Effect of Agavins and Agave Syrup Use in the Formulation of a Synbiotic Gelatin Gummy with Microcapsules of Saccharomyces Boulardii.

Agavins are reserve carbohydrates found in agave plants; they present texture-modifying properties and prebiotic capacity by increasing the viability of the intestinal microbiota. Through its hydrolysis, agave syrup (AS) can be obtained and can be used as a sweetener in food matrices. The objective of this work was to evaluate the effect of the variation in the content of agavins and AS on the physical, structural, and viability properties of Saccharomyces boulardii encapsulates incorporated into gelatin gummies. An RSM was used to obtain an optimized formulation of gelatin gummies. The properties of the gel in the gummy were characterized by a texture profile analysis and Aw. The humidity and sugar content were determined. A sucrose gummy was used as a control for the variable ranges. Alginate microcapsules containing S. boulardii were added to the optimized gummy formulation to obtain a synbiotic gummy. The viability of S. boulardii and changes in the structure of the alginate gel of the microcapsules in the synbiotic gummy were evaluated for 24 days by image digital analysis (IDA). The agavins and agave syrup significantly affected the texture properties (<1 N) and the Aw (>0.85). The IDA showed a change in the gel network and an increase in viability by confocal microscopy from day 18. The number of pores in the gel increased, but their size decreased with an increase in the number of S. boulardii cells. Agavins and cells alter the structure of capsules in gummies without affecting their viability.

Effect of Agave Fructans on Changes in Chemistry, Morphology and Composition in the Biomass Growth of Milk Kefir Grains.

Prebiotic effects have been attributed to agave fructans through bacterial and yeast fermentations, but there are few reports on their use as raw materials of a carbon source. Kefir milk is a fermented drink with lactic acid bacteria and yeast that coexist in a symbiotic association. During fermentation, these microorganisms mainly consume lactose and produce a polymeric matrix called kefiran, which is an exopolysaccharide composed mainly of water-soluble glucogalactan, suitable for the development of bio-degradable films. Using the biomass of microorganisms and proteins together can be a sustainable and innovative source of biopolymers. In this investigation, the effects of lactose-free milk as a culture medium and the addition of other carbon sources (dextrose, fructose, galactose, lactose, inulin and fructans) in concentrations of 2, 4 and 6% w/w, coupled with initial parameters such as temperature (20, 25 and 30 °C), % of starter inoculum (2, 5 and 10% w/w) was evaluated. The method of response surface analysis was performed to determine the optimum biomass production conditions at the start of the experiment. The response surface method showed that a 2% inoculum and a temperature of 25 °C were the best parameters for fermentation. The addition of 6% w/w agave fructans in the culture medium favored the growth of biomass (75.94%) with respect to the lactose-free culture medium. An increase in fat (3.76%), ash (5.57%) and protein (7.12%) content was observed when adding agave fructans. There was an important change in the diversity of microorganisms with an absence of lactose. These compounds have the potential to be used as a carbon source in a medium culture to increase kefir granule biomass. There was an important change in the diversity of microorganisms with an absence of lactose, where the applied image digital analysis led to the identification of the morphological changes in the kefir granules through modification of the profile of such microorganisms.

In Vitro Bile Salt Hydrolase (BSH) Activity Screening of Different Probiotic Microorganisms.

Bile salt hydrolase (BSH) activity in probiotic strains is usually correlated with the ability to lower serum cholesterol levels in hypercholesterolemic patients. The objective of this study was the evaluation of BSH in five probiotic strains of lactic acid bacteria (LAB) and a probiotic yeast. The activity was assessed using a qualitative direct plate test and a quantitative high-performance thin- layer chromatography assay. The six strains differed in their BSH substrate preference and activity. Lactobacillus plantarum DGIA1, a potentially probiotic strain isolated from a double cream cheese from Chiapas, Mexico, showed excellent deconjugation activities in the four tested bile acids (69, 100, 81, and 92% for sodium glycocholate, glycodeoxycholate, taurocholate, and taurodeoxycholate, respectively). In the case of the commercial probiotic yeast Saccharomyces boulardii, the deconjugation activities were good against sodium glycodeoxycholate, taurocholate, and taurodeoxycholate (100, 57, and 63%, respectively). These last two results are part of the novelty of the work. A weak deconjugative activity (5%) was observed in the case of sodium glycocholate. This is the first time that the BSH activity has been detected in this yeast.

Protection of L. rhamnosus by spray-drying using two prebiotics colloids to enhance the viability.

Protection of probiotics by substances considered as prebiotics can be an alternative to increase their viability in the large intestine. The objective of this study was to use two wall materials (native rice starch and inulin) without bonding agent to protect Lactobacillus rhamnosus during spray-drying and determine the viability of the microorganism under two storage conditions. For spray-drying conditions tested in this work the product yield with native rice starch (NRS) ranged between 65% and 74% whereas for inulin (IN) it ranged between 43% and 54%. In general, IN solutions exhibited higher outlet temperature than NRS dispersions. Capsules of IN had smaller particle size than those of NRS. Due to the higher hydrophilic nature of IN capsules as compared to NRS, IN capsules exhibited higher water activity than NRS capsules. Confocal microscopy showed marked differences between both wall materials, which could in turn cause differences in the release profile of encapsulated microorganisms. Agglomerates of NRS provided better protection to the microorganisms as evidenced by the lower reduction in viability when compared to IN, and this effect was corroborated by the stability study. It is possible to protect probiotics using both colloids, but differences in the viability and stability during storage were determined. The use of IN could prove beneficial in the encapsulation of probiotic strains since this carbohydrate is not hydrolyzed by human digestive enzymes and may act as prebiotic.