印榕仙人掌成熟节片营养成分与黄酮含量分析

分析了印榕仙人掌红果和黄果2个类型成熟节片的主要营养成分及黄酮含量,结果表明:①黄果类型节片的粗蛋白、粗脂肪和粗纤维含量分别为0.69％、0.09％和1.00％,明显高于红果类型,但总糖和多糖含量分别为4.48％和3.82％,明显低于红果类型.②红果类型的总氨基酸和必需氨基酸含量分别为527和226 mg/100g,明显高于黄果类型.2个类型节片必需氨基酸与总氨基酸比值、必需氨基酸与非必需氨基酸比值以及必需氨基酸占总氨基酸的相对含量均优于FAO/WHO的模式谱标准.谷氨酸、赖氨酸、天冬氨酸、亮氨酸含量较高,其中主食中普遍缺乏的赖氨酸,在红果和黄果类型中的含量分别达到58和47 mg/100g.③节片富含Fe和Ca.红果类型Fe含量3.16 mg/100g,Ca含量408.29 mg/100g,分别是黄果类型的1.28倍和1.44倍,是普通蔬菜胡萝卜的3.16和12.76倍.除Vc、VE含量低于普通蔬菜外,2个类型节片的VB1和VB2含量与胡萝卜等蔬菜接近.④节片富合黄酮类物质.2个类型节片含黄酮类物质约40 mg/100g,其中红果类型以芦丁和槲皮素为主,含量分别为32.92和5.87 mg/1009,分别是黄果类型的1.41和9.62倍,而黄果类型以芦丁和桑色素为主,其桑色素含量为15.38 mg/100g,是红果类型的12.71倍.     

分光光度法测定老鹰茶中黄酮类化合物

采用索氏提取法提取老鹰茶中的黄酮类化合物,以芦丁作为标准,以亚硝酸钠-硝酸铝-氢氧化钠作为显色体系对老鹰茶中总黄酮含量进行分光光度法测定。该方法在0.00~0.08 mg/mL时与吸光度有良好的线性关系(r2>0.999),加标回收率为90.4%~93.7%,相对标准偏差(n=5)为2.8%~4.0%,操作简单方便,适用于老鹰茶提取液中总黄酮含量的测定,用该方法测得黄酮含量达2.83%。     

黑豆皮中黄酮提取及粗提物抑菌效果研究

通过对影响黑豆皮中黄酮类物质提取率的乙醇浓度、提取温度、提取时间、料液比、提取次数等因素进行了单因素试验、PB试验和响应面分析,将提取工艺进行了优化.结果表明:对黄酮提取具有显著影响的因子为乙醇浓度(P=0.0207)、提取温度(P=0.0285)和料液比(P=0.0170).最佳工艺为乙醇浓度70%、提取温度76.2...     

微波辅助提取莲心黄酮类物质工艺参数的优化

为了探讨微波辅助提取莲心中黄酮类物质的工艺条件,研究微波功率、微波提取时间及料液比对莲心黄酮类物质提取效果的影响,通过正交试验设计优化其提取工艺参数。结果表明:影响莲心黄酮类物质提取效果的主次因素顺序为微波提取时间>微波功率>料液比,最佳提取工艺参数为微波功率700W,微波提取时间10min,料液比2:100(g:mL),在此条件下莲心黄酮类物质提取率为1.8725%;与传统水浸提方法相比,该方法可以提高提取率,缩短提取时间。     

Phenolic composition and antioxidant capacity of six artemisia species

The aim of this work was to establish the antioxidant capacities and the polyphenolic profile of six different Artemisia species that could potentially be used in the human diet. A high-performance liquid chromatographic method coupled with photodiode-array detector was used to identify and quantify individual phenolic compounds of the Artemisia leaves. A total of 18 polyphenolic compounds were identified and quantified in Artemisia leaves, including hydroxybenzoic acids (4), hydroxycinnamic acids (5), flavonols (3), and catechins (2). It was observed that total phenolic content of A. annua and A. stelleriana leaves were significantly lower than the other four species. Ferulic and caffeic conjugates acids were the most dominant hydroxycinnamic acid and gallic acid and catechin were the most dominant hydroxycinnamic acid and catechins respectively. According to DPPH assays, the antioxidant capacity of A. arborescens spp., A. ludoviciana spp., A. oleandica spp. and A. princepts spp., were found to be higher (reflecting a 2-fold difference) than that of the other two species. Compared with those of major commercial leafy vegetables, leaves of Artemisia contain a higher content of flavonoids and phenolic acids, which provide significant health benefits and may be used as natural colorants.     

