Descriptive analysis of bacterial profile, physicochemical and sensory characteristics of grape juice containingSaccharomyces cerevisiaecell wall-coated probiotic microcapsules during storage

Protein-polysaccharide based double network microbeads improves stability of Bifidobacterium infantis ATCC 15697 in a gastro-Intestinal tract model (TIM-1)

Microencapsulation of probiotics is a main technique employed to improve cell survival in gastrointestinal tract (GIT). The present study investigated the impact of utilizing proteins i.e. Whey Protein Isolates (WPI), Pea Protein Isolates (PPI) or (WPI + PPI) complex based microbeads as encapsulating agents on the encapsulation efficiency (EE), diameter, morphology along with the survival and viability of Bifidobacterium infantis ATCC 15697. Results revealed that WPI + PPI combination had the highest EE% of the probiotics up to 94.09 % and the smoothest surface with less visible holes. WPI based beads revealed lower EE% and smaller size than PPI based ones. In addition, WPI based beads showed rough surface with visible signs of cracks, while PPI beads showed dense surfaces with pores and depressions. In contrast, the combination of the two proteins resulted in compact and smooth beads with less visible pores/wrinkles. The survival in gastrointestinal tract (GIT) was observed through TNO in-vitro gastrointestinal model (TIM-1) and results illustrated that all microbeads shrank in gastric phase while swelled in intestinal phase. In addition, in-vitro survival rate of free cells was very low in gastric phase (18.2 %) and intestinal phase (27.5 %). The free cells lost their viability after 28 days of storage (2.66 CFU/mL) with a maximum log reduction of 6.76, while all the encapsulated probiotic showed more than 106-7 log CFU/g viable cell. It was concluded that encapsulation improved the viability of probiotics in GIT and utilization of WPI + PPI in combination provided better protection to probiotics.

Application of Encapsulation Strategies for Probiotics: From Individual Loading to Co-Encapsulation

Consumers are increasingly showing a preference for foods whose nutritional and therapeutic value has been enhanced. Probiotics are live microorganisms, and their existence is associated with a number of positive effects in humans, as there are many and well-documented studies related to gut microbiota balance, the regulation of the immune system, and the maintenance of the intestinal mucosal barrier. Hence, probiotics are widely preferred by consumers, causing an increase in the corresponding food sector. As a consequence of this preference, food industries and those involved in food production are strongly interested in the occurrence of probiotics in food, as they have proven beneficial effects on human health when they exist in appropriate quantities. Encapsulation technology is a promising technique that aims to preserve probiotics by integrating them with other materials in order to ensure and improve their effectiveness. Encapsulated probiotics also show increased stability and survival in various stages related to their processing, storage, and gastrointestinal transit. This review focuses on the applications of encapsulation technology in probiotics in sustainable food production, including controlled release mechanisms and encapsulation techniques.

Potential Application of Yeast Cell Wall Biopolymers as Probiotic Encapsulants

Biopolymers of yeast cell walls, such as β-glucan, mannoprotein, and chitin, may serve as viable encapsulants for probiotics. Due to its thermal stability, β-glucan is a suitable cryoprotectant for probiotic microorganisms during freeze-drying. Mannoprotein has been shown to increase the adhesion of probiotic microorganisms to intestinal epithelial cells. Typically, chitin is utilized in the form of its derivatives, particularly chitosan, which is derived via deacetylation. Brewery waste has shown potential as a source of β-glucan that can be optimally extracted through thermolysis and sonication to yield up to 14% β-glucan, which can then be processed with protease and spray drying to achieve utmost purity. While laminarinase and sodium deodecyle sulfate were used to isolate and extract mannoproteins and glucanase was used to purify them, hexadecyltrimethylammonium bromide precipitation was used to improve the amount of purified mannoproteins to 7.25 percent. The maximum chitin yield of 2.4% was attained by continuing the acid-alkali reaction procedure, which was then followed by dialysis and lyophilization. Separation and purification of yeast cell wall biopolymers via diethylaminoethyl (DEAE) anion exchange chromatography can be used to increase the purity of β-glucan, whose purity in turn can also be increased using concanavalin-A chromatography based on the glucan/mannan ratio. In the meantime, mannoproteins can be purified via affinity chromatography that can be combined with zymolase treatment. Then, dialysis can be continued to obtain chitin with high purity. β-glucans, mannoproteins, and chitosan-derived yeast cell walls have been shown to promote the survival of probiotic microorganisms in the digestive tract. In addition, the prebiotic activity of β-glucans and mannoproteins can combine with microorganisms to form synbiotics.

