Preparation of Polysaccharide-Protein Hydrogels with an Ultrafast Self-Healing Property as a Superior Oral Delivery System of Probiotics

Oral administration of probiotic supplements can effectively regulate intestinal disorders. However, harsh gastrointestinal conditions greatly limit the bioavailability of probiotics. In this work, biomass-derived polysaccharide-protein hydrogels (Dex-sBSA hydrogels) were constructed as an oral probiotic delivery system. The hydrogel encapsulation significantly promoted the growth and proliferation of probiotics and protected them from gastric acid, bile salts, reactive oxygen species, and antibiotics. In vivo experiments demonstrated that the hydrogel encapsulation significantly enhanced the bioavailability of probiotics, of which the cell number in the intestine, colon, and cecum was 35 times, 8 times, and 203 times higher than the free one, respectively. Attributed to the superior ultrafast self-healing property, the Dex-sBSA hydrogel successfully prevented the probiotics from quick elimination and prolonged the retention time in the gut, providing great possibilities for colonization and proliferation. These results clearly indicate the great potential of the Dex-sBSA hydrogel as a superior oral delivery system for probiotics.

The internal aqueous phase gelation improves the viability of probiotic cells in a double water/oil/water emulsion system

This research studied the viability of probiotic bacterium Lactobacillus plantarum (L. plantarum) encapsulated in the internal aqueous phase (W 1) of a water-in-oil-in-water (W 1/O/W 2) emulsion system, with the help of gelation and different gelling agents. Additionally, the physicochemical, rheological, and microstructural properties of the fabricated emulsion systems were assessed over time under the effect of W 1 gelation. The average droplet size and zeta potential of the control system and the systems fabricated using gelatin, alginate, tragacanth gum, and carrageenan were 14.7, 12.0, 5.1, 6.4, and 7.3 μm and - 21.1, -34.1, -46.2, -38.3, and -34.7 mV, respectively. The results showed a significant increase in the physical stability of the system and encapsulation efficiency of L. plantarum after the W 1 gelation. The internal phase gelation significantly increased the viability of bacteria against heat and acidic pH, with tragacanth gum being the best gelling agent for increasing the viability of L. plantarum (28.05% and 16.74%, respectively). Apparent viscosity and rheological properties of emulsions were significantly increased after the W 1 gelation, particularly in those jellified with alginate. Overall, L. plantarum encapsulation in W 1/O/W 2 emulsion, followed by the W 1 gelation using tragacanth gum as the gelling agent, could increase both stability and viability of this probiotic bacteria.

Effect of Fluidized Bed Drying, Matrix Constituents and Structure on the Viability of Probiotic Lactobacillus paracasei ATCC 55544 during Storage at 4 °C, 25 °C and 37 °C

The stabilization of probiotics for application in non-refrigerated food products is a challenging task. In the present study, probiotic Lactobacillus paracasei (Lacticaseibacillus paracasei) ATCC 55544 cells were immobilized in a dairy matrix comprising of whole milk powder, skim milk powder, or milk protein isolate using fluidized bed drying technology. The samples were taken out at different drying stages, with an apparent water activity (a_w) of a_w 0.5, a_w 0.4, and a_w 0.3, respectively, and vacuum-packed to maintain the a_w and stored at three different temperatures of 4 °C, 25 °C, and 37 °C. The study evaluated the impact of matrix constituents, milk fat, protein, and carbohydrate on the viability of encapsulated probiotic L . paracasei ATCC 55544 during storage for 1 month. The whole milk powder matrix provided superior protection to the bacteria. Confocal Laser Scanning Microscopy (CLSM) was used to investigate the structure of the immobilizing matrix and the location of the probiotic L. paracasei cells embedded within the matrix. The CLSM study revealed that the probiotic bacterial cells are mostly embedded as clusters beneath the top layer. We hypothesize that the biofilm-like structure, together with the protective whole milk powder matrix, helps to retain the superior viability of probiotic cells during storage at non-refrigerated storage conditions of 25 °C and 37 °C.

Physicochemical properties of soy protein hydrolysate and its formulation and stability with encapsulated probiotic under in vitro gastrointestinal environment

The objective of this study was to prepare protein isolate from defatted soybean and identify an optimal hydrolysis protocol to create improved hydrolysates and ascertain the optimum encapsulation technique for probiotics. Soy protein isolate (SPI) was prepared using an alkaline extraction procedure for solubility within a neutral, beverage-specific pH range. The soy protein hydrolysate (SPH) was prepared from aqueous extracted SPI using pepsin. The physicochemical properties of the SPH were investigated by solubility, degree of hydrolysis (DH), surface hydrophobicity, and electrophoresis. Hydrolysates from 2, 2.5, and 3 hr of hydrolysis time achieved the suitable DH between 2.5% to 5.0%. The 2.5 to 3 hr hydrolysates were also significantly more soluble than SPI at all pH levels from 85% to 95% solubility. Surface hydrophobicity of the hydrolysates ranged from 15 to 20 S0 values. Alginate (1%), resistant starch (2%), and probiotic culture (0.1%) were used as an encapsulation agent to protect probiotics. Alginate microcapsules were observed to be 1 mm in size using environmental scanning electron microscopy. The dried SPH and encapsulated probiotics with alginate in a dry powder formulation were tested for its gastrointestinal resistance and probiotic viability under in vitro simulated digestion. Approximately 1-log decrease was observed for all experimental groups after simulated digestion (final log colony forming units [CFU]/mL range: 6.55 to 6.19) with free probiotics having the lowest log CFU/mL (6.10 ± 0.10) value. No significant difference was observed among experimental groups for probiotic viability (P = 0.445). The findings of this research will provide an understanding of formulation for easily digestible protein and encapsulated probiotics. PRACTICAL APPLICATION: The findings of this research provide an understanding of improved formulation for more suitable soy protein hydrolysate and viability of encapsulated probiotics in gastrointestinal environment. Probiotics with the prebiotics in an encapsulated environment provide a technology for the enhancement of probiotics viability and for applications in suitable products for health and wellness.

The Effect of the Ultra-High-Pressure Homogenization of Protein Encapsulants on the Survivability of Probiotic Cultures after Spray Drying

Interest in probiotic foods and ingredients is increasing as consumers become more aware of their potential health benefits. The production of these products often involves the use of dry culture powders, and the techniques used to produce such powders often suffer from significant losses of viable cells during drying or require the use of expensive drying technologies with limited throughput (e.g., freeze drying). In this study, the authors examined whether culture survivability during spray drying could be increased via the treatment of two common protein encapsulants with ultra-high-pressure homogenization (UHPH). Lactobacillus plantarum NRRL B-1927 (also known as ATCC 10241), a probiotic strain, was suspended in either soy protein isolate (SPI) or whey protein isolate (WPI) which had been either treated with UHPH at 150 Mpa or left untreated as a control. The suspensions were then dried using either concurrent-flow spray drying (CCSD), mixed-flow spray drying (MFSD) or freeze drying (FD) and evaluated for cell survivability, particle size, moisture content and water activity. In all cases, UHPH resulted in equal or greater survivability among spray dried cultures, showed reductions in particle size measures and, except for one marginal case (CCFD SPI), significantly reduced the moisture content of the dried powders. The combination of these findings strongly suggests that UHPH could allow probiotic powder manufacturers to replace freeze drying with spray drying while maintaining or increasing product quality.