Uv visible spectroscopy

The initial characterization for prepared nano-MgO was monitored by measuring the UV–vis absorbance spectrum by using a UV-Visible Spectroscopy (Shimadzu, Tokyo, Japan) to detect the surface plasmon resonance band^{6 ,8 (link)–10 (link)}. The structural properties (real estate properties) of the nano-MgO were analyzed by transmission electron microscope (JEOL JEM2100F- Japan), scanning electronmicroscopy (SEM) (JEOL JSM 6360LA, Japan), scientific particle size analyzer (PSA) and its chemical composition was demonstrated by an energy dispersive X-Ray (EDX) analyzer. The FTIR spectrums were measured using Shimadzu FTIR-8400 S, Japan, over the wavelength range 400–4000 cm⁻¹. X-ray diffraction patterns were obtained using Schimadzu 7000 diffractometer operating with Cu Kα₁ radiation(λ = 0.15406 nm) generated at 30 kV and 30 mA with the scan rate of 2°/min for 2θ values between 20° and 80°. The average particle size was estimated using the Scherrer formula Eq. (1). $$\mathbf{D}=k\mathbf{\lambda }/\mathbf{\beta }\cos \mathbf{\theta }$$ where D is particle diameter, k is a constant equals 0.9, λ is wavelength of X-ray source (0.1541 nm), β is the full width at half maximum (FWHM) and θ is the half diffraction angle.

The percentage entrapment efficiency (%EE) of nicotine loading into SLNs was determined by the ultrafiltration method using centrifugal filter tubes (molecular weight cut-off: 10 kDa) (Amicon Ultra^®-0.5 mL) [30 (link),31 (link)] by placing 0.5 mL of SLN suspension into a centrifugal filter tube and centrifuging the samples at 10,000 rpm for 20 min at 20 °C. The amount of unentrapped nicotine in the aqueous phase (filtrate) was measured by UV–visible spectroscopy (Shimadzu, Kyoto, Japan) at λ_max of 261 nm. The following equations were used for calculating the entrapment efficiency and loading capacity: $$\mathrm{Entrapment}\mathrm{efficiency}(\%\mathrm{EE})=100\times \left[\frac{W_i-W_f}{W_i}\right]$$
W_i is the amount of nicotine initially added and W_f is the mount of free nicotine.
$$\mathrm{Loading}\mathrm{capacity}(\%\mathrm{LC})=100\times \left[\frac{W_i-W_f}{W_{lipid}+W_i}\right]$$
W_i is the amount of nicotine initially added, W_f is the amount of free nicotine, and W_lipid is the amount of lipid added.

Dried carotenoids isolated from C. sakazakii BAA894, DH5α/pWSK29-EiZYIB and DH5α/pWSK29-EiZYIBX were dissolved in methanol, and that from DH5α/pWSK29-EiIB and DH5α/pWSK29-EiYIB were dissolved in hexane. Their absorption spectra were determined by a Shimadzu UV-visible spectroscopy.