Javier Nakamatsu

Anthocyanins are natural pigments responsible for the red, blue, and purple colors in various fruits and vegetables. These compounds exhibit a wide range of biological activities, including antioxidant, anti-inflammatory, bactericidal, and, recently, antidiabetic activity. However, their application is limited due to their instability under pH changes, light exposure, oxygen, and temperature. To overcome these challenges, anthocyanins were extracted with ultrasound from Sambucus peruviana (elderberry) and Vaccinium corymbosum (blueberry) and then evaluated for enzymatic inhibition. The polysaccharides alginate and chitosan were used to encapsulate the extracts; the procedure involved the ionotropic gelation of alginate with calcium ions, followed by polyelectrolyte complexation with chitosan. The physicochemical stability of the resulting nanocapsules was evaluated based on particle size, polydispersity index (PDI), zeta potential, and UV–visible spectroscopy. The elderberry extract exhibited the highest total phenolic content (5.52 ± 0.66 μg gallic acid equivalents per mg of dry weight), whereas the blueberry extract contained a greater concentration of anthocyanins (2.69 ± 0.53 μg cyanidin-3-glucoside equivalents per mg of lyophilized product). Ethanolic extracts of both fruits demonstrated approximately twice the antioxidant capacity compared to their aqueous counterparts and exhibited notable inhibitory activity against lipase and α-amylase. The resulting nanoparticles displayed promising physicochemical properties, with average sizes of 515.03 ± 50.96 nm and 437.5 ± 12.59 nm for elderberry and blueberry extracts, respectively, low PDI values (0.31 ± 0.08 and 0.30 ± 0.03), and stable negative zeta potentials (−26.36 ± 2.00 mV and −27.45 ± 3.26 mV). These findings highlight the potential of ultrasound-assisted extraction and nanoencapsulation for enhancing anthocyanin stability and bioactivity, particularly for applications targeting enzyme inhibition associated with diabetes.

This article describes the development and characterization of a curcumin-loaded alginate-xanthan gum hydrogel, designed to provide both antibacterial activity and controlled drug release.The hydrogel formulation consisted of 4% (w/v) alginate, 4% (w/v) xanthan gum, and 500 μg/mL of curcumin. Sterilization was achieved through ethanol immersion, UV irradiation, and autoclaving, with the latter two methods proving to be the most effective in maintaining long-term sterility. Antibacterial efficacy was tested against Staphylococcus aureus, demonstrating a significant inhibition zone around the hydrogel. The curcumin release profile indicated a sustained release over 72 hours, suggesting its suitability for prolonged antibacterial applications.

Una de las causas principales de pérdida de patrimonio histórico en los museos es el ataque de insectos. En el Museo del Convento de los Descalzos (Lima, Perú) este problema es muy agudo, especialmente en sus libros corales, que datan de los siglos XVII a XIX, debido a los materiales utilizados en su fabricación. Algunos tratamientos para desinsectar objetos requieren compuestos que pueden dañarlos o que son tóxicos. Una alternativa no agresiva y efectiva para la desinsectación es el tratamiento anóxico. En este caso, los libros fueron introducidos en bolsas de aluminio plastificado llenas de nitrógeno y con un inhibidor de oxígeno. La efi-cacia del tratamiento fue confirmada con placas radiográficas de los libros. Este método de desinsectación, poco costoso y fácilmente adaptable, fue exitoso y constituye una buena manera de detener el deterioro por infestación de xilófagos, tanto de los libros corales como de otros objetos de valor artístico e histórico. __________ One of the main causes of loss of historical heritage in museums is an insect attacks. At the Museo del Convento de los Descalzos in Lima, Peru, this is a severe problem, particularly in its choral books, which date from the 17th to 19th centuries, due to the materials used in their manufacture. Some disinfestation treatments for objects require compounds that either damage them or are toxic. A non-aggressive and effective alternative to disinfestation is anoxic treatment. In this case, the books were placed in laminated aluminum bags filled with nitrogen and an oxygen inhibitor. The treatment's efficiency was confirmed through X-ray images of the books. This inexpensive and easily adaptable disinfestation method was successful and constitutes a noteworthy way to stop the deterioration caused by xylophagous infestation, both of choral books and other objects of artistic and historical value.