Enzymatic Characterization of Pectinex XXL,a Pectinase Produced by Aspergillus niger,and Its Application in Fruit Juice Production

Pectinex XXL,a commercially prepared pectinase,was investigated for its potential application in the fruit juice industry.Polygalacturonic acid was used as the substrate for determining the enzymatic properties of Pectinex XXL using the DNS method.According to the results,the optimal pH for Pectinex XXL activity was 4.5,and the enzyme was stable in the pH range of 3.0~4.5.The optimal pH and pH stability range are consistent with those of some tropical and subtropical fruits.The optimal temperature for Pectinex XXL activity was 60℃,and the enzyme remained stable after one hour in a water bath set at 40℃.Additionally,the enzymatic activity was not inhibited in the presence of 1 mmol/L of Na^(+),Mg^(2+),Ba^(2+),Co^(2+),Zn^(2+),and Fe^(2+),whereas it was slightly inhibited in the presence of 2 mmol/L of K^(+)and Fe^(2+)and partially inhibited in the presence of 1 and 2 mmol/L of Ca^(2+)and Mn^(2+),demonstrating its good stability in acids and excellent thermal catalytic performance.Based on the above experimental results,depectinization experiments were performed on plantain and cherry tomato juices using different amounts of Pectinex XXL.After one hour reaction with 16 U/mL of the enzyme,the yields of the plantain and cherry tomato juices were substantially increased by 119.03%and 15.97%,respectively,while their light transmittance was remarkably enhanced by 37.65%and 12.35%,respectively.Furthermore,the enzyme reduced the viscosity of the plantain and cherry tomato juices by 88.29%and 29.50%,respectively.The juice production experiments confirmed that this enzyme can significantly improve the yield and light transmittance of plantain juice,while effectively reducing its viscosity.These findings indicate the potential of Pectinex XXL in the industrial production of plantain juice.

Health effects of fruit juices and beverages with varying degrees of processing

The degree of processing is rarely considered an independent factor in the health effects of fruit juices and beverages(FJBs)consumption.In fact,the consumption of ultra-processed foods has been shown to pose health risks.In this study,we first integrated 4 systems used to classify the degree of food processing and then classified FJBs into three major categories,low(minimal),moderate and high.Second,we compared the differences in attitudes towards FJBs in dietary guidelines.Third,we integrated the results of existing epidemiological surveys,randomized controlled trials,and animal experiments to explore the health risks associated with consuming FJBs.Deepening the processing of FJBs has been found to lead to an increased risk of diseases.Dietary pattern,nutrients,addition agents and consumer preferences may be influential factors.Finally,we investigated whether there were any changes in the health benefits of 100%fruit juices produced by different processing methods.In conclusion,minimally/moderately processed 100%fruit juices provide more health benefits than highly processed fruit beverages.The results support the need to consider the extent of FJBs processing in future studies to adjust official nutritional recommendations for beverage consumption.

Assessment of Some Secondary Metabolites, Minerals and Alcohol Content of Noni Juice Obtained by Fermentation of Morinda citrifolia L. Fruit from Senegal

The fruit of Morinda citrifolia L., commonly known as noni, has an extensive history of use as a food and traditional medicine around the world. Adding value to Morinda citrifolia L. products, particularly the fruit, could be one way of building resilience in vulnerable farming households. The aim of this study was to determine the secondary metabolite and mineral composition of noni juice obtained by fermenting the fruit of Morinda citrifolia L. Fruits were collected in August 2022 from the local field in Thiès region, West of Senegal. Extraction yields were determined and the secondary metabolites were determined using conventional analytical methods. Calcium, magnesium, iron, sodium and potassium were determined by atomic absorption spectrophotometer coupled with a CCD detector. The results show that an average fruit mass (503.2 ± 110.96 g) consists of 171.44 ± 50.01 g pulp and 34.06 ± 10.35 g seeds. The traditional extraction yield of noni juice is 16.46% after three weeks of fermentation. The contents of total polyphenols, flavonoids and tannins obtained in noni are 608.97 ± 4.53 mg EAG/100mL, 7.78 ± 0.01 mg EQ/100mL and 0.191 ± 0.01 mg EC/100mL respectively. The ethanol content of noni varies from 3.57 to 5.23 mL/100mL during extraction. Noni has a high calcium content with a concentration of 383.79 ± 33.23 mg/L. This is followed by a good concentration of magnesium, potassium and sodium, at 278.47 ± 26.30, 187.43 ± 10.7 and 155.95 ± 28.66 mg/L respectively. Noni also has an iron content of 202.15 ± 0.05 mg/L.

Early detection of pancreatic cancer

The diagnosis of pancreatic cancer associates an appalling significance.Detection of preinvasive stage of pancreatic cancer will ameliorate the survival of this deadly disease.Premalignant lesions such as Intraductal Papillary Mucinous Neoplasms or Mucinous Cystic Neoplasms of the pancreas are detectable on imaging exams and this permits their management prior their invasive development.Pancreatic intraepithelial neoplasms(PanIN)are the most frequent precursors of pancreatic adenocarcinoma(PDAC),and its particular type PanIN high-grade represents the malignant non-invasive form of PDAC.Unfortunately,PanINs are not detectable on radiologic exams.Nevertheless,they can associate indirect imaging signs which would rise the diagnostic suspicion.When this suspicion is established,the patient will be enrolled in a follow-up strategy that includes performing of blood test and serial imaging test such as computed tomography or magnetic resonance imaging,which will cost in the best-case scenario a burden of healthcare systems,and potential mortality in the worst-case scenario when the patient underwent resection surgery,worthless when there is no moderate or high grade dysplasia in the final histopathology.This issue will be avoid having at its disposal a diagnostic technique capable of detecting high-grade PanIN lesions,such is the cytology of pancreatic juice obtained by nasopancreatic intubation.Herein,we review the possibility of detection of early malignant lesions before they become invasive PADC.

Nutraceutical Potentiality of Fruits of Red Variety of Pseudospondias microcarpa (A. Rich) Engl.

The red fruits of Pseudospondias microcarpa (A. Rich) Engl. are widely consumed by the populations of northern Congo for their sweet and tangy flavor as well as for their characteristic smell. The objective of this study was to show the food potential of the fruits of this plant for their valorization. Organic solvent extracts were prepared and subjected to phytochemical screening to determine the nutrients and phytonutrients of this fruit. Raw juice was extracted by trituration without adding water and subjected to physicochemical and biochemical analyses in order to determine its quality and its antiradical activity. The raw juice obtained is moderately acidic (pH 3.28), very cloudy and colored (turbidity of 1019 NTU). It has a dry matter content of 3.771% ± 0.013% reflecting the 70% dominance of water in the weight of the fruit and the presence of dissolved organic matter in its juice. Energy nutrients (sugars, amino acids), carotenoids, coumarins, tannins, flavonoids, terpenes and sterols have been highlighted as nutrients with therapeutic potential commonly called phytonutrients of this fruit. The juice presented a dominance in polyphenols (134.8500 ± 0.0023 mg gallic acid/100 g) than in carotenoids (5.100 ± 0.010 mg carotene/100 g), high levels of mineral macroelements (calcium: 3570.00 ± 2.05 mg and potassium: 4576.00 ± 9.49 mg) and trace elements (copper: 11.13 ± 0.10 mg, iron: 3.02 ± 0.03 mg and zinc: 2.57 ± 0.08 mg). These compounds exhibited good antioxidant activity. The presence of these nutrients and phytonutrients in these fruits is interesting for the proper functioning of certain organs and the prevention of certain diseases. This fruit is therefore an energizing and functional food that can compete with conventional fruits whose juices are marketed.

Study on Compound Stabilizer Formulation for Mango Juice with Skin

[Objectives]The effects of stabilizers such as sodium carboxymethyl cellulose,pectin,sodium alginate and xanthan gum on the stability of mango juice with skin were discussed using mango as the raw material.[Methods]The formula and stability of mango beverage with skin were studied using mango juice with skin as the raw material.Four stabilizers,including pectin,sodium alginate and sodium carboxymethyl cellulose,were added to improve the stability of the juice.Based on single factor experiments and a response surface experiment,the stability model of mango juice was established to determine the best compound stabilizer.[Results]According to an orthogonal experiment on the stability of mango juice with skin,the optimum technical parameters were as follows:sodium carboxymethyl cellulose 0.20%,xanthan gum 0.08%,sodium alginate 0.18%,and pectin 0.14%,with which the optimal suspension stability was 69.12%.The optimum technical parameters from the response surface experiment were as follows:sodium carboxymethyl cellulose 0.199%,pectin 0.1185%,sodium alginate 0.163%,and xanthan gum 0.077%,with which the suspension stability was 70.32%.It was found that the stability of mango juice with skin obtained by the response surface experiment was better than that by the orthogonal experiment,and the order of factors affecting the stability of mango was sodium alginate(C)>sodium carboxymethyl cellulose(A)>pectin(D)>xanthan gum(B).[Conclusions]The formula of compound stabilizer for mango juice was optimized by the orthogonal experiment and the response surface method,providing a theoretical basis for the actual production of mango juice with skin.

Characterization of the key aroma compounds in four varieties of pomegranate juice by gas chromatography-mass spectrometry(GC-MS),gas chromatography-olfactometry(GC-O),odor activity value(OAV),aroma recombination,and omission tests

P omegranate(Punica granatum L.)has attracted considerable attention in world markets due to its valuable nutrients and highly appreciated sensory properties.The aroma profiles of 4 varieties of pomegranate juice,including Dahongtian(DP),Jingpitian(JP),Luyudan(LP),and Tianhonngdan(TP),were investigated via gas chromatography-mass spectrometry(GC-MS)and gas chromatography-olfactometry(GC-O)analyses.A total of 43 volatile compounds were identified by using GC-MS.Among these compounds,16 were considered as potential aroma-active compounds as detected by GC-O.These compounds belonged to the classes of terpinenes,alcohols,and aldehydes.Eleven volatile compounds were defined as the main contributors to the overall aroma of pomegranate juice due to their high odor activity values(OAVs≥1).Aroma recombination and omission tests confirmed thatβ-myrcene,1-hexanol,and(Z)-3-hexen-1-ol were the key aroma compounds,and limonene,1-octen-3-ol,linalool,and hexanal were important aroma-active compounds in DP samples.

Characterization and discrimination of fermented sweet melon juice by different microbial strains via GC-IMS-based volatile profiling and chemometrics

The main purpose of this study was to investigate the effect of different lactic acid bacteria and yeast strains on the volatile composition of fermented sweet melon juice.Headspace gas chromatography-ion mobility spectrometry(HS-GC-IMS)coupled with chemometrics was performed to identify the potential volatiles for the discrimination of different fermented sweet melon juice.In total,70 volatile compounds were found in the fermented sweet melon juices.Of them,45 compounds were annotated according to the GC-IMS database and classified into esters,alcohols,aldehydes,ketones and furans.Results from the multivariate analysis reveal that sweet melon juice fermented by different combinations of microbial strains could be distinctly separated from each other.A total of 15 volatiles with both variable importance in projection value>1 and P<0.05 were determined as potential markers for the discrimination of fermented sweet melon juice.This study confirms the effect of microorganisms on the flavor of the fermented sweet melon juice and shows the potential of HS-GC-IMS combined with chemometrics as a powerful strategy to obtain volatile fingerprints of different fermented sweet melon juice.

Effect of Ultrasound and Thermal Pasteurization on Physicochemical Properties and Antioxidant Activity of Juice Extracted from Ripe and Overripe Pineapple

It has become necessary to assess how food processing methods affect qualitative qualities due to the increased consumer awareness of the health benefits of various nutrients in food. In the current study, the effects of ultrasound treatment (37°C, 5 min), pasteurization (90°C, 5 min), and their combination on quality parameters, including pH, total soluble solids (TSSs), titratable acidity (TA), color values (L*, a*, b*), ascorbic acid (AA), total phenolic content (TPC), and antioxidant activity (DPPH), of pineapple juice from ripe and overripe pineapples were assessed. Color values (L*), ascorbic acid (AA), total phenolic content (TPC), and DPPH radical scavenging activity in all juice samples that were sonicated alone and in combination with pasteurization improved significantly (p and color value (a* and b*) decreased in comparison to the control. Whereas pH and acidity did not change significantly (p < 0.05). Pasteurization significantly (p , but sonicated samples significantly (p quality parameters and antioxidant activity, notably in ripe juice. Overall, pasteurization degraded these liquids but sonication, either alone or in combination with it, was advantageous for preserving their quality by retaining nutrients.

Bio-capped and green synthesis of ZnO/g-C_(3)N_(4) nanocomposites and its improved antibiotic and photocatalytic activities: An exceptional approach towards environmental remediation

In this research study, we have synthesized the bio-capped ZnO/g-C_(3)N_(4) nanocomposites by employing lemon juice(Citrus limon) as a stabilizer and mediator. Fruitfully, lemon juice which contains various acidic functional groups and citric acid has the capability to block the surface of g-C_(3)N_(4) from chemical reactivity and activated the surface of g-C_(3)N_(4) for various reactions. Consequently, the agglomeration behavior and controlled shape of g-C_(3)N_(4) has also been achieved. Our experimental results i.e. XRD,TEM, HRTEM, PL, FS, XPS, and PEC have confirmed that the lemon juice mediated and green g-C_(3)N_(4)(L-CN) have good performances and remarkable visible light photocatalytic activities as compared to the chemically synthesized g-C_(3)N_(4)(CN). Furthermore, the small surface area and low charge separation of g-C_(3)N_(4) is upgraded by coupling with Zn O nanoparticles. It is proved that the coupling of Zn O worked as a facilitator and photoelectron modulator to enhance the charge separation of g-C_(3)N_(4). Compared to pristine lemon-mediated green g-C_(3)N_(4)(L-CN), the most active sample 5Zn O/L-CN showed ~ 5-fold improvement in activities for ciprofloxacin(CIP) and methylene blue(MB) degradation. More specifically,the mineralization process and degradation pathways, and the mineralization process of ciprofloxacin(CIP) and methylene blue(MB) are suggested. Finally, our present novel research work will provide new access to synthesize the eco-friendly and bio-caped green g-C_(3)N_(4)nanomaterials and their employment for pollutants degradation and environmental purification.

木星系探测与JUICE任务概述

北京时间2023年4月14日,JUICE探测器的成功发射标志着木星系探测进入黄金时代,后续将重点针对冰卫星的宜居性进行全面探测。除了木星系探测共有的辐射环境恶劣、能源供给困难等技术难点,JUICE任务还有研制难度大、科学载荷多、任务周期长、轨道设计复杂等特点。本文对目前木星系探测发展形势及JUICE任务要点进行了梳理,总结了关键科学问题及技术挑战,对我国未来木星系探测具有借鉴意义。

Intraprocedural gastric juice analysis as compared to rapid urease test for real-time detection of Helicobacter pylori

BACKGROUND Endofaster is an innovative technology that can be combined with upper gastrointestinal endoscopy(UGE)to perform gastric juice analysis and real-time detection of Helicobacter pylori(H.pylori).AIM To assess the diagnostic performance of this technology and its impact on the management of H.pylori in the real-life clinical setting.METHODS Patients undergoing routine UGE were prospectively recruited.Biopsies were taken to assess gastric histology according to the updated Sydney system and for rapid urease test(RUT).Gastric juice sampling and analysis was performed using the Endofaster,and the diagnosis of H.pylori was based on real-time ammonium measurements.Histological detection of H.pylori served as the diagnostic gold standard for comparing Endofaster-based H.pylori diagnosis with RUT-based H.pylori detection.RESULTS A total of 198 patients were prospectively enrolled in an H.pylori diagnostic study by Endofasterbased gastric juice analysis(EGJA)during the UGE.Biopsies for RUT and histological assessment were performed on 161 patients(82 men and 79 women,mean age 54.8±19.2 years).H.pylori infection was detected by histology in 47(29.2%)patients.Overall,the sensitivity,specificity,accuracy,positive predictive value,and negative predictive value(NPV)for H.pylori diagnosis by EGJA were 91.5%,93.0%,92.6%,84.3%,and 96.4%,respectively.In patients on treatment with proton pump inhibitors,diagnostic sensitivity was reduced by 27.3%,while specificity and NPV were unaffected.EGJA and RUT were comparable in diagnostic performance and highly concordant in H.pylori detection(κ-value=0.85).CONCLUSION Endofaster allows for rapid and highly accurate detection of H.pylori during gastroscopy.This may guide taking additional biopsies for antibiotic susceptibility testing during the same procedure and then selecting an individually tailored eradication regimen.

