苜蓿叶蛋白脱色脱腥最佳工艺参数的研究

以无水乙醇为浸提剂,设计单因素试验研究浸提温度、浸提级数、浸提时间及浸提料液比对苜蓿叶蛋白脱色、脱腥效果的影响;在此基础上采用四因素三水平正交试验对苜蓿叶蛋白脱色、脱腥最佳工艺进行优化,研究结果表明:影响因素的主次顺序为浸提级数、浸提温度、浸提时间及浸提料液比;其最佳工艺条件为浸提料液比为1∶8 g/mL,浸提温度60℃,浸提时间7 h,浸提级数2级。该研究旨在使苜蓿叶蛋白成为植物性蛋白源。     

Growth environment,harvest management and germplasm impacts on potential ethanol and crude protein yield in alfalfa

An alfalfa (Medicago sativa L) biomass energy production system would produce two products. Leaves would be separated from stems to produce a protein feed for livestock while stems would be processed to produce ethanol. Therefore, maximum yields of both leaves and stems are essential for profitability of this biomass production system. Our objective was to evaluate the impact of growth environment (locations, years and plant density) and harvest maturity stage (early bud (4 annual cuts) and late flower (3 annual cuts)) on leaf crude protein and potential ethanol yields for four alfalfa germplasms, two with high forage quality, and two non-lodging biomass types. Potential ethanol yield was greater at late flower compared to early bud, while leaf crude protein concentration was similar at the two harvest maturity stages at both locations. Leaf crude protein yield was greater at the Minnesota (MN) site compared to Wisconsin (WI) site. The two non-lodging biomass germplasms had greater potential ethanol yield compared to the high forage quality cultivars in WI, but no differences among the alfalfa germplasms were found for ethanol yield at MN. In WI, no differences were found among the germplasms for leaf crude protein yield, but the high quality cultivars had greater leaf crude protein yield than the non-lodging germplasms in MN. While germplasm differences were found for leaf crude protein and potential ethanol yields, the environmental influences of harvest date and locations had the greatest impact on these two alfalfa biomass energy products.     

紫花苜蓿化学成分的研究进展

本文对紫花苜蓿的国内外化学成分研究进展进行了综述,可为今后该属植物的研究与应用提供参考。     

Microbial Quality of Alfalfa Seeds and Sprouts after a Chlorine Treatment and Packaging Modifications

ABSTRACT: Alfalfa seeds were treated with chlorine to determine the effect on microbial populations during soaking, sprouting, and refrigerated storage in three packaging environments. Chlorine was effective in reducing microbial populations on the seeds, but numbers increased during sprouting. Chlorine treatments had the most impact on yeast and molds during storage. Yeast and molds were significantly higher in sprouts that were stored in vacuum packages and in sprouts from non-chlorine treated seeds stored in MAP. Yeast and mold counts on all sprouts stored in perforated packaging did not significantly increase during storage. A combination of chlorine treatment of the seeds and preforated packaging of sprouts may increase the shelf-life.     

Antioxidant activity of peptides isolated from alfalfa leaf protein hydrolysate

Alfalfa leaf protein, a potential source of high quality protein for human consumption, was hydrolyzed with protease. Alfalfa leaf protein hydrolysate was fractionated by ultrafiltration and the obtained peptides were purified by dynamical adsorption. The antioxidant activity of alfalfa leaf peptides (ALPs) was investigated and compared with that of a native antioxidant, reduced glutathione (GSH), which was used as a reference. The reducing power of ALPs was 0.69 at 2.00 mg/mL. ALPs at 1.60 mg/mL and 0.90 mg/mL exhibited 79.71% and 67.00% of scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide radical, respectively. In addition, ALPs showed 65.15% chelating effect on ferrous ion at 0.50 mg/mL. The molecular weight of the peptides was determined and 67.86% of the total amount was below 1000 Da. Combined with the result of the amino acid profiles, ALPs was believed to have high nutritive value in addition to antioxidant activity.     

苜蓿叶蛋白中氨基酸的含量及营养分析

应用模糊识别法和氨基酸比值系数法,以鸡蛋蛋白质为标准蛋白,以WHO/FAO氨基酸参考模式为评价标准,对苜蓿叶蛋白营养价值进行了全面评价,并与4种叶蛋白进行对照比较.结果表明:苜蓿叶蛋白中总氨基酸含量为56.30%～70.54%,蛋白质中氨基酸种类齐全,必需氨基酸(EAA)占总氨基酸量的40.00%～40.60%,第一限制性氨基酸为赖氨酸,氨基酸比值系数分为78.52～85.76,其叶蛋白营养价值高,是一种值得开发利用的优质植物蛋白.     

RAPD analysis of alfalfa DNA mutation via N~+ implantation

Germination capacity of alfalfa seeds under low energy N+ implantation manifests oscillations going down with dose strength. From analyzing alfalfa genome DNA under low energy N+ implantation by RAPD (Random Amplified Polymorphous DNA), it is recommended that 30 polymorphic DNA fragments be amplified with 8 primers in total 100 primers, and fluorescence intensity of the identical DNA fragments amplified by RAPD is different between CK and treatments. Number of different polymorphic DNA fragments between treatment and CK via N+ implantation manifests going up with dose strength.     

苜蓿多糖提取优选工艺条件的研究

选择热水浸提，以浸提时间，温度，浸提固液比以及提取次数作为单因素进行梯度实验，通过方差分析，并进行LSD多重比较作显著性分析，确定其条件范围，再通过进一步的正交实验L9(3^4)得到苜蓿水溶性多糖浸提工艺的优选因素组合：浸提时间1h，温度100℃，固液比1：40，浸提三次。粗多糖提取率达6．80％，经醇沉，5％三氯乙酸正丁醇溶液及氯仿正丁醇溶液（5：1）分离纯化，得脱蛋白粗多糖。     

紫花苜蓿根系拉拔试验研究

为了研究紫花苜蓿根系的拉拔力学性质和评价其根系固土力学机制的增强效应,采用室外原位拉拔试验分析了影响苜蓿根系拉拔力的因素。试验结果表明：① 紫花苜蓿根系拉拔力随着直径、根长、根系表面积的增大而增大,抗拉力与直径增长趋势呈指数关系,根长L2（20~30 cm）比根长L1（10~20 cm）平均拉拔力增大了69.62%,根长L3（30~40 cm）比根长L2平均拉拔力增大了61.7%,根长L3平均拉拔力比根长L1增大156.16%。② 拉拔力随根系表面积的增大而增大;根长L2、L3的平均根系表面积分别是根长L1的2.28倍和5.17倍;根长L2、L3平均拉拔力分别是根长L1的1.70倍和2.66倍。③ 紫花苜蓿根系拉拔力与植物根径呈负相关,满足幂指函数关系。拉拔强度T的大小为T3 (30~40 cm)>T2 (20~30 cm)>T1 (10~20 cm),根长L2、L3的平均拉拔强度比根长L1的减小了14.70%,53.71%。     

不同丛枝菌根真菌对铁尾矿基质的改良效果

将4种不同生态型的丛枝菌根真菌接种于马钢南山铁矿尾矿基质中,通过紫花苜蓿盆栽试验比较菌根真菌对尾矿基质的改良效果。研究结果表明:4种不同生态型菌根真菌与对照相比,均能增强紫花苜蓿根际土壤酸性磷酸酶的活性,提高紫花苜蓿对基质中磷元素的吸收能力,增加紫花苜蓿的生物量,其中来源于某铜尾矿的Glomus intraradices在改善尾矿基质理化性状、促进紫花苜蓿生长方面的效果最佳。