Microencapsulation of Lactobacillus casei Shirota by spray drying using different combinations of wall materials and application for probiotic dairy dessert

Microencapsulation of Limosilactobacillus reuteri (DSM 23878) for application in infant formula: Heat resistance and bacterial viability during long-time storage

This study aimed to evaluate the survival capacity of the probiotic culture Limosilactobacillus reuteri (DSM 23878) to microencapsulation by spray drying, and its potential as component of an infant formula. Preliminary tests were performed between skim milk (SM) and infant formula (IF) as wall material and two inlet temperatures, evaluating the encapsulation efficiency, moisture content, water activity and stability, to choose the drying parameters. After drying in optimized conditions, the powder of microencapsulated L. reuteri was characterized and the viability after dilution in an infant formula at 70 °C was determined. In addition, the survival rate throughout 360 days of storage was assessed. As results, encapsulation efficiency was superior to 90 % in both wall materials. However, the use of IF as for microencapsulation produced microparticles with lower water activity (Aw) and moisture, as compared with the SM. Final microparticles produced with IF as wall material presented values of Aw, moisture content, and particle diameter averaged 0.11 ± 0.02, 2.10 ± 0.35 % and 10.30 ± 0.12 μm, respectively. The viability of microencapsulated L.reuteri decreased 1 Log CFU/mL after dilution at 70 °C and the powder maintained a survivor of 73.5 % after 365 days of storage at 4 °C. Thus, the microencapsulation by spray drying under the conditions of this study proved to be an effective technique to protect the probiotic L. reuteri for application in infant formulas, obtaining an adequate number of viable cells after reconstitution at 70 °C and during long time the storage.

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.

The Survival of Psychobiotics in Fermented Food and the Gastrointestinal Tract: A Review

In recent years, scientists have been particularly interested in the gut-brain axis, as well as the impact of probiotics on the nervous system. This has led to the creation of the concept of psychobiotics. The present review describes the mechanisms of action of psychobiotics, their use in food products, and their viability and survival during gastrointestinal passage. Fermented foods have a high potential of delivering probiotic strains, including psychobiotic ones. However, it is important that the micro-organisms remain viable in concentrations ranging from about 10⁶ to 10⁹ CFU/mL during processing, storage, and digestion. Reports indicate that a wide variety of dairy and plant-based products can be effective carriers for psychobiotics. Nonetheless, bacterial viability is closely related to the type of food matrix and the micro-organism strain. Studies conducted in laboratory conditions have shown promising results in terms of the therapeutic properties and viability of probiotics. Because human research in this field is still limited, it is necessary to broaden our understanding of the survival of probiotic strains in the human digestive tract, their resistance to gastric and pancreatic enzymes, and their ability to colonize the microbiota.

Development of engineered probiotics with tailored functional properties and their application in food science

The potential health benefits of probiotics may not be cognized because of the substantial curtailment in their viability during food storage and passage through the gastrointestinal system. Intestinal flora composition, and resistance against pathogens are among the health benefits associated with probiotic consumption. In the gastric environment, pH 2.0, probiotics dramatically lose their viability during the transit through the gastrointestinal system. The challenge remains to maintain cell viability until it reaches the large intestine. In extreme conditions, such as a decrease in pH or an increase in temperature, encapsulation technology can enhance the viability of probiotics. Probiotic bacterial strains can be encapsulated in a variety of ways. The methods are broadly systematized into two categories, liquid and solid delivery systems. This review emphasizes the technology used in the research and commercial sectors to encapsulate probiotic cells while keeping them alive and the food matrix used to deliver these cells to consumers.

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Microencapsulation of Yarrowia lipolytica: cell viability and application in vitro ruminant diets

Microencapsulation is an alternative to increase the survival capacity of microorganisms, including Yarrowia lipolytica, a widely studied yeast that produces high-value metabolites, such as lipids, aromatic compounds, biomass, lipases, and organic acids. Thus, the present study sought to investigate the effectiveness of different wall materials and the influence of the addition of salts on the microencapsulation of Y. lipolytica, evaluating yield, relationship with cell stability, ability to survive during storage, and in vitro application of ruminant diets. The spray drying process was performed via atomization, testing 11 different compositions using maltodextrin (MD), modified starch (MS) and whey protein concentrate (WPC), Y. lipolytica (Y. lipo) cells, tripolyphosphate (TPP), and sodium erythorbate (SE). The data show a reduction in the water activity value in all treatments. The highest encapsulation yield was found in treatments using MD + TPP + Y. lipo (84.0%) and WPC + TPP + Y. lipo (81.6%). Microencapsulated particles showed a survival rate ranging from 71.61 to 99.83% after 24 h. The treatments WPC + Y. lipo, WPC + SE + Y. lipo, WPC + TPP + Y. lipo, and MD + SE + Y. lipo remained stable for up to 105 days under storage conditions. The treatment WPC + SE + Y. lipo (microencapsulated yeast) was applied in the diet of ruminants due to the greater stability of cell survival. The comparison between the WPC + SE + Y. lipo treatment, wall materials, and the non-microencapsulated yeast showed that the microencapsulated yeast obtained a higher soluble fraction, degradability potential, and release of nutrients.

Health Benefits of Consuming Foods with Bacterial Probiotics, Postbiotics, and Their Metabolites: A Review

Over the years, probiotics have been extensively studied within the medical, pharmaceutical, and food fields, as it has been revealed that these microorganisms can provide health benefits from their consumption. Bacterial probiotics comprise species derived from lactic acid bacteria (LAB) (genus Lactobacillus, Leuconostoc, and Streptococcus), the genus Bifidobacterium, and strains of Bacillus and Escherichia coli, among others. The consumption of probiotic products is increasing due to the current situation derived from the pandemic caused by COVID-19. Foods with bacterial probiotics and postbiotics are premised on being healthier than those not incorporated with them. This review aims to present a bibliographic compilation related to the incorporation of bacterial probiotics in food and to demonstrate through in vitro and in vivo studies or clinical trials the health benefits obtained with their metabolites and the consumption of foods with bacterial probiotics/postbiotics. The health benefits that have been reported include effects on the digestive tract, metabolism, antioxidant, anti-inflammatory, anticancer, and psychobiotic properties, among others. Therefore, developing food products with bacterial probiotics and postbiotics is a great opportunity for research in food science, medicine, and nutrition, as well as in the food industry.

The Role of Microencapsulation in Food Application

Modern microencapsulation techniques are employed to protect active molecules or substances such as vitamins, pigments, antimicrobials, and flavorings, among others, from the environment. Microencapsulation offers advantages such as facilitating handling and control of the release and solubilization of active substances, thus offering a great area for food science and processing development. For instance, the development of functional food products, fat reduction, sensory improvement, preservation, and other areas may involve the use of microcapsules in various food matrices such as meat products, dairy products, cereals, and fruits, as well as in their derivatives, with good results. The versatility of applications arises from the diversity of techniques and materials used in the process of microencapsulation. The objective of this review is to report the state of the art in the application and evaluation of microcapsules in various food matrices, as a one-microcapsule-core system may offer different results according to the medium in which it is used. The inclusion of microcapsules produces functional products that include probiotics and prebiotics, as well as antioxidants, fatty acids, and minerals. Our main finding was that the microencapsulation of polyphenolic extracts, bacteriocins, and other natural antimicrobials from various sources that inhibit microbial growth could be used for food preservation. Finally, in terms of sensory aspects, microcapsules that mimic fat can function as fat replacers, reducing the textural changes in the product as well as ensuring flavor stability.

Impact of a Novel Nano-Protectant on the Viability of Probiotic Bacterium Lactobacillus casei K17

Probiotics are considered as desirable alternatives to antibiotics because of their beneficial effects on the safety and economy of farm animals. The protectant can ensure the viability of probiotics, which is the prerequisite of the beneficial effects. The objective of this study was to evaluate the effects of a novel nano-protectant containing trehalose, skim milk powder, phytoglycogen nanoparticles, and nano-phytoglycogen Pickering emulsions on the viability of Lactobacillus casei K17 under different conditions. The results indicated that the optimal concentration of the carbohydrate substrate was determined to be 10% skim milk powder (w/w) instead of trehalose. The combination of 10% skim milk powder (w/w), 1% phytoglycogen nanoparticles (w/w), and 10% Pickering emulsions (w/w) was selected as the optimal component of the protectant. Trilayer protectants with an optimal component had a more significant protective effect on the bacteria than that of the monolayer and bilayer protectants, or the control in feed storage, freeze-drying, and simulated gastrointestinal environment. A scanning electron microscope was used to monitor the morphological characteristics of the protectants for different layers on L. casei. In conclusion, the trilayer protectant exhibited a substantial effect on L. casei during storage and consumption, which could be used in the feed and functional food.

Microencapsulation of Lactobacillus plantarum NRRL B-1927 with Skim Milk Processed via Ultra-High-Pressure Homogenization

Several health benefits are associated with the consumption of probiotic foods. Lyophilized probiotic cultures are commonly used to manufacture probiotic-containing products. Spray drying (SDR) is a cost-effective process to microencapsulate probiotics. However, the high temperatures of the drying air in SDR can inactivate significant numbers of probiotic cells. Ultra-high-pressure homogenization (UHPH) processing can modify the configuration of proteins found in skim milk which may increase its protective properties as microencapsulating agent towards probiotic cells during SDR. The aim of this study was to evaluate the effect of microencapsulating probiotic Lactobacillus plantarum NRRL B-1927 (LP) with UHPH-treated skim milk after SDR or freeze drying (FD). Dispersions containing LP were made with either UHPH-treated (at 150 MPa or 300 MPa) or untreated skim milk and dried via concurrent SDR (CCSD), mixed-flow SDR (MXSD) or FD. Higher cell survival (%) of LP was found in powders microencapsulated with 150 MPa-treated skim milk than in those microencapsulated with non-UHPH-treated and 300 MPa-treated skim milk via FD followed by MXSD and CCSD, respectively. Increasing UHPH pressures increased the particle size of powders produced via CCSD; and reduced particle agglomeration of powders produced via MXSD and FD. This study demonstrated that UHPH processes improves the effectiveness of skim milk as a microencapsulating agent for LP, creating powders that could be used in probiotic foods.

Survival and behavior of free and encapsulated probiotic bacteria under simulated human gastrointestinal and technological conditions

The present study was designed with the objective to compare the viability and stability of free and encapsulated probiotics under simulated technological and human gastrointestinal conditions. L. acidophilus was encapsulated using two wall materials (sodium alginate, soy protein isolate, and SA-SPI) by extrusion method for enhanced viability under stressed conditions. Free and encapsulated probiotics were subjected to some simulated technological and gastrointestinal conditions. Furthermore, free and encapsulated probiotics were also incorporated in dairy dessert to evaluate the viability and stability during storage. Encapsulation using sodium alginate and SPI as a coating materials significantly (p < .05) improved the survival of probiotics under simulated gastrointestinal and thermal conditions. The buffering effect of microbeads prolonged their survival and stability of under simulated conditions. The number of surviving probiotic cells encapsulated with sodium alginate, SPI, and SA-SPI over 120 days of product storage was 7.85 ± 0.39, 7.45 ± 0.37, and 8.50 ± 0.43 cfu/ml, respectively. In case of free cells, the surviving cells were just 3.5 ± 0.18 cfu/ml over the period of storage. In short, the study depicted that encapsulation provides protection during exposure to various hostile conditions.

Effect of different encapsulating agent combinations on viability of Lactobacillus casei Shirota during storage, in simulated gastrointestinal conditions and dairy dessert

In this study, the effects of various matrices consisting of maltodextrin and reconstitute skim milk and their binary and ternary mixtures with gum Arabic in the microencapsulation of Lactobacillus casei Shirota by freeze-drying technique were assessed. Microcapsules produced with reconstitute skim milk showed high viability (>99%) after freeze drying. While the free cells were completely inactivated after exposure to simulated gastrointestinal conditions, the survival rates of microencapsulated L. casei Shirota were found high for all microcapsules except for maltodextrin and maltodextrin:gum Arabic formulas. The viability of microencapsulated L. casei Shirota during storage at refrigerate and room temperatures decreased between 0.39 and 2.43 log cycles and microcapsules produced with reconstitute skim milk:gum Arabic was found more durable at the both storage conditions. Reduction in the number of free cells was higher than encapsulated L. casei Shirota numbers during production of dessert, however the viability of encapsulated L. casei Shirota was found stable for 14 days of storage and consequently desserts containing encapsulated L. casei Shirota (except maltodextrin) showed stable pH values. This study revealed that combination of reconstitute skim milk:gum Arabic was an effective wall matrix for microencapsulation of L. casei Shirota by freeze drying and also very resistant against gastrointestinal fluids and storage conditions in view of protection of L. casei Shirota.

Dairy foods and positive impact on the consumer's health

The objective of the present chapter was to demonstrate the state of the art in the recent advances in nutritional and functional components of dairy products research. In this chapter, the main mechanisms responsible and essential for a better understanding of nutritional and functional values of the components of milk and dairy products are highlighted. It also includes a discussion about the positive impacts of fermented milk, cheese, butter, ice cream, and dairy desserts components on the consumer's health.

Different stress tolerance of spray and freeze dried Lactobacillus casei Shirota microcapsules with different encapsulating agents

In this study, the effects of encapsulation with maltodextrin and reconstituted skim milk (RSM) and their binary and ternary blends with gum arabic (GA) by spray and freeze drying methods on viability of probiotic Lactobacillus casei Shirota under different stress conditions were evaluated. All microcapsules showed high survival ratios (7.91-9.37 log cfu/g) after microencapsulation. The viability of microencapsulated cells was significantly higher than free cells when exposed to stress conditions. Spray dried microcapsules exposed to low pH showed small decrease in the viability of cells compared to freeze dried microcapsules, but freeze drying microcapsules showed higher protective effect at 85 and 90 °C. After exposure to 3% bile salt, almost 2.5 log decreases in the encapsulated cell counts were determined for both methods. The results indicated that using RSM:GA mixture as an encapsulating agent showed the higher cell protection against high temperature, acidic pH and bile salts.