Vasudha Bansal

Review of PAH contamination in food products and their health hazards.

Public concern over the deleterious effects of polycyclic aromatic hydrocarbons (PAHs) has grown rapidly due to recognition of their toxicity, carcinogenicity, and teratogenicity. The aim of this review is to describe the status of PAH pollution among different food types, the route of dietary intake, measures for its reduction, and legislative approaches to control PAH. To this end, a comprehensive review is outlined to evaluate the status of PAH contamination in many important food categories along with dietary recommendations. Our discussion is also extended to describe preventive measures to reduce PAH in food products to help reduce the risks associated with human intake.

Synthesis and energy applications of metal organic frameworks

The unique and tunable properties of metal organic framework (MOF) provide a new technological opportunity to challenge various issues in energy sectors. This review critically assesses the unique features regarding the synthesis methods of MOFs and discusses their vigorous role in light emitting device and photovoltaic devices. This review article also aims to help upgrade the feasibility of MOFs for the future applications towards energy systems and to provide an outline for the future opportunities in this field.

Coupling of chromatographic analyses with pretreatment for the determination of bioactive compounds in Emblica officinalis juice

A simple and new method for the simultaneous detection and quantification of vitamin C (ascorbic acid), phenolic acids (gallic acid and ellagic acid), hydroxycinnamic acid (chlorogenic acid) and flavonoids (myricetin, quercetin and kaempferol) in Emblica juice is developed. The compounds are separated in 18 minutes by an intangible curved gradient of 0.1% ortho-phosphoric acid in water (v/v) and acetonitrile, as mobile phase A and B, respectively, using Zorbax SB RP C-18 column at a wavelength of 254 nm. The assay was optimized by varying the mobile phase, gradient type, pretreatment method (thermal and non-thermal) and detection wavelength. The method was validated in terms of linearity, precision, detection limits and quantification limits. Good linear response was observed over the range specified for all the analytes, as confirmed by the correlation coefficient which ranged from 0.991 and 0.995. The limit of detection (LOD) and limit of quantification (LOQ) were found to be in the range of 0.129–0.685 μg ml−1 and 0.43–2.883 μg ml−1 respectively. Pulsed electric field (PEF) was used as the non-thermal pretreatment sample technique. HPLC-PDA showed increased levels of phenolic acids, as gallic and ellagic acid, and flavonoid, as quercetin, in PEF treated Emblica juice with respect to the untreated and thermally treated juice samples (p < 0.05). The overall precision values obtained for standards and samples were within the range 0.01–0.2 and 0.15–0.23 respectively. Further, total polyphenolic content and free radical scavenging capacity of the untreated, thermally and PEF treated Emblica juice were corroborated by HPLC.

Biological applications of zinc imidazole framework through protein encapsulation

The robustness of biomolecules is always a significant challenge in the application of biostorage in biotechnology or pharmaceutical research. To learn more about biostorage in porous materials, we investigated the feasibility of using zeolite imidazolate framework (ZIF-8) with respect to protein encapsulation. Here, bovine serum albumin (BSA) was selected as a model protein for encapsulation with the synthesis of ZIF-8 using water as a media. ZIF-8 exhibited excellent protein adsorption capacity through successive adsorption of free BSA with the formation of hollow crystals. The loading of protein in ZIF-8 crystals is affected by the molecular weight due to diffusion-limited permeation inside the crystals and also by the affinity of the protein to the pendent group on the ZIF-8 surface. The polar nature of BSA not only supported adsorption on the solid surface, but also enhanced the affinity of crystal spheres through weak coordination interactions with the ZIF-8 framework. The novel approach tested in this study was therefore successful in achieving protein encapsulation with porous, biocompatible, and decomposable microcrystalline ZIF-8. The presence of both BSA and FITC–BSA in ZIF-8 was confirmed consistently by spectroscopy as well as optical and electron microscopy.

Rapid HPLC Method for Determination of Vitamin C, Phenolic Acids, Hydroxycinnamic Acid, and Flavonoids in Seasonal Samples of Emblica officinalis Juice

The work proposes a simple method for simultaneous detection and quantification of vitamin C (ascorbic acid), phenolic acids (gallic acid and ellagic acid), hydroxycinnamic acid (chlorogenic acid), and flavonoids (myricetin, quercetin, and kaempferol) in seasonal samples of emblica juice. The compounds were separated by an intangible curved gradient of 0.1% orthophosphoric acid in water (v/v) and acetonitrile as mobile phase A and B using Zorbax SB RP C-18 column at a wavelength of 254 nm in 18 min. The assay was optimized by varying the mobile phase, gradient type, and detection wavelength. The method was validated in terms of linearity, precision, detection limits, and quantification limits. Good linear response was observed over the range specified for all the analytes, as confirmed by the correlation coefficient which ranged from 0.991 and 0.995. The limit of detection and limit of quantification were found to be in the range of 0.129–0.685 µg mL−1 and 0.43–2.883 µg mL−1, respectively. Complete resolution of the phenolic compounds was achieved without the need of pre-analysis processes. The overall precision values obtained for standards and samples were within the range of 0.01–0.2 and 0.15–0.23, respectively.

Minimally Processed Foods: Overview

Over the past decades, consumers want fresh like foods with their natural nutritive values and sensory attributes, such as flavor, odor, texture and taste (Huxley et al. 2004). Fresh fruits and vegetables are the good examples of convenient foods. This growing consumers’ demandof minimally processed foods with no or lesser synthetic additives pose challenges to food technologists. In addition, demand of functional foods to prevent or control of diseases are growing (Monteiro et al. 2011). All these demands force to develop safe foods with minimal processing techniques (Gilbert 2000). This is not a simple task to produce safe minimally processed foods with desired shelf-life.

Core–shell nanostructures as a platform for sensing applications

Abstract In this chapter, we thoroughly explore core–shell nanostructures as a platform for various sensing applications. We cover both fundamental science and the current progress achieved in this field. The first part of the paper focuses on the types, properties, and applications of diverse core–shell-nanostructure-(CSN)-based materials (nanoparticles, quantum dots (QDs), carbon nanotubes (CNTs), graphene, nano porous materials, and nanocomposites/hybrid materials). Then, sensor design (electrochemical, colorimetric, fluorescent) and the fabrication of CSN materials are explained based on their working principles as they apply to photo electrochemical, electromechanical, electromagnetic, and other sensor applications.

Effect of atmospheric cold plasma (ACP) with its extended storage on the inactivation of Escherichia coli inoculated on tomato

The study investigated the efficacy of atmospheric cold plasma (ACP) treatment on inactivation of E. coli load during extended storage period of 48h at both the temperatures of refrigeration (4°C) as well as room (25°C). The tomato samples were spot inoculated with E. coli and exposed to ACP at 15 and 60kV for 5, 10, 15, and 30min followed by their storage at 4°C and 25°C. The highest log reduction of 6logCFUmL-1 was achieved in population of E. coli after 15min of ACP treatment at 60kV, which was sustained up to storage duration of 48h at both the temperatures. Furthermore, significant reduction in E. coli was found at plasma treatment of 60kV in comparison to 15kV. The inactivation of E. coli was significantly (p<0.01) affected by combination of treatment higher voltage at extended treatment time, however, treatment time with prolonged storage of sealed ACP treated tomato was observed as a key factor in reduction of E. coli. In addition, investigation of E. coli exposed tomato surface was done using scanning electron microscopy that clearly showed the breakdown of cell cover of E. coli as a consequence of ACP. The study predicts the promising potential of the technique in sanitization of vegetables that are eaten raw like tomato.