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991.
目的 优化三七茎叶-桑叶固体饮料的加工工艺, 为云南特色食品的深度开发利用提供科学支撑。方法 考察原料比例, 优化浸提条件, 经过提取、浓缩、喷雾干燥制备三七茎叶-桑叶固体饮料, 并测定抗氧化活性。结果 三七茎叶-桑叶的最佳质量比(m:m)为7:3, 以20倍 (质量体积比, m:V)体积分数为49%食的用酒精浸提49 h, 浸提2次, 过滤液浓缩至1/3体积, 120 ℃喷雾干燥制备出三七茎叶桑叶固体饮料, 得粉率37.74%。 所得固体饮料, 具 有清香、微苦、回甘等感官特性。并检测出人参皂苷Re(38.58 mg/g)、Rb3(40.82 mg/g)和三七皂苷Fd(26.40 mg/g)等11种皂苷化合物。测定发现该固体饮料具有较好的抗氧化能力, 清除ABTS+· 、DPPH·、O2-·、OH-·的IC50值分别为1.08、0.66、0.47、0.50 mg/mL。结论:以三七茎叶、桑叶复合原料开发得到一种风味良好具有抗氧化活性的固体饮料, 具有一定的市场应用前景。 相似文献
992.
Arif IA Bakir MA Khan HA Ahamed A Al Farhan AH Al Homaidan AA Al Sadoon M Bahkali AH Shobrak M 《International journal of molecular sciences》2010,11(9):3149-3157
Molecular marker techniques have been widely used for cultivar identification of inbred date palms (Phoenix dactylifera L.; Arecaceae) and biodiversity conservation. Isolation of highly pure DNA is the prerequisite for PCR amplification and subsequent use such as DNA fingerprinting and sequencing of genes that have recently been developed for barcoding. To avoid problems related to the preservation and use of liquid nitrogen, we examined sterile sand for grinding the date palm leaves. Individual and combined effects of sodium chloride (NaCl), polyvinylpyrrolidone (PVP) and lithium chloride (LiCl) with the cetyltrimethylammonium bromide (CTAB) method for a DNA yield of sufficient purity and PCR amplification were evaluated in this study. Presence of LiCl and PVP alone or together in the lysis buffer did not significantly improve the DNA yield and purity compared with the addition of NaCl. Our study suggested that grinding of date palm leaf with sterile sand and inclusion of NaCl (1.4 M) in the lysis buffer without the costly use of liquid nitrogen, PVP and LiCl, provides a DNA yield of sufficient purity, suitable for PCR amplification. 相似文献
993.
Nikolaos Nenadis Avgi Moutafidou Dimitrios Gerasopoulos Maria Z. Tsimidou 《European Journal of Lipid Science and Technology》2010,112(12):1337-1344
Olive leaf‐olive oil preparations were obtained by vigorous mixing at various levels of addition (5, 10, 15%w/w) of new or mature leaves. After removal of the plant material via centrifugation, quality and sensory characteristics of the preparations were determined. Oxidative stability (120°C, 20 L/h) and DPPH radical scavenging were increased ~2–7 fold depending on the level of leaves used due to enrichment with polar phenols, mainly oleuropein, and a‐tocopherol. The extraction process affected the chlorophyll content and organoleptic traits as indicated by acceptability and preference tests (n = 50). Forty‐four % of the panelists identified a strong pungency in preparations with 15% w/w new leaves. Fifty‐four % of them identified a bitter taste in those with 15% w/w mature leaves, which was attributed to high levels of oleuropein (~200 mg/kg oil). Olive leaf‐olive oil preparations had interesting properties regarding antioxidants present that can attract the interest of a functional product market. Practical applications: The wider use of olive oil and derived products is highly desirable. In this sense, the current study presents data that support introduction to the market of a new specialty olive oil based solely on olive tree products (olive oil and leaves). Thus, in addition to olive oil and olive paste, a new product, that is an olive oil enriched with olive leaf antioxidants, especially oleuropein produced via a “green” technique (mechanical means instead of extraction with organic solvent) can be made available for consumers. 相似文献
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995.
超声波辅助提取花椒叶总黄酮及其体外抗氧化性研究 总被引:1,自引:0,他引:1
以3种溶剂提取花椒叶中总黄酮类化合物,比较其黄酮抗氧化性活性。试验结果表明:水提取花椒叶中总黄酮最佳温度80℃,料液比1:70,时间30 min,功率360 W,总黄酮得率3.51%。乙醇溶液提取花椒中总黄酮最佳温度70℃,乙醇体积分数24%,料液比1:40,时间25 min,功率360 W,总黄酮得率3.30%。丙酮-水(2:1)溶液提取花椒叶黄酮得率为3.53%。水溶液、乙醇溶液、丙酮溶液、VC提取总黄酮的清除DPPH自由基能力IC50分别为24、17.5、7.6、75μg/mL。花椒叶总黄酮具有较强的还原能力和清除DPPH自由基能力,其排序为:丙酮溶液提取总黄酮乙醇溶液提取总黄酮水溶液提取总黄酮VC;对.OH自由基的清除能力排序为:VC丙酮溶液提取总黄酮乙醇溶液提取总黄酮水溶液提取总黄酮。花椒叶总黄酮活性强,是一种值得开发的植物资源。 相似文献
996.
997.
Increasing concentrations of p-coumaric acid applied to (cucumber seedling)–[Cecil A
p
soil–sand mixture (or soil)] systems inhibited evapotranspiration (primarily transpiration) and leaf area expansion of cucumber seedlings and increased soil moisture. Higher soil moisture resulting from the inhibition of evapotranspiration lowered soil solution concentrations of p-coumaric acid by 14–40% but did not significantly influence the inhibitory effects of p-coumaric acid on seedlings. Inhibition of evapotranspiration and total leaf area and increases in lowest daily soil water were observed 1–3 d after the first p-coumaric acid treatment, whereas inhibition of absolute and relative rates of leaf expansion was observed within a 24-hr period. Development of the maximum effects of p-coumaric acid required several additional days. Recovery from effects, i.e., return to control levels, after p-coumaric acid depletion from soil solution was a gradual process requiring days for evapotranspiration, lowest daily soil water, and total leaf area, but was slightly faster for leaf area expansion. It appears, at least for short-term studies, that the initial input or treatment concentrations of p-coumaric acid represented a reasonable estimate of dose despite the dynamic nature of soil solution concentrations, and that the lowering of available p-coumaric acid concentrations, associated with the elevation of soil moisture, did not result in a concurrent detectable seedling response. However, increased soil moisture associated with p-coumaric acid treatments of sensitive species suggests a means by which the magnitude of some allelopathic interactions may be modified and resource competition and allelopathy could interact.Electronic Supplementary Material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
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液体肥料的应用与发展 总被引:4,自引:0,他引:4
介绍了液体肥料及其在叶面喷施、浸种、滴灌、冲施、无土栽培等方面的应用效果。探讨了液体肥料的发展趋势和研究方向,并分析了液体肥料的发展前景。 相似文献