Studies on the Flavonoids and Antioxidant Activities in Leaves of Black Currant

The fresh leaves and oven dried leaves from three varieties of black currant (Brodtrop,liangye,Risager)were analysed for the total contents of flavonoids by spectrophotometric methods in terms of rutin equivalent.In addition,antioxidant activities of different addition amounts of extracts of black currant (Brodtrop)leaves in lard were measured by the Oven-Storage Test,and compared with the synthetic antioxidants.The results showed the contents of the flavonoids were very rich in the leaves of three varieties from black currant.Among them the leaves of Brodtrop had the highest contents of flavonoids followed by liangye and Risager.The total contents of flavonoids in fresh leaves reach 231 70 mg/100 g,170 01 mg/100 g and 78 07 mg/100 g respectively.In the same circumstance the oven dried leaves were 397 82 mg/100 g,275 89 mg/100 g and 169 73 mg/100 g.The extracts of the leaves from Brodtrop exhibited strong antioxidant activities on lard,which increased with the addition amount of the flavonoid extracts.The antioxidant activities decreased in the order of 0 02% quercetin >0 02% BHT(butylated hydroxy toluene)>0 40% extracts>0 20% extracts>0 10% extracts>0 05% extracts>0 02% extracts>control.

Effects of fruit thinning on ascorbate–glutathione cycle metabolism in black currants(Ribes nigrum L.)

To elucidate mechanisms regulating ascorbic acid (AsA) biosynthesis and accumulation in the fruit and leaves of black currants, AsA and the activities of key enzymes in the ascorbate-glutathione (AsA-GSH) cycle were measured from fruit set to fruit ripening during fruit thinning treatments of three common commercial black currant cultivars that differed in their AsA levels: 'Risager' (low), 'Brodtrop' (medium) and 'Adelinia' (high). Treatments were 50% fruit reduction (50% of total fruit set) by hand, control was no thinning. Fruit thinning treatment significantly increased AsA content in fruit of all three cultivars from weeks 2 to 8, significantly decreased AsA content in leaves from weeks 3 to 8. Dehydroascorbate reductase and monodehydroascorbate reductase activities in fruit and leaves had a similar pattern, increasing during week 2, rose until they peaked in week 4. Ascorbate peroxidase activity in fruit in the thinning treatment was slightly lower than in the control. Fruit thinning was shown to be a good model to test AsA biosynthesis regulation and accumulation in black currants. The results from our study provided strong evidence that AsA-GSH cycle involved in AsA synthesis and accumulation in fruit.

Effects of GA3 and ABA on the respiratory pathways during the secondary bud burst in black currants

The effects of exogenous gibberellic acid (GA(3)) and abscisic acid (ABA) on the total respiratory rate, percentages of total respiratory rate contributed by respiratory pathways [Embden-Meyerhof- Parnas Pathway (EMP), Pentose Phosphate Pathway (PPP), and Tricarboxylic Acid Cycle (TCA)], and conversion of starch to soluble sugars in the buds of black currants during secondary bud burst were investigated to determine the relationship between respiratory rates and secondary bud burst. 'Adelinia', a black currant cultivar that is prone to secondary bud burst after the first harvest, was used in this study. Mature bushes of Adelinia were sprayed with 30 mg/L GA(3) and 50 mg/L ABA to manipulate bud burst. The results showed that exogenous applications of GA(3) and ABA had opposite effects on bud respiratory rate. Generally, GA(3) treatment increased the total respiratory rate and respiratory rate of the TCA and PPP, and the respiratory rates after GA(3) treatment were higher than those of control. While ABA treatment mostly decreased the total respiratory rate and the respiratory rate of TCA and PPP in buds in comparison to control. In terms of the percentage of the three respiratory rates in comparison to the total respiratory rate, GA(3) treatment significantly increased the percentage of TCA and PPP respiratory rate in comparison to the control (P < 0.01), whereas ABA decreased the rates. GA(3) significantly increased the content of soluble sugars and decreased the starch content, while the starch content in buds after ABA treatment was significantly higher than that of the control. All results showed that PPP is a critical process for the second bud burst in black currants. While the EMP-TCA pathway is still dominant in bud respiration, provides a series of basic materials and energy (ATP). The conversion of starch to soluble sugars is essential for bud burst. Thus, we conclude that an energy shortage is a main contributor in ABA inhibition of the secondary bud burst of black currants.

