The objective of this work was to assess the suitability of the Droplet-vitrification protocol previously developed with Agave peacockii shoot tips for the cryopreservation of six Agave species. Shoot tips were precultured for 1 day on a medium with 0.3 M sucrose in the dark, loaded in a solution with 1.6 M glycerol and 0.4 M sucrose for 20 min, and dehydrated by exposure to Plant Vitrification Solution 2 (PVS2) at 0 °C for 20 min. Complementary studies using histological analysis, Differential scanning calorimetry (DSC), and evaluation of morphological characteristics in cryo-derived plants were performed. Survival rates ranged from 84% to 100% and from 76% to 97% before and after cryopreservation regardless of the Agave species belonging to two taxonomic subgenera. Thermal analysis of shoot tips subjected to the successive steps of the Droplet-vitrification protocol identified ice crystal formation after loading treatment and glass transition after osmotic dehydration with PVS2. The average glass transition temperature (Tg) was −55.44 °C based on the results of four Agave species. The histological studies showed the anatomical differences that could be found in the meristematic structures depending on the loss of apical dominance. This is the most advanced research on cryopreservation of Agave shoot tips.
In the present study, a whey protein-based hydrogel was developed as an alternative for the microencapsulation of Hibiscus extracts. The resulting hydrogels showed a high percentage of moisture and water activity, along with a partial degradation of anthocyanins during their production and storage. The hydrogels exhibited particle sizes between 8 and 15 μm and retained some of the characteristic color properties of extracts. The results obtained provide a novel alternative for the microencapsulation of bioactive compounds through the use of protein-based carrier systems, highlighting their potential for the development of innovative encapsulation systems.
Tamarillo (Solanum betaceum) processing is characterized by early biomass exclusion and thermal stabilization, which may limit in-process retention of phytochemicals. This study evaluated an integrated sequence combining Flash Vacuum Expansion (FVE) under different processing conditions with whey protein-based cryostructuring as a strategy to enhance the redistribution and structural immobilization of tamarillo bioactives. FVE promoted migration of phenolics and pigments prior to mechanical fractionation. Selected FVE-treated puree was incorporated into a whey protein matrix and subjected to cryostructuring and freeze-drying to generate a porous stabilization scaffold. Structural characterization by scanning electron microscopy and gas adsorption confirmed the formation of an interconnected porous matrix. Cryostructuring reduced water activity to 0.17 ± 0.01 and produced high porosity (91.9%) with low bulk density (0.109 g·cm−3). Total phenolic retention exceeded 83%, while anthocyanins showed greater sensitivity (46% retention). No statistically significant additional losses of phenolics or antioxidant activity were observed during cryostructuring relative to gelation. The integrated approach illustrates a process-level stabilization pathway in which redistributed phytochemicals are physically confined within a porous scaffold, providing a structurally differentiated alternative to conventional drying for improved in-stream resource utilization.
In the present work, the effect of the Flash Vacuum Expansion (FVE) process on the recovery of total phenolic content (TPC) from entire coffee peel was evaluated. The resulting extracts were microencapsulated by spray drying using maltodextrin (MD10) and arabic gum (GA). The FVE increased TPC by 20.97% in the ethanolic extracts. The use of MD10 allowed obtention of smaller, less hygroscopic particles, with better color and flow properties as well as a higher concentration of TPC. Both powders were considered microbiologically stable based on humidity and water activity.
Pulque is an ethnic and traditional fermented beverage produced and consumed in Mexico; it is obtained from certain varieties of Agave, and its final alcohol content is around 4% to 7%. It is rich in protein and its carbohydrate content brings it a characteristic flavor; also, some probiotic bacteria are present in pulque. On the other hand, foams are a colloid system where the air bubble phase is dispersed in a continuous liquid phase. The foaming of liquids has been recognized as a method that shortens processes such as drying and preserves quality attributes. The present work studied the drainage kinetics of different pulque foams prepared with egg white in order to obtain a product suitable for further drying. Different egg white and pulque concentrations, as well as mixing times, were evaluated. The drainage volume was recorded and foam density was determined among different experiments. It was found that the lowest volume was drained when mixing for 20 min, and the lowest foam density was obtained when egg white and pulque were mixed in a 2:1 ratio. The drainage kinetics of the foam determines important information for its further use in a new product with pulque.