Development of a shelf-stable, gel-based delivery system for probiotics by encapsulation, 3D printing, and freeze-drying

Design of probiotic delivery systems and their therapeutic effects on targeted tissues

The microbiota at different sites in the body is closely related to disease. The intake of probiotics is an effective strategy to alleviate diseases and be adjuvant in their treatment. However, probiotics may suffer from harsh environments and colonization resistance, making it difficult to maintain a sufficient number of live probiotics to reach the target sites and exert their original probiotic effects. Encapsulation of probiotics is an effective strategy. Therefore, probiotic delivery systems, as effective methods, have been continuously developed and innovated to ensure that probiotics are effectively delivered to the targeted site. In this review, initially, the design of probiotic delivery systems is reviewed from four aspects: probiotic characteristics, processing technologies, cell-derived wall materials, and interactions between wall materials. Subsequently, the review focuses on the effects of probiotic delivery systems that target four main microbial colonization sites: the oral cavity, skin, intestine, and vagina, as well as disease sites such as tumors. Finally, this review also discusses the safety concerns of probiotic delivery systems in the treatment of disease and the challenges and limitations of implementing this method in clinical studies. It is necessary to conduct more clinical studies to evaluate the effectiveness of different probiotic delivery systems in the treatment of diseases.

Shaping the Future of Functional Foods: Using 3D Printing for the Encapsulation and Development of New Probiotic Foods

Consumers have been demanding foods that, besides providing nutrition, bring some health benefits, known as functional foods. The insertion of probiotics in foods is a strategy for developing functional foods. Still, it has been a challenge because these matrices have different pHs and undergo different process temperatures and times that can reduce the viability of these microorganisms. In this sense, encapsulation using 3D printing emerges to protect probiotic microorganisms and ensure that they reach the intestine viable and carry out the expected beneficial action. Thus, this review evaluates the current advancements in 3D printing to encapsulate and develop novel probiotic foods. Research has shown that 3D printing effectively encapsulates probiotic microorganisms, preserving their viability throughout the gastrointestinal tract. Studies have proven the effectiveness of 3D printing encapsulation in protecting probiotics during processing, storage, and digestion. Innovative formulations for 3D bioprinted products with probiotics, such as food structures based on cereals, mashed potatoes, and cream, have been developed. Producing products with shelf life and combining applications of phytochemicals and probiotics aims to improve personalized nutrition, textural characteristics, and sensory attributes of the foods produced by this emerging approach. Therefore, 3D printing of foods with probiotics has the potential to create new products that meet this demand.

Novel Encapsulation Approaches in the Functional Food Industry: With a Focus on Probiotic Cells and Bioactive Compounds

Bioactive substances can enhance host health by modulating biological reactions, but their absorption and utilization by the body are crucial for positive effects. Encapsulation of probiotics is rapidly advancing in food science, with new approaches such as 3D printing, spray-drying, microfluidics, and cryomilling. Co-encapsulation with bioactives presents a cost-effective and successful approach to delivering probiotic components to specific colon areas, improving viability and bioactivity. However, the exact method by which bioactive chemicals enhance probiotic survivability remains uncertain. Co-crystallization as an emerging encapsulation method improves the physical characteristics of active components. It transforms the structure of sucrose into uneven agglomerated crystals, creating a porous network to protect active ingredients. Likewise, electrohydrodynamic techniques are used to generate fibers with diverse properties, protecting bioactive compounds from harsh circumstances at ambient temperature. Electrohydrodynamic procedures are highly adaptable, uncomplicated, and easily expandable, resulting in enhanced product quality and functionality across various food domains. Furthermore, food byproducts offer nutritional benefits and technical potential, aligning with circular economy principles to minimize environmental impact and promote economic growth. Hence, industrialized nations can capitalize on the growing demand for functional foods by incorporating these developments into their traditional cuisine and partnering with businesses to enhance manufacturing and production processes.

