This study aimed to microencapsulate Lactobacillus rhamnosus ( L. rhamnosus) ATCC 7469 with whey protein concentrate (WPC), maltodextrin and trehalose by spray drying and to assess the impact of microencapsulation on cell viability and the properties of the dried powders. Spray-drying conditions, including inlet air temperature, air flow rate and feed pump, were fixed as independent variables, while probiotic survival, moisture content, water activity and effective yield were established as dependent variables. The survival of encapsulated L. rhamnosus by spray drying was optimized with response surface methodology, and the stability of the powder was assessed. The optimum spray-drying conditions were an inlet air temperature, air flow rate and feed pump rate of 169 °C, 33 m3/h and 16 mL/h, respectively, survival of 70%, air aspiration of 84% and outlet air temperature of 52 °C, achieving an overall desirability of 0.96. The physicochemical and structural characteristics of the produced powder were acceptable for application with regard to residual water content, hygroscopicity, water activity, and particle size. The results indicated that a protein-trehalose-maltodextrin mixture is a good wall material to encapsulate L. rhamnosus, showing important thermal protection during the drying process and increasing survival. However, a decrease in this capacity is observed at an air outlet temperature of approximately 101 °C. The possible effects of the wall materials and the drying conditions on survival are also discussed.
This study evaluated the efficacy of active packaging containing albumin (ALB) and pectin (PEC) cryogels loaded with pink pepper essential oil in preserving strawberries during 7 days of storage at 4 °C. The cryogels were prepared in different ratios (ALB:PEC 50:50 and 30:70) and applied in sachets within the strawberry packaging, varying the amounts from 0.4 g to 1.0 g. Analyses included the evaluation of mass loss, soluble solids, pH, titratable acidity, color, firmness, anthocyanin content, volatile compound composition and release from the essential oil (GC-FID and GC-MS), and microbiological analyses. Results showed that the cryogels maintained the stability of soluble solids and pH, and did not significantly affect the color or anthocyanin content. Strawberry firmness was influenced by the amount of cryogel, with 0.4 g of the ALB:PEC 30:70 cryogel’s best-preserving texture. A GC-MS analysis identified monoterpenes (α-pinene, 3-carene, and D-limonene) and sesquiterpenes (caryophyllene and germacrene D) as the major volatile compounds of the essential oil, with a controlled release over time. Cryogels, especially ALB:PEC 30:70, reduced the count of mesophilic aerobic bacteria (1 g) and yeasts and molds (0.4 g). This formulation extends shelf life and preserves the quality of strawberries through controlled antimicrobial release and firmness preservation.
This review analyzes the critical interdependence among the three key components—ink formulation, printing process parameters, and post-processing—in Three-dimensional (3D) Food Printing (3DFP) and Four-dimensional (4D) Food Printing (4DFP). While extensive research addresses individual phases, a significant opportunity remains to integrate these three pillars systematically to bridge the gap between initial design and final product viability. The analysis reveals that successful 3D printing demands a formulation optimized to resist thermal and mechanical stresses; thus, printability assessments must be extended to include post-processing stability. Conversely, 4D printing intentionally exploits this relationship, utilizing post-processing (e.g., heat or pH) as a strategic trigger to activate programmed deformation. Joint optimization of formulation, printed food microstructure, and final post-processing stages is necessary to produce foods with the desired final quality.