Luminescence-encoded microbeads are important tools for many applications in the life and material sciences that utilize luminescence detection as well as multiplexing and barcoding strategies. The preparation of such beads often involves the staining of premanufactured beads with molecular luminophores using simple swelling procedures or surface functionalization with layer-by-layer (LbL) techniques. Alternatively, these luminophores are sterically incorporated during the polymerization reaction yielding the polymer beads. The favorable optical properties of semiconductor quantum dots (QDs), which present broadly excitable, size-tunable, narrow emission bands and low photobleaching sensitivity, triggered the preparation of beads stained with QDs. However, the colloidal nature and the surface chemistry of these QDs, which largely controls their luminescence properties, introduce new challenges to bead encoding that have been barely systematically assessed. To establish a straightforward approach for the bead encoding with QDs with minimized loss in luminescence, we systematically assessed the incorporation of oleic acid/oleylamine-stabilized CdSe/CdS-core/shell-QDs into 0.5–2.5 µm-sized polystyrene (PS) microspheres by a simple dispersion polymerization synthesis that was first optimized with the organic dye Nile Red. Parameters addressed for the preparation of luminophore-encoded beads include the use of a polymer-compatible ligand such as benzyldimethyloctadecylammonium chloride (OBDAC) for the QDs, and crosslinking to prevent luminophore leakage. The physico-chemical and optical properties of the resulting beads were investigated with electron microscopy, dynamic light scattering, optical spectroscopy, and fluorescence microscopy. Particle size distribution, fluorescence quantum yield of the encapsulated QDs, and QD leaking stability were used as measures for bead quality. The derived optimized bead encoding procedure enables the reproducible preparation of bright PS microbeads encoded with organic dyes as well as with CdSe/CdS-QDs. Although these beads show a reduced photoluminescence quantum yield compared to the initially very strongly luminescent QDs, with values of about 35%, their photoluminescence quantum yield is nevertheless still moderate.

The study was carried out to develop and compare Ginger candy from fresh indigenous and China Ginger. Ginger was immersed into the sugar solution with the concentrations of 50%, 60% and 70% sugar solution. Moisture, ash, protein, fat, crude fiber and total sugar content and organoleptic quality and microbial status of the prepared candy were analyzed. Moisture, ash, protein, fat and crude fiber content was found to be lower with increased concentration of sugar solution used, whereas total sugar content was found to be higher. Total bacterial count was increased with increasing the concentration of sugar solution. The best characteristic of Ginger candy was found with 50% sugar solution, with highest nutrient and lowest microbial load than candy prepared with 60% and 70% sugar solution.

The aim of the current study was the comparative analysis of the physical, biochemical and antioxidant properties of Mustard, Litchi, and Nigella honey. The physical parameters include the mean moisture content of Mustard, Litchi and Nigella honey were found 14.32%, 15.27%, and 14.12% respectively; P H content were 6.97, 5.8, 4.78; the TSS content were71%, 70%, and 73% respectively. The biochemical parameters including protein content were 1.103%, 0.57% and 0.985%; mean ash content were 0.2%, 0.19%, and0.188%, total carbohydrate content were 84.377%, 83.97% and 84.496% and the minerals contents Na were 539.238 ppm, 424.3565 ppm and 588 ppm; K were 239.216 ppm, 219.017 ppm and1063.774 ppm; Ca were 1710.499 ppm, 611.4852 ppm and 75.4 ppm for the Mustard, Litchi and Nigella honey respectively. The Antioxidant properties such as polyphenol content were found 42.572 ± 0.00529 mg gallic acid /50 ml, 30.625 ± 0.00529 mg gallic acid /50 ml and 95.5 ± 0.00529 mg gallic acid /50 ml; flavonoid content were found 1.052 ± 0.000577 mg catechin /50 ml, 0.6 ± 0.000577 mg catechin /50 ml and 2.66 ± 0.000577 mg catechin /50 ml and vitamin C content were 0.41 mg/100ml, 0.63 mg/100ml and 0.7 mg/100ml for Mustard, Litchi and Nigella honey respectively.