Evaluation of the Spray Drying Conditions of Blueberry Juice-Maltodextrin on the Yield, Content, and Retention of Quercetin 3-d-Galactoside

Abstract

The influence of the processing conditions during the spray drying of mixtures of blueberry juice (BJ) and maltodextrin (MX) was determined quantitatively by the analysis of variance (ANOVA), and qualitatively by the surface response plots (SRP). The effect of two independent variables (inlet temperature, and MX concentration), and one categorical variable (type of MX), was determined on the yield (Y), content (Q), and retention (R) of the antioxidant quercetin 3-d-galactoside. From the ANOVA results, the concentration was the main variable affecting Y and Q, while temperature had a negligible effect, and the low molecular weight MXs exhibited a better response. The physicochemical characterization showed that the powder appearance and microstructure remained unaffected, but size and morphology of the particles varied with the processing conditions. This study established the optimal processing conditions for the spray drying of BJ-MX, and the application limits of the MXs based on the molecular weight distribution.

Spray Drying of Blueberry Juice-Maltodextrin Mixtures: Evaluation of Processing Conditions on Content of Resveratrol

“…Saavedra-Leos et al determined an inverse relation between T g and DE of maltodextrins [21]. Through several works reported by the Saavedra-Leos group [14,22,37,38,39], we have observed that in some juices such as orange and blueberries, their physicochemical properties varied with the differences in the type and distribution of molecular weight of the carrier agent. In these studies, we have attributed this behavior mainly to: (i) Differences in the molecular weight distribution of the carrier agent, (ii) the arrangement of polymer chains (i.e., entangled or linear) and (iii) the type of molecule in these chains (for example, glucose for maltodextrin or fructose for inulin).…”

“…In this section we compared the results of the content of resveratrol reported herein, against those for quercetin 3-D-galacoside previously reported [22]. The effect of spray drying processing conditions showed similar behavior for both antioxidants, but the main difference relied on the values of the content of each antioxidant.…”

“…This was calculated considering the initial concentration of resveratrol in fresh BJ, and the content of antioxidant determined in dried samples. On the other hand, content and retention values were relatively lower than those obtained for quercetin 3-D-galactoside [22]. Therefore, based on these observations, it is evident that resveratrol is less prone to interact chemically with maltodextrins, being more exposed to thermal degradation during the spray drying process.…”

“…From 25 experiments, 18 runs were successfully spray-dried, while in seven runs the microstructure collapsed. Since the results for resveratrol were discussed herein, results of physicochemical characterization and yield can be consulted in the work previously reported for quercetin 3-D-galactoside [22], since both works are parts of the same experiment. Table 2 shows the detailed experimental description of the 25 runs and results of content, and retention (R) of resveratrol at different processing conditions.…”

“…Besides, maltodextrins are commercially found in a wide range of molecular weight distributions (MWD), which lead to different thermal properties and potential applications [21]. Recently, Saavedra-Leos et al used a set of four maltodextrins as carrying agents in spray drying of BJ [22]. Through analysis of variance (ANOVA) and response surface plots (RSP), they determined the effect of processing conditions, found an optimal set of experimental variables for drying the juice and conserving of quercetin 3-D-galactoside, and set the application limits of maltodextrins based on their MWD.…”