The application of encapsulation technology in the food Industry: Classifications, recent Advances, and perspectives

Encapsulation technology has been extensively used to enhance the stability, specificity, and bioavailability of essential food ingredients. Additionally, it plays a vital role in improving product quality and reducing production costs. This study presents a comprehensive classification of encapsulation techniques based on the state of different cores (solid, liquid, and gaseous) and offers a detailed description and analysis of these encapsulation methods. Specifically, it introduces the diverse applications of encapsulation technology in food, encompassing areas such as antioxidant, protein activity, physical stability, controlled release, delivery, antibacterial, and probiotics. The potential impact of encapsulation technology is expected to make encapsulation technology a major process and research hotspot in the food industry. Future research directions include applications of encapsulation for enzymes, microencapsulation of biosensors, and novel technologies such as self-assembly. This study provides a valuable theoretical reference for the in-depth research and wide application of encapsulation technology in the food industry.

Tailoring microstructure and mechanical properties of pectin cryogels by modulate intensity of ionic interconnection

Porous morphology and mechanical properties determine the applications of cryogels. To understand the influence of the ionic network on the microstructure and mechanical properties of pectin cryogels, we prepared low-methoxyl pectin (LMP) cryogels with different Ca2+ concentrations (measured as R-value, ranging from 0 to 2) through freeze-drying (FD). Results showed that the R-values appeared to be crucial parameters that impact the pore morphology and mechanical characteristics of cryogels. It is achieved by altering the network stability and water state properties of the cryogel precursor. Cryogel precursors with a saturated R-value (R = 1) produced a low pore diameter (0.12 mm) microstructure, obtaining the highest crispness (15.00 ± 1.85) and hardness (maximum positive force and area measuring 2.36 ± 0.31 N and 12.30 ± 1.57 N·s respectively). Hardness showed a negative correlation with Ca2+ concentration when R ≤ 1 (-0.89), and a similar correlation with the porosity of the gel network when R ≥ 1 (-0.80). Given the impacts of crosslinking on the pore structure, it is confirmed that the pore diameter can be designed between 56.24 and 153.58 μm by controlling R-value in the range of 0-2.

Unravelling the functionality of anionic and non-ionic plant seed gums on milk protein cryogels conveying Lacticaseibacillus rhamnosus GG

Cryogels offer a promising macroporous platform that can be employed as either a functional ingredient in food composites or a colloidal template for incorporating bioactives, including probiotic living cells. The aim of the present work is to explore the functionality of two plant seed polysaccharides, flaxseed gum (FG) and alfalfa galactomannan (AAG), in individual and combined (1:1 ratio) milk protein-based cryogels, namely sodium caseinate (NaCas) and whey protein isolate (WPI). These cryogels were created by freeze-drying hydrogels formed via L.rhamnosus GG - a human gut-relevant probiotic strain - fermentation. Our findings showed that including gum in the composition limited volume contraction during lyophilisation, reduced macropore size and thickened cryogel skeleton vessels. Furthermore, gum-containing cryogels displayed improved thermal stability and slower water disintegration rates. The AAG-stabilised cryogels specifically showed a notable reduction in monolayer water content compared to FG. From a mechanistic viewpoint, AAG influenced the physicochemical and microstructural properties of the cryogels, most probably via its self-association during cryogenic processing, promoting the development of intertwined protein-gum networks. FG, on the other hand, enhanced these properties through electrostatic complexation with proteins. Cryogels made from protein-polysaccharide blends exhibited promising techno-functional properties for enhancing and diversifying food product innovation.

A comprehensive review on the utilization of biopolymer hydrogels to encapsulate and protect probiotics in foods

Probiotics must survive in foods and passage through the human mouth, stomach, and small intestine to reach the colon in a viable state and exhibit their beneficial health effects. Probiotic viability can be improved by encapsulating them inside hydrogel-based delivery systems. These systems typically comprise a 3D network of cross-linked polymers that retain large amounts of water within their pores. This study discussed the stability of probiotics and morphology of hydrogel beads after encapsulation, encapsulation efficiency, utilization of natural polymers, and encapsulation mechanisms. Examples of the application of these hydrogel-based delivery systems are then given. These studies show that encapsulation of probiotics in hydrogels can improve their viability, provide favorable conditions in the food matrix, and control their release for efficient colonization in the large intestine. Finally, we highlight areas where future research is required, such as the large-scale production of encapsulated probiotics and the in vivo testing of their efficacy using animal and human studies.

