Delivery of Probiotics with Cellulose-Based Films and Their Food Applications

Abstract

Probiotics have attracted great interest from many researchers due to their beneficial effects. Encapsulation of probiotics into biopolymer matrices has led to the development of active food packaging materials as an alternative to traditional ones for controlling food-borne microorganisms, extending food shelf life, improving food safety, and achieving health-promoting effects. The challenges of low survival rates during processing, storage, and delivery to the gut and low intestinal colonization, storage stability, and controllability have greatly limited the use of probiotics in practical food-preservation applications. The encapsulation of probiotics with a protective matrix can increase their resistance to a harsh environment and improve their survival rates, making probiotics appropriate in the food packaging field. Cellulose has attracted extensive attention in food packaging due to its excellent biocompatibility, biodegradability, environmental friendliness, renewability, and excellent mechanical strength. In this review, we provide a brief overview of the main types of cellulose used for probiotic encapsulation, as well as the current advances in different probiotic encapsulating strategies with cellulose, grafted cellulose, and cellulose-derived materials, including electrospinning, cross-linking, in-situ growth, casting strategies, and their combinations. The effect of cellulose encapsulation on the survival rate of probiotics and the patented encapsulated probiotics are also introduced. In addition, applications of cellulose-encapsulated probiotics in the food industry are also briefly discussed. Finally, the future trends toward developing encapsulated probiotics with improved health benefits and advanced features with cellulose-based materials are discussed.

Keywords: cellulose; encapsulation; food application; probiotic.

Figure 2

Morphology and production of BC. (a) Photographs of the freshly prepared BC film (left top), freeze-dried BC film (left bottom), and a scanning electron microscope (SEM) image of the BC film (right). (b) Schematic illustration of the bacterial cellulose preparation process by the bacterial cultivation method. Adapted from Ref. [57] with permission of SAGE Publications Ltd., 2022. (c) Illustration of the BC production process via the cell-free system. (I) Cultivation of cell-free enzyme solution with glucose source as carbon source, (II) formation of fibrils, (III) self-assembly of fibrils, (IV) formation of bio-cellulose pellicles, (V) formation of bio-cellulose pellicles, and (VI) harvesting of bio-cellulose pellicles. Adapted from Ref. [59] with permission of Elsevier Ltd., 2015.

Figure 1

Schematic illustration of the types of cellulose used for probiotic encapsulation, probiotic encapsulating strategies with cellulose or cellulose-based materials, and the applications of encapsulated probiotics in the food field.

Figure 3

Probiotics encapsulated in electrospun cellulose-based film. (a) Novel cellulose acetate (CA) and polyvinyl alcohol (PVA) mixed fibers prepared by inclined double-nozzle electrospinning. Adapted from Ref. [36], with permission of Elsevier Ltd., 2021. (b) Electrospun acetate nanofiber membrane for the enrichment of L. paracasei biofilms. Adapted from Ref. [87], with permission of American Chemical Society, 2021.

Figure 4

Probiotic encapsulation by cross-linking method. (a) Preparation of cellulose-based encapsulation films by cross-linking CMC and HEC with CA. Adapted from Ref. [88], with permission of Elsevier Ltd., 2019. (b) The enhanced storage stability of probiotics after ACFP composite capsule encapsulation. Black: AG, Ca-alginate gel with L. plantarum. Red: ACG, Ca-alginate/cellulose gel with L. plantarum. Blue: ACFP, Ca-alginate/cellulose/cryoprotectant gel with L. plantarum. Adapted from Ref. [37], with permission of Elsevier Ltd., 2019. (c) Scheme illustrating the morphology of ACMS encapsulated probiotics and the pH-responsive mechanisms. Adapted from Ref. [80], with permission of American Chemical Society, 2018.

Figure 5

Probiotics films prepared by in-situ growth method. (a) Graphic illustrating the preparation process of probiotic cellulose by co-culturing Ax and probiotics. Adapted from Ref. [89], with permission of Elsevier BV, 2021. (b) Scheme illustrating the preparation of PC-Lf by co-incubating Kx and Lf. Adapted from Ref. [90], with permission of American Chemical Society, 2022. (c) Electron micrographs of the freeze-dried KBC incorporated with L. plantarum TISTR 541 cells by the adsorption–incubation method. (i–iii) L. plantarum attached on KBC fibrils at different magnifications (Green arrows represent L. plantarum). Adapted from Ref. [38], with permission of MDPI, 2023.

Figure 6

Probiotic films prepared by casting. (a) Preparation of carboxymethyl cellulose based probiotic film by casting (the red arrow represents the probiotic bacteria). Adapted from Ref. [31], with permission of Elsevier Ltd., 2020. (b) The spore-producing drug-resistant bacteria (B. coagulans) combined with a biopolymer mixture (bacterial cellulose—BC and cashew gum—CG) as a carrier substrate, four different films were produced by casting. Adapted from Ref. [91], with permission of Elsevier Ltd., 2020.

Figure 7

Application of cellulose encapsulated probiotics in food packaging. (a) Nanocellulocellulose-nano-chitosan gelatin film was used to encapsulate L. casei and B. coagulans GBI-306086 and their combination for preservation of meat products. Adapted from Ref. [35], with permission of Elsevier Ltd., 2022. (b) Based on CMC/βMglucan (BG), L. acidophilus LA-5 was prepared according to four ratios of 100:0, 75:25, 50:50, and 25:75, and different proportions of inulin (IL, 2%, 4%) were added to predict the shelf life of food. Adapted from Ref. [34], with permission of Elsevier BV, 2022.

Figure 8

Application of cellulose encapsulated probiotics in food manufacturing. (a) Probiotic biofilm fermentation of milk. Adapted from Ref. [21], with permission of American Chemical Society, 2019. (b) Viable cells in the fermented milk with the recycled lyophilized powders of L. plantarum biofilms in six batches. Adapted from Ref. [21], with permission of American Chemical Society, 2019. (c) The lactic acid bacteria (LAB) culture was fixed on bacterial cellulose (BC) as a biological starter. Adapted from Ref. [30], with permission of MDPI, 2022.