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The prepared dispersions were dried by spray-drying as well as dispersions which had been treated with mechanical homogenizers such as ultraturrax (IKA, Germany) with the purpose of incorporating air into the suspensions in order to obtain porous microparticles. The macroscopic appearance of the microparticles did not vary after drying with respect to the SPI, being a fine yellowish white powder. By SEM it was observed that the SPI dried sample has smaller size respect to not dried SPI, which represents an advantage for oil impregnation because of the greater surface area of this material. On the other hand, no differences were found between the dry SPI that suffered the incorporation of air and the one that did not in terms of its porosity, for which reason it was chosen to work with the SPI dried samples without the air incorporation process (MP). By using a laser dispersion particle size analyzer for solid samples, could be observed that the undried SPI has a bimodal particle size distribution with an average size of 80 ± 7 μm, a D10, D50 and D90 of 23±0 μm, 55±2 μm and 180±23 μm , respectively, while dry microparticles (MP) showed a unimodal distribution with an average size of 8 ± 1 μm, a D10, D50 and D90 of 5±1 μm, 9±5 μm and 14 ± 3 μm, respectively. From these data, it was concluded that the drying process makes it possible to obtain microparticles of smaller dispersion and size with respect to the SPI without drying. These results coincide with those observed by SEM micrographs. The MP were impregnated with chia oil varying the operating conditions. After 23 assays and through a statistical analysis, it was concluded that the set of variables that gave the best results were 160 bar, 40 °C, with added alcohol and 4 h of impregnation obtaining %ER of 38.5% and %EE of 93.9%. The moisture content of MP and MC was studied, observing values of 5.18±0.08 % and 7.79±0.40 % for MC before and after impregnation, respectively. The surface morphology of the CM was analyzed by SEM microscopy and the images that can be seen in Figure 1. It could be observed that the obtained particles were spherical with some "deformations", without the presence of cracks or pores. Ascan be seen, no significant morphological changes have beendetermined in the impregnated microcapsules respect to nonimpregnated,so we can affirm that the impregnation processdoes not alter the surface structure of the material.Chemical quality parameters such as the hydroperoxides indexand the relative composition of fatty acids, were evaluated inmicroencapsulated and non-microencapsulated oils. Thesemeasurements were carried out in samples stored for differentperiods of time under shelf conditions in order to analyze theeffect of the impregnation process on the oil quality and thelifetime of each product. Tables 1 and 2 show the obtainedvalues of hydroperoxide index (HPV) and fatty acidcomposition, respectively of MC impregnated in the optimumconditions, studying their variation for 0, 15 and 30 days ofstorage and compared with unencapsulated oils.Analyzing the HPV and fatty acids values obtained for freshlyprepared samples, we can observe that the impregnationprocess did not produce oxidative deterioration on the oil sincesimilar values of HPV and acidic profile were determined forthe encapsulated and unencapsulated samples. On the otherhand, analyzing the HPV values at different storage times, avery marked increase in HPV could be observed for samples ofunencapsulated oil (AC), while this value remains constant atlow and equal values to those determined for an oil ofoptimum conditions for encapsulated oils.On the other hand, the relative quantification of fatty acidsshowed a similar trend to that achieved by the determinationof HPV. Analyzing the samples stored for 15 days we canobserve marked differences mainly in the proportion ofomega-3. This amount was not altered for themicroencapsulated oil, showing a value equal to zero day(optimum chemical quality), while the proportion of this fattyacid markedly decreases for the unencapsulated sample. Thesesimilar trends, achieved by both quality parameters weregenerated according to the protective effect, caused by themicrocapsules on the contained oil. This protection effectagainst oxidation is reflected both in the impregnation processand in the storage time. At day 30 it was observed that theproportion of omega-3 decreases in the same way for bothsamples (encapsulated and not encapsulated), which wouldseem not to follow the trend found until the 15th day.However, it remains to conclude these assays, being in processthe determinations for 60 and 90 days of storage.The oil release from microcapsules was studied by means of anin-vitro digestion test, which consisted of subjecting the MC togastrointestinal conditions through exposure to salivary, gastricand intestinal simulated fluids. From this, it was determinedthat 93.64% of the oil originally contained in MCs can bereleased and be available for absorption in the intestine.