Francisco J. García-Suárez

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.

Banana and mango flours.

Publisher Summary Flours obtained from unripe fruits such as mango and banana are an important source of indigestible carbohydrates and polyphenol compounds. Banana is a climateric fruit cultivated in many countries, primarily those located in the tropical and subtropical regions, and it represents a major staple. Annual world production of banana is approximately 104 millions tons. The chemical composition of banana varieties depends of the ripening state; however, agronomic traits, the type of soil, and climatic conditions alter the major and minor components of the fruit. Mango fruits are harvested at a mature green stage and stored for ripening. When fruit is fully grown and ready for picking, the stem snaps easily. The main components of mango are water and carbohydrates, with small amounts of dietary fruit (DF), protein, lipid, and vitamins. These fruits have significant amounts of associated bioactive compounds (flavonoids, carotenoids, etc.) and a more balanced composition. Mango and banana flours can reduce the glycemic response. Unripe banana flour can be modified by enzymatic and chemical treatments to increase the amount of indigestible carbohydrates. Mango and banana flours can be added to diverse bakery products, and evaluation of their nutraceutical potential is necessary.