Improvement of Probiotic Viability by Mixing with Ultrasound-Treated Yeast Cells and Spray Drying

The objective of the study was to determine the efficacy of ultrasound-treatment Saccharomyces cerevisiae and spray drying in preserving the viability of Lactiplantibacillus plantarum. The combination of ultrasound-treated S. cerevisiae and L. plantarum was evaluated. Next, the mixture was blended with maltodextrin and either Stevia rebaudiana-extracted fluid, prior to undergoing spray drying. The L. plantarum viability was assessed after the spray drying process, during storage, and in simulated digestive fluid (SDF) conditions. The results showed that the impact of ultrasound caused the crack and holes in the yeast cell wall. Besides, the moisture content values were not significantly different in all samples after spray drying. Although the amount of powder recovery in stevia-supplemented samples was not higher than that of the control sample, the L. plantarum viability was significantly improved after the spray drying process. The density of L. plantarum tended to be stable during the first 30 days of storage and decreased more rapidly after that. The results reveal that there was no statistically significant difference in the trend of the samples before and after storage. In the SDF test, the L. plantarum viability mixing with ultrasound-treated yeast cells in the spray drying samples was significantly improved. Besides, the presence of Stevia showed positive efficiency on the L. plantarum viability. The L. plantarum viability mixing with ultrasound-treated yeast cells and stevia-extracted fluid by spray drying process showed potential application due to making powder form which helped to improve the L. plantarum stability during the storage time.

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.

Anthocyanin-Colored Microencapsulation Effects on Survival Rate of Lactobacillus rhamnosus GG, Color Stability, and Sensory Parameters in Strawberry Nectar Model

Probiotic microencapsulation is a promising way to produce functional food, while their stability and sensory acceptability still a challenge. This study aims to enhance the functional properties of strawberry (Fragaria × ananassa, cultivar Camarosa) nectar and sensory acceptance using novel anthocyanin-colored microencapsulation of Lactobacillus rhamnosus. Four formulations (F1–F4) of coated materials (alginate, whey protein, and pullulan) integrated with anthocyanin pigment were used for encapsulation. The physical properties of microencapsulated probiotics (size, color, efficiency, stability, and survival rate) and quality parameters of nectar (pH, anthocyanin, and sensory acceptability) during 4 weeks of storage at 4 and 25 °C were evaluated. All formulations exhibited high encapsulation efficiency (> 89%), medium bead size (406–504 μm), and proper color (red color). The microencapsulated cells were stable in simulated gastrointestinal and processing conditions (up 7 log10 CFU mL−1) compared to free cells. F4 (alginate 2% + anthocyanin 0.1% + whey protein 2% + pullulan 2% + cocoa butter 1% + L. rhamnosus GG) showed the greatest viability in nectar during storage (6.72 log10 CFU mL−1/4 °C/4 weeks), while a significant decrease in pH (< 2) and anthocyanin (< 60 mg 100 g−1) was observed in nectar-containing free cells. The sensory scores with a difference-preference test as exploratory and preliminary responses revealed that colored probiotic microcapsules enhanced the sensory characters (up to 4 weeks) and commercially accepted (> 80% agreed) of strawberry nectar. Results demonstrated that anthocyanin-colored alginate-whey protein-pullulan matrix had the potential to enhance probiotic viability in functional nectar without negative impact.

