Microencapsulation of Lactobacillus casei and Lactobacillus rhamnosus in pectin and pectin-inulin microgel particles: Effect on bacterial survival under storage conditions.

The main objective of the research was to evaluate the performance of synbiotic delivery systems using pectin microgels on the protection of two probiotic strains (Lactobacillus casei ATCC 393 and Lactobacillus rhamnosus strain GG [ATCC 53103]) to simulated gastrointestinal digestion (GD) and storage conditions (4 ± 1 °C) in a 42 days trial. Microgel particles were prepared by ionotropic gelation method and three variables were evaluated: incubation time (24 and 48 h), free vs encapsulated cells, and presence or absence of prebiotic (commercial and Jerusalem artichoke inulin). Results demonstrated an encapsulation efficiency of 96 ± 4% into particles with a mean diameter between 56 and 118 µm. The viability of encapsulated cells after 42 days storage stayed above 7 log units, being encapsulated cells in pectin-inulin microgels more resistant to GD compared to non-encapsulated cells or without prebiotics. In all cases incubation time influenced the strains' survival.

Pectin extraction from quince (Cydonia oblonga) pomace applying alternative methods: effect of process variables and preliminary optimization.

The objectives of this study were to introduce alternative methods in the process of pectin extraction from quince pomace, to determine the effect of selected process variables (factors) on the obtained pectin, and to perform a preliminary optimization of the process. A fractional factorial experimental design was applied, where the factors considered were six: quince pomace pretreatment (washing vs blanching), drying method (hot air vs LPSSD), acid extraction conditions (pH, temperature, and time), and pectin extract concentration method (vacuum evaporation vs ultrafiltration). The effects of these factors and their interactions on pectin yield (Y: 0.2-34.2 mg/g), GalA content (44.5-76.2%), and DM (47.5-90.9%), were determined. For these three responses, extraction pH was the main effect, but it was involved in two and three factors interactions. Regarding alternative methods, LPSSD was required for maximum Y and GalA, and ultrafiltration for maximum GalA and DM. Response models were used to predict optimum process conditions (quince blanching, pomace drying by LPSSD, acid extraction at pH 2.20, 80 , 3 h, and concentration under vacuum) to simultaneously maximize Y (25.2 mg/g), GalA (66.3%), and DM (66.4%).