L-ascorbic acid is a water soluble vitamin (vitamin C) widely used as an additive in foods and cosmetics. It has high instability against certain environmental factors; the main cause of its deterioration is oxidation. Microencapsulation is an effective protection technique of L-ascorbic acid from its degradation reactions. This work is focused on the encapsulation of L-ascorbic acid by spray drying technique using sodium alginate as wall material. The microcapsules morphology was observed by scanning electron microscopy (SEM) and the encapsulation efficiency was determined by spectrophotometric analysis. Results showed that encapsulation efficiency was of 93.48% and after 30 days was of 92.55%; differences were not significant, so that the stability of L-ascorbic acid was not affected. Encapsulation yields obtained were low, at around 30%, but the microcapsules morphology obtained is spherical.

Encapsulation confers protection to substances as essential oils from processes like oxidation, evaporation or uncontrolled release. In this study almond oil capsules were obtained by co-extrusion/gelling technique. Chitosan was used as shell material and sodium triphosphate pentabasic as cross linking agent. Different encapsulation process variables were studied: cross-linker concentration, nozzles size and potential. Optical microscopy was used to determine the capsules morphology and degradability tests were performed in order to study capsules degradation over time. Results showed that nozzles size and cross linking concentration are key variables to consider in the encapsulation process. Degradability tests showed rapid weight loss.

Enzymes have been used in detergents over the years. They can improve the detergent's efficiency due to their activities against hard stains. Nevertheless, enzymes cannot maintain their properties indefinitely, since they are exposed to stress factors, like temperature, pH, mechanical processes and others. Consequently, enzymes lose their structure and they are not functional. For this reason, microencapsulating these proteins is a feasible solution to improve their use in industrial processes and commercial products. Spray drying technology has been selected because a lot of scientific literature proved its useful application in a variety of industries. In particular, savinase and lipase are the two encapsulated enzymes in this work. Savinase attacks proteins and lipase removes fats, so they are suitable enzymes for detergent industry. Arabic gum has been used as wall material. Morphology, size and activity of the obtained microcapsules have been analyzed in order to find the best conditions to produce them. In conclusion, useful microcapsules of lipase and savinase can be obtained with the mentioned technology.

Coating protects substances such as L-ascorbic acid from natural processes like oxidation. In this study, L-ascorbic acid was coated by fluid bed technology. A pH-dependent polymer was used as a coating material in order to release L-ascorbic acid (dissolution above pH 5.5) under conditions closest to the skin's natural condition. Different techniques were used to determine the coating (SEM and size distribution) and to evaluate the percentage of coated L-ascorbic acid and its diffusion through the skin.

Interference reflection microscopy is used for measuring changes in the resulting interference image of the measurement system. The measurement system consists of several parallel layers. The set-up includes metal layers evaporated on a glass slide and elastic polymer film with another metal layer serving as a substrate on which cells can be cultured in media. Total reflectance that depends on the thickness of the polymer layer of the system can he calculated. Cell moves on a gold layer and exert forces leading to a deformation of a polymer underneath.Deformation of a polymer and change of its thickness results in a change in the measured intensity of the light reflected from the whole system. Then the detected intensity can be compared with the calculated reflectance after the calibration according to measured values of the systems of known reflected intensities. The important parameters of the set-up are properties of the polymer layer -its elasticity modulus, refractive index and thickness. The method could enable the measurement of the component of a cell force perpendicular to the surface at which a cell moves. A cell can be viewed as an indentor deforming a polymer film at a certain area.