Impact of High-Pressure Homogenization Parameters on Physicochemical Characteristics,Bioactive Compounds Content,and Antioxidant Capacity of Blackcurrant Juice

High-pressure homogenization (HPH) is one of the food-processing methods being tested for use in food preservation as an alternative to pasteurization. The effects of the HPH process on food can vary depending on the process parameters used and product characteristics. The study aimed to investigate the effect of pressure, the number of passes, and the inlet temperature of HPH processing on the quality of cloudy blackcurrant juice as an example of food rich in bioactive compounds. For this purpose, the HPH treatment (pressure of 50, 150, and 220 MPa; one, three, and five passes; inlet temperature at 4 and 20 °C) and the pasteurization of the juice were performed. Titratable acidity, pH, turbidity, anthocyanin, vitamin C, and total phenolics content, as well as colour, and antioxidant activity were measured. Heat treatment significantly decreased the quality of the juice. For processing of the juice, the best were the combinations of the following: one pass, the inlet temperature of 4 °C, any of the used pressures (50, 150, and 220 MPa); and one pass, the inlet temperature of 20 °C, and the pressure of 150 MPa. Vitamin C and anthocyanin degradation have been reported during the HPH. The multiple passes of the juice through the machine were only beneficial in increasing the antioxidant capacity but negatively affected the colour stability.     

Lycium Barbarum Polysaccharides and Wolfberry Juice Prevent DEHP-Induced Hepatotoxicity via PXR-Regulated Detoxification Pathway

Environmental di(2-Ethylhexyl) phthalate (DEHP) is widely used in various industries as a plasticizer, and has been reported to induce reproductive and developmental toxicities in organisms. The purpose of this study was to evaluate the detoxification capacity of Lycium barbarum polysaccharides (LBP) and wolfberry juice (WJ) against DEHP-induced hepatotoxicity. Two groups of rats were purchased to study two different intervention method experiments: LBP (50, 100, 200 mg/kg·bw) intervention before DEHP (2000 mg/kg·bw) exposure, and LBP (200 mg/kg·bw) or WJ (8 mL/kg·bw) intervention after DEHP (3000 mg/kg·bw) exposure. The rats were exposed to DEHP once, while the intervention lasted for seven days. At the end of the intervention, enzyme-linked immunosorbent assay (ELISA) was used to measure the related index. The LBP intervention before DEHP exposure experiment (the first experimental method) found that LBP group rats showed a strong capacity toward DEHP detoxification, evidenced by the significant upregulation of activities and concentrations of the partner retinoid, X receptor alpha (RXRα), and downstream regulators Cytochrome P4502E1 (CYP2E1), Cytochrome P4503A1 (CYP3A1), Glutathione S-Transferase Pi (GSTpi), and UDP-glucuronosyltransferase 1 (UGT1) in a dose-dependent manner. The LBP and WJ intervention after DEHP exposure experiment (the second intervention experiment) found that WJ could downregulate pregnane X receptor (PXR), and upregulate downstream regulators, CYP2E1, CYP3A1, and Glutathione S-Transferase (GST) with the extension of intervention time, to alleviate the toxicity of DEHP. However, the intervention effect of WJ was more obvious than that of LBP. These results suggested that LBP and WJ might be effective detoxification agents against DEHP-induced toxic effects, by activating PXR and PXR-related detoxifying enzymes.     

Enzyme-assisted extraction and ionic liquid-based dispersive liquid–liquid microextraction followed by high-performance liquid chromatography for determination of patulin in apple juice and method optimization using central composite design

A simple and highly sensitive analytical methodology for isolation and determination of patulin in apple-juice samples, based on enzyme-assisted extraction (EAE) and ionic liquid-based dispersive liquid–liquid microextraction (IL-DLLME) was developed and optimized. Enzymes play essential roles in eliminating interference and increasing the extraction efficiency of patulin. Apple-juice samples were treated with pectinase and amylase. A mixture of 80 μL ionic liquid and 600 μL methanol (disperser solvent) was used for the IL-DLLME process. The sedimented phase was analyzed by high-performance liquid chromatography (HPLC). Experimental parameters controlling the performance of DLLME, were optimized using response surface methodology (RSM) based on central composite design (CCD). Under optimum conditions, the calibration curves showed high levels of linearity (R² > 0.99) for patulin in the range of 1–200 ng g⁻¹. The relative standard deviation (RSD) for the seven analyses was 7.5%. The limits of detection (LOD) and limits of quantification (LOQ) were 0.15 ng g⁻¹ and 0.5 ng g⁻¹, respectively. The merit figures, compared with other methods, showed that new proposed method is an accurate, precise and reliable sample-pretreatment method that substantially reduces sample matrix interference and gives very good enrichment factors and detection limits for investigation trace amount of patulin in apple-juice samples.     

