Stability of nanoparticle stabilized oil-in-water Pickering emulsion under high pressure and high temperature conditions: comparison with surfactant stabilized oil-in-water emulsion

In this work, a novel molecularly imprinted polymer (MIP) with water-soluble CdTe quantum dots (QDs) was synthesized by oil-in-water Pickering emulsion polymerization using whole Listeria monocytogenes as the template. Listeria monocytogenes was first treated by acryloyl-functionalized chitosan with QDs to form a bacteria–chitosan network as the water phase. This was then stabilized in an oil-in-water emulsion comprising a cross-linker, monomer, and initiator, causing recognition sites on the surface of microspheres embedded with CdTe QDs. The resulting MIP microspheres enabled selective capture of the target bacteria via recognition cavities. The target bacteria Listeria monocytogenes was detected. Scanning electron microscopy (SEM) characterization showed that the MIPs had a rough spherical shape. There was visual fluorescence detection via quenching in the presence of the target molecule, which offered qualitative detection of Listeria monocytogenes in milk and pork samples. The developed method simplified the analysis process and did not require any sample pretreatment. In addition, the fluorescence sensor provided an effective, fast, and convenient method for Listeria monocytogenes detection in food samples.

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Enzymatic Coupled Mechanical Defibrillation Process for the Production of Corn (Zea Mays) Cob Microfibrillated Cellulose: Preparation, Characterization and Evaluation as Pickering Emulsifier for Oil-In-Water Emulsion

10.21203/rs.3.rs-282587/v1 ◽

2021 ◽

Author(s):

Teck-Kim Tang ◽

Yee-Ying Lee ◽

Eng-Tong Phuah ◽

Chin-Ping Tan ◽

Sivaruby Kanagaratnam ◽

...

Keyword(s):

High Pressure ◽

Shear Viscosity ◽

Microfibrillated Cellulose ◽

High Pressure Homogenization ◽

Corn Cob ◽

Water Emulsion ◽

Homogenization Process ◽

Oil In Water ◽

High Pressure Homogenizer ◽

Oil In Water Emulsion

Abstract Microfibrillated cellulose (MFC) is a type of nanocellulose having multiple functionalities. Typically, MFC was produced from mechanical high pressure homogenization process. However, this process is energy intensive and the fibrous nature of MFC often causes instrument blockage. The present study aims to utilize endoglucanse enzyme as environmentally friendly approach to pretreat fiber structure prior to undergoing mechanical defibrillation for the production of MFC from corn cob. Alkaline and bleached pretreated corn cob was treated with endoglucanase Fibercare R from 0% to 2.5% before passing through high pressure homogenizer. It was found that incorporation of 0.02% of endoglucanase was sufficient to soften the corn cob cellulose and further prevent the blockage of homogenizer. Subsequently, the 0.02% endoglucanse treated corn cob was passed through different cycles of homogenization from 0 cycle to 10 cycle for MFC production. It was observed that the water retention, zeta potential and shear viscosity of the MFC increases with homogenization cycle. MFC produced had a gel like consistency. Next, emulsifying stabilizing properties of MFC produced from cycle 0 to cycle 10 as well as their amount from 0 % to 1% were also assessed. Increase in homogenization cycle and the amount of MFC promote emulsion stability as observed from the low creaming index which is mainly attributed to the high shear viscosity and G’G’’ crossover of the emulsion. In all, the MFC derived from corn cob via enzymatic coupled with high pressure homogenization process has the potential to be used as gel like stabilizer in oil-in-water food emulsion system.

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