Three-dimensional food printing: its readiness for a food and nutrition insecure world

Three-dimensional (3D) food printing is a rapidly emerging technology offering unprecedented potential for customised food design and personalised nutrition. Here, we evaluate the technological advances in extrusion-based 3D food printing and its possibilities to promote healthy and sustainable eating. We consider the challenges in implementing the technology in real-world applications. We propose viable applications for 3D food printing in health care, health promotion and food waste upcycling. Finally, we outline future work on 3D food printing in food safety, acceptability and economics, ethics and regulations.

Structural, rheological, and gelling characteristics of starch-based materials in context to 3D food printing applications in precision nutrition

Starch-based materials have viscoelasticity, viscous film-forming, dough pseudoplasticity, and rheological properties, which possess the structural characteristics (crystal structure, double helix structure, and layered structure) suitable for three-dimensional (3D) food printing inks. 3D food printing technology has significant advantages in customizing personalized and precise nutrition, expanding the range of ingredients, designing unique food appearances, and simplifying the food supply chain. Precision nutrition aims to consider individual nutritional needs and individual differences, which include special food product design and personalized precise nutrition, thus expanding future food resources, then simplifying the food supply chain, and attracting extensive attention in food industry. Different types of starch-based materials with different structures and rheological properties meet different 3D food printing technology requirements. Starch-based materials suitable for 3D food printing technology can accurately deliver and release active substances or drugs. These active substances or drugs have certain regulatory effects on the gut microbiome and diabetes, so as to maintain personalized and accurate nutrition.

Designing future foods: Harnessing 3D food printing technology to encapsulate bioactive compounds

Bioactive compounds (BCs) provide numerous health benefits by interacting with one or more components of living tissues and systems. However, despite their potential health benefits, most of the BCs have low bioaccessibility and bioavailability, hindering their potential health-promoting activities. The conventional encapsulation techniques are time-consuming and have major limitations in their food applications, including the use of non-food grade chemicals, undesired sensory attributes, and storage stability issues. A cutting-edge, new technique based on 3D printing can assist in resolving the problems associated with conventional encapsulation technologies. 3D food printing can help protect BCs by incorporating them precisely into three-dimensional matrices, which can provide (i) protection during storage, (ii) enhanced bioavailability, and (iii) effective delivery and controlled release of BCs. Recently, various 3D printing techniques and inks have been investigated in order to create delivery systems with different compositions and geometries, as well as diverse release patterns. This review emphasizes the advances in 3D printing-based encapsulation approaches, leading to enhanced delivery systems and customized food formulations.

An In Vitro Study of the Impacts of Sweet Potato Chips with Potentially Probiotic Levilactobacillus brevis and Lactiplantibacillus plantarum on Human Intestinal Microbiota : Impacts of potato chips with probiotics on intestinal microbiota

This study formulated sweet potato chips with powdered potentially probiotic Levilactobacillus brevis (SPLB) and Lactiplantibacillus plantarum (SPLP) and evaluated their impacts on human intestinal microbiota during 48 h of in vitro colonic fermentation. L. brevis and L. plantarum kept high viable cell counts (> 6 log CFU/g) on sweet potato chips after freeze-drying and during 60 days of storage. SPLB and SPLP had satisfactory quality parameters during 60 days of storage. SPLB and SPLP increased the relative abundance of Lactobacillus ssp./Enterococcus spp. (3.84-10.22%) and Bifidobacterium spp. (3.25-12.45%) and decreased the relative abundance of Bacteroides spp./Prevotella spp. (8.56-2.16%), Clostridium histolyticum (8.23-2.33%), and Eubacterium rectale/Clostridium coccoides (8.07-1.33%) during 48 h of in vitro colonic fermentation. SPLB and SPLP achieved high positive prebiotic indexes (> 8.24), decreased pH values and sugar contents, and increased lactic acid and short-chain fatty acid production, proving selective stimulatory effects on beneficial bacterial groups forming the intestinal microbiota. The results showed that SPLB and SPLP have good stability and high viable cell counts of L. brevis and L. plantarum when stored under room temperature and caused positive impacts on human intestinal microbiota, making them potentially probiotic non-dairy snack options.

