scholarly journals Preparation of Fluorescent Molecularly Imprinted Polymers via Pickering Emulsion Interfaces and the Application for Visual Sensing Analysis of Listeria Monocytogenes

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 984 ◽  
Author(s):  
Xiaolei Zhao ◽  
Yan Cui ◽  
Junping Wang ◽  
Junying Wang

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.

2019 ◽  
Vol 135 ◽  
pp. 445-452 ◽  
Author(s):  
Digambar Kavitake ◽  
Sangeeta Balyan ◽  
Palanisamy Bruntha Devi ◽  
Prathapkumar Halady Shetty

2014 ◽  
Vol 12 (2) ◽  
pp. 242-249 ◽  
Author(s):  
Jania Milić ◽  
Irena Petrinić ◽  
Andreja Goršek ◽  
Marjana Simonič

AbstractIn this study, a Taguchi experimental design methodology was used to determine the importance of process parameters influencing the ultrafiltration (UF) of oil-in-water emulsions. Four parameters including pH (5–11), oil concentration (φ) (0.5–3% (v/v)), temperature (T) (25–45°C) and trans-membrane pressure (TMP) (1–5 bar) were studied at three levels. The highest flux was used as optimization criterion. In order to reduce the number of experiments, a Taguchi method was applied. Analysis of variance (ANOVA) was used to determine the most significant parameters affecting the optimization criterion.Filtration experiments were performed in a cross-flow operation at a total recycle condition in a laboratory-scale plant. The ceramic UF membrane with a pore size of 50 nm was employed in a tubular module with an active area of 0,418 m2. We used water-soluble cutting oil mixed with water as a model oil-in-water emulsion. During the experiment, the drop size and zeta potential distributions were evaluated.The optimum conditions for UF providing the highest flux were found at TMP = 5 bar, pH = 7, and φ = 0.5 v/v%. The pH of emulsion had the highest impact on COD retention. The results of this study could be used as a guideline for operating UF systems with ceramic membranes at optimal conditions.


2018 ◽  
Vol 57 (1) ◽  
pp. 63-70
Author(s):  
V. Nagarajappa ◽  
S.N. Battula ◽  
S. Arora ◽  
L.N. Naik

AbstractPhytosterols are a group of lipophilic steroid alcohols found in plants, which have been shown to lower cholesterol when supplemented in the diet. A commercial phytosterol preparation was added to milk in the form of an oil-in-water emulsion. For the preparation of an emulsion, diacetyl tartaric acid ester of mono- and diglycerides was used as an emulsifier and butteroil was used as a source of fat. Three emulsion formulations, i.e. A (8% phytosterols), B (10% phytosterols) and C (12% phytosterols), were prepared in which the levels of emulsifier (6.5%) and butteroil (10%) were kept constant, and each emulsion was added to milk at a rate of 5% (w/w). Based on sensory evaluation, B-emulsion formulation was selected for fortification of milk. The phytosterol content of the fortified milk determined by reverse-phase high-performance liquid chromatography was 410.8 mg/100 g. No significant loss in the initial content of phytosterol was observed after 1 week of storage. Sensory and physicochemical analyses indicated that significant differences were not observed between control and fortified milk samples up to 7 days of refrigerated storage. The present study suggests that it is feasible to add phytosterol as a functional ingredient in milk in the form of water-soluble emulsion to enhance health benefits of consumers. Two servings of such fortified milk per day provide almost the entire recommended daily requirement of phytosterol.


Sign in / Sign up

Export Citation Format

Share Document