Physiological Effects of Rare Earths on Black Currant Plants

Various concentrations of ''Nongle'' rare earth were applied on 'Xinbin'' cultivar of black currant plants. The results indicated that leaf chlorophyll contents, photosynthetic rate, stomatal conductance, photon flux density and leaf transpiration rate of black currant plants were influenced significantly by rare earth applied on leaves. Foliage application of 300 to 800 mg/L rare earth two times in the growing season was better than those applied once.

Studies on Optimal Extraction Conditions of Flavonoid in Leaves of Black Currnt

Employing the orthogonal design,the optimal extraction conditions for flavonoid in leaves of black currant were determined by colorimetric estimation,which were extraction agent of 75% EtOH-H 2O,the material ratio(ratio of weight of fresh leaves to volume of the solvent)of 1:16,the temperature of 35℃,the time of 1 h and times of three.A total extraction rate of over 97% and the flavonoid contents of 179 33 mg/100 g were obtained under the optimal extraction conditions.

Black-scholes期权定价公式的显式差分近似

研究了期权价格变化的Black-scholes方程,利用Δ-对冲原理和Itô积分公式,通过函数变换转化为抛物线方程,并通过泰勒展开得到了方程的差分格式。证明了差分格式的相容性、差分解的稳定性以及敛散性.通过数值模拟,验证了差分格式的有效性。

黑穗醋栗汁和鼠李汁混合发酵酒工艺研究

将鼠李和黑穗醋栗进行混合发酵得到一种新的发酵酒,通过对发酵酒的感官特性及正交试验进行综合评定,确定出该混合发酵酒的最佳配比为:将新鲜的鼠李汁和黑穗醋栗汁按照1∶1的比例混合后,糖度为25%,酸度pH为3.2,温度为14℃,接种量为8%,按此配方生产出的发酵酒果味纯正、酒体透明澄清、入口清爽、轻快柔和、酸甜适口。对发酵酒的微生物和理化指标进行测定,表明其安全健康。

黑穗醋栗优良品种——黑珍珠

由国外引入的黑穗醋栗品种中选出丰产、抗寒、晚熟、果实大、含糖量高、抗白粉病能力强的‘黑珍珠’品种。该品种适宜东北、西北等地商业性栽培。

大果优质黑穗醋栗新品种‘布劳德’

‘布劳德’是由波兰引入经试栽后选育出来的黑穗醋栗新品种。多年的观察结果表明 :该品种果实个大 ,整齐 ,平均单果质量 2 .6g ,最大 3.8g ,熟期一致 ,可以一次性采收 ,未见感染白粉病 ,整个生育期不用施药 ,丰产性强 ,为大果、抗病、丰产、生食与加工兼用型品种。

响应面法优化黑加仑果醋的发酵条件

采用响应面分析法(RSM)优化黑加仑果醋发酵的工艺条件。在初始酒精体积分数、pH值、装液量、摇床转速4个因素的单因素试验基础上,采用Box-Behnken试验设计,通过响应面分析,对黑加仑果醋的发酵工艺条件进行优化。结果表明:黑加仑果醋发酵的最佳工艺条件为:初始酒精体积分数5.7%、pH4.5、装液量97mL/500mL、摇床转速126r/min,在此条件下的验证实验表明,黑加仑果醋的醋酸转化率为96.78%。黑加仑发酵型果醋呈玫瑰红色,果香浓郁,酸爽柔和。

溶剂法提取黑加仑籽油

采用多种不同溶剂对黑加仑籽进行提取,选定了丙酮为最佳提取溶剂,通过正交实验确定最佳提取条件为:提取温度55℃,提取时间40min,料溶比1∶2.5。在最佳提取条件下,可得到平均出油率为13.648%的较好结果。

