Encapsulation of Lactobacillus gasseri: Characterization, Probiotic Survival, In Vitro Evaluation and Viability in Apple Juice

Bioactive compound encapsulation: Characteristics, applications in food systems, and implications for human health

Nanotechnology plays a pivotal role in food science, particularly in the nanoencapsulation of bioactive compounds, to enhance their stability, bioavailability, and therapeutic potential. This review aims to provide a comprehensive analysis of the encapsulation of bioactive compounds, emphasizing the characteristics, food applications, and implications for human health. This work offers a detailed comparison of polymers such as sodium alginate, gum Arabic, chitosan, cellulose, pectin, shellac, and xanthan gum, while also examining both conventional and emerging encapsulation techniques, including freeze-drying, spray-drying, extrusion, coacervation, and supercritical anti-solvent drying. The contribution of this review lies in highlighting the role of encapsulation in improving system stability, controlling release rates, maintaining bioactivity under extreme conditions, and reducing lipid oxidation. Furthermore, it explores recent technological advances aimed at optimizing encapsulation processes for targeted therapies and functional foods. The findings underline the significant potential of encapsulation not only in food supplements and functional foods but also in supportive medical treatments, showcasing its relevance to improving human health in various contexts.

Stability of probiotics through encapsulation: Comparative analysis of current methods and solutions

Probiotics have awakened a great interest in the scientific community for their potential beneficial effects on health. Although only allowed by the European Food Safety Agency as a nutrition declaration associated with the improvement of lactose digestion, recent in vitro and in vivo studies have demonstrated their varied beneficial effect for the improvement of certain pathologies. However, probiotics face stability and viability challenges, which make their delivery difficult in sufficient quantities for these effects to be observed. Thus, there is a dire need for the development and implantation of innovative technological protection procedures. In this sense, encapsulation rises as a widely applied technique, offering additional advantages. In the present study, a systematic review was conducted for the evaluation of the main encapsulation technologies applied in literature, considering operating conditions, probiotics, and encapsulation efficacy. For this purpose, several conditions are evaluated: a) the characteristics, storage conditions and viability of probiotics; b) evaluation and comparison of the probiotic stabilization for the main encapsulation methods; and c) co-encapsulation with potential bioactive molecules as a new alternative for improving cell viability. This evaluation revealed the efficacy of seven encapsulation techniques on the improvement of the stability and viability of probiotics.

Physiological and Technological Properties of Probiotic Lacticaseibacillus rhamnosus GG Encapsulated with Alginate-Chitosan Mixture and Its Incorporation in Whole Milk

This study developed and evaluated chitosan-sodium alginate capsules containing the probiotic Lacticaseibacillus rhamnosus GG using extrusion and emulsification techniques. The encapsulated L. rhamnosus GG cells were also evaluated for technological and probiotic-related physiological functionalities, as well as when incorporated in UHT and powdered milk. Extrusion (86.01 ± 1.26%) and emulsification (74.43 ± 1.41%) encapsulation techniques showed high encapsulation efficiency and high survival rates of L. rhamnosus GG during 28 days of refrigeration and room temperature storage, especially emulsification capsules (> 81%). The encapsulated L. rhamnosus GG cells showed high survival rates during exposure to simulated gastrointestinal conditions (72.65 ± 1.09-114.15 ± 0.44%). L. rhamnosus GG encapsulated by extrusion and emulsification performed satisfactorily in probiotic-related physiological (pH and bile salts tolerance) and technological properties (positive proteolytic activity, diacetyl and exopolysaccharides production, high NaCl tolerance (> 91%), besides having high heat tolerance (> 76%)). L. rhamnosus GG in extrusion and emulsification capsules had high survival rates (> 89%) and did not significantly affect physicochemical parameters in Ultra-High Temperature (UHT) and powdered milk during storage. The results demonstrate that L. rhamnosus GG can be successfully encapsulated with alginate-chitosan as a protective material through extrusion and emulsification techniques. UHT and powdered milk could serve as appropriate delivery systems to increase the intake of this encapsulated probiotic by consumers.

Survivability and behavior of probiotic bacteria encapsulated by internal gelation in non-dairy matrix and In Vitro GIT conditions

The primary objective of this investigation was to assess the viability of free and encapsulated Lactobacillus plantarum probiotics in mango juice and under simulated gastrointestinal conditions. Specifically, the probiotics were encapsulated using sodium alginate and alginate-soy protein isolate through the internal gelation method, and the obtained probiotics were characterized for various attributes. Both free and encapsulated probiotics were exposed to challenging conditions, including thermal stress, low temperature, and simulated gastrointestinal conditions. Additionally, both types of probiotics were incorporated into mango juice, and their survival was monitored over a 28-day storage period. Following viability under simulated gastrointestinal conditions, the count of free and encapsulated probiotic cells decreased from initial levels of 9.57 log CFU/mL, 9.55 log CFU/mL, and 9.53 log CFU/mL, 9.56 log CFU/mL to final levels of 6.14 log CFU/mL, 8.31 log CFU/mL, and 6.24 log CFU/mL, 8.62 log CFU/mL, respectively. Notably, encapsulated probiotics exhibited a decrease of 1.24 log CFU and 0.94 log CFU, while free cells experienced a reduction of 3.43 log CFU and 6.24 log CFU in mango juice over the storage period. Encapsulated probiotics demonstrated higher viability in mango juice compared to free probiotics throughout the 28-day storage period. These findings suggest that mango juice can be enriched with probiotics to create a health-promoting beverage.

Lactic acid bacteria viability in different refrigerated food matrices: a systematic review and Meta‑analysis

The aim of this systematic review and meta-analysis was to determine which variables affect the viability of lactic acid bacteria (LAB) added to different types of refrigerated foods during the first 28 days. Scopus, ScienceDirect, PubMed and Cochrane Central Register of Reviews databases were searched from 1997 to April 2022. A total of 278 studies, which showed randomized and controlled experiments published in peer reviewed journals, were included. The viability of LAB in different moments during the storage process was synthesized as mean point estimate (MPE) via random-effects meta-analyses and the effect of multiple factors on the LAB´s viability was evaluated by multiple meta-regression. The meta-analysis showed that the decrease in LAB viability will be more abrupt the greater the initial dose. The physical structure of food may influence bacterial viability. Fruit was the type of product that most quickly lost viability. Co-culture of two or more species did not affect viability. Preservation methods had an unfavorable effect and prebiotics had a beneficial effect on bacterial viability. Viability was genus dependent. The data obtained in this study provide an overview of the factors to be taken into account for the design of new foods.

Stability and Survivability of Alginate Gum-Coated Lactobacillus rhamnosus GG in Simulated Gastrointestinal Conditions and Probiotic Juice Development

Survivability of probiotics is severely affected by harsh gastrointestinal conditions. In the present study, microbeads of Lactobacillus rhamnosus GG were formulated using alginate (1.5% w/v) and combination of alginate (1.5% w/v) with xanthan gum (0.5% w/v) through an emulsion technique to improve bacterial viability in low pH orange juice and in gastrointestinal conditions. The microbeads were tested for encapsulation efficiency, survivability in bile salt, SGF (simulated gastric juice), SIF (simulated intestinal fluid), and storage stability. Probiotic orange juice was formulated and tested for physicochemical parameters (pH, titratable acidity, and total sugars) and sensorial properties during storage. Gum-coated alginate microbeads (T3) showed higher encapsulation efficiency, i.e., 95.2% compared to alginate microbeads (T2), i.e., 86.85%. Similarly, T3 showed the highest resistance against bile salt (8.50 log CFU/g), SGF (7.95 log CFU/g), and SIF (8.0 log CFU/g) during 80 min exposure compared to T2 and free cells. The viability of gum-coated alginate beads (T3) remained above 107 CFU/g in gastrointestinal conditions and at the end of 21 days storage (8.3 log CFU/mL). All physicochemical parameters of probiotic juice were significantly ( $p\le 0.05$ ) decreased with respect to storage except acidity. In addition, minimal changes in physicochemical parameters were observed in T3 compared to other treatments. Treatment had no significant impact on the sensory characteristics of juice, but storage had a significant effect ( $p\le 0.05$ ) on the sensory characteristics of juice. The alginate gum microbeads improve the survivability of probiotics for targeted delivery. Hence, encapsulated probiotics can be used for functional beverage development to take advantage of their therapeutic benefits.

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.

Assessment of Ultrasonic Stress on Survival and β-Glucosidase Activity of Encapsulated Lactiplantibacillus plantarum BCRC 10357 in Fermentation of Black Soymilk

The enhanced β-glucosidase activity of encapsulated Lactiplantibacillus plantarum BCRC 10357 within calcium alginate capsules was investigated by ultrasonic stimulation to induce the stress response of the bacteria for the biotransformation of isoflavones in black soymilk. The effects of various ultrasound durations, sodium alginate concentrations (% ALG), and cell suspensions on the β-glucosidase activity of encapsulated bacteria were explored. The β-glucosidase activity of encapsulated L. plantarum BCRC 10357 with ultrasonic stimulation (40 kHz/300 W) was greater than that without ultrasound. With 20 min of ultrasonic treatment, the β-glucosidase activity of encapsulated L. plantarum BCRC 10357 from 2% ALG/0.85% NaCl cell suspension was 11.47 U/mL at 12 h, then increased to 27.43 U/mL at 36 h and to 26.25 U/mL at 48 h in black soymilk at 37 °C, showing the high adaptation of encapsulated L. plantarum BCRC 10357 encountering ultrasonic stress to release high β-glucosidase until 48 h, at which point the ratio of isoflavone aglycones (daidzein and genistein) in total isoflavones (daidzin, genistin, daidzein, and genistein) was 98.65%, reflecting the effective biotransformation of isoflavone glycosides into aglycones by β-glucosidase. In this study, the survivability and β-glucosidase activity of encapsulated L. plantarum BCRC 10357 were enhanced under ultrasonic stimulation, and were favorably used in the fermentation of black soymilk.