CO2超临界流体法提取银杏叶黄酮工艺的研究

通过正交试验对二氧化碳超临界流体法提取银杏叶中黄酮工艺进行研究。正交实验结果分析表明超临界流体萃取最佳工艺条件为：萃取压力35MPa,萃取温度50℃,萃取时间1．5h,夹带剂浓度90％。     

葛根的解剖结构及主要化学成分的组织化学定位

笔者采用植物显微技术和组织化学方法,对葛根进行了解剖学和组织化学定位试验.结果表明,葛根次生结构中木栓层发达,纤维束多数,韧皮纤维居多,可行使良好的保护和支持功能;木质部导管数量多且管腔较大,三生结构中导管多数,可充分满足水分与养分的长途运输和较高的生理需求;多糖类物质主要贮藏在栓内层、韧皮部以及周皮和韧皮部之间的基本组织内;黄酮类物质主要贮藏在栓内层、韧皮薄壁组织及木薄壁组织.     

水分胁迫对苦荞幼苗黄酮类物质含量的影响

以苦荞"榆6-21"为试验材料,对不同水分胁迫下的苦荞芽菜总黄酮、芦丁和槲皮素含量进行了测定和分析,结果表明在荞麦芽菜中,槲皮素的含量甚微。水分胁迫可以增加荞麦总黄酮和芦丁含量。复水以后,水分胁迫处理的幼苗总黄酮和芦丁含量仍高于对照。荞麦幼苗的黄酮和芦丁含量同样受发育的调节。     

赤楠叶总黄酮微波-碱水法提取工艺及其含量动态研究

[目的]探索赤楠叶总黄酮的提取工艺及含量动态变化。[方法]采取微波-碱水法提取赤楠叶总黄酮,通过单因素试验与正交试验对其工艺条件进行正交优选,以优选工艺条件提取不同月份的赤楠叶总黄酮,紫外分光光度法测定与考察其含量动态变化。[结果]微波功率对赤楠叶总黄酮提取率有显著影响,碱水pH值有极显著影响,优化的微波-碱水法提取工艺条件为:以原料50倍量的pH值为12的碱水,在微波功率300 W的条件下提取8 min,提取次数为1次;赤楠叶总黄酮含量在11月份左右达到最高,8月份左右降到最低。[结论]微波-碱水法提取工艺是一种高效的、节约成本的赤楠叶黄酮提取方法,叶黄酮提取的最佳采叶期以11～12月为宜。     

菊芋总黄酮提取工艺研究

采用乙醇提取法从菊芋中提取总黄酮,在单因素试验的基础上用正交试验进行工艺参数的优化。结果表明,最优提取条件为:提取温度80℃,70%乙醇,料液比1:20,提取时间40 min。     

Investigation of amber durum wheat for production of yellow alkaline noodles

Samples of Canadian amber durum wheat varieties, of various protein content and a composite of export cargo samples, were milled to yield straight-grade and patent flours by reducing semolina and processed into yellow alkaline noodles (YAN). Samples of Canada Hard White Spring (CWHWS) and Canada Western Red Spring (CWRS) were included for comparative purposes. YAN from durum wheat displayed a colour advantage over CWRS and CWHWS YAN. The durum YAN displayed an approximate 9–20 unit greater b* (yellowness) value than CWRS and CWHWS at 2 and 24 h after preparation. This relates to greater yellow pigment and flavonoid contents in the durum flours. All durum wheat YAN exhibited excellent noodle brightness, which was retained over time due to lower levels of the enzymes polyphenol oxidase (PPO) and peroxidase (POD). Durum noodles displayed significantly fewer specks than CWRS and were comparable to CWHWS. Durum wheat YAN cooking quality was equal to or slightly superior to CWRS and CWHWS. Durum wheat flour refinement imparted no significant effects on cooked noodle texture (maximum cutting stress, recovery, resistance to compression). However, the various texture parameters improved with durum wheat protein content and gluten strength.     

Anti-hyperglycemic action of apigenin-6-C-β-fucopyranoside from Averrhoa carambola

A stimulatory effect of apigenin-6-C-β-fucopyranoside (1) on glucose uptake was observed when rat soleus muscle was incubated with 1, 10 and 100μM of this flavonoid glycoside. The presence of specific insulin signaling inhibitors, such as wortmannin, an inhibitor of phosphoinositide 3-kinase (PI3K), RO318220, an inhibitor of protein kinase C (PKC), PD98059, an inhibitor of mitogen-activated protein kinase (MEK), and HNMPA(AM)(3), an insulin receptor tyrosine kinase activity inhibitor showed that apigenin-6-C-β-fucopyranoside triggers different metabolic pathways in skeletal muscle. The oral administration of crude extract, fractions and isolated flavonoids (apigenin-6-C-β-fucopyranoside (1) and apigenin-6-C-(2″-O-α-rhamnopyranosyl)-β-fucopyranoside (2)) from Averrhoa carambola leaves exhibited a potential hypoglycemic activity in hyperglycemic normal rats. Additionally, both flavonoids significantly increased the muscle and liver glycogen content after an acute treatment. The results indicate that A. carambola can be regarded as a potent antihyperglycemic agent with insulin secretagogue and insulin mimetic properties.     

滁菊中黄酮和酚酸的鉴定及其对卷烟感官质量的影响

[目的]研究滁菊提取物对卷烟感官质量的影响,探寻滁菊开发利用的新途径。[方法]采用LC-MS方法对滁菊中的黄酮和酚酸进行了分离鉴定,并对滁菊提取物对卷烟感官质量的影响进行了研究。[结果]滁菊中的黄酮类物质主要是芹黄素、木犀草素、香叶木素、槲皮素及它们的糖苷,酚酸类物质主要是绿原酸、咖啡酸和咖啡酰奎宁酸。总多酚中,酚酸含量超过60%。滁菊提取物在卷烟中添加量0.4～0.6 g/kg时可显著改善余味,降低刺激性,增加香气量,是较为理想的卷烟香味前体物。[结论]该研究为滁菊的开发利用提供了新平台。     

天然植物防腐剂在酱腌菜中的应用

[目的]探讨天然植物防腐剂能否成为酱腌菜中有效的防腐剂并应用于生产中。[方法]以苦荞麦、蒲公英、丁香为原料,对其中的黄酮、丁香乙醇提取物、蒲公英甾醇等功能性成分进行提取,并对其抑菌性进行研究。[结果]按照丁香提取物:苦荞麦提取物:蒲公英提取物=3∶3∶2的最佳比例添加到酱腌菜中,进行防腐试验。结果表明,天然植物防腐剂在pH为4～5的条件下的防腐效果最好,冷藏环境好于常温和恒温环境,在常温条件下天然植物防腐剂的防腐效果可达60 d。[结论]天然植物防腐剂对于酱腌菜的风味有改善的作用,且其防腐效果与化学防腐剂的效果相当。     

马蹄金叶片黄酮提取条件的优化及其抗氧化活性的研究

研究了马蹄金叶片中黄酮类化合物的提取及其对菜油的抗氧化作用。采用超声波法对马蹄金叶片中的黄酮类化合物进行提取,并采用正交分析确定马蹄金叶片中总黄酮提取的最佳条件,通过对提取液浓度、提取时间、提取液体积和提取次数4因素3水平的选择试验,得出最佳提取条件为:以70%的乙醇作为提取液、提取体积为80mL、提取时间为1.5h、提取1次。在此条件下,马蹄金叶片总黄酮平均提取量为4.2820mg/mL。将马蹄金叶片提取物以不同比例添加到菜油中,恒温70±1℃并定期用碘量法测定油样的POV值。结果表明,马蹄金叶片中的黄酮类化合物对菜油具有明显的抗氧化作用,且黄酮类化合物的添加量在试验计量范围内与其抗氧化活性成正相关;当其添加量0.5%时,马蹄金叶片中黄酮类化合物的抗氧化性可与0.02%BHT相媲美。同时还研究了马蹄金叶片黄酮类化合物清除羟基自由基的能力,发现其浓度大于0.5mg/mL时清除羟基自由基的能力与VC相当。