Comparison of Electrostatic Spray Drying, Spray Drying, and Freeze Drying for Lacticaseibacillus rhamnosus GG Dehydration

Abstract

Spray drying (SD) is extensively used to encapsulate lactic acid bacteria in large-scale industrial applications; however, bacteria combat several harms that reduce their viability. In this study, a novel technique called electrostatic spray drying (ESD) was used to explore the benefits and disadvantages of using electrostatic charge and lower temperatures in the system. Freeze drying (FD) was used as a reference. The effect of different encapsulation agents, like maltodextrin, arabic gum, and skim milk, on the viability of Lacticaseibacillus rhamnosus GG (LGG) was investigated. The initial cell concentration, particle size distribution, aspect ratio, sphericity, scanning-electron-microscopy images, moisture content, water activity, glass transition, rehydration abilities, and survival during storage were compared. Skim milk was proven to be the best protectant for LGG, regardless of the drying process or storage time. A huge reduction in cell numbers (4.49 ± 0.06 log CFU/g) was observed with maltodextrin using SD; meanwhile, it was protected with minimum loss (8.64 ± 0.62 log CFU/g) with ESD. In general, ESD preserved more LGG cells during processing compared to SD, and provided better stability than FD and SD during storage, regardless of the applied voltage. The ESD product analysis demonstrated an efficient LGG preservation, close to FD; therefore, ESD presented to be a promising and scalable substitute for SD and FD.

Investigation of Freezing and Freeze-Drying for Preserving and Re-Using a Whole Microbial Cheese Community

“…Milk has been widely used as a protective molecule for improving the survival rate (viability recovery) after freezing and freeze-drying of a wide variety of individual bacteria, especially lactic acid bacteria [ 35 , 36 , 37 , 38 , 39 ]. More recently, maltodextrin, or a mixture of maltodextrin and sugar, was evidenced as efficient for preserving LAB following freeze-drying [ 20 , 37 ].…”

Innovative Methods of Encapsulation and Enrichment of Cereal-Based Pasta Products with Biofunctional Compounds

“…As a result, the water molecules move more rapidly to the outer surface of the droplet for evaporation. This allows one to reduce the drying temperature up to 90 °C, which has a positive effect on reducing the degradation of thermolabile compounds [50,51]. Liposomes are created by mixing phospholipids with other compounds in an aqueous solution.…”

Experimental Investigation of Electrospraying Properties Based on Ring Electrode Modification

“…23 The system can be operated at lower temperatures (80 °C) compared to spray dryers (150−200 °C), reducing energy consumption compared to other conventional systems. 24 In food drying, these electrospraying properties enable rapid drying at lower temperatures, prevent nutrient destruction, delay oxidation, and retain color and highly volatile acetaldehyde. 25,26 Various spraying modes have been developed based on experimental conditions and fluidic properties.…”

“…Lastly, it exhibits environmental friendliness because no downstream droplet processing is necessary . The system can be operated at lower temperatures (80 °C) compared to spray dryers (150–200 °C), reducing energy consumption compared to other conventional systems …”