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The halofluorination reaction of a variety of alkenes by using tetrabutylammonium bifluoride (TBABF) in the presence of IV-halosuccinimide is described. This process occurs stereospecifically to afford anti addition products, and with unsymmetrical olefins a marked Markovnikov-type regioselectivity is observed. In some cases, formation of a remarkable amount of the corresponding dihalo derivatives was found, but this undesirable side reaction can be avoided by using N-iodosuccinimide (NIS) as halogenating agent. If jV-bromosuccinimide (NBS) or jV-chlorosuccinimide (NCS) is utilized, these dihalo compounds can be easily removed, from the halofluorinated compounds by simple column chromatography on silica gel. A mechanism for this side reaction is postulated.

Acid proteases from sábalo stomach mucosa were recovered using salting-out procedure. This single step produced an enzyme extract purified 1.8-fold over the crude extract with a recovery of 45.1% of its initial proteolytic activity. Sábalo proteases exhibited the highest activity at 45 °C-pH 2.0, showed pH stability between 2.0 and 5.0 and retained more than 70% of its activity after incubation at pH 7.0 for 2 h. Fish extract was unstable at temperatures greater than 45 °C. Its activity was inhibited by pepstatin A but not by PMSF, while EDTA and SDS showed partial inhibitory effects. Presence of CaCl and MgCl increased the proteolytic activity, while increasing concentrations of NaCl strongly decreased it. In addition, compared to the acid extraction method, the use of sábalo enzymatic extract increased 1.7 times the yield of collagen extraction.

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Essential grapefruit oil with high concentrations of limonene is used in food, cosmetic and pharmaceutical industries due to its antimicrobial properties, fragrance, and flavor. To facilitate its manipulation and protect it from adverse environmental factors, the microencapsulation is used. The objective of this work was to optimize the microencapsulation process of grapefruit oil using external ionic gelation coupled to extrusion with sodium alginate and calcium chloride. We achieved the best encapsulation conditions with calcium chloride concentration at 7.4% w/v and a crosslinking time of 58 minutes, obtaining a yield of 62% and an efficiency of 100% with an oil loading capacity of 10% w/w. The chemical adsorption of calcium as well during the crosslinking process was studied, observing a significant fit with the Elovich equation. And an adjustment of the controlled release of the oil was obtained to the empirical kinetic model of Korsmeyer and Peppas.