Development of a combined low-methoxyl-pectin and rice-bran-extract delivery system to improve the viability of Lactobacillus plantarum under acid and bile conditions

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.

Modification methods, biological activities and applications of pectin: A review

Pectin is a complex and functionally rich natural plant polysaccharide that is widely used in food, medical, and cosmetic industries. It can be modified to improve its properties and expand its applications. Modification methods for natural pectin can be divided into physical, chemical, enzymatic, and compound methods. Different modification methods can result in modified pectins (MPs) exhibiting different physicochemical properties and biological activities. The objectives of this paper were to review the various pectin modification methods explored over the last decade, compare their differences, summarize the impact of different modification methods on the biological activity and physicochemical properties of pectin, and describe the applications of MPs in food and pharmaceutical fields. Finally, suggestions and perspectives for the development of MPs are discussed. This review offers a theoretical reference for the rational and efficient processing of pectin and the expansion of its applications.

Development and characterization of rice bran-gum Arabic based encapsulated biofertilizer for enhanced shelf life and controlled bacterial release

Introduction

Currently, microbe-based approaches are being tested to address nutrient deficiencies and enhance nutrient use efficiency in crops. However, these bioinoculants have been unsuccessful at the commercial level due to differences in field and in-vivo conditions. Thus, to enhance bacterial stability, microbial formulations are considered, which will provide an appropriate microenvironment and protection to the bacteria ensuring better rhizospheric-colonization.

Methods

The present study aimed to develop a phosphobacterium-based encapsulated biofertilizer using the ion-chelation method, wherein a bacterial strain, Myroid gitamensis was mixed with a composite solution containing rice bran (RB), gum Arabic (GA), tricalcium phosphate, and alginate to develop low-cost and slow-release microbeads. The developed microbead was studied for encapsulation efficiency, shape, size, external morphology, shelf-life, soil release behavior, and biodegradability and characterized using SEM, FTIR, and XRD. Further, the wheat growth-promoting potential of microbeads was studied.

Results

The developed microbeads showed an encapsulation efficiency of 94.11%. The air-dried beads stored at 4°C were favorable for bacterial survival for upto 6 months. Microbeads showed 99.75% degradation within 110 days of incubation showing the bio-sustainable nature of the beads. The application of dried formulations to the pot-grown wheat seedlings resulted in a higher germination rate, shoot length, root length, fresh weight, dry weight of the seedlings, and higher potassium and phosphorus uptake in wheat.

Discussion

This study, for the first time, provides evidence that compared to liquid biofertilizers, the RB-GA encapsulated bacteria have better potential of enhancing wheat growth and can be foreseen as a future fertilizer option for wheat.

Rice bran as an encapsulating material to produce a healthy synbiotic product with improved gastrointestinal tolerance

To date, the coffee industry has the second highest market value in the world and consumer behavior has transitioned from drinking coffee just for its caffeine content to reduce sleepiness into an overall experience. Instant cold brew coffee in powder form can preserve the taste of coffee well; moreover, it is easy to transport. Several consumers have increasing interests in implementing lactic acid bacteria in healthy food due to their growing awareness of the probiotic's role. Several scholars have presented stress adaptation characteristics of single probiotic strains; however, comparisons of the stress-tolerant capacities of different probiotic strains are incomplete. Five lactic acid strains are tested for adaptation under four sublethal conditions. Lactobacillus casei is the most resilient probiotic in terms of heat and cold adaptation, while Lactobacillus acidophilus is more tolerant to low acid and bile salt; Then, these probiotics are subjected to a stress challenge that stimulates drying temperature, including a heat and cold stress challenge. The results show that acid adaptation can improve Lactobacillus acidophilus TISTR 1338 tolerance to harsh drying temperatures. In addition, encapsulation using prebiotic extracts from rice bran, with pectin and resistant starch combined through crosslinking and treated by freeze-drying, provides the highest encapsulation efficiency. In summary, acid-adapted L. acidophilus TISTR 1388 at the sublethal level can be applied to high and low temperature processing techniques. Additionally, the amount of viable probiotic after in vitro digestion remains at 5 log CFU/g, which is suitable for application in the production of synbiotic cold brew coffee.

