Evidence of an oviposition stimulant for peachtree borer

Peachtree borer (PTB) cocoons, peach tree bark, and a mixture of frass and gum obtained arount PTB wounds were extracted with organic solvents of increasing polarity. Female PTB moths,Synanthedon exitiosa (Say), laid the greatest number of eggs on filter paper substrates treated with acetone extracts of PTB cocoons, ethyl acetate extracts of peach tree bark and acetone extracts of frass and gum mixtures. The extracts of cocoons or frass and gum mixture were separated by liquid chromatography and thin layer chromatography.Synanthedon exitiosa (Say).Mention of a commercial or proprietory product does not constitute an endorsement of this product by the USDA.     

基于多元素和稳定同位素技术的桃产地溯源

目的 研究利用桃中多元素和稳定同位素地域特征进行产地溯源的可行性。方法 应用电感耦合等离子体质谱和稳定同位素比质谱技术,测试桃样品中54种元素和碳(13C/12C)、氮(15N/14N)、氢(2H/1H)、氧(18O/16O) 4种稳定同位素比值,分析不同产地桃的特征指标,采用逐步判别分析,建立产地判别模型,开展平谷、顺平和丹东桃产地溯源。结果 不同产地桃中碳和氧同位素比值差异显著(P<0.05),Na、Mg、Al、K、Mn、Cu、Zn、Rb、Sr、Cd和Ba等11种元素含量差异显著(P<0.05)。筛选C、H、O、Mg、Al、K、Fe、Cu、Zn、Cd等10项指标建立产地判别模型,进行原始回代检验和留一交叉检验,判别准确率均为100%。结论 研究表明,同时利用桃中多元素含量和稳定同位素比值特征指标建立产地判别模型,能够区分不同产地的桃,为桃产地溯源的可行性提供方法依据。     

大孔吸附树脂纯化樱桃叶中总黄酮的研究

以樱桃叶总黄酮的吸附率和解吸率为指标,采用静态吸附解吸法确定出合适的大孔吸附树脂;动态吸附与解吸法确定纯化条件,分析了样品液pH、吸附流速以及洗脱液浓度、洗脱流速、洗脱液用量对动态纯化的影响;同时采用高效液相色谱法进行分析检测以表征纯化效果。实验结果表明,大孔吸附树脂D101对樱桃叶总黄酮有很好的吸附解吸性能,其最佳动态纯化条件为:樱桃叶总黄酮样品液浓度1.0mg/mL、pH4、吸附流速2BV/h,D101树脂的最大吸附容量为17.34mg/g(以干树脂计)。洗脱剂为70%乙醇,以2BV/h的流速,3倍柱体积即可充分洗脱吸附在D101树脂上的黄酮,纯化后樱桃叶黄酮纯度提升到74.29%,约为纯化前的3倍。     

液固串淋法生产光核桃果醋的工艺

采用液固串淋发酵工艺,对光核桃果醋的生产工艺进行初步探讨。实验表明,纤维素酶和果胶酶处理后发酵,液固串淋发酵得到酒精发酵率86.4%,醋酸转化率为75.3%,发酵周期为15d～16d。     

山桃稠李果实花色苷对HepG2细胞抗氧化系统的影响

目的:研究山桃稠李果实花色苷对人肝癌细胞(HepG2)抗氧化系统的影响.方法:质量浓度0.1 ～ 1.2mg/mL的花色苷作用于HepG2细胞,MTT法检测HepG2细胞生长抑制率;检测各组细胞内抗氧化酶活性和谷胱甘肽、丙二醛的含量变化;采用DCFH-DA探针检测细胞内活性氧(ROS)含量的变化.结果:随着花色苷质量浓度的增加,HepG2细胞的抗氧化酶(T-SOD、GSH-PX)活性显著降低;谷胱甘肽(GSH)含量下降,丙二醛(MDA)及活性氧的含量上升.结论:山桃稠李果实花色苷能够明显的降低HepG2细胞的抗氧化能力.     

Wild Prunus Fruit Species as a Rich Source of Bioactive Compounds

Sugars, organic acids, carotenoids, tocopherols, chlorophylls, and phenolic compounds were quantified in fruit of 4 wild growing Prunus species (wild cherry, bird cherry, blackthorn, and mahaleb cherry) using HPLC‐DAD‐MSn. In wild Prunus, the major sugars were glucose and fructose, whereas malic and citric acids dominated among organic acids. The most abundant classes of phenolic compounds in the analyzed fruit species were anthocyanins, flavonols, derivatives of cinnamic acids, and flavanols. Two major groups of anthocyanins measured in Prunus fruits were cyanidin‐3‐rutinoside and cyanidin‐3‐glucoside. Flavonols were represented by 19 derivatives of quercetin, 10 derivatives of kaempferol, and 2 derivatives of isorhamnetin. The highest total flavonol content was measured in mahaleb cherry and bird cherry, followed by blackthorn and wild cherry fruit. Total phenolic content varied from 2373 (wild cherry) to 11053 mg GAE per kg (bird cherry) and ferric reducing antioxidant power antioxidant activity from 7.26 to 31.54 mM trolox equivalents per kg fruits.     

紫叶稠李果实及叶片的色素抗氧化活性研究

利用溶剂法提取紫叶稠李果实及叶片的色素,研究了其色素对DPPH自由基、ABTS+自由基、羟基自由基的清除能力和总还原能力以评价色素的抗氧化活性,并以VC作对照。结果表明,当样品质量浓度小于0.15mg/mL时,紫叶稠李叶片色素对DPPH自由基清除能力大于果实色素的清除能力,而当样品质量浓度大于0.15mg/mL时,紫叶稠李叶片色素对DPPH自由基清除能力小于果实色素的清除能力。紫叶稠李叶片色素对ABTS+自由基、羟自由基的清除能力均大于果实色素的清除能力,紫叶稠李果实及叶片的抗氧化活性均随样品浓度升高而增强。并且,叶片色素表现出更强的还原力,在样品质量浓度为0.2mg/mL时,其还原力是VC的3倍、果实的6倍。     

青脆李果酒发酵及澄清工艺研究

采用青脆李为试材,研究青脆李果酒发酵及澄清工艺。结果表明果酒酵母RV818对青脆李果酒的发酵性能最佳,其最适发酵温度为25℃、添加量为0.05%、发酵时间12 d;壳聚糖、硅藻土、明胶3种常用澄清剂对青脆李果酒透光率和色度的影响结果表明,3.0 g/L壳聚糖(酸溶解)澄清透光率为96.8%,色度为0.046;3.0 g/L壳聚糖(沸水溶解)澄清透光率为93.0%,色度为0.069;壳聚糖可作为青脆李果酒优选澄清剂。     

Effects of ripening on microstructure and texture of “Ameixa d’Elvas” candied plums

The plums used to produce a traditional candied product, “Ameixa d’Elvas”, were obtained from two orchards, Vila Viçosa (VV) and Cano (CA). These orchards were selected because the fruits were behaving differently: (1) The day of harvesting for candying, established by the total soluble solids and titratable acidity, was one week earlier in VV; (2) VV yielded candied plums with good texture properties whereas CA gave poor processed fruits. In order to understand the origin of these differences, fruits from both orchards were harvested on the day established as the harvesting day for VV (day 1) and for CA (day 8). Comparable texture properties were obtained in firmness, rigidity and deformation work between the VV fresh plums harvested on day 1 and the CA plums harvested on day 8 but these were lower in CA when the flesh was analysed separately, in accordance with the activities of pectin methyl esterase (PME), polygalacturonase (PG) and cellulase (Cel). The increase of the intercellular area of parenchyma cells and the decrease in cell area caused by boiling, which resulted in a pronounced loss of textural properties, were partially recovered after the immersion of the fruits in sucrose syrup. The CA plums harvested on day 8 had a more pronounced degradation with boiling and lower recovery of cell shape, size and textural characteristics than had those of VV harvested on day 1. Upon candying, similar properties were observed for the fruits harvested on the same day: good candied products were observed for VV and CA fruits harvested on day 1 and poor candied products were observed for VV and CA fruits harvested on day 8. This work shows that the characteristics of the flesh of the fresh fruits are key parameters in defining the textural properties of the candied plum. The establishment of the harvesting moment for candying should take into account the changes that occur in the flesh of the plums during ripening.