Response surface optimization of mechanochemical-assisted extraction of flavonoids and terpene trilactones from Ginkgo leaves

Mechanochemical-assisted extraction (MCAE) method was developed for extraction of flavonoids and terpene trilactones from Ginkgo leaves. The MCAE parameters and the antioxidant activities of Ginkgo biloba extract (GBE) were investigated. Through response surface methodology design experiments, the processing conditions were optimized as follows: amount of solid reagent (NaHCO₃) 21%, milling time 7.5 min, and ratio of solvent to solid 33 mL/g. Under these conditions, the yields of flavonoids and terpene trilactones in GBE were 6.83 mg/g and 1.72 mg/g, respectively. Compared with the heat reflux extraction method, the yields of flavonoids and terpene trilactones are higher, and the extraction time was significantly shortened. What is more, the MCAE method only used water as solvent. GBE of MCAE possessed notable antioxidant activity with IC₅₀ values of 11.7 and 13.8 μg/mL, respectively.     

桑椹成熟过程中酚类物质、总黄酮及花色苷含量的动态变化

以新选育的鲜食用果桑品种‘粤椹28’和全国种植面积较大的果桑品种‘粤椹大10’和‘塘10’为试材,研究不同发育时期桑椹果实中总酚类物质、总黄酮及花色苷的动态变化规律。结果表明:幼果期桑椹中含有较高含量的总酚类物质和总黄酮类物质,随着果实的成熟,合成速率逐渐减慢,全红期后又开始大量积累;花色苷从白熟期后开始合成,随着成熟度的增加,花色苷的合成速率加快,桑椹中的花色苷主要在全红期到紫黑期发育阶段合成,到紫黑期含量达到最大值;紫黑期‘粤椹28’桑椹中总酚类物质、总黄酮类物质及花色苷含量均高于‘粤椹大10’和‘塘10’。     

Enzyme pretreatment and negative pressure cavitation extraction of genistein and apigenin from the roots of pigeon pea [Cajanus cajan (L.) Millsp.] and the evaluation of antioxidant activity

An enzyme pretreatment and negative-pressure cavitation extraction (E-NPCE) method was investigated for extraction genistein and apigenin from pigeon pea roots. The important parameters involved in E-NPCE process were optimized by single-factor experiments and then critical parameters were investigated by a 2³ full factorial central composite design (CCD) to optimize extract conditions. Under optimal conditions, the yields of genistein and apigenin were 0.628 mg/g and 0.359 mg/g, which represented an increase of 44.70% and 53.05%, respectively, compared to standard NPCE. Furthermore, from DPPH scavenging activity test the extract of E-NPCE showed better antioxidant activity than these of other methods. The results demonstrated that E-NPCE would have lower energy consumption, higher efficiency and could be an alternative method for natural compounds extraction.     

Potential insulin secretagogue effects of isovitexin and swertisin isolated from Wilbrandia ebracteata roots in non-diabetic rats

The antihyperglycemic effect and mechanism of action of extracts, fractions and compounds from Wilbrandia ebracteata was studied. The crude extract reduced the glycemia, increased glycogen content and serum insulin in hyperglycemic rats. Also, a significant effect was observed with the n-butanol and metanol subfraction. However, the antihyperglycemic effect of the n-butanol fraction was not observed in diabetic rats. The C-glycosylflavones isovitexin and swertisin showed a strong antihyperglycemic action compared with the extracts and fractions. These results show that the extracts, fractions, and isolated C-glycosylflavones have an antihyperglycemic action that was reinforced by the stimulation on in vivo insulin secretion.     

Yield,essential oil and pigment content of Calendula officinalis L. flower heads cultivated under salt stress conditions

Flower heads of Calendula officinalis L. are used for medicinal or culinary purposes. Since Egyptian agricultural lands contain salt, this study investigated the effects of saline irrigation water on yield (fresh and dry weights of flower heads), essential oil (EO) yield, chemical constituents of the EO and total flavonoids and carotenoids of flower heads at three flowering stages, i.e. initial (21 days after bud formation (DABF)), full flowering (81 DABF) and final (111 DABF). After plants were treated with different levels of saline irrigation water (0.39, 1.56, 3.13, 4.69, 6.25, 7.81 and 9.38 dS m⁻¹) consisting of NaCl, CaCl₂ and MgCl₂ salts, the flower head yield and pigment (total flavonoids and carotenoids) content were significantly reduced. Irrigation with saline water increased the EO content and its main components (α-cadinol, γ- and Δ-cadinene). Fresh and dry weights of flower heads and EO increased near 81 DABF while the content of pigments increased by 111 DABF.