DSC) results demonstrated that HHP and thermal treatments both significantly reduced SPP thermodynamic stability. Circular dichroism analyses revealed that native SPP contains α-helixes, β-sheets and random coils (4.3, 48.0 and 47.7 %, respectively). After thermal treatment at 127 °C for 20 min, the content of α-helixes and turns increased significantly (13.2 and 27.6 %, respectively), whereas the content of β-sheets decreased significantly (12.3 %). In contrast, HHP treatment increased the content of β-sheets, but decreased the content of random coils. This study suggested that the SPP structure changes might be the main reason affecting the in vitro digestibility of SPP, and thermal treatment was more effective at changing SPP secondary structures and improving in vitro SPP digestibility than HHP treatment.     

关于玉米品种DUS测试的几点思考

针对玉米品种DUS测试中存在的实际问题,从标准品种、测试性状、对照品种、繁殖材料提供、特异性、分子标记等方面进行了全面分析,并对部分问题提出了相应的解释或解决方法。     

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。     

玉米大豆长期轮作对土壤物理特性与水热特征的影响

合理耕层能够提高土壤应对气候变化的缓冲能力,有利于协调土壤中水、肥、气、热的关系,为作物生长发育创造适宜的水热环境。借助长期定位试验,开展了玉米连作、玉米-大豆轮作以及大豆连作等不同处理下的土壤物理性状与土壤水热特征评价。土壤采样分析与田间水热定位观测发现,玉米连作处理与玉米-大豆轮作和大豆连作处理相比,可显著降低土壤容重,增加土壤总孔隙度(P0.05),其中0~10 cm土壤层次下土壤容重分别降低12.9%和19.8%,10~20 cm层次分别低21.4%和23.2%,20~40 cm层次分别降低23.9%和29.2%,40~60 cm层次则分别降低20.3%和25.2%;玉米连作处理可显著提高5~6月份土壤水分储量,特别是0~40 cm土层下,玉米连作处理分别比玉米-大豆轮作和大豆连作处理高6.5%和6.3%、3.6%和3.4%,且差异显著,而玉米连作处理下较高的土壤水分含量有利于促进作物前期生长和后期群体质量改善;从0~30 cm土壤温度来看,不同处理间全生育期无显著差异。上述结果表明,长期玉米连作配合合理施肥可显著改善土壤结构,增加土壤水分储量,促进作物前期生长发育。     

大豆与玉米、小麦、高粱根系分泌物的比较分析

为研究大豆根系分泌物在大豆连作障碍中的作用,以二氯甲烷作为溶剂,提取培养28 d的大豆,小麦,玉米,高粱的根系分泌物,运用气质连用仪分离鉴定,找出大豆与其它3种作物根系分泌物的差异.结果表明:用该法鉴定出大豆根系分泌物成分77种,小麦97种,玉米84种,高粱80种.4种作物均鉴定出烷烃、醇、酸、酯、苯、酚、萘、酰胺、酮、醛类以及其他类化合物.将4种作物的根系分泌物进行比较,相同成分有丙三醇、2,4-戊二醇、邻苯二甲酸、乙苯、对二甲苯、苯乙烯、4-甲基-2,6-二叔丁基苯酚、甲基酚和一部分烷烃等.二苯呋喃,芴,3-甲基-4-氧-戊酸,2-亚甲基-丁醛,3-羟摹-丁醛,己醛,9,10-二氢-11,12-乙酰-9,10-桥亚乙基总等是大豆根系分泌物中独有成分,其在大豆生长过程中的化感作用有待进一步研究.