Biomaterials and Encapsulation Techniques for Probiotics: Current Status and Future Prospects in Biomedical Applications

Probiotics have garnered significant attention in recent years due to their potential advantages in diverse biomedical applications, such as acting as antimicrobial agents, aiding in tissue repair, and treating diseases. These live bacteria must exist in appropriate quantities and precise locations to exert beneficial effects. However, their viability and activity can be significantly impacted by the surrounding tissue, posing a challenge to maintain their stability in the target location for an extended duration. To counter this, researchers have formulated various strategies that enhance the activity and stability of probiotics by encapsulating them within biomaterials. This approach enables site-specific release, overcoming technical impediments encountered during the processing and application of probiotics. A range of materials can be utilized for encapsulating probiotics, and several methods can be employed for this encapsulation process. This article reviews the recent advancements in probiotics encapsulated within biomaterials, examining the materials, methods, and effects of encapsulation. It also provides an overview of the hurdles faced by currently available biomaterial-based probiotic capsules and suggests potential future research directions in this field. Despite the progress achieved to date, numerous challenges persist, such as the necessity for developing efficient, reproducible encapsulation methods that maintain the viability and activity of probiotics. Furthermore, there is a need to design more robust and targeted delivery vehicles.

3D printing of microencapsulated Lactobacillus rhamnosus for oral delivery

3D Printing is an innovative technology within the pharma and food industries that allows the design and manufacturing of novel delivery systems. Orally safe delivery of probiotics to the gastrointestinal tract faces several challenges regarding bacterial viability, in addition to comply with commercial and regulatory standpoints. Lactobacillus rhamnosus CNCM I-4036 (Lr) was microencapsulated in generally recognised as safe (GRAS) proteins, and then assessed for robocasting 3D printing. Microparticles (MP-Lr) were developed and characterised, prior to being 3D printed with pharmaceutical excipients. MP-Lr showed a size of 12.3 ± 4.1 µm and a non-uniform wrinkled surface determined by Scanning Electron Microscopy (SEM). Bacterial quantification by plate counting accounted for 8.68 ±0.6 CFU/g of live bacteria encapsulated within. Formulations were able to keep the bacterial dose constant upon contact with gastric and intestinal pH. Printlets consisted in oval-shape formulations (15 mm × 8 mm × 3.2 mm) of ca. 370 mg of total weight, with a uniform surface. After the 3D printing process, bacterial viability remained even as MP-Lr protected bacteria alongside the process (log reduction of 0.52, p>0.05) in comparison with non-encapsulated probiotic (log reduction of 3.05). Moreover, microparticle size was not altered during the 3D printing process. We confirmed the success of this technology for developing an orally safe formulation, GRAS category, of microencapsulated Lr for gastrointestinal vehiculation.

Microencapsulation of Probiotics by Oil-in-Water Emulsification Technique Improves Cell Viability under Different Storage Conditions

Probiotics are associated with health benefits to the host. However, their application can be limited due to a decrease in cell viability during processing, storage, and passage through the gastrointestinal tract. Microencapsulation is a simple and efficient alternative to improve the physical protection and stability of probiotics. The present study aimed to produce and characterize alginate or gelatin-based microparticles containing Lactobacillus acidophilus NRRL B-4495 or Lactiplantibacillus plantarum NRRL B-4496 by oil-in-water (O/W) emulsification and to evaluate the stability under storage conditions. The results showed that L. acidophilus and L. plantarum encapsulated in gelatin (LAEG and LPEG) presented diameters of 26.08 ± 1.74 μm and 21.56 ± 4.17 μm and encapsulation efficiencies of 89.6 ± 4.2% and 81.1 ± 9.7%, respectively. However, those encapsulated in alginate (LAEA and LPEA) showed an encapsulation efficiency of <1.0%. Furthermore, LAEG was stable for 120 days of storage at 5 °C and 25 °C. Therefore, encapsulation in gelatin by O/W emulsification is a promising strategy for protecting and stabilizing probiotic bacteria, enabling future application in foods.