黑加仑提取物抗疲劳作用的动物实验研究

目的研究黑加仑提取物抗疲劳作用。方法将SPF级昆明种小鼠按体重随机分成黑加仑提取物高、中、低剂量组、黑加仑原汁组和溶剂对照组。每日灌胃1次,连续30d后,分别测定小鼠负重游泳时间、肝糖原含量、血清尿素氮含量。结果黑加仑提取物各剂量组能延长小鼠负重游泳时间、增加肝糖原含量、减少血清尿素氮含量。与黑加仑原汁组比较,黑加仑提取物高、中、低剂量组负重游泳时间均延长,肝糖原含量均升高,高、中剂量组血清尿素氮含量均降低。结论黑加仑提取物具有一定的抗疲劳作用,且优于黑加仑原汁组。

黑穗醋栗营养成分和保健功能及产业发展前景

黑穗醋栗是一种在北半球广泛栽培的小浆果,果实中富含糖、酸、多种维生素、多酚、类黄酮、花青素、氨基酸、各种无机元素如磷、钙、镁、铁、锌等,及不饱和脂肪酸等具有生物活性的营养成分,种子、果实和叶子均可利用,实际生产中主要利用的是果实。该文主要针对黑穗醋栗果实中的营养成分及保健功能进行了综述,旨在为黑穗醋栗营养价值的开发利用提供一定的参考和指导作用。

响应面法优化黑加仑果酒发酵条件的研究

以黑加仑果汁为原料,利用自选的优良酵母菌株Y-21,进行黑加仑果酒发酵条件的研究。采用单因素试验和Box-Behnken试验设计,通过响应面分析装液量、接种量、发酵温度、发酵时间、初始糖度对黑加仑果酒发酵的影响,并优化了发酵工艺参数。结果表明,自选酵母发酵黑加仑果酒的最佳工艺条件为接种量7%、初始糖度22°Bx、发酵温度24℃、发酵时间10d、装液量73.6%,该条件下得到黑加仑果酒的酒精转化率为97.4%。

黑穗醋栗成熟期间营养成分变化规律和适宜采收期研究

对黑珍珠、黑金星、早生黑、密穗、布劳德、寒丰6个黑穗醋栗品种采收期间的果实营养成分变化进行了研究。结果表明：在采收期间，除维生素C呈下降趋势外，可滴定酸和色价在果实90％着色后的12～16d出现最高值，而可溶性糖的高峰值在果实90％着色后的8～20d均有分布。果实腐烂率和震动落果率随采收期的推迟而上升。果实90％着色后的第8～16d为适宜采收期。

乙烯利对黑穗醋栗果实品质的影响

研究了前期喷施低浓度乙烯利和采前喷施高浓度乙烯利对黑穗醋栗“黑珍珠”果实品质的影响。结果表明 :在正常采收期前 2 5d喷 1～ 2次 10 ,5 0 ,2 0 0mg/L乙烯利溶液 ,对果实中还原糖、总糖、维生素C和色素含量的增加以及有机酸含量的降低都起到了促进作用。采前 2～ 4d喷施 2 6 7,5 0 0和 10 0 0mg/L乙烯利溶液 ,只对色素含量增加起到了明显的促进作用 ,而对糖。

叶面喷施稀土对黑穗醋栗叶片生理特性的影响

应用不同浓度的稀土对黑穗醋栗新品种“黑珍珠”进行了叶面喷施试验。结果表明，低浓度（３００～８００ｍｇ／Ｌ）处理能明显提高叶片叶绿素ａ和ｂ的含量，从而使叶绿素总量增加，提高了净光合速率（Ｐｎ），对叶片光量子通量密度（ＰＦＤ）、气孔导度（Ｇｓ）和蒸腾速率（ＴＲ）均有良好影响；提高了叶片硝酸还原酶（ＮＲ）活性，有利于氮素代谢。高浓度处理出现抑制作用。从本试验看，以低浓度处理喷２次较为适宜。

