A review on the immobilization of bromelain.

This review shows the endeavors performed to prepare immobilized formulations of bromelain extract, usually from pineapple, and their use in diverse applications. This extract has a potent proteolytic component that is based on thiol proteases, which differ depending on the location on the fruit. Stem and fruit are the areas where higher activity is found. The edible origin of this enzyme is one of the features that determines the applications of the immobilized bromelain to a more significant degree. The enzyme has been immobilized on a wide diversity of supports via different strategies (covalent bonds, ion exchange), and also forming ex novo solids (nanoflowers, CLEAs, trapping in alginate beads, etc.). The use of preexisting nanoparticles as immobilization supports is relevant, as this facilitates one of the main applications of the immobilized enzyme, in therapeutic applications (as wound dressing and healing components, antibacterial or anticancer, mucus mobility control, etc.). A curiosity is the immobilization of this enzyme on spores of probiotic microorganisms via adsorption, in order to have a perfect in vivo compatibility. Other outstanding applications of the immobilized enzyme are in the stabilization of wine versus haze during storage, mainly when immobilized on chitosan. Curiously, the immobilized bromelain has been scarcely applied in the production of bioactive peptides.

Effect of UV-B Radiation on Flavonoids and Phenols Accumulation in Tempisque (Sideroxylon capiri Pittier) Callus.

Tempisque (Sideroxylon capiri Pittier) is classified as a threatened species and has been reported with a high content of phenols and flavonoids in the leaves. The use of abiotic elicitors such as radiation has been reported due to the changes it produces in the metabolism of plants by activating their defense mechanisms and increasing the biosynthesis of bioactive compounds with antioxidant capacity such as phenols and flavonoids. Therefore, the aim of this work was to evaluate the effect of UV-B radiation on growth parameters and the synthesis of bioactive compounds in in vitro culture of tempisque callus. For the callus induction, we used thidiazuron (TDZ) and 2,4-dichlorophenoxyacetic acid (2,4-D) at 0, 0.5 and 1 mg/L. Calluses were exposed to UV-B radiation (0, 1, 2, 3 and 4 h/day) for two and four weeks. The highest callus formation index was obtained with TDZ and 2,4-D at 1 mg/mL. The greatest increase in the concentration of phenols and flavonoids was detected in the fourth week with 4 h of exposure per day. The highest concentrations of quercetin (230 µg/g dry weight), kaempferol (235 µg/g dry weight) and gallic acid (240 µg/g dry weight) were found in callus obtained from leaves explants.

Totipotency of Daucus carota L. Somatic Cells Microencapsulated Using Spray Drying Technology.

The carrot is considered a model system in plant cell culture. Spray drying represents a widely used technology to preserve microorganisms, such as bacteria and yeasts. In germplasm conservation, the most used methods are freeze drying and cryopreservation. Therefore, the aim of this work was to evaluate the effect of spray drying on the viability and totipotency of somatic carrot cells. Leaf, root and stem explants were evaluated to induce callus with 2 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). Calli obtained from the stem were cultivated in a liquid medium with 1 mg/L of 2,4-D. Cell suspensions were spray dried with maltodextrin-gum Arabic and maltodextrin-xanthan gum mixtures, two outlet air temperatures (50 and 60 °C) and 120 °C inlet air temperature. Results showed that carrot cells were viable after spray drying, and this viability remained for six months at 8 °C. The totipotency of the microencapsulated cells was proven. Cells that were not spray dried regenerated 24.6 plantlets, while the spray dried cells regenerated 19 plantlets for each gram of rehydrated powder. Thus, spray drying allowed researchers to obtain viable and totipotent cells. This work is the first manuscript that reported the spray drying of plant somatic cells.