Senthil Vadivu Kulandhaivelu’s research while affiliated with Anna University, Chennai and other places

This study explores the eco-friendly modification of AZ91E alloy with MWCNT casting to enhance surfaces crucial for food processing, storage, and transportation, with a specific focus on reducing bacterial biofilm formation and preventing corrosion. Incorporating nanomaterials like MWCNT into magnesium alloys offers promising prospects for improving the surfaces of equipment and structures used in food-related industries. The advanced mechanical properties observed in MWCNT-doped alloys can lead to the development of lightweight yet durable surfaces essential for maintaining hygiene standards and ensuring food safety during processing, storage, and transportation. Employing sophisticated systematic practices such as XRD, FTIR, and Vickers hardness testing allows for comprehensive evaluation of surface modifications and mechanical enhancements. Furthermore, the demonstrated corrosion resistance of MWCNT-doped magnesium alloys is crucial for protecting surfaces from degradation caused by exposure to corrosive environments commonly encountered in food processing facilities and transportation systems. Additionally, the remarkable antibacterial properties exhibited by MWCNT-doped alloys hold promise for mitigating bacterial biofilm formation on surfaces, thereby contributing to enhanced sanitation and hygiene practices in food-related industries. KEY WORDS: Multiwalled carbon nanotube, Magnesium alloys, Anticorrosion, Squeeze casting, Antibacterial, Biofouling Bull. Chem. Soc. Ethiop. 2024, 38(6), 1897-1914. DOI: https://dx.doi.org/10.4314/bcse.v38i6.30

Sodium alginate (SA), carboxymethyl cellulose (CMC) and potato starch (PS) based functional packaging films were prepared by solvent casting method. The sample films were prepared with varying concentrations of SA/CMC and PS. The chemical, morphological, and thermal characterisation of the prepared films was investigated using FTIR, XRD, SEM and TGA analysis. The physical, optical, moisture, mechanical, and barrier properties were evaluated as a function of the SA/CMC and PS concentrations, and the results were analysed. The increased concentration of PS improved the barrier properties against UV, oxygen, and water vapour, along with decreasing the moisture content and elongation of the sample film. The prepared films with PS had uniform thickness, enhanced thermal stability and high tensile strength. The incorporation of 50% PS reduced the UV transmittance from 25.80% to 1.89%, and the tensile strength of the sample film was increased from 20.44 MPa to 31.95 MPa, whereas the elongation reduced from 34.86% to 13.78% and the moisture content from 29.15% to 16.21%. The shelf life analysis revealed that the produced film has the efficiency to enhance the post-harvest shelf life of black and green grapes by up to 16 days, confirming the potential use of SA/CMC/PS films in packaging applications.

In this study, carboxymethyl cellulose, carrageenan-based films and a blend film with 1:1 concentration were prepared using the solvent casting method and the influence of various concentrations of jackfruit seed starch (0, 0.5, 1.0, 1.5, and 2 g) on its functional properties were investigated. The effect of jackfruit seed starch on strength properties such as tensile strength and elongation, as well as waterrelated characteristics such as water contact angle, water vapour permeability, and moisture content, were evaluated and compared with the results of the control blend films. FT-IR, TGA, SEM, XRD were performed to identify the functional group and its potential interactions, thermal stability, surface morphology and crystallinity of prepared films. The results suggests that addition of jackfruit seed starch from 0 to 1.5 g enhanced the tensile strength from 26.62 MPa to 33.26 MPa, but thereafter the tensile strength drops to 32.58 MPa and the elongation decreases. When compared to the carboxymethyl cellulose carrageenan control film, some physical parameters of the film, such as water vapour permeability and moisture content, decreased while thickness and contact angle increased significantly. The results of scanning electron microscopy exhibited rough and heterogeneous morphology for films with more starch content, while the control films exhibited smooth and homogenous structure. The presence of starch increased the crystallinity of all films, which attributed to improved thermal and mechanical stability of the prepared films.

Abstract Packaging primarily serves to protect and preserve the product inside the package. However, designing packages for food, pharmaceutical, and medicinal products necessitate careful consideration since it may directly affect human health. Plastic is frequently used for packaging food, cosmetics, and pharmaceuticals due to its low cost, ease of processing, inertness, lightweight, and excellent product protection. Despite the many practical advantages of plastic, dependence on single-use plastic currently has significant environmental consequences. Because of the adverse environmental effect of synthetic packaging materials, researchers and industry experts are investigating the use of alternate materials derived from natural sources for packaging applications. Several polymers derived from natural resources, including carbohydrates, lipids, and proteins, have been studied for their potential use in food packaging. Sodium alginate is a linear polysaccharide derived from brown marine seaweeds. In recent years, sodium alginate-based films and coatings with active and functional constituents have drawn a lot of interest because of their barrier, mechanical, optical, and antibacterial qualities. Alginate was chosen for numerous packaging studies due to its widespread availability, biodegradability, nontoxic film-forming capabilities, and compatibility with other polysaccharides. This chapter reviews and summarises recent research findings on sodium alginate combined with other functional materials for active and intelligent packaging applications.

Edible packaging materials have widespread applications in pharmaceutical industries. In this study, the physical, thermal, colour, mechanical, and water barrier properties of a novel edible film based on pullulan (PUL) and carboxymethyl cellulose (CMC) were investigated. The blend films were made by the solution casting method with 3 g of total solid content. The following percentages of 100/0, 75/25, 50/50, 25/75, and 0/100 were used to prepare the films. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) were used to analyze the interaction between PUL and CMC. At the level of 75/25 percentage of PUL, CMC film showed the lowest EAB% (5.55%), the highest values for TS (17.30 MPa), WVP value ( 4.12 × 10 − 10 g m-1s-1Pa-1), and water contact angle of 63.43°. By increasing the CMC concentration, blend films became slightly greenish and yellowish but appeared transparent with UV blocking ability. This study reveals that 75/25 (PUL/CMC) blend film has a good potential that can be used in producing edible packaging films to protect the quality of pharmaceutical products with interesting specifications.

A novel biopolymer film has been developed based on natural renewable materials such as sodium alginate (SA) and carboxymethyl cellulose (CMC), which can be used as an alternative food packaging medium. The various proportions of the film-forming solution were prepared by the solvent casting method in an aqueous medium using a magnetic stirrer. Thickness uniformity, moisture content, surface morphology, moisture barrier property, optical property, and mechanical property of the prepared samples were investigated. Significant changes were observed for moisture content, UV barrier property, ductility, and water vapour permeability values concerning changes in SA/CMC concentrations. The increase in CMC concentration increased the moisture content of the film, while SA concentration leads to a decrease in the permeability to water vapor. Both SA and CMC films have strong mechanical strength, but for films with greater CMC concentration, elongation values are found to be higher. The prepared films, which contain varying concentrations of SA/CMC, have a high mechanical and barrier strength that allows them to control and retain moisture within the package, making them ideal for preserving the freshness of post-harvest fruits and vegetables.