Self-demise of soft rot bacteria by activation of microbial predators by pectin-based carriers

Soft rot pectobacteria (SRP) are phytopathogens of the genera Pectobacterium and Dickeya that cause soft rots on a wide range of crops and ornamental plants. SRP produce plant cell wall degrading enzymes (PCWDEs), including pectinases. Bdellovibrio and like organisms are bacterial predators that can prey on a variety of Gram-negative species, including SRP. In this research, a low methoxyl pectin (LMP)-based immobilization system for B. bacteriovorus is established. It takes advantage that pectin residues induce PCWDE secretion by the pathogens, bringing upon the release of the encapsulated predators. Three commercial LMPs differing in the degree of esterification (DE) and amidation (DA) were tested as potential carriers, by examining their effect on SRP growth, enzymes secretion and substrate breakdown. A clear advantage was observed for pectin 5 CS with the lowest DE and DA content. The degradation of 5 CS pectin-based carriers was further optimized by reducing cross-linker and pectin concentration, by adding gelatin and by dehydration. This resulted in SRP-induced disintegration of the carrier within 72 h. The released encapsulated predator caused a large decrease in SRP population while its own significantly increased, demonstrating the efficiency of this system in which the pathogen brings about its own demise.

Effect of Cellulose–Chitosan Hybrid-Based Encapsulation on the Viability and Stability of Probiotics under Simulated Gastric Transit and in Kefir

Encapsulation comprises a promising potential for the targeted delivery of entrapped sensitive agents into the food system. A unique combination of cellulose/chitosan (Cl-Ch)-based hybrid wall material was employed to encapsulate L. plantarum by emulsion technique. The developed beads were further subjected to morphological and in vitro studies. The viability of free and encapsulated probiotics was also evaluated in kefir during storage. The developed beads presented porous spherical structures with a rough surface. A 1.58 ± 0.02 log CFU/mL, 1.26 ± 0.01 log CFU/mL, and 1.82 ± 0.01 log CFU/mL reduction were noticed for Cl-Ch hybrid cells under simulated gastro-intestinal and thermal conditions, respectively. The encapsulated cells were found to be acidic and thermally resistant compared to the free cells. Similarly, encapsulated probiotics showed better viability in kefir at the end of the storage period compared to free cells. In short, the newly developed Cl-Ch hybrid-based encapsulation has a promising potential for the targeted delivery of probiotics, as career agents, in gastric transit, and in foods.

In vitro digestion of sodium alginate/pectin co-encapsulated Lactobacillus bulgaricus and its application in yogurt bilayer beads

The purpose of this study was to prepare sodium alginate (SA)/pectin (PE) hydrogel microspheres using the extrusion method to encapsulate Lactobacillus bulgaricus. Microscopic observation showed that the beads were spherical with a smooth and uniform surface. For microspheres with a diameter range of 140-156 μm, the encapsulation efficiency reached 85.67%. After simulating saliva, gastric juice, and intestinal juice, the activity of the microcapsules was estimated to be 5.78 × 10⁴ log colony forming unit (CFU)/mL. These data show that the use of SA and PE encapsulated probiotics exhibit enhanced viability. In addition, double-layer beads containing probiotic microspheres and yogurt were prepared, and physical and chemical analysis was performed using scanning electron microscopy, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. Texture and sensory property analysis revealed that the beads had good elasticity, chewiness, and high commercial value. Collectively, these findings indicate that SA and PE can be used for the encapsulation, protection, and gastrointestinal delivery of probiotics. Moreover, these microcapsules exhibit good stability in vitro and improve yogurt characteristics by increasing the survival rate of encapsulated probiotics, thus demonstrating their commercial application potential.

Resistant Starch-Based Edible Coating Composites for Spray-Dried Microencapsulation of Lactobacillus acidophilus, Comparative Assessment of Thermal Protection, In Vitro Digestion and Physicochemical Characteristics

Polysaccharides have excellent potential as food-grade coating materials for microencapsulation in pro- and prebiotics-based functional food industry. In this study, potato, maize, and rice resistant starches composite coatings with D-mannose, maltodextrin, and whey protein concentrate were prepared for the spray-dried microencapsulation of Lactobacillus acidophilus KLDS 1.1003. Assessment of different polysaccharide coatings to enhance the longevity of probiotics at high temperatures of spray-drying process, storage, and targeted delivery in the gastrointestinal tract were the key objectives of the present study. The highest microencapsulation efficiencies were shown by maize (95.80%) and potato (94.30%) resistant starches. Similarly, maize resistant starch (MRS)-based composites provided the highest thermal resistance, with Tg 38.77 ± 1.10–93.13 ± 0.81 °C and showed the least 2.1 log cycles viability loss in simulated GI tract. Viability losses during storage were in the following order: control > RRS > PRS > MRS, and the inactivation rate of the microencapsulated cells followed the first-order kinetics (R2 = 0.9264–0.9918). The resistant starch-based spray-dried microcapsules possessed 27.00 ± 0.03 to 52.28 ± 1.02 µm size range and SEM micrographs showed a unified smooth surface without cracks and ruptures. These findings will expand the potential use of natural food-grade coatings in functional foods and allied industries involving spray-dried products.

Pectin-microfibrillated cellulose microgel: Effects on survival of lactic acid bacteria in a simulated gastrointestinal tract

Using high pressure microfluidization, we prepared micro-fibrillated soybean cellulose (MFSC) and analyzed its morphology and structure. MFSC was then incorporated into low-methoxyl pectin (PC) to coat lactic acid bacteria (LAB) by ionotropic gelation, and the effects of PC-MFSC microgel on LAB survival in a simulated gastrointestinal tract were investigated. Particle size analysis showed that the MFSC particle size decreased significantly with increasing jet pressure. Transmission electron microscopy analysis indicated that many cellulosic microfibers appeared at 150 MPa. Infrared spectroscopy and X-ray diffraction analysis revealed that the crystal structure changed from β-cellulose I type to II type with increasing jet pressure, but excessive pressure (200 MPa) damaged the crystalline structure of MFSC. Scanning microscopy indicated that cellulosic microfibers not only promoted a compact pectin gel morphology but also adhered to and coated the LAB in the pectin gel. MFSC-150 stabilized the pectin gel network, preventing the weakening of the gel under low pH conditions. Compared with other PC-MFSCs, PC-MFSC-150 microgel significantly decreased LAB susceptibility to gastrointestinal juice and increased the viability of LAB.

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.

A new delivery system based on apple pomace-pectin gels to encourage the viability of antimicrobial strains

This work was aimed to investigate the concept of the valorization of apple processing by-products to produce a new preservation system based on apple pomace gels to encourage the viability of antimicrobial Lactobacillus strains. A high frequency (850 kHz) low power (1.3 W/cm²) ultrasound-stimulated cavitation was used for the structure modulating of gels under low-temperature (50 ℃) conditions. Medium esterified apple pectin was added to apple pomace to improve its texture properties and stability. The monitoring of the process of gelation was performed by using acoustic technique and method, based on the measurement of the distance (parameter h, mm) traveled by a free-falling module. The obtained data were then compared to gel texture measurements. The results suggest that low power ultrasound leads to a reduced jelly mass stickiness and increased gel hardness, compared to the thermally treated sample. The immobilization of probiotic cells in low pectin apple pomace gels did not sufficiently protect the microorganisms. The higher viability of immobilized Lactobacillus paracasei (54-77%) compared to L. plantarum (43-59%) was recorded after incubation at acidic conditions (pH 2.0). The most suitable system for preserving bacterial cells during storage can be the apple pomace-pectin gel containing up to 53% pectin as a stabilizer retaining 84% of viable cells after one-month storage at 4 ℃. The apple pomace-pectin hydrogels with gelation rate (dh/dt) of 0.03-0.05 mm/s can be used for the preservation of bacterial cells as a suitable functional ingredient for food.

Effects of Astaxanthin from Shrimp Shell on Oxidative Stress and Behavior in Animal Model of Alzheimer's Disease

This study aimed to investigate the effect of astaxanthin (ASX) extracted and ASX powder from shrimp (Litopenaeus vannamei) shells on Wistar rats with Alzheimer's disease, induced by amyloid-β (1-42) peptides. In this task, the rats were divided into eight groups: (1) Control, (2) sham operate, (3) negative control (vehicle) + Aβ_1-42, (4) ASX extract+Aβ_1-42, (5) commercial ASX + Aβ_1-42, (6) ASX powder + Aβ_1-42, (7) blank powder + Aβ_1-42, and (8) vitamin E + Aβ_1-42. All treatments were orally administrated for 30 days. At 14- and 29-days post injection, animals were observed in behavioral tests. On the 31st day, animals were sacrificed; the hippocampus and cortex were collected. Those two brain areas were then homogenized and stored for biochemical and histological analysis. The results showed that the Aβ_1-42 infused group significantly reduced cognitive ability and increased memory loss, as assessed by the Morris water maze test, novel object recognition test, and novel object location test. Moreover, the Aβ_1-42 infused group exhibited a deterioration of oxidative markers, including glutathione peroxidase enzymes (GPx), lipid peroxidation (MDA), products of protein oxidation, and superoxide anion in the cortex and the hippocampus. Meanwhile, ASX powder (10 mg/kg body weight) showed a significant reduction in cognitive and memory impairments and oxidative stress which is greater than ASX extract in the same dose of compound or vitamin E (100 mg/kg body weight). Our study indicates the beneficial properties of ASX in alleviation of cognitive functions and reducing neurodegeneration in Wistar rats induced by amyloid-β (1-42) peptides.

Application of Polysaccharide-Based Hydrogels as Probiotic Delivery Systems

Polysaccharide hydrogels have been increasingly utilized in various fields. In this review, we focus on polysaccharide-based hydrogels used as probiotic delivery systems. Probiotics are microorganisms with a positive influence on our health that live in the intestines. Unfortunately, probiotic bacteria are sensitive to certain conditions, such as the acidity of the gastric juice. Polysaccharide hydrogels can provide a physical barrier between encapsulated probiotic cells and the harmful environment enhancing the cells survival rate. Additionally, hydrogels improve survivability of probiotic bacteria not only under gastrointestinal track conditions but also during storage at various temperatures or heat treatment. The hydrogels described in this review are based on selected polysaccharides: alginate, κ-carrageenan, xanthan, pectin and chitosan. Some hydrogels are obtained from the mixture of two polysaccharides or polysaccharide and non-polysaccharide compounds. The article discusses the efficiency of probiotic delivery systems made of single polysaccharide, as well as of systems comprising more than one component.

Statistical optimization of bambara groundnut protein isolate-alginate matrix systems on survival of encapsulated Lactobacillus rhamnosus GG

Encapsulation may protect viable probiotic cells. This study aims at the evaluation of a bambara groundnut protein isolate (BGPI)-alginate matrix designed for encapsulating a probiotic Lactobacillus rhamnosus GG. The response surface methodology was employed to gain the optimal concentrations of BGPI and alginate on encapsulation efficiency and survival of encapsulated cells. The capsules were prepared at the optimal combination by the traditional extrusion method composed of 8.66% w/v BGPI and 1.85% w/v alginate. The encapsulation efficiency was 97.24%, whereas the survival rates in an acidic condition and after the freeze-drying process were 95.56% and 95.20%, respectively-higher than those using either BGPI or alginate as the encapsulating agent individually. The designed capsules increased the probiotic L. rhamnosus GG survival relative to free cells in a simulated gastric fluid by 5.00 log cfu/ml after 3 h and in a simulated intestinal fluid by 8.06 log cfu/ml after 4 h. The shelf-life studies of the capsules over 6 months at 4 °C and 30 °C indicated that the remaining number of viable cells in a BGPI-alginate capsule was significantly higher than that of free cells in both temperatures. It was demonstrated that the BGPI-alginate capsule could be utilized as a new probiotic carrier for enhanced gastrointestinal transit and storage applied in food and/or pharmaceutical products.

Emerging concepts in the nutraceutical and functional properties of pectin-A Review

Pectin is a structural heteropolysaccharide found ubiquitously in terrestrial plants. It finds diverse food applications such as that of a gelling agent, stabilizer, and fat replacer. In the pharmaceutical arena, pectin exhibits a number of functions, from decreasing blood fat to combating various types of cancers. This review shows the shift of pectin from its conventional roles to its progressive applications. Insights into the advances in the production of pectin, the role it plays as a nutraceutical, possible prebiotic potential and a delivery vehicle for probiotics, and food applications are highlighted. Bioactive and functional properties of pectin are discussed and how the structural built up defines them, is emphasized. As a biopolymer, the applications of pectin in active packaging are also mentioned.