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Human health-related issues are increasing in day to day life because of the modern and unhygienic food lifestyles. In recent times, green tea (GT) gains more attention due to its numerous health benefits. It contains more biologically active compounds that improve mental health, increase metabolism, reduce cancer risks, and serve as an anti-aging agent for the brain. As it is globally consumed, the evaluation of the compounds present in it is very important. Hence, an attempt has been performed to evaluate these components in GT by using a cobalt nickel iron-based trimetallic zeolitic imidazolate framework as microfibers (CoNiFe-ZIF-MFs) synthesized via an electrospinning technique. Interestingly, the synthesized CoNiFe-ZIF-MFs catalyst simultaneously detects three major catechin (CT) groups, namely, epigallocatechin-3-gallate (EGCG), epicatechin (EC), and epicatechingallate (ECG). Further, the square wave voltammetry findings showed that there is a wide linear range of 50 ng to 1 mg for all the three CTs with LODs 45, 8, and 4 ng for EGCG, EC, and ECG, respectively. These results confirm the excellent sensing behavior of the composite toward GT extracts, proposing its practical utility in real-time compound analysis in food sectors. Other results like stability and reproducibility also promote its usage in the biomedical field. This study mainly focuses on the direct sensing of CTs present in GT without spiking any commercially purchased sample, and the sensing was performed simultaneously for all the three analytes; thus, this work gains novelty from the existing ones.

Monitoring of food-based products is mandatory in recent days as a result of increasing health-related issues and to produce ready-to-eat foods. Generally, in the food industry, the antioxidant property of phenolic compounds is utilized to improvize human health. Gallic acid (GA) is a widely known and abundant phenolic acid found used in numerous foods because of its huge health benefits. So far, many methods have been developed for the detection of GA using diverse nanocomposites. Likewise in the view of providing a simple and inexpensive material, we propose a zeolitic imidazolate framework (ZIF-8) functionalized with guar gum (GG) towards GA sensing. Here, the composite is prepared in a very easy and time-efficient manner using biocompatible GG. The physiochemical properties confirm the material formation due to the electrostatic interaction between the zinc ion of ZIF-8 and GG’s hydroxyl or carboxyl groups. Morphological studies confirm the nanostructured rhombic dodecahedral ZIF-8 particles embellished on the surface of GG’s microlayers. Further, electrochemical studies reveal the composite excellent behaviuor towards the GA sensing with a wide linear range of 200 nM–2.5 mM and a detection limit (LOD) of 60 nM. In addition to this, the composite offers significant selectivity, and good stability of up to 84% for 100 cycles along with acceptable repeatability and reproducibility. Finally, the investigation of the practical utility of unspiked wine, grape juice and tea samples also profound the composite’s exceptional sensing with remarkable recovery. Considering all these results, the proposed ZIF-8@GG composite can be fit for the fabrication of sensor devices towards food product testing in industries.

The finite element method is applied to the small deflection bending analysis of nonuniform thin axisymmetric circular plates made of linear elastic material. Elements with annular and circular geometry with only 4 degrees of freedom are used in the analysis of both symetrically and nonsymmetrically loaded plates. Non-symmetric loads are expanded in Fourier series and elements restricted to deform with specified number of nodal diameters are used for each component of loading. The method is checked with several numerical examples. Although applicable to only axisymmetric plates, the method gives better results compared to other finite element methods besides offering savings in computer storage and time.