Turbidimetric definition of growth limits in probiotic Lactobacillus strains from the perspective of an adaptation strategy

The application of an adaptation strategy for probiotics, which may improve their stress tolerance, requires the identification of the growth range for each parameter tested. In this study, 4 probiotics (Lactobacillus acidophilus, Lacticaseibacillus casei, Lacticaseibacillus rhamnosus, and Lactiplantibacillus plantarum) were grown under different pH, NaCl, and sucrose concentrations at 25°C, 30°C, and 37°C. Turbidimetric growth curves were carried out and lag phase duration, maximum growth rate, and amplitude (i.e., the difference between initial and stationary phase optical density) were estimated. Moreover, cell morphology was observed, and cell length measured. The growth response, as well as the morphological changes, were quite different within the 4 species. The L. acidophilus was the most sensitive strain, whereas L. plantarum was shown to better tolerate a wide range of stressful conditions. Frequently, morphological changes occurred when the growth curve was delayed. Based on the results, ranges of environmental parameters are proposed that can be considered suboptimal for each strain, and therefore could be tested. The quantitative evaluation of the growth kinetics as well as the morphological observation of the cells can constitute useful support to the choice of the parameters to be used in an adaptation strategy, notwithstanding the need to verify the effect on viability both in model systems and in foods.

Barley-based probiotic food mixture: health effects and future prospects

Consumers around the globe are increasingly aware of the relation between nutrition and health. In this sense, food products that can improve gastrointestinal health such as probiotics, prebiotics and synbiotics are the most important segment within functional foods. Cereals are the potential substrates for probiotic products as they contain nutrients easily assimilated by probiotics and serve as the transporters of Lactobacilli through the severe conditions of gastrointestinal tract. Barley is one of the important substrates for the probiotic formulation because of its high phenolic compounds, β-glucans and tocols. The purpose of this review is to examine recent information regarding barley-based probiotic foods with a specific focus on the potential benefits of barley as a substrate for probiotic microorganisms in the development of dairy and nondairy based food products, and to study the effects of food matrices containing barley β-glucans on the growth and features of Lactobacillus strains after fermentation.

Yeast cells for encapsulation of bioactive compounds in food products: A review

Nowadays bioactive compounds have gained great attention in food and drug industries owing to their health aspects as well as antimicrobial and antioxidant attributes. Nevertheless, their bioavailability, bioactivity, and stability can be affected in different conditions and during storage. In addition, some bioactive compounds have undesirable flavor that restrict their application especially at high dosage in food products. Therefore, food industry needs to find novel techniques to overcome these problems. Microencapsulation is a technique, which can fulfill the mentioned requirements. Also, there are many wall materials for use in encapsulation procedure such as proteins, carbohydrates, lipids, and various kinds of polymers. The utilization of food-grade and safe carriers have attracted great interest for encapsulation of food ingredients. Yeast cells are known as a novel carrier for microencapsulation of bioactive compounds with benefits such as controlled release, protection of core substances without a significant effect on sensory properties of food products. Saccharomyces cerevisiae was abundantly used as a suitable carrier for food ingredients. Whole cells as well as cell particles like cell wall and plasma membrane can act as a wall material in encapsulation process. Compared to other wall materials, yeast cells are biodegradable, have better protection for bioactive compounds and the process of microencapsulation by them is relatively simple. The encapsulation efficiency can be improved by applying some pretreatments of yeast cells. In this article, the potential application of yeast cells as an encapsulating material for encapsulation of bioactive compounds is reviewed.

Saccharomyces cerevisiae as a delivery system of Zataria multiflora Boiss. essential oil as a natural preservative for food applications: Encapsulation of Iranian Zataria multiflora Boiss. essential oil

BACKGROUND

The following study is an evaluation of the encapsulation, stability and release profile of Iranian Zateria multiflora boiss essential oil (ZEO) in Saccharomyces cerevisiae yeast cells. Encapsulation was performed with different essential oil / yeast weight ratios at different temperatures. The encapsulation efficiency and stability of the loaded yeasts and the release profiles of carvacrol and thymol (as the main active ingredients of ZEO) were also investigated.

