Role of Calcium Alginate and Mannitol in Protecting Bifidobacterium

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>Fourier transform infrared (FTIR) spectroscopy was carried out to ascertain the mechanism of Ca-alginate and mannitol protection of cell envelope components and secondary proteins of<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">Bifidobacterium animalis</jats:named-content>subsp.<jats:italic>lactis</jats:italic>Bb12 after freeze-drying and after 10 weeks of storage at room temperature (25°C) at low water activities (a<jats:sub>w</jats:sub>) of 0.07, 0.1, and 0.2. Preparation of Ca-alginate and Ca-alginate-mannitol as microencapsulants was carried out by dropping an alginate or alginate-mannitol emulsion containing bacteria using a burette into CaCl<jats:sub>2</jats:sub>solution to obtain Ca-alginate beads and Ca-alginate-mannitol beads, respectively. The wet beads were then freeze-dried. The a<jats:sub>w</jats:sub>of freeze-dried beads was then adjusted to 0.07, 0.1, and 0.2 using saturated salt solutions; controls were prepared by keeping Ca-alginate and Ca-alginate-mannitol in aluminum foil without a<jats:sub>w</jats:sub>adjustment. Mannitol in the Ca-alginate system interacted with cell envelopes during freeze-drying and during storage at low a<jats:sub>w</jats:sub>s. In contrast, Ca-alginate protected cell envelopes after freeze-drying but not during 10-week storage. Unlike Ca-alginate, Ca-alginate-mannitol was effective in retarding the changes in secondary proteins during freeze-drying and during 10 weeks of storage at low a<jats:sub>w</jats:sub>s. It appears that Ca-alginate-mannitol is more effective than Ca-alginate in preserving cell envelopes and proteins after freeze-drying and after 10 weeks of storage at room temperature (25°C).</jats:p>

Lactobacillus casei loaded Soy Protein-Alginate Microparticles prepared by Spray-Drying

“…Therefore, for the cross-linking density to be increased, series of microparticles cross-linked with Ca 2+ were prepared. A stronger molecular framework of Ca-alginate, formed by cooperative binding of Ca 2+ with the aligned polyguluronate ribbons and partial covalent bonds between Ca 2+ and oxygen atom of C-O-C groups of alginate (33), was expected to compensate for viability loss during freeze-drying and provide higher probiotic viability in low pH and controlled release at pH≥6.8. This expectation was supported by a previous study that pointed to significant improvement of the L. casei 01 stability/viability in the SGJ and SIJ with the increase in CaCl 2 concentration, when chitosan-coated alginate microparticles were additionally cross-linked with Ca 2+ (16).…”

Whey Protein-Pullulan (WP/Pullulan) Polymer Blend for Preservation of Viability ofLactobacillus acidophilus

“…The plates were incubated anaerobically at 37 C for 72 h and colony forming units were estimated. The enumeration of microencapsulated bacteria in microcapsules were calculated according to the methods proposed by Hernández-Carranza and López-Malo.…”

“…Samples of 1 ml of the peptone water were diluted to an appropriate dilution and plated by the pour plate technique using MRS agar. Colonies were counted after 72 h of incubation at 37 C. The viable cell number was expressed as 1224 Ç ABUK AND HARSA CFU per gram of microcapsule (CFU=g) and the yield was determined following Eq. (1):…”

“…Trypsin was dissolved in sterile deionized water and filtered through a 0.45 mm sterile membrane filter, then suspended in sterile saline solution to a final concentration of 1 g=L. [35] 1.0 ml of free or 1.0 g of microencapsulated bacteria were transferred into 9.0 ml of simulated intestinal juice and incubated at 37 C under orbital shaking at 160 rpm for 24 h. After incubation, samples were taken from supernatant and viable bacteria released in SIJ were enumerated. Released rate (%) was calculated according to Eq.…”

Improved viability ofLactobacillus acidophilusNRRL-B 4495 during freeze-drying in whey protein-pullulan microcapsules

“…Water activity of the microcapsules was determined using a Hygrolab C1 water activity meter (Hygrolab C1, Rotronic, Bassersdorf, Switzerland) (Dianawati et al, 2012). The moisture content of the microcapsules was determined gravimetrically by oven-drying at 105 C for 24 h to reach weight equilibrium (Rajam et al, 2012).…”