Seabuckthorn juice alleviates allergic symptoms in shrimp-induced food allergy mice

Tropomyosin(TM)in shrimp is one of the predominant causes of food allergy around the world.In the present study,the effect of seabuckthorn juice against TM-induced shrimp allergy was investigated in BALB/c mice.Allergic symptoms,spleen index,intestinal section and diarrhea were measured in shrimp allergy mice.As the results,seabuckthorn juice suppressed the lesions in jejunum tissue,diarrhea and allergic symptoms in shrimp allergy mice.Seabuckthorn juice also reduced serum concentrations of tumor necrosis factor-a(TNF-α)as well as immunoglobulin E(IgE)and stimulated the secretion of interleukin-10(IL-10)in mice with shrimp allergy.Taken together,our findings suggest that increased IL-10 by seabuckthorn juice inhibits Th2 cytokine production to suppress shrimp allergic symptoms.Furthermore,seabuckthorn juice also regulates shrimp allergy by reducing jejunum lesions,inhibiting levels of TNF-αand IgE.

Appraisal of Improvement in Physiological and Metabolic Processes by Exogenously Applied Natural and Synthetic Ascorbic Acid in Okra(Abelmoschus esculentus L.)Fruit Subjected to Water Deficit Stress

To counteract the effects of drought stress,scientists have adopted several approaches including the use of different chemicals both inorganic and organic,which is contemplated as a highly efficient and cost-effective shot-gun approach.Ascorbic acid(AsA)is a potential organic substance,which widely occurs in plants,and is considered to be an effective antioxidant to counteract reactive oxygen species(ROS).Thus,a pot experiment was performed to assess the relative mitigating impacts of synthetic AsA and naturally occurring AsA in the form of lemon juice(LJ)and orange juice(OJ)on two cultivars of okra(Abelmoschus esculentus L.)namely Sabz Pari and Bhindi Sanwali under varying water deficit conditions.After 30 days of seed germination,okra seedlings were subjected to different irrigation regimes,i.e.,water deficit stress[(65%and 50%F.C.)and control conditions(100%F.C.)].Different levels of AsA[control(no spray),14 mg L^(−1)LJ,24 mg L^(−1)OJ and 150 mg L^(−1)AsA]obtained from different sources were applied as a foliar spray to control and water-stressed plants.Drought stress prominently reduced plant growth and yield attributes of the okra cultivars.Water-deficit conditions(65%and 50%F.C.)substantially decreased the fruit chlorophyll(a,b)pigments and the activity of superoxide dismutase(SOD)enzyme,while an increase was observed in the contents of fruit’s hydrogen peroxide(H_(2)O_(2)),malondialdehyde(MDA),total phenolics,total soluble sugars,AsA,and total soluble proteins.Drought stress also increased the activities of antioxidant enzymes like peroxidase(POD)and catalase(CAT).However,plant growth and yield attributes,fruit chlorophyll pigments,total phenolics,total soluble sugars,total free amino acids,total soluble proteins,AsA,GB,H_(2)O_(2),and the activities of antioxidant enzymes(POD and CAT)were increased by the AsA exogenous treatment in both okra cultivars under water deficit and control conditions.Overall,LJ and OJ were more effective than the synthetic AsA in upregulating the physiological and metabolic processes of okra plants.So,cost-effective as well as multi-nutrient natural sources of AsA could be suggested for alleviating the harmful effects of water deficit stress on plants.

Consumer Perceptions of Noni Juice Health Benefits during a 90-Day In-Home Use Test

Noni juice, made from the fruit of Morinda citrifolia, is a health-promoting food from the Pacific Islands with an extensive history of traditional use. Human clinical trials have revealed that noni juice has antioxidant, immunomodulatory and anti-inflammatory properties. Previously, regular noni juice consumers in Europe and traditional healers in Fiji were surveyed to identify potential noni juice health benefits. But to better understand the perception of its health benefits among those with no previous experience with noni juice, an in-home study was conducted in the United States. Three hundred and nineteen adults with untreated chronic health conditions were provided with a 90-day supply of a blinded (unlabeled) commercial noni juice product (Tahitian Noni® Juice), instructed to consume 4 fluid ounces (1/2 cup) each day, and responded to a questionnaire given on days 30, 60 and 90 to evaluate product appeal and perceived effectiveness. A total of 299 people (94%) felt that their health improved in some way after drinking TNJ for 90 days. More than 80% of the subjects reported feeling better or healthier in general. Most participants also concurred with more than two dozen additional positive health perception statements, especially on days 60 and 90. More than 70% of consumers also indicated that noni juice helped them feel better than other wellness supplements they had tried in the past, including other so-called “super fruit” products. These findings seem to corroborate the results of clinical trials and previous consumer surveys regarding the potential for noni juice to provide discernable health benefits when used consistently over time. Such findings may help guide additional placebo-controlled clinical trials in which specific effects may be evaluated more rigorously.