加热对黑加仑花色苷含量及抗氧化活性的影响

通过研究加热温度和加热时间对黑加仑花色苷含量及抗氧化活性的影响,探讨黑加仑花色苷及其抗氧化能力的热稳定性。将黑加仑花色苷提取物在60、80、100℃分别加热1～5h,测定不同加热温度和加热时间下的花色苷含量,分析花色苷热降解动力学;同时测定DPPH自由基清除率、还原能力和ABTS+.清除率,评价花色苷抗氧化能力的热稳定性。结果表明:加热处理会导致花色苷含量显著降低(P<0.05),其降解符合一级动力学反应,随着温度的增加,反应速率常数k增加,半衰期t1/2降低,反应活化能为71.97kJ/mol;随着加热温度的升高和加热时间的延长,花色苷的DPPH自由基清除率、还原能力和ABTS+.清除率均有不同程度的下降。因此,加工过程中应避免长时间、高温处理,以防止花色苷降解,从而保护花色苷的抗氧化活性。

黑穗醋栗果实多糖的制备、结构鉴定及生物活性研究

以黑穗醋栗果实为原料,采用超声波法提取黑穗醋栗果实粗多糖。利用大孔树脂D4006,阴离子交换剂Q-Sepharose FF和葡聚糖凝胶Sephadex G-100对粗多糖进行分离纯化,得到均一黑穗醋栗多糖(black currant polysaccharide,BCP)。高效液相色谱法测定BCP的重均分子质量为16 329 k D。气相色谱法测定BCP单糖组成及物质的量比为:n(半乳糖醛酸)∶n(鼠李糖)∶n(阿拉伯糖)∶n(木糖)∶n(甘露糖)∶n(葡萄糖)∶n(半乳糖)=0.31∶0.66∶1.63∶0.36∶0.23∶0.31∶1.00。傅里叶变换红外光谱分析表明BCP含有多糖的特征吸收峰,紫外光谱和定性实验表明BCP不含花色苷、蛋白质、核酸和淀粉。刚果红实验表明BCP不具有三螺旋结构。生物活性研究结果表明:在0.2~1.2 mg/m L范围内,BCP对1,1-二苯基-2-三硝基苯肼自由基、·OH、超氧阴离子自由基(O2-·)均有较明显的清除作用,随着质量浓度增大,清除率明显升高。BCP对糖基化反应3个阶段产物(Amadori产物、二羰基化合物和糖基化终产物)的形成均表现出良好的抑制作用,抑制率高于阳性对照氨基胍,且随质量浓度的增加,抑制率升高。BCP对α-淀粉酶具有一定的抑制活性,但抑制效果低于阳性对照阿卡波糖。

新疆天然植物黑加仑对食管癌细胞增殖、凋亡的影响

目的:观察新疆天然植物黑加仑水提物对食管癌细胞的影响及其作用机制。方法:采用四甲基偶氮唑蓝(MTT)法测定不同浓度(10-1、10-2、10-3g/ml)黑加仑水提物作用不同时间(12、24、36h)对人食管癌细胞株Eca109的细胞存活量的影响,以大鼠正常肝细胞(BRL)为正常对照细胞株;用Bradford法测定肿瘤细胞蛋白质合成的变化;采用流式细胞技术(FCM)观察黑加仑作用后肿瘤细胞周期变化及凋亡情况;通过倒置显微镜观察细胞的形态变化。结果:黑加仑水提物10-1g/ml组对人食管癌细胞株Eca109作用24h后,癌细胞的生长和蛋白合成均有明显抑制作用(P<0.05),对正常肝细胞的存活量及蛋白合成均无影响;流式细胞仪检测二倍体峰前出现凋亡峰,细胞凋亡率为49.6%;并且癌细胞呈现典型的凋亡细胞形态。结论:黑加仑水提物可通过诱导细胞凋亡而抑制人食管癌细胞株Eca109细胞的生长。