Water-soluble microencapsulation using gum Arabic and skim milk enhances viability and efficacy of Pediococcus acidilactici probiotic strains for application in broiler chickens

OBJECTIVE

This study aimed to develop and evaluate the effectiveness of a water-soluble microencapsulation method for probiotic strains using gum Arabic (GA) and skim milk (SKM) over a three-month storage period following processing.

METHODS

Four strains of Pediococcus acidilactici (BYF26, BYF20, BF9, and BF14) that were typical lactic acid bacteria (LAB) isolated from the chicken gut were mixed with different ratios of GA and SKM as coating agents before spray drying at an inlet temperature 140°C. After processing, the survivability and probiotic qualities of the strains were assessed from two weeks to three months of storage at varied temperatures, and de-encapsulation was performed to confirm the soluble properties. Finally, the antibacterial activity of the probiotics was assessed under simulated gastrointestinal conditions.

RESULTS

As shown by scanning electron microscopy, spray-drying produced a spherical, white-yellow powder. The encapsulation efficacy (percent) was greatest for a coating containing a combination of 30% gum Arabic: 30% skim milk (w/v) (GA:SKM30) compared to lower concentrations of the two ingredients (p<0.05). Coating with GA:SKM30 (w/v) significantly enhanced (p<0.05) BYF26 survival under simulated gastrointestinal conditions (pH 2.5 to 3) and maintained higher survival rates compared to non-encapsulated cells under an artificial intestinal juices condition of pH 6. De-encapsulation tests indicated that the encapsulated powder dissolved in water while keeping viable cell counts within the effective range of 106 for 6 hours. In addition, following three months storage at 4°C, microencapsulation of BYF26 in GA:SKM30 maintained both the number of viable cells (p<0.05) and the preparation's antibacterial efficacy against pathogenic bacteria, specifically strains of Salmonella.

CONCLUSION

Our prototype water-soluble probiotic microencapsulation GA:SKM30 effectively maintains LAB characteristics and survival rates, demonstrating its potential for use in preserving probiotic strains that can be used in chickens and potentially in other livestock.

Encapsulated Bifidobacterium BB-12 addition in a concentrated lactose-free yogurt: Its survival during storage and effects on the product's properties

This work aims to manufacture a new concentrated lactose-free probiotic yogurt. For this purpose, the probiotic Bifidocaterium BB-12 was incorporated in a concentrated lactose-free yogurt, both in its free form and previously encapsulated. Previous cell encapsulation was performed using the spray-drying technique with the following wall materials: lactose-free milk, lactose-free milk and inulin, and lactose-free milk and oligofructose. Thus, three different probiotic powders were obtained and added separately to three fractions of concentrated lactose-free yogurt. The probiotic survival of both powders and yogurts was evaluated during refrigerated storage. Likewise, the viability of starter cultures in yogurt (Lactobacillus bulgaricus and Streptococcus thermophilus) was controlled. In addition, the physicochemical properties of the four yogurts were also measured (color, pH and acidity, and texture properties). All three powders showed good probiotic viability (>8 log CFU g^-1) throughout 120 days of storage at 4 °C. In turn, yogurt formulations (with the addition of powders or free bifidobacteria) presented probiotic viability above 7 log CFU g^-1 after storage; as well as the starter cultures (>8 log UFC g^-1). Yogurt with probiotic powder from lactose-free milk showed a more yellowish color; however, these differences would not be detected by the human eye (ΔE < 3.00). The yogurt with bifidobacteria free cells showed a greater post-acidification process (pH 4.18 to 4.02 and titratable acidity 1.52 to 1.89). It was not observed differences for firmness values of yogurt with free cells addition and yogurt with lactose-free milk and oligofructose powder addition. A slight significant decrease in the cohesiveness was observed in the yogurt elaborated with bifidobacteria free cells. The gumminess showed fluctuating values between all concentrated lactose-free yogurts. At the end of this study, we conclude that these probiotic powders can be incorporated into innovative lactose-free yogurts.