The Influence of Noni Fruit Juice on Immune System Function

Morinda citrifolia (noni) fruit juice has the potential to influence immune system function. This review discusses results from several human and animal studies that provide insight into the potential mechanisms of action by which noni juice exerts its immunomodulatory effects. Increased natural killer cell activity is a likely a major contributor to the improved health outcomes and increased survival times described in case reports and as observed in LLC and S180 tumor bearing mice. Increased interferon-gamma (IFN-γ) production is also an important mechanism of action through which noni improves immune function. IFN-γ promotes natural killer cell activity and phagocytosis, activities both seen in human and bovine studies as well as in rodents. Noni promotes regulatory cytokine expression, such as IL-2 which stimulates CD4+ T cell differentiation. Noni juice appears to influence this process via kinase 1/2 (ERK1/2), protein kinase B (Akt) and nuclear factor-kappa-beta signaling. As oxidative status is known to influence immune function, this review also discusses the notable antioxidant properties of noni juice that have been demonstrated in human trials.

Synthesis, Characterization, and Effects of Morphology on the Magnetic Application Base Properties of Pure Nickel Oxide (NiO) and Cobalt-Doped Nickel Oxide/Nickel Hydroxide (CoxNi1-xO/Ni(OH)2) Nanocomposites

Nano particle (NP) morphology is one of the material properties at the origin of potential application base properties exploited in several engineering and technology domains, such as fuel cell, electrodes, catalysis, sensing, electric, thermal, magnetic, and photovoltaic applications. The general properties and particle morphology of nickel oxide/Nickel hydroxide NPs can be modified by the introduction of impurity atoms or ions. Nano sized nickel oxide/nickel hydroxide nanocomposites were obtained from the thermal decomposition of single molecular precursors synthesized by a modified oxalate route using Carambola fruit juice as a precipitating agent. The compositional and morphological variations were studied by introducing cobalt as an impurity ion at different w/w% fractions (0%, 0.1%, 0.3%, 0.5%, 1%, 3%, 5.0%, 40.0% and 50.0%) into the microstructure of the nickel oxide/hydroxide. The precursors were characterized by FT-IR, while TGA/DTG analysis was carried out to decompose the precursors. The precursors decomposed at 400°C and were characterized by PXRD and SEM/TEM. The results revealed that Pure Nickel Oxide (NiO) and, Cobalt-doped Nickel Oxide/nickel hydroxide (CoxNi1-xO/Ni(OH)2) Nano composites have been synthesized and the synthesized samples have exhibited three distinct morphologies (porous face-centered cubic nano rods, rough and discontinuous CoxNi1-xO/Ni(OH)2) composite and, smooth and continuous mix spherical/cuboidal mixed morphological phase of (NiO/CoO). The morphology of the NPs varied with the introduction of the dopant atoms and with increase in the concentration of dopant atoms in the composite. Magnetic studies using vibrating sample magnetometry revealed superparamagnetic properties which correlated strongly with particle size, shape and morphology. Observed values of retention (4.50 × 10-3 emu/g) and coercivity (65.321 Oe) were found for 0.5 w/w% corresponding to impregnated porous nanorods of Co-doped NiO, and retention (9.03 × 10-3 emu/g) and coercivity (64.341 Oe), for X = 50.0%, corresponding to an aggregate network of a Nano spherical/cubic CoO/NiO mixed phase. Magnetic properties within this range are known to improve the magnetic memory and hardness of the magnetic materials. Therefore, the synthesized Cobalt-doped Nickel Oxide/nickel hydroxide (CoxNi1-xO/Ni(OH)2) Nano composites have potential applications in Magnetic memories and hardness of magnetic materials.

Synthesis, Characterization, and Effects of Morphology on the Magnetic Application Base Properties of Pure Nickel Oxide (NiO) and Cobalt-Doped Nickel Oxide/Nickel Hydroxide (CoxNi1-xO/Ni(OH)2) Nanocomposites

Nano particle (NP) morphology is one of the material properties at the origin of potential application base properties exploited in several engineering and technology domains, such as fuel cell, electrodes, catalysis, sensing, electric, thermal, magnetic, and photovoltaic applications. The general properties and particle morphology of nickel oxide/Nickel hydroxide NPs can be modified by the introduction of impurity atoms or ions. Nano sized nickel oxide/nickel hydroxide nanocomposites were obtained from the thermal decomposition of single molecular precursors synthesized by a modified oxalate route using Carambola fruit juice as a precipitating agent. The compositional and morphological variations were studied by introducing cobalt as an impurity ion at different w/w% fractions (0%, 0.1%, 0.3%, 0.5%, 1%, 3%, 5.0%, 40.0% and 50.0%) into the microstructure of the nickel oxide/hydroxide. The precursors were characterized by FT-IR, while TGA/DTG analysis was carried out to decompose the precursors. The precursors decomposed at 400°C and were characterized by PXRD and SEM/TEM. The results revealed that Pure Nickel Oxide (NiO) and, Cobalt-doped Nickel Oxide/nickel hydroxide (CoxNi1-xO/Ni(OH)2) Nano composites have been synthesized and the synthesized samples have exhibited three distinct morphologies (porous face-centered cubic nano rods, rough and discontinuous CoxNi1-xO/Ni(OH)2) composite and, smooth and continuous mix spherical/cuboidal mixed morphological phase of (NiO/CoO). The morphology of the NPs varied with the introduction of the dopant atoms and with increase in the concentration of dopant atoms in the composite. Magnetic studies using vibrating sample magnetometry revealed superparamagnetic properties which correlated strongly with particle size, shape and morphology. Observed values of retention (4.50 × 10-3 emu/g) and coercivity (65.321 Oe) were found for 0.5 w/w% corresponding to impregnated porous nanorods of Co-doped NiO, and retention (9.03 × 10-3 emu/g) and coercivity (64.341 Oe), for X = 50.0%, corresponding to an aggregate network of a Nano spherical/cubic CoO/NiO mixed phase. Magnetic properties within this range are known to improve the magnetic memory and hardness of the magnetic materials. Therefore, the synthesized Cobalt-doped Nickel Oxide/nickel hydroxide (CoxNi1-xO/Ni(OH)2) Nano composites have potential applications in Magnetic memories and hardness of magnetic materials.

Simultaneous Determination of Four Pesticide Residues in Fruit Juice by HPLC

[Objective] This study was conducted to develop a system for simultaneous determination of imidacloprid, diflubenzuron, thiabendazole and carbendazim in fruit juice by HPLC. [Method] Using acetonitrile as the extraction solvent, the pesticides in fruit juice were purified through a NH2 solid phase extraction （SPE） cartridge, then detected by HPLC. [Result] There was a good linear relationship between the peak area and the concentrations of imidacloprid, diflubenzuron, thiabendazole and carbendazim in a range of 0.05-5.0 μg/ml, and the linear correlation coefficient varied in a range of 0.999 0-0.999 8; the limit of detection for imidacloprid, diflubenzuron, thiabendazole and carbendazim was 0.003, 0.005, 0.003 and 0.007 mg/kg, respectively. The recovery rate of imidacloprid, diflubenzuron, thiabendazole and carbendazim standards added at three levels （0.1, 0.5 and 1.0 mg/kg） ranged from 82% to 107%, with RSD less than 4.5%. [Conclusion] The sensitivity, accuracy and precision of this method were able to meet the requirements for pesticide residue analysis.

气相色谱-质谱联用对浓缩苹果汁中多种拟除虫菊酯类农药的快速测定

A GC-MS method was established for determination of 10 pyrethroids in apple juice concentrate.The sample was extracted by acetone and hexane,and the 10 pyrethroids were separated on a capillary column(DB-5,30 m×250 μm×0.25 μm) and determined by GC-MSD.The recoveries of pyrethroids were range of 84%-96% with the detection limits of 3-46 μg/kg.The relative standard deviations were range of 0.68%-5.11%.