The encapsulation strategy to improve the survival of probiotics for food application: From rough multicellular to single-cell surface engineering and microbial mediation

The application of probiotics is limited by the loss of survival due to food processing, storage, and gastrointestinal tract. Encapsulation is a key technology for overcoming these challenges. The review focuses on the latest progress in probiotic encapsulation since 2020, especially precision engineering on microbial surfaces and microbial-mediated role. Currently, the encapsulation materials include polysaccharides and proteins, followed by lipids, which is a traditional mainstream trend, while novel plant extracts and polyphenols are on the rise. Other natural materials and processing by-products are also involved. The encapsulation types are divided into rough multicellular encapsulation, precise single-cell encapsulation, and microbial-mediated encapsulation. Recent emerging techniques include cryomilling, 3D printing, spray-drying with a three-fluid coaxial nozzle, and microfluidic. Encapsulated probiotics applied in food is an upward trend in which "classic probiotic foods" (yogurt, cheese, butter, chocolate, etc.) are dominated, supplemented by "novel probiotic foods" (tea, peanut butter, and various dry-based foods). Future efforts mainly include the effect of novel encapsulation materials on probiotics in the gut, encapsulation strategy oriented by microbial enthusiasm and precise encapsulation, development of novel techniques that consider both cost and efficiency, and co-encapsulation of multiple strains. In conclusion, encapsulation provides a strong impetus for the food application of probiotics.

A dark purple multifunctional ingredient from blueberry pomace enhanced with lactic acid bacteria for various applications

Nowadays, large quantities of berries are still being dumped or used for composting and animal feeding. The objective of this study was to customize a technological design for appropriate valorization of blueberry pomace into a shelf-life-stable, dark purple multifunctional ingredient, containing lactic acid bacteria (Lactobacillus casei), by freeze-drying. The main anthocyanins in blueberries freeze-dried inoculated pomace are malvidin 3-O-glucoside, peonidin 3-O-glucoside, and cyanidin 3-O-glucoside. A viable cells content of 4.75×10⁸ CFU/g DW was found after freeze-drying and the ability of the freeze-dried powder to inhibit the DPPH radical was 171.98 ± 1.73 mMol Trolox/g DW. The results obtained from CIElab analysis show a tendency to red and blue, characteristic of blueberry anthocyanins. The bioaccesibility of anthocyanins from blueberry powder was 37.8% and the probiotic survival rate after passing through the digestion process was 49.56%. The inhibitory potential of the obtained powder on α-amylase, pancreatic lipase, and α-glucosidase and tyrosinase was assessed. A significant antidiabetic potential of the powder was found, with IC50 values for α-amylase of 2.61 ± 0.24 mg/ml and for α-glucosidase of 1.37 ± 0.01 mg/ml, significantly lower when compared to corresponding drugs used in current practices. The powder also showed a significant potential to inhibit tyrosinase, supporting the hypothesis that the pomace resulting from juice and wine manufacturing may be successfully used to develop multifunctional ingredients with significant health benefits. PRACTICAL APPLICATION: Nowadays, food scientists and industry are seeking technological alternatives to obtain functional ingredients, due to the global interest in translating and applying scientific knowledge to address consumers' health issues. In our study, a freeze-drying customized design involving the use of the blueberry pomace, pectin, and Lactobacillus casei was applied to develop an ingredient with multiple functions. Besides a remarkable color, the powder showed good antioxidant activity, in vitro cells viability, and inhibitory activity against some metabolic syndrome-associated enzymes.