Selective Voltammetric Determination of Tartrazine in the Presence of Red 10B by Nanogold‐modified Carbon Paste Electrode

A nanogold modified carbon paste electrode (NG‐CPE) was fabricated and used as selective voltammetric sensor for determination of Tartrazine in the presence of Red 10B using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CHA). Electrochemical parameters including the diffusion coefficient (D), the electron transfer coefficient (aXXXXX), and the electron transfer number (n) were determined for the oxidation of Tartrazine. This modified electrode can be applied to simultaneous determination of Tartrazine and Red 10B, because of considerable decreases of anodic overpotentials for both compounds. After optimizing the experimental conditions, the anodic peak current of Tartrazine was linear to its concentration in the range of 0.05‐1.5 μmol l^?1, and the detection limit was 0.017 μmol l^?1 in phosphate buffer solution (PBS) at pH 4.0. The modified electrode has good stability and repeatability. It was applied to the determination of Tartrazine and Red 10B in soft drinks with satisfactory results.     

液相色谱串联质谱法测定冷冻饮品中环己基氨基磺酸钠

建立了液相色谱～串联质谱测定冷冻饮品中环己基氨基磺酸钠的方法。冷冻饮品经净化、冷冻离心后用水稀释定容,采用C18色谱柱（50mm×2．1mm,1．7μm）,以乙腈-0．01mol／L乙酸铵缓冲溶液为流动相,电喷雾离子源负离子模式（MRM）定性、定量测定环己基氨基磺酸钠。环己基氨基磺酸钠的质量浓度在2—1000μg／L范围内与峰面积呈线性关系,相关系数,=0．9999,方法的定量限为0．02mg／kg。在10—100μg／L范围内,3水平加标回收率为87．5％～101．8％,测定结果的相对标准偏差为3．0％（H=6）。该方法净化效果好,灵敏度高,能快速完成冷冻饮品中环己基氨基磺酸钠的测定。     

Determination of α‐hydroxy acids and their enantiomers in fruit juices by ligand exchange CE with a dual central metal ion system

The content of α‐hydroxy acids and their enantiomers can be used to distinguish authentic and adulterated fruit juices. Here, we investigated the use of ligand exchange CE with two kinds of central metal ion in a BGE for the simultaneous determination of enantiomers of dl ‐malic, dl ‐tartaric and dl ‐isocitric acids, and citric acid. Ligand exchange CE with 100 mM d ‐quinic acid as a chiral selector ligand and 10 mM Cu(II) ion as a central metal ion could enantioseparate dl ‐tartaric acid but not dl ‐malic acid or dl ‐isocitric acid. Addition of 1.8 mM Sc(III) ion to the BGE with 10 mM Cu(II) ion to create a dual central metal ion system permitted the simultaneous determination of these α‐hydroxy acid enantiomers and citric acid. The proposed ligand exchange CE was thus well suited for detecting adulteration of fruit juices.     

Single-step extraction and cleanup of bisphenol A in soft drinks by hemimicellar magnetic solid phase extraction prior to liquid chromatography/tandem mass spectrometry

Hemimicelles of tetradecanoate chemisorbed onto magnetic nanoparticles (MNPs) are here proposed as a sorbent for the single-step extraction and cleanup of bisphenol A (BPA) in soft drinks. The purpose of this work was to develop a simple, rapid and low-cost sample treatment suitable to assess the human exposure to BPA from this type of high consumption food. The nanoparticles were easily coated by mixing commercially available magnetite of 20–30 nm mean particle diameter with tetradecanoate at 85 °C for 30 min. The extraction/cleanup procedure involved stirring the samples (3 mL) with 200 mg of tetradecanoate-coated MNPs for 20 min, isolating the sorbent with a Nd–Fe–B magnet and eluting BPA with methanol. The extraction efficiency was not influenced by salt concentrations up to 1 M and pH values over the range 4–9. No cleanup of the extracts was needed, and the method proved matrix-independent. The extracts were analyzed by liquid chromatography, electrospray ionization tandem mass spectrometry. Quantitation was performed by internal standard calibration using BPA-¹³C₁₂. The limit of quantitation obtained for the method, 0.03 ng mL⁻¹, was below the usual range of concentrations reported for BPA in soft drinks (0.1–3.4 ng mL⁻¹). The proposed method was successfully applied to the determination of BPA in different samples acquired from various supermarkets in southern Spain; the concentrations found ranged from 0.066 to 1.08 ng mL⁻¹. Recoveries from samples spiked with 0.33 ng mL⁻¹ of BPA ranged from 91% to 105% with relative standard deviations from 3% to 8%.     

Impact of high-intensity thermosonication treatment on spinach juice: Bioactive compounds,rheological, microbial,and enzymatic activities

To study the impacts of thermosonication (TS), the spinach juice treated with TS (200 W, 400 W, and 600 W, 30 kHz, at 60 ± 1 °C for 20 mint) were investigated for bioactive compounds, antioxidant activities, color properties, particle size, rheological behavior, suspension stability, enzymatic and microbial loads. As a result, TS processing significantly improved the bioactive compounds (total flavonols, total flavonoids, total phenolic, carotenoids, chlorophyll, and anthocyanins), antioxidant activities (DPPH and FRAP assay) in spinach juice. Also, TS treatments had higher b*, L*, hue angle (h⁰), and chroma (C) values, while minimum a* value as compared to untreated and pasteurized samples. TS processing significantly reduced the particle size, improved the suspension stability and rheological properties (shear stress, apparent viscosity, and shear rate) of spinach juice as compared to the untreated and pasteurized sample. TS plays a synergistic part in microbial reduction and gained maximum microbial safety. Moreover, TS treatments inactivated the polyphenol oxidase and peroxidase from 0.97 and 0.034 Abs min⁻¹ (untreated) to 0.31 and 0.018 Abs min⁻¹, respectively. The spinach juice sample treated at a high intensity (600 W, 30 kHz, at 60 ± 1 °C for 20 mint, TS3) exhibited complete inactivation of microbial loads (<1 log CFU/ml), the highest reduction in enzymatic activities, better suspension stability, color properties, and highest bioactive compounds. Collectively, the verdicts proposed that TS processing could be a worthwhile option to pasteurize the spinach juice to enhance the overall quality.     

Application of ultrasonication at different microbial growth stages during apple juice fermentation by Lactobacillus plantarum: Investigation on the metabolic response

In this work, low-intensity ultrasonication (58.3 and 93.6 W/L) was performed at lag, logarithmic and stationary growth phases of Lactobacillus plantarum in apple juice fermentation, separately. Microbial responses to sonication, including microbial growth, profiles of organic acids profile, amino acids, phenolics, and antioxidant capacity, were examined. The results revealed that obvious responses were made by Lactobacillus plantarum to ultrasonication at lag and logarithmic phases, whereas sonication at stationary phase had a negligible impact. Sonication at lag and logarithmic phases promoted microbial growth and intensified biotransformation of malic acid to lactic acid. For example, after sonication at lag phase for 0.5 h, microbial count and lactic acid content in the ultrasound-treated samples at 58.3 W/L reached 7.91 ± 0.01 Log CFU/mL and 133.70 ± 7.39 mg/L, which were significantly higher than that in the non-sonicated samples. However, the ultrasonic effect on microbial growth and metabolism of organic acids attenuated with fermentation. Moreover, ultrasonication at lag and logarithmic phases had complex influences on the metabolism of apple phenolics such as chlorogenic acid, caffeic acid, procyanidin B2, catechin and gallic acid. Ultrasound could positively affect the hydrolysis of chlorogenic acid to caffeic acid, the transformation of procyanidin B2 and decarboxylation of gallic acid. The metabolism of organic acids and free amino acids in the sonicated samples was statistically correlated with phenolic metabolism, implying that ultrasound may benefit phenolic derivation by improving the microbial metabolism of organic acids and amino acids.     

Coaxial flow‐gating interface for capillary electrophoresis

A coaxial flow‐gating interface is described in which the separation capillary passes through the sampling capillary. Continuous flow of the sample solution flowing out of the sampling capillary is directed away from the injection end of the separation capillary by counter‐current flow of the gating solution. During the injection, the flow of the gating solution is interrupted, so that a plug of solution is formed at the inlet into the separation capillary, from which the sample is hydrodynamically injected. Flow‐gating interfaces are originally designed for on‐line connection of capillary electrophoresis with analytical flow‐through methods. The basic properties of the described coaxial flow‐gating interface were obtained in a simplified arrangement in which a syringe pump with sample solution has substituted analytical flow‐through method. Under the optimized conditions, the properties of the tested interface were determined by separation of K⁺, Ba²⁺, Na⁺, Mg²⁺ and Li⁺ ions in aqueous solution at equimolar concentrations of 50 μM. The repeatability of the migration times and peak areas evaluated for K⁺, Ba²⁺ and Li⁺ ions and expressed as relative standard deviation did not exceed 1.4%. The interface was used to determine lithium in mineral water and taurine in an energy drink.