The effects of six phenolic acids and tannic acid on colour stability and the anthocyanin content of mulberry juice during refrigerated storage

Six phenolic acids and tannic acid are added to fresh mulberry juice to enhance the colour. Effects of these copigments on colour stability and the anthocyanin content of mulberry juice are investigated while being stored at 4 °C for 30 days. Results suggest that the addition of the copigments markedly increases the maximum absorbance of mulberry juice. Cyanidin-3-glucoside is the major anthocyanin, followed by cyanidin-3-rutinoside. Furthermore, the retention rate of the total anthocyanin, cyanidin-3-rutinoside and cyanidin-3-rutinoside increases after the addition of all copigments. The effect of ferulic acid on the stability of total anthocyanin, cyanidin-3-glucoside and cyanidin-3-rutinoside in mulberry juice is the best, 89.52%, 86.90% and 94.46% respectively (66.56%, 62.58% and 73.60% in the control group). Researchers recommend the addition of ferulic acid, p-coumaric acid and caffeic acid – all of which belong to the hydroxycinnamic acid group, to the mulberry juice to enhance the colour stability and anthocyanin content.     

桑叶粉添加量对生鲜面条品质及抗氧化活性的影响

为探究桑叶粉对生鲜面条品质及抗氧化活性的影响，扩大桑叶粉在面制品中的利用范围。该试验采用不同比例桑叶粉（0、2%、4%、6%、8%、10%）替代小麦粉制成混粉面团，进行温度扫描测定面团黏弹性。测定面条蒸煮特性、色差、质构、感官、抗氧化性等指标。结果表明，混合面团的黏弹性均在75~95 ℃左右显著增大。在一定范围内，随着桑叶粉比例增加，面筋网络结构致密均匀，内部结构显著改善，面条的硬度也显著增强，但是过量添加，导致淀粉颗粒之间缝隙较大，蛋白结构无序化，影响面筋网络结构稳定性。当桑叶粉添加量为4%时，生鲜面条断条率为0，蒸煮损失为5.07%，弹性、咀嚼性、感官评分皆达到最大值，分别为0.96 mm、7.70 mJ、90分。DPPH和ABTS+自由基清除率与对照组相比分别提高了2.69和1.27倍。在生鲜面条制作时加入一定量的桑叶粉制成的面团具有较好黏弹性，可以有效改善面条的蒸煮特性、质构特性、色泽以及感官评价，同时提高面条的抗氧化活性，为桑叶粉在面食及焙烤食品中的应用提供了参考依据。     

桑叶染色液的提取及贮存过程的变化

为解决桑叶作为天然植物染料源在工厂实用化中的一些问题进行了本研究。桑叶染色液既可用鲜桑叶也可用桑叶粉提取,用桑叶粉有利于工厂贮存和加工;桑叶粉可由桑叶经日晒粉碎、烘干粉碎得到,日晒式节约、方便,即有利于农户也有利于厂商;桑叶提取染色液为碱性、在阴凉的室温下避光可以保存一段时间,还原剂的加入可使保存时间延长;用20g/L的Na OH作为提取剂时,采用大浴比1∶100,一次性沸煮提取的方法较节约。     

Efficient gene delivery to mesenchymal stem cells by an ethylenediamine-modified polysaccharide from mulberry leaves

This study investigates the use of a natural polysaccharide isolated from mulberry leaves as a nonviral gene vector. Ethylenediamine is chemically grafted to the backbone of a polysaccharide from mulberry leaves (MPS) to acquire nucleic acid binding affinity. A particle-size observation indicates that the cationic mulberry leaf polysaccharide (CMPS) can efficiently combine with plasmid transforming growth factor β1 (TGF-β1) to form nanoscaled particles. In addition, the electrophoresis assay indicates a retarded plasmid migration when the CMPS/pTGF-β1 weight ratio is increased to 30:1. The in vitro cell transfection experiment is performed based on bone marrow mesenchymal stem cells (MSCs) derived from rat femurs and tibias, and the findings reveal that the complex with a CMPS/pTGF-β1 weight ratio of 50:1 exhibits the highest cell transfection effect, which is significantly higher than that of branched poly(ethyleneimine) (PEI) (25 kDa; p = 0.001, Student's t-test) and slightly higher than Lipofectamine 2000. Moreover, the cytotoxicity assay also demonstrates that all of these tested complexes and the plasmid TGF-β1 are nontoxic to mesenchymal stem cells (MSCs). The results of the living cell imaging confirm that more of the CMPS/plasmid TGF-β1 nanoparticles can be taken up and at a faster rate by the MSCs than by the positive control Lipofectamine 2000; these data are consistent with the transfection efficiency data. Together, these results suggest that the CMPS/pTGF-β1 nanoparticle can potentially be developed into a promising alternative for the transfer of therapeutic genes into cells.     

浅析蚕丝被生产现状与发展前景

介绍了蚕丝被的特性、生产现状和传统手工制作工艺存在的弊端;阐述了应用非织造技术生产蚕丝被的工艺过程及其优势。蚕丝被和蚕丝非织造絮片有着很好的市场前景。     

药桑红色素纯化工艺研究

对药桑红色素的纯化工艺进行了研究,比较了AB-8、D-101、氧化铝、聚酰胺(14-30目)、聚酰胺(100-200目)五种吸附剂对药桑红色素的静态吸附-脱附性能,结果表明:AB-8大孔树脂对药桑红色素具有较强的选择性,在相同试验条件下,吸附量大,且易被解吸。在此研究的基础上进行了AB-8大孔树脂分离纯化药桑红色素的最佳工艺研究,比较了原料液浓度,NaCl浓度,原料液pH值,洗脱剂浓度,洗脱剂pH值等对树脂静态吸附-解吸的影响,并在静态试验的基础上,进行了动态吸附-解吸试验的研究,以确定最佳吸附、解吸流速,结果表明,AB-8大孔树脂对药桑红色素分离纯化最优吸附条件为:原料色素液pH值为2.04,吸光度为0.567,吸附流速1mL/min;最优洗脱条件为:洗脱剂(乙醇)浓度95%,pH值为1,洗脱流速0.8mL/min。此工艺条件能够较好地分离纯化药桑红色素。     

Physiological optimality,allocation trade‐offs and antioxidant protection linked to better leaf yield performance in drought exposed mulberry

BACKGROUND: Mulberry (Morus spp. L.), usually linked to silkworm rearing, is now considered as a potential forage for livestock feeding and has great potential in world agriculture. Trait‐based investigations for leaf yield stability in mulberry under water stress have not been studied extensively. The present study aims to identify candidate traits conferring leaf yield stability in mulberry under drought. RESULTS: Four popular, indigenous mulberry cultivars (Morus indica L. cvs AR‐12, K‐2, M. Local and V‐1) were investigated. Low leaf temperature (T_l), higher internal/ambient CO₂ ratios (C_i/C_a), greater stomatal conductance to CO₂ (g_s) and stability in photosystem II efficiency were associated with better net photosynthetic rates (P_n) in V‐1, generating maximum leaf yield when compared to other drought‐exposed cultivars. Increased accumulation of foliar α‐tocopherol and ascorbic acid–glutathione pool, associated with higher carotenoids, proline and glycine betaine, facilitated lower lipid peroxidation and better leaf yield in V‐1 under drought. CONCLUSION: Minimal plasticity in photosynthetic gas exchange traits and better quantitative growth characteristics were attributed to leaf yield stability under drought. Lower photoinhibition, stabilized photochemistry, effective osmoregulation and enhanced activity of foliar antioxidants extensively contributed to drought tolerance and higher leaf yield in mulberry. Copyright © 2010 Society of Chemical Industry