Probiotic capacity of commensal lactic acid bacteria from the intestine of Guinea pigs (Cavia porcellus).

The intricate balance of intestinal microbiota is significantly influenced by the pivotal role of indigenous lactic acid bacteria (LAB). These LAB not only contribute to antimicrobial activity and enhance animal health and productivity but also serve as defense against intestinal infections. In the present study, the probiotic potential of LAB strains isolated from various intestinal sections of adult and young guinea pigs (Cavia porcellus) was comprehensively assessed. Strains belonging to the genera Ligilactobacillus, Weissella, Enterococcus, and Limosilactobacillus were also identified. The antibacterial activities of the LAB strains against Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus were quantified. Exopolysaccharide production, adherence capacity, antibiotic resistance, and bile salt tolerance (0.15 %, 0.30 %, and 0.45 %) of LAB were quantified. Further analyses focused on the effects of pH (2.9, 5.0, 6.4, and 7.4), temperature (40, 50, and 60 °C) and NaCl concentrations (3.5 % and 6.5 % w/v) on LAB growth. Strains GCI9 and GDE10 (Ligilactobacillus salivarius), isolated from the cecum and intestine of guinea pigs, exhibited significant antimicrobial activity against S. typhimurium, E. coli and S. aureus. Remarkable adherence capacity to porcine gastric mucin was demonstrated by L. salivarius strains, specifically ACI1, GCI9, and GDE10, with the highest exopolysaccharide levels produced by ACI1 and GCI9 (1.71 and 1.76 mg/mL, respectively). The probiotic potential was further underscored by remarkable bile salt tolerance, especially in strain GDE10, and substantial exopolysaccharide production. These strains displayed notable adaptability to varying environmental conditions, including NaCl concentrations at 3.5 % and 6.5 %, temperatures ranging from 40 to 60 °C, and pH levels of 2.9, 5.0, 6.4, and 7.4. This comprehensive assessment of the probiotic properties of L. salivarius strains, particularly ACI1, GCI9, and GDE10, shows promise for the development of probiotic formulations aimed at enhancing the intestinal health of guinea pigs.

Viability of Lactobacillus reuteri DSM 17938 Encapsulated by Ionic Gelation during Refractance Window® Drying of a Strawberry Snack.

The selection of appropriate probiotic strains is vital for their successful inclusion in foods. These strains must withstand processing to reach consumers with ≥106 CFU/g, ensuring effective probiotic function. Achieving this in commercial products is challenging due to sensitivity to temperature during processing. In this work, Lactobacillus reuteri DSM 17938 was microencapsulated by ionic gelation (with alginate or pectin) followed by polymeric coating (with whey protein concentrate or chitosan). Then, such microcapsules were incorporated into a strawberry puree, which was subsequently dehydrated at three temperatures (40 °C, 45 °C, and 50 °C) by Refractance Window®. The ultimate aim was to demonstrate the efficacy of the proposed methods from a technological point of view. Kinetic curves of the probiotic's viability showed a high cell loading (>109 CFU/g). Additionally, an average encapsulation efficiency of 91% and a particle size of roughly 200 µm were found. A decrease in the viability of the microorganism was observed as drying temperature and time increased. As a demonstration of the above, in a particular case, drying at 45 °C and 50 °C, viable cells were found up to 165 min and 90 min, respectively; meanwhile, drying at 40 °C, viable cells were reported even after 240 min. The greatest viability preservation was achieved with Refractance Window® drying at 40 °C for 240 min when microcapsules coated with whey protein concentrate were incorporated into puree; this procedure showed great potential to produce dehydrated strawberry snacks with moisture (15%), water activity (aw < 0.6), and viability (≥106 CFU/g) suitable for functional foods. The membrane-stabilizing properties of whey protein concentrate could prevent cell damage. In contrast, probiotics in chitosan-coated capsules showed reduced viability, potentially due to antimicrobial properties and the formation of cracks. These findings signify a breakthrough in the production of dehydrated snacks with the addition of probiotics, addressing challenges in preserving the viability of these probiotics during processing; thus, opening the possibility for the development of a probiotic strawberry snack.

Enhancing the physicochemical stability and antioxidant activity of cape gooseberry calyx extract through nanoencapsulation in soy lecithin liposomes.

The focus of this study was on the development, physicochemical characterisation and evaluation of the antioxidant activity of cape gooseberry calyx extract loaded into nanoliposomal systems. Various nanoliposomes were prepared and optimised using the ethanol injection method and characterised based on particle size, polydispersity and zeta potential measurements. Subsequently, the encapsulation efficiency and in vitro release profile of the natural antioxidant extract (NAE) were evaluated, and its antioxidant activity was assessed using the oxygen radical absorbance capacity assay. The results revealed that NAE-loaded nanoliposomes described desired quality features (e.g., particle size of < 200 nm, polydispersity index of < 0.3, zeta potential of > -40 mV and encapsulation efficiency of ∼70%). Furthermore, it was found that NAE release is controlled by various stages, and its antioxidant activity improves by around 30% when loaded into the nanoliposomes, suggesting that it could be a promising antioxidant functional raw material.

Adhesion factors and antimicrobial resistance of Escherichia coli strains associated with colibacillosis in piglets in Colombia.

Background and Aims: The pathogenicity of Escherichia coli is determined by the presence of genes that mediate virulence factors such as adherence capacity and toxin production. This research aimed to identify the adhesion factors and antibiotic resistance capacity of E. coli strains associated with diarrhea in piglets in Colombia. Materials and Methods: Presumptive E. coli strains were isolated from the rectal swabs of piglets in swine farms between 4 and 40 days of age with evidence of diarrhea. Presumptive E. coli strains were tested for antibiotic resistance. The hemolytic capacity of presumptive E. coli strains was measured and molecularly identified. Strains confirmed as hemolytic E. coli was evaluated for the presence of five adhesion factors (F4, F5, F6, F18, and F41) and resistance to 11 antibiotics. Results: Fifty-two putative E. coli strains were isolated, six of which showed a hemolytic capacity. The hemolytic strains were molecularly identified as E. coli. Adhesive fimbriae were found in five of six ß-hemolytic E. coli isolates. Combinations of the adhesion factors F6-F18 and F6-F41 were linked to antibiotic resistance capacity. Conclusion: The phenomenon of E. coli strains resistant to multiple antibiotics on pig farms represents a constant risk factor for public health and pig production.

Rutin: Family Farming Products' Extraction Sources, Industrial Applications and Current Trends in Biological Activity Protection.

In vitro and in vivo studies have demonstrated the bioactivity of rutin, a dietary flavonol naturally found in several plant species. Despite widespread knowledge of its numerous health benefits, such as anti-inflammatory, antidiabetic, hepatoprotective and cardiovascular effects, industrial use of rutin is still limited due to its low solubility in aqueous media, the characteristic bitter and astringent taste of phenolic compounds and its susceptibility to degradation during processing. To expand its applications and preserve its biological activity, novel encapsulation systems have been developed. This review presents updated research on the extraction sources and methodologies of rutin from fruit and vegetable products commonly found in a regular diet and grown using family farming approaches. Additionally, this review covers quantitative analysis techniques, encapsulation methods utilizing nanoparticles, colloidal and heterodisperse systems, as well as industrial applications of rutin.

Co-Plasticization of Starch with Glycerol and Isosorbide: Effect on Retrogradation in Thermo-Plastic Cassava Starch Films.

Thermoplastic starch (TPS) has emerged as an essential alternative to produce environmentally friendly packaging; however, retrogradation is a disadvantage that affects its shelf life. This study analyzed the co-plasticizing effect of isosorbide on the mechanical, thermal, physicochemical, and microstructural properties and the retrogradation of films obtained by blown film extrusion from thermoplasticized starch with mixtures of glycerol and isosorbide in different ratios (3:0, 2:1, 1:2, and 0:3, respectively). The results showed that the higher concentration of isosorbide significantly increased the tensile strength; however, it reduced the elongation. Retrogradation modeled using the Avrami equation showed that the presence of isosorbide reduced the retrogradation rate (k) and modified the recrystallization mechanism (n). The relative crystallinity in the plasticized TPS films was reduced to 89%, and the adsorption significantly decreased. Isosorbide was very important in reducing the retrogradation of TPS. The best performance was obtained with the 2:1 ratio of glycerol/isosorbide due to the synergistic effect between the plasticizers. The results would allow tuning the properties of TPS films by combining glycerol/isosorbide in different ratios, which enables the design of materials tailored to potential application requirements.

Propiedades nutritivas y tecno funcionales de barras de pseudocereales adicionadas con soya, mango y granada / Nutritional and techno functional properties of pseudocereal bars added with soy, mango and pomegranate

Las barras de cereal (BC), se comercializan como un snack saludable, no obstante, su calidad nutricional es baja. Una alternativa para mejorar esto, es la incorporación de ingredientes como pseudocereales, germinados y subproductos de fruta. Objetivo. Evaluar el contenido nutricional y propiedades tecnofuncionales de una barra de cereal formulada a partir de pseudocereales, germinados de soya y subproductos del procesamiento de frutas. Materiales y Métodos. Se desarrollaron 6 formulaciones (F0-F5). Se determinó el contenido de proteína y fibra cruda, se seleccionó la formulación que presentó el mayor contenido de estos componentes. A la BC seleccionada se le determinó la digestibilidad in-vitro de la proteína, las propiedades tecnofuncionales potencial prebiótico y actividad inhibitoria de ECA-I. Resultados. La formulación seleccionada fue F1 (13,6 g/100 g p.s. proteína y 13,1 g/100 g p.s. fibra cruda). La digestibilidad de la proteína fue del 69 %, el cual es cercano a valores reportados para algunos componentes de la BC. La capacidad de hinchamiento y retención de agua fue 2,55 ml/g; 12,74 %, respectivamente. El crecimiento de L. brevis en medio MRS modificado con BC no presentó diferencias estadísticas con el medio control, indicando el potencial prebiótico presente en la BC. La barra de cereal tuvo un 39% de actividad inhibitoria de ECA-I, demostrando la acción de los compuestos bioactivos posiblemente liberados durante la digestión de la BC. Conclusión. La formulación desarrollada presenta propiedades funcionales importantes y podría generar beneficios para la salud(AU)

Introduction. Cereal bars (CB) are marketed as a healthy snack; however, their nutritional quality is low. An alternative to improve this is the incorporation of ingredients such as soybean sprouts, which have a higher protein content than some seeds; as well as fruit by-products that contain important bioactive compounds. Objective. To evaluate the nutritional content and techno-functional properties of a cereal bar formulated from pseudocereals, soybean sprouts, and fruit processing by-products. Materials and Methods. 6 formulations (F0-F5) were developed. The content of protein and crude fiber was determined, the formulation that presented the highest content of these components was selected. The in-vitro digestibility of the protein, the technofunctional properties, potential prebiotic and inhibitory activity of ACE-I were determined for the selected BC. Results. The selected formulation was F1 (13.6g/100g p.s. protein and 13.1g/100 g p.s. crude fiber). Protein digestibility was 69%, which is close to reported values for some CB components. The swelling and water retention capacity was 2.55 ml/g; 12.74%, respectively. The growth of L. brevis in modified MRS medium with CB did not present statistical differences with the control medium, indicating the prebiotic potential present in CB. The cereal bar had 39% ACE-I inhibitory activity, demonstrating the action of bioactive compounds possibly released during CB digestion. Conclusion. The developed formulation has important functional properties and could generate health benefits(AU)

Effect of the addition of fique bagasse microparticles in obtaining a biobased material based on cassava starch.

The indiscriminate accumulation of plastic waste has prompted research that leads to obtaining biobased materials. The research aim was to evaluate the effect of incorporating fique bagasse microparticles (FBM) in a cassava starch-based foamed material. First, the FBM extraction conditions were established by acid hydrolysis, for which the effect of acid concentration (5, 10 and 15% H2SO4), temperature (70, 80 and 90 °C) and extraction time (3, 5 and 7 h) on particle size, functional groups, color, and thermal properties was evaluated. The addition of FBM to the foamed material was then carried out. To do this, a completely randomized design with five treatments (0, 0.5, 0.75, 1.0 and 1.25% FBM) was evaluated. The response variables were the apparent density, expansion and spring index, compressibility, water absorption, thermal properties and FTIR. The results showed that the acid concentration, temperature and time had an effect on the morphological, chemical and thermal properties of FBM, with 10%, 70 °C and 7 h being the conditions that allowed obtaining the smallest particle size (61.69 ± 12.88 µm2). Moreover, the FBM concentration had a significant effect on the physical and mechanical properties of the foam, unleashing the treatment properties of 0.75%. This indicates that FBM have potential for use in obtaining biobased materials.

Quality of Physalis peruviana fruits coated with pectin and pectin reinforced with nanocellulose from P. peruviana calyces.

Physalis peruviana is marketed without its calyx, which generates byproducts and a decrease in the shelf life of these fruits. The aim of this study was to evaluate the effect of edible pectin-coatings reinforced with nanocellulose from calyx on the physical-chemical and physiological parameters of P. peruviana fruits during refrigerated storage