RESULT

The encapsulation efficiencies of carvacrol and thymol at a ZEO / yeast weight ratio of 1.25 were 30.9% ± 0.01% and 44.5% ± 0.02%, respectively. Loaded yeast cells were stable during the 4-week storage period. Both carvacrol and thymol showed substantial releases of around 60% during the first hour and around 70% during the second hour at two different water temperatures, followed by steady release.

CONCLUSION

Zateria multiflora boiss essential oil can be encapsulated effectively in S. cerevisiae yeast cells, refrigerated without degradation, and released efficiently. Zateria multiflora boiss essential oil encapsulated into S. cerevisiae yeast may be used as a potential preservative for the food and drug industry. © 2020 Society of Chemical Industry.

Co-encapsulation of probiotics with prebiotics and their application in functional/synbiotic dairy products

Oral administration of live probiotics along with prebiotics has been suggested with numerous beneficial effects for several conditions including certain infectious disorders, diarrheal illnesses, some inflammatory bowel diseases, and most recently, irritable bowel syndrome. Though, delivery of such viable bacteria to the host intestine is a major challenge, due to the poor survival of the ingested probiotic bacteria during the gastric transit, especially within the stomach where the pH is highly acidic. Although microencapsulation has been known as a promising approach for improving the viability of probiotics in the human digestive tract, the success rate is not satisfactory. For this reason, co-encapsulation of probiotics with probiotics has been practised as a novel alternative approach for further improvement of the oral delivery of viable probiotics toward their targeted release in the host intestine. This paper discusses the co-encapsulation technologies used for delivery of probiotics toward better stability and viability, as well the incorporation of co-encapsulated probiotics and prebiotics in functional/synbiotic dairy foods. The common encapsulation technologies (and the materials) used for this purpose, the stability and survival of co-encapsulated probiotics in the food, and the release behavior of the co-encapsulated probiotics in the gastrointestinal tract have also been explained. Most studies reported a significant improvement particularly in the viability of bacteria associated with the presence of prebiotics. Nevertheless, the previous research has mostly been carried out in the simulated digestion, meaning that future systematic research is to be carried out to investigate the efficacy of the co-encapsulation on the survival of the bacteria in the gut in vivo.

Maillard conjugates from spent brewer's yeast by-product as an innovative encapsulating material

Yeast-based by-products are greatly available, have a rich nutritional composition and functional properties. The spent brewer's yeast (SBY) cells after enzymatic hydrolysis may be a sustainable and low-cost alternative as carrier material for encapsulation processes by spray drying. Our work had as main purpose to characterise the hydrolysed SBY cell debris after the Maillard reaction and to study their potential as a microencapsulation wall material. SBY-based Maillard reaction products (MRPs) were used to encapsulate ascorbic acid (AA) by spray drying. The Maillard Reaction was able to improve the solubility of solids and proteins by 15% and promoted brown color development (230% higher Browning Index). SBY-based MRPs resulted in particles of a high encapsulation yield of AA (101.90 ± 5.5%), a moisture content of about 3.4%, water activity of 0.15, hygroscopicity values ranging from 13.8 to 19.3 g_H2O/100 g and a glass transition temperature around 71 °C. The shape and microstructure of the produced particles were confirmed by scanning electron microscopy (MEV), indicating very similar structure for control and AA encapsulated particles. Fourier Transform Infrared Spectroscopy (FT-IR) results confirmed the presence of yeast cell debris in the surface of particles. Ascorbic acid was successfully encapsulated in Maillard conjugates of hydrolyzsd yeast cell debris of Saccharomyces pastorianus and maltodextrin as confirmed by optical microscopy, differential scanning calorimetry, MEV and FT-IR.

Application of nano/microencapsulated phenolic compounds against cancer

Nowadays, polyphenols as bioactive compounds are being used in producing anti-cancer drugs. Low stability against harsh environmental conditions, untargeted release, low solubility, and low absorption of pure phenolic molecules are significant barriers, which decrease the functions of polyphenols. Recently, the nanoencapsulation processes have been applied to overcome these restrictions, in which the anti-cancer activity of polyphenols has been noticeably increased. This review will focus on the anti-cancer activity of polyphenols, and the effect of loading polyphenolics into various micro/nanoencapsulation systems on their anti-cancer activity. Different encapsulation systems such as lipid and polymer based nanoparticles, and solid form of encapsulated phenolic molecules by nano-spray dryer and electrospinnig have been used for loading of polyphenols. Incorporation of phenolic molecules into various carriers inevitably increases their anti-cancer activity. Because, in this way, encapsulated cargos can provide a targeted release, which will increase the bioavailability of phenolic molecules and their functions such as absorption into cancer cell.

Isolation of Yeasts from Guajillo Pepper (Capsicum annuum L.) Fermentation and Study of Some Probiotic Characteristics

Three yeast strains were isolated from the spontaneous fermentation of guajillo pepper: Hanseniaspora opuntiae, Pichia kudriavzevii, and Wickerhamomyces anomalus, which were identified by amplification of the ITS/5.8S ribosomal DNA. Some probiotic characteristics of these strains were evaluated and compared with one commercial probiotic yeast (Saccharomyces boulardii). The survival percentage of all the yeasts was similar to that of the commercial product. They showed different hydrophobicity characteristics with hydrocarbons, autoaggregation > 90%, and characteristics of co-aggregation with pathogenic microorganisms. The adhesion capacity to mucin of the three yeast samples was similar to the reference yeast. The antioxidant activity of the yeasts varied between 155 and 178 μM Trolox equivalents. All exhibited cholesterol reduction capacity, and W. anomalus was able to decrease up to 83% of cholesterol after 48 h of incubation. The 7.5-fold concentrated H. opuntiae supernatant had antimicrobial activity against Salmonella enterica ser. Typhimurium ATCC 14028 and Candida albicans ENCBDM2; tests suggest this activity against S. Typhimurium is due to a proteinaceous metabolite with a weight between 10 and 30 kDa. Among the yeasts, P. kudriavzevii exhibited the highest protective effect on the viability of Lactobacillus casei Shirota in gastric and intestinal conditions. These results suggest that yeasts isolated from guajillo pepper may have a probiotic potential.

Development of Whey Protein Concentrate-Pectin-Alginate Based Delivery System to Improve Survival of B. longum BL-05 in Simulated Gastrointestinal Conditions

Bifidobacterium longum BL-05 encapsulated beads were developed by using whey protein concentrate (WPC) and pectin (PE) as encapsulating material through extrusion/ionic gelation technique with the objective to improve survival of probiotics in harsh gastrointestinal conditions. B. longum BL-05 was grown in MRS (de man rogosa and sharpe) broth, centrifuged and mixed with polymeric gel solution. Bead formulations E₄ (2.5% WPC + 1.5% PE) and E₅ (2% PE) showed the highest value for encapsulation efficiency, size, and textural properties (hardness, cohesiveness, springiness) due to increasing PE concentration. The survivability and viability of free and encapsulated B. longum BL-05 was assessed through their resistance to simulated gastric juice (SGJ), tolerance to bile salt, release profile in simulated intestinal fluid (SIF), and storage stability during 28 days at 4 °C. The microencapsulation provided protection to B. longum BL-05 and encapsulated cells were exhibited significant (p < 0.05) resistance to SGJ and SIF as compared to free cells. Bead formulations E₃ (5.0% WPC + 1.0% PE) and E₄ (2.5% WPC + 1.5% PE) exhibited more resistance to SGJ (at pH 2 for 2 h) and at 2% bile salt solution but comparatively slow release as compared to other bead formulations. Free cells lost their viability when stored at 4 °C after 28 days but microencapsulated cells demonstrated promising results during storage and viable cell count was > 10⁷ CFU/g. This study revealed that extrusion using WPC and PE as encapsulating material could be considered as one of the novel technologies for protection and effective delivery of probiotics.

Loading lime by-product into derivative cellulose carrier for food enrichment

The objective here is to enrich orange juice through encapsulated lime by-product extract (LBE) through freeze-drying, in order to increase lime by-product consumption, in addition to increasing nutrition value of orange juice. The properties of both the LBE and microparticles are measured. The total polyphenolic compound (TPC) was measured to be 34.5 ± 0.5 (mg gallic acid/g LBE). The obtained value of encapsulation efficiency (EE) was within the 55%-70% range. The encapsulation method was satisfactory. The particle size is within 10-21 μm range, and differences between all treatments were statistically notable (p < 0.05). The lack of melting peaks in the thermal profiles by differential scanning calorimeter (DSC) of microparticles confirmed that hesperidin was well embedded in the polymeric cover. According to the sensory evaluations of orange juice which was enriched with LBE microparticles, the bitter taste was not perceived in some treatments.

Advances in Spray-Drying Encapsulation of Food Bioactive Ingredients: From Microcapsules to Nanocapsules

Many natural food bioactive ingredients are sensitive to processing and environmental conditions and thus it is necessary to improve their stability to create products with long shelf lives. Encapsulation by spray drying is a widely used economical strategy to tackle this issue, and many scientists and manufacturers are using it in their research, development, and production activities. In this review, the spray-drying process is described, as are recent trends in the encapsulation of fish oils, essential fatty acids, probiotics, phenolic compounds, and natural food colorants. The formulation and process conditions used in previous research and the results obtained are tabulated. Also, new innovations in bioactive encapsulation using nano-spray drying are described.

Survival of encapsulated probiotics in pasteurized grape juice and evaluation of their properties during storage

In this study, probiotic bacteria such as Lactobacillus acidophilus and Bifidobacterium bifidum were encapsulated in alginate beads with a mean diameter of 54.25 ± 0.18 µm by internal gelation. Encapsulated and free cells as control samples were then added to the pasteurized grape juice and stored for 60 days. At the end of the storage period, the survivability of the bacteria in the encapsulated samples was significantly ( P<0.05) higher than that in the free cells (8.67 ± 0.12 and 7.57 ± 0.08 log cfu mL−1 for L. acidophilus and 8.27 ± 0.05 and 7.53 ± 0.07 log cfu mL−1 for B. bifidum for encapsulated and free forms, respectively). The results generally showed a decrease in °Brix, pH, and color, whereas acidity and turbidity have increased the in probiotic grape juice after the storage period of 60 days. For all treatments, the numbers of surviving cells were more than the recommended minimum (107 cfu g−1) at the end of the storage period.

The cell wall compound of Saccharomyces cerevisiae as a novel wall material for encapsulation of probiotics

Yeast cell wall is known as a food grade ingredient which is recently being used increasingly as a novel coating for encapsulation of different materials in the food industry. This application is limited to core materials smaller than yeast in size. In this study, we have tried to encapsulate larger particles by crushing yeast cells. Hence, probiotic bacteria of Lactobacillus acidophilus and Bifidobacterium bifidum were encapsulated firstly by calcium alginate using the emulsion method and these microbeads were coated again by Saccharomyces cerevisiae cell wall compound and another layer of calcium alginate. The average diameter of microcapsules for single layer microbeads (M), microbeads coated by two layers of alginate (MCA), and microbeads coated by a layer of yeast cell and two layers of alginate (MCYA) were 54.25±0.18, 77.43±8.24 and 103.66±13.33μm, respectively. In simulated gastrointestinal conditions, there was a significant (P<0.05) enhancement in resistance of L. acidophilus when applying a layer of S. cerevisiae cell wall compound. For MCA and MCYA after 2h exposure to simulated gastric juice, it was revealed a log reduction of 1.53±0.1 and 1.1±0.02 with pH1.55 and in simulated intestinal juice, 2.92±0.04 and 2.42±0.06 with 0.6% bile after previous 1h incubation in gastric conditions, respectively. It can be concluded that the cell wall compound of S. cerevisiae is a suitable protective coating for probiotics and it can improve the survival of probiotics within food products.