**4.3 Thermal analysis**

*Microencapsulation - Processes, Technologies and Industrial Applications*

Distribution and mean particle

2-Thiobarbituric acid reactive substances (TBARS)

Amount or payload Oil content High-performance liquid

Interaction between materials in encapsulated emulsions

The difference between total and free oil concentration on

Thermal profile

encapsulation

*Different characterization of microencapsulated vegetable oils.*

size

**Indicators Measurements References**

Particle size Dynamic light scattering technique [8, 44, 57, 66]

Moisture content Hot air oven moisture analyzer [23, 57, 66] Bulk density Volumeter [44]

Peroxide value Peroxide [8, 44, 48]

p-Anisidine value (p-AV) p-Anisidine [48]

(GC/MS)

technique

or transmission electron microscopy

Malondialdehyde [8]

Differential scanning calorimeter (DSC)

Thermal gravimetric analysis Dynamic mechanical analysis

chromatography (HPLC), gas chromatography (GC), or gas chromatography/mass spectrometry

Fourier transform infrared (FT-IR)

Encapsulation efficiency (EE) [57, 66]

Zeta potential (ζ-potential) Surface charge [8] Particle morphology Scanning electron microscopy (SEM)

(TEM)

Laser light diffraction [8, 44, 57]

[8, 21, 23, 25, 48, 57, 65]

[67]

[23]

[25, 48, 57, 66]

**Encapsulated characterizations**

Oxidative stability (under accelerated storage conditions)

Thermal analysis Melting point

Particle characterizations

**34**

**4.1 Particles characterization**

**Table 3.**

that reflects their long-term stability.

**4.2 Oxidative stability of encapsulated particles**

• Particle size, distribution, and mean particle size can be determined by dynamic light scattering technique that has the advantage of being fast and

• Zeta potential (ζ-potential) of particles is a scientific term for electrokinetic potential in particles dispersions and a measure of surface charge of particles

• Particle morphology: scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron spectroscopy can visualize surface morphology, dispersed and agglomerated particles, and surface functionalization [65]; in addition, transmission electron microscopy (TEM) or dynamic light scattering.

In an approach to evaluating the oxidative stability of oil, the encapsulated particles are evaluated for oxidation at storage times, for example, peroxide value,

noninvasive, but it does require low particle concentrations [64].

• Moisture content and bulk density of encapsulated powders.

This is one of the popular analyses where the properties of microencapsulated vegetable oil are studied as they change with temperature. Several methods are used:

