Preparation and characterization of octenylsuccinylated plantain starch.

Plantain starch was esterified with octenylsuccinic anhydride (OSA) at two concentrations (3 and 15% w/w) of OSA. The morphology, granule size distribution, pasting, gelatinization, swelling, and solubility of granules and structural features of the starch polymers were evaluated. Granules of the OSA-modified starches increased in size during cooking more than did the granules of the native starch, and the effect was greater at the higher OSA concentration. Pasting viscosities also increased, but gelatinization and pasting temperatures and enthalpy of gelatinization decreased in the OSA-modified starches. It was concluded that insertion of OS groups effected disorder in the granular structure. Solubility, weight average molar mass, Mw¯, and z-average radius of gyration, RGz, of the amylopectin decreased as the OSA concentration increased, indicating a decrease in molecular size.

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.