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.

[Yield of starch extraction from plantain (Musa paradisiaca). Pilot plant study]. / Rendimiento del proceso de extraccion de almidon a partir de frutos de platano (Musa paradisiaca). Estudio en planta piloto.

In México, the banana (Musa paradisiaca) is cooked (boiling or deep frying) before being eaten, but the consumption is not very popular and a big quantity of the product is lost after harvesting. The unripe plantain has a high level of starch and due to this the use of banana can be diversified as raw material for starch isolation. The objective of this work was to study the starch yield at pilot plant scale. Experiments at laboratory scale were carried out using the pulp with citric acid to 0,3 % (antioxidant), in order to evaluate the different unitary operations of the process. The starch yield, based on starch presence in the pulp that can be isolated, were between 76 and 86 %, and the values at pilot plant scale were between 63 and 71 %, in different lots of banana fruit. Starch yield values were similar among the diverse lots, showing that the process is reproducible. The lower values of starch recovery at pilot plant scale are due to the loss during sieving operations; however, the amount of starch recovery is good.