In this work, a spray‐drying process is used to encapsulate a probiotic strain of Lactobacillus plantarum with mixtures of Aloe vera mucilage (AVM) (Aloe barbadensis Miller) and agave fructans of high degree of polymerization (AFHDP). Physicochemical properties of the powders reveal moisture contents lower than 10% and water activity between 0.195 and 0.3, suggesting stability during storage. A non‐Newtonian shear‐thinning behavior arises in the reconstituted powders under steady shear flow and viscosity is shown to depend on the concentration, pH, and temperature. A predominant viscous behavior is exhibited in the viscoelastic properties under small amplitude oscillatory flow with equal values of the elastic and viscous moduli at high frequencies (G´ = G´´), suggesting a random coil conformation. Scanning electron microscope observations reveal a spherical microcapsule morphology possessing homogeneous surfaces with modal particle‐size distribution (D [4,3] =21.3 μm). The addition of arabic gum to the AVM‐AFHDP mixtures induces a shift in the glass transition temperature (Tg) to 150°C. Preserved stability of the AVM‐AFHDP functional groups with the probiotic after spray drying reveals the effective encapsulation of the microorganism, as corroborated by transmission electron microscopy and Fourier‐transform infrared. Enhanced microorganism survival rate of 70% in the mixture is recorded, representing an alternative for probiotic encapsulation.PRACTICAL APPLICATIONSNowadays, the use of mixtures of prebiotic biopolymers as encapsulating wall materials is highly appreciated by the food and pharmaceutical industry. This research demonstrated that mixtures of Aloe vera mucilage and agave fructans are suitable for the microencapsulation of L. plantarum through studies on their rheological, morphological, and calorimetric properties. High survival rates and stable powders are obtained in samples subjected to spray drying. Results of this investigation may help to develop new delivery drug systems, which are able to protect bioactive compounds or probiotic cells through the gastrointestinal tract. Increasing health benefits, including probiotic and symbiotic effects, are expected with the intake of dietary fibers.

Modelado de la biodegradación en biorreactores de lodos de hidrocarburos totales del petróleo intemperizados en suelos y sedimentos (Biodegradation modeling of sludge bioreactors of total petroleum hydrocarbons weathering in soil and sediments)

Skim milk was microfiltered in a pilot system equipped with ceramic membranes that have a novel configuration in their active layer, for the production of microbiologically-stable milk. The linear velocity (LV), temperature (T), and transmembrane pressure (TMP) were studied to assess the effect on bacterial reduction and protein permeation in the microfiltration system. Statistical analysis showed significant effects (α = 0.05) of T on flux, LV on protein permeation, and all the three conditions on the logarithmic reduction of microorganisms. The optimal operational conditions in the system obtained by the surface response method were LV = 6 m/s, T = 30 C, and TMP = 1.5 bar. These operational conditions ensured high filtration performance and a logarithmic reduction of bacteria by 4.55 log and extension of the shelf life to 5 days during storage at 4 C, the microbiological stability of microfiltered milk was not affected by the addition of prebiotic agave fructans of a high degree of polymerization. The microfiltration allows microbiological stability, conservation of functional compounds, and preservation of organoleptic sensory properties of milk, for the production of healthy and innocuous fresh dairy products with higher shelf life.

The physico-mechanical properties of fructan fractions in different agave species without Tequila Denomination of Origin (DOT) need to be studied to identify and expand industrial applications. The rheological and physicochemical characterization of three fractions of Agave tequilana cv. cenizo fructans without DOT, with different degree of polymerization (DP) was carried out to propose their use as an additive in the food industry. Fractions were obtained by apparent DP enrichment (DPa) by stepwise ultradiafiltration with 10, 5 and 1 kilodalton (kDa) membranes and classified on the basis of the enriched fraction evidenced by HPLC profiling with amperometric detector. The ultradiafiltrate of the membrane with 10 kDa, called High Degree of Polymerization (HDP), showed enrichment of fructans with high DPa ≥ 30, the one with 5 kDa called Intermediate Degree of Polymerization (IDP), presents enrichment in DPa between 10 to 30, these fractions dried by spray, showed a modal particle size distribution (D [4,3] < 20 µm). In the ultradiafiltrate of the 1 kDa membrane, called Low Polymerization Grade (LDP), fructo-oligosaccharides (FOS) and fructans with maximum DPa of 15 were enriched; this sample was concentrated to 72 °Brix. The glass transition (Tg) showed a DPa-dependent increase (LDP = 152.17 °C, IDP = 216.12 °C and HDP = 227.5 °C). Viscosity was dependent on the degree of polymerization, exhibiting thermo-mechanically stable flow behavior. The reconstituted powders exhibited Newtonian and flow-stable behavior in a concentration range of 2-50 %, temperature of 5-45 °C and pH of 2-9. The macro and micro structural properties identified in the respective fractions of agave fructans, diversify possible applications with potential interest as encapsulating material, stabilizer and prebiotic sweetener, among others that agave fructans have in the food and nutraceutical industry.