Assessment on in vitro medicinal properties and chemical composition analysis of Solanum virginianum dried fruits

The study was aimed to screen the presence of phytoconstituents and determine distinct in vitro medicinal traits of aqueous and ethanolic extracts of Solanum virginianum dried fruits. Aqueous and ethanolic extract showed total phenolic content of 207.5 ± 0.16 and 268.4 ± 0.42 GAE/mg, respectively. Likewise, total flavonoid content of 50.12 ± 0.39 and 192.88 ± 0.27 QE/mg was estimated for the aqueous and ethanolic extract, respectively. In vitro antibacterial, antioxidant, α-amylase inhibition, anti-inflammatory, and anticancer attributes of extracts were assessed using standard protocols. The antibacterial traits of both the extracts were assessed against certain pathogenic bacteria which exhibited maximum zone of inhibition of 22.3 ± 0.6 mm against Staphylococcus aureus. Antioxidant tests showed not only significant scavenging of DPPH, superoxide, hydroxyl, and ABTS^●+ radicals but also estimated ferric reducing power and phosphomolybdenum reduction activities of extracts in a concentration dependent manner. The aqueous extract (54.12 ± 0.44–86.80 ± 0.27%) depicted higher rate of α-amylase inhibition than ethanolic extract (23.07 ± 0.47–81.61 ± 0.43%) at distinct concentrations. Similarly, the aqueous extract protected the haemolysis (46.19 ± 0.14–66.21 ± 0.17%) effectively as compared to the ethanolic extract (12.67 ± 0.19–38.03 ± 0.41%). The aqueous and ethanolic extract showed cytotoxicity against HepG2 cell lines in the range of 32.23 ± 0.34–54.82 ± 0.26% and 49.25 ± 0.38–73.2 ± 0.3%, respectively. Additionally, the GC–MS analysis confirmed the availability of total 15 predominant bioactive constituents in both extracts. Findings of this context indicated pronounced applications of S. virginianum fruits as future therapeutic.     

Switch-on fluorescence sensor for ascorbic acid detection based on MoS2 quantum dots-MnO2 nanosheets system and its application in fruit samples

In this work,molybdenum disulfide quantum dots(MoS_2 QDs) were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO_2 nanosheets into MoS_2 QDs solution,they produced an obvious fluorescence quenching,which should be due to inner filter effect(IFE).Meanwhile,the fluorescent probe was formed,Interestingly,we found that this quenching phenomenon disappeared with the addition of ascorbic acid,In other words,the fluorescence gradually restored.This recovery phenomenon is mainly due to the reduction effect of ascorbic acid for MnO_2 nanosheets.Under the optimum conditions,the limit of detection(LOD) of 39 nmol/L for ascorbic acid was achieved with a linear range of 0.33-5.00 μmol/L.The repeatability was better than 5.0% for ascorbic acid in both standard and fruit samples(n = 3).Moreover,the as-fabricated fluorescent sensing system was successfully employed to detect the ascorbic acid levels in hawthorn and jujube with satisfactory results.     

Evaluation of pesticide residue in grape juices and the effect of natural antioxidants on their degradation rate

Various studies have been drawn toward the beneficial properties of fruit juices because they have several components, such as phenols, vitamins, and flavonoids, with antioxidant effects. However, fruit juices can also contain residues of pesticides used as standard pest control methods in crops. Many of these pesticides are degraded through oxidative mechanisms, and their persistence in juices can be enhanced by antioxidants. This study covers the degradation of four pesticides, aldicarb, demeton-S-methyl, fenamiphos, and methiocarb, to their respective sulfoxide and sulfone in grape juices, water (pH 3.5) and water (pH 3.5) with quercetin (one of the most important flavonoids of grape) added in an attempt to establish whether the presence of antioxidants can affect the degradation rate of pesticides. For this purpose, a multiresidue method based on solid-phase extraction (SPE) was developed for the simultaneous determination of these pesticides and their metabolites in commercial juices. The extraction procedure was carried out in C₁₈ columns. The subsequent elution of pesticides was performed with dichloromethane prior to the determination by liquid chromatography-tandem mass spectrometry (LC-MS/MS), using two precursor-product ion transitions. Average recoveries for all the pesticides studied were higher than 80%, with relative standard deviations lower than 15% in the concentration range 0.005–0.05 μg/mL, and the quantification limits achieved ranged from 0.1 to 4.6 μg/L. The results demonstrated that degradation was slower in fruit juices and aqueous solutions with quercetin than in water. Several commercial grape juices were also analyzed to establish the levels of these pesticides. Methiocarb, fenamiphos, and demeton-S-methyl were found at low levels in some samples.     

Development of an electronic tongue based on a PEDOT-modified voltammetric sensor

Three different electrodes were tested for use as nonspecific amperometric sensors for blind analysis on real matrices, namely different fruit juices from different fruits or different brands. The first two electrodes were traditional Pt and Au electrodes, while the third one was modified with poly(3,4-ethylenedioxythiophene) conducting polymer. The sensors were tested separately, tested coupled to each other, and also tested together. The responses of the electrode system(s) were first screened via PCA and then their discriminant capabilities were quantified in terms of the sensitivities and specificities of their corresponding PLS-DA multivariate classification models. Particular attention was paid to analyzing the evolution of the response over subsequent potential sweeps. The modified electrode demonstrated the most discriminating ability, and it was the only system capable of satisfactorily performing the most complex task attempted during the analysis: discriminating between juices from the same fruit but from different brands. Moreover, the electrode "cleaning" procedure required between two subsequent potential sweeps was much simpler for the modified electrode than for the others. This electrode system was therefore shown to be a good candidate for use as an informative element in an electronic tongue applied to the analysis of other food matrices.     

Mapping of Malus domestica allergens by 2-D electrophoresis and IgE-reactivity

The importance of apple allergens has been repeatedly emphasized, and their presence has been confirmed both in pollen and in fruits. In the present study, a combination of proteomic tools have been used to build a complete allergen map of apple. The water-soluble fraction of an apple extract was precipitated using a phenol-based procedure and separated by 2-DE. Initially four previously classified allergens, Mal d 1, Mal d 2, Mal d 3 and Mal d 4, could be identified in Western blots with polyclonal rabbit antibodies directed to the four respective allergens, and subsequently matched to the bands recognized by several patient sera. Further, all four known apple allergens were localized on a 2-DE map and they were matched with spots recognized by sera of patients with different allergic patterns. Moreover, a new, putative allergen could be identified using MS. We evaluated the influence of post-translational modifications and the immunoreactivity under different analytical conditions. The comparison of different visualization methods for 2-DE gels and blots revealed that even very low concentrations of the intact epitopes are detectable by IgEs of patients, and therefore might be sufficient to trigger allergic symptoms in sensitized individuals.     

果皮的紫外吸收剂提取筛选及优化复配研究

本实验对8种天然常见果皮采用索氏提取方法进行紫外吸收剂的提取,并对提取液进行紫外吸收光谱特性分析。选择以橙皮为原料提取天然紫外吸收剂,采用正交法优化其提取条件,并选用姜黄提取液与橙皮进行复配,得到的提取液的透射率均小于3%（250—400nm）。     

基于激光光致发光光谱的果实成熟度测试方法研究

介绍了一种探测果实成熟度的新方法。采用红光半导体激光器(655 nm)对果实样品进行照射,所得激光光致发光光谱在685 nm附近产生明显峰值。通过传统的糖度含量检测法测定样品的糖度含量,得到果实的激光光致发光光谱峰值强度随糖度含量增加而降低。利用最小二乘法原理对光致发光强度与糖度含量值进行比较分析,建立了两者的拟合曲线。以红心李和桃子为例, 两者之间的相关系数分别为98.92%与97.31%。设计针对该激光光致发光光谱检测系统的分析软件,实现了生成标准成熟光谱及检测未知成熟度的果实光致发光光谱两部分功能,通过比较可以自动得出果实成熟度等级的判定。结果证明,激光光致发光光谱的成熟度检测方法具有非破坏性、设备小型化、低能耗的优点,在果实成熟度的实时快速检测方面具有应用价值。     

应用近红外光谱技术快速检测果醋糖度

为了对果醋糖度值进行快速准确检测,应用近红外光谱技术并结合最小二乘支持向量机分析方法建立了果醋糖度检测模型.应用近红外透射光谱获取五种类型共计300份果醋样本的光谱透射曲线,利用主成分分析方法对原始光谱数据进行降维处理,根据主成分的累计贡献率选取6个主成分.选取的主成分即作为光谱优化特征子集以替代原来复杂的光谱数据.随后将300份果醋样本数据随机分为定标集和预测集,利用最小二乘支持向量机在225个定标集样本数据基础上建立起果醋糖度预测模型,应用此模型对75个预测集样本进行糖度预测.根据预测均方根误差(RMSEP)和预测结果的相关系数(r)对预测模型进行评价,利用此模型得到的样本糖度预测值r=0.993 9,RMSEP=0.363,均达到了较好的预测效果.     

Investigation of Trace Metals Content and Carbon Isotopic Composition on the Soil Leaf-Fruit Chain from Some Transylvanian Areas

Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Isotopic Ratio Mass Spectrometry (IRMS) were used in this study to trace heavy metal and isotopic content of soil into the fruit juices. This work presents a preliminary study on the carbon isotope signature and trace metal content investigated on the soil-plant-fruit pulp chain. The samples were collected from Transylvanian areas. Our results for fruit juices are compared with allowable limits for drinking water in the United Kingdom (NS30). The results for soil samples were compared with the maximum value reported for normal range values of natural soils cited by the EEA (European Environment Agency) report. The results obtained for δ¹³C values on the soil - leaf - fruit pulp chain for grape, pear, and apple samples show depletion in ¹³C isotope, as the trend of the values reported in literature for the soil–leaf–fruit chain.     

Identification of the Flavone in the Flower Bud of Panax Quinquefolium and Its Content Determination in the Different Parts

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