Optimization of Encapsulation by Ionic Gelation Technique of Cryoconcentrated Solution: A Response Surface Methodology and Evaluation of Physicochemical Characteristics Study

Abstract

The objective of this study was to evaluate the optimal conditions to encapsulate cryoconcentrate solutions via ionic gelation technique. Hydrogel beads were prepared using alginate (1%, 2% and 3% (w/w)) and cornstarch (0.5%, 1% and 2% (w/w)). Later, a sucrose/acid gallic solution was concentrated through block freeze concentration (BFC) at three cycles. Thus, each solution was a mixture with the respective combination of alginate/cornstarch. The final solution was added drop-wise on a CaCl2 solution, allowing the formation of calcium alginate-cornstarch hydrogel beads filled with sucrose/acid gallic solution or cryoconcentrated solution. The results showed that alginate at 2% (w/w) and cornstarch at 2% (w/w) had the best efficiency to encapsulate any solution, with values close to 63.3%, 90.2%, 97.7%, and 75.1%, and particle sizes of approximately 3.09, 2.82, 2.73, and 2.64 mm, for initial solution, cycle 1, cycle 2, and cycle 3, respectively. Moreover, all the samples presented spherical shape. Therefore, the appropriate content of alginate and cornstarch allows for increasing the amount of model cryoconcentrated solution inside of the hydrogel beads. Furthermore, the physicochemical and morphological characteristics of hydrogel beads can be focused for future food and/or pharmaceutical applications, utilizing juice or extract concentrated by BFC as the solution encapsulated.

Encapsulation of Concentrated Solution Obtained by Block Freeze Concentration in Calcium Alginate and Corn Starch Calcium Alginate Hydrogel Beads

“…Figure 1 shows the EE% of the CSAlg and Alg hydrogel beads filled with initial model solution (IMS), concentrate from cycle 1 (C1), concentrate from cycle 2 (C2), and concentrate from cycle 3 (C3) solutions. In the present study, it is important to mention that our research group studied the encapsulation efficiency of the different concentrations of sucrose/gallic acid solution (called IMS, C1, C2, and C3) and used the best results in terms of concentration of CSAlg (corn starch at 2% (w/w) and sodium alginate at 2% (w/w)) from a previous study [20]; in addition, we added only sodium alginate (2% w/w) as control (Alg) (the procedure is indicated in Section 4.4). Through this method, the results revealed statistically significant differences between each concentrated solution (IMS vs. C1 vs. C2 vs. C3) and materials (CSAlg vs. Alg) to encapsulate the solutions.…”

“…Various studies have shown the beneficial effect of encapsulation using calcium alginate hydrogel beads in the protection of bioactive compounds, for example, polyphenols from chokeberry extracts [15], anthocyanins from hibiscus extracts (the beads were added to a yogurt sample, obtaining a high sensory perception) [16], stevia extracts [17], olive leaf extracts [18], and Moringa oleifera extract [19], among others. In the same way, in the last year, our group has successfully explored the potential to form stable calcium alginate hydrogel beads filled with model solution (mix of sucrose and gallic acid) obtained by block FC (BFC), where loading capacity, particles size, shape, water activity, moisture content, and bulk density were studied [20]. Nevertheless, there is still a significant research gap, and future innovative studies on the rheological and thermal behaviors, among other interesting properties, and post-encapsulation of concentrated solutions acquired by BFC are required to obtain scientific knowledge that makes it possible to predict the kinetics of release of polyphenols encapsulated under simulated digestion conditions.…”

“…Therefore, the present work is a continuation on the study of sucrose/gallic acid solution obtained by BFC encapsulated in calcium alginate (Alg) hydrogel beads and corn starch-calcium alginate (CSAlg) hydrogel beads [20], where the innovation is emphasized on the new information obtained in the analysis of the rheological properties, thermal characteristics, and the different behavior patterns inside an artificial digestive system. Additionally, this work offers information for the elaboration of future foods with a high content of polyphenols inside an edible material that allows the controlled release of bioactive compounds in specific sites.…”

Block freeze concentration by centrifugation and vacuum increases the content of lactose‐free milk macronutrients

“…From previous studies on centrifugation‐assisted BFC (Casas‐Forero, Moreno‐Osorio, et al., 2021; Guerra‐Valle et al., 2022; Orellana‐Palma et al., 2021), the present work considers the application of this technology at a first moment. Subsequently, as performed by Dantas et al.…”

“…From previous studies on centrifugation-assisted BFC (Casas-Forero, Moreno-Osorio, et al, 2021;Guerra-Valle et al, 2022;Orellana-Palma et al, 2021), the present work considers the application of this technology at a first moment. Subsequently, as performed by Dantas et al (2021), an ice fraction was subjected to the vacuumassisted BFC aiming for better utilization of the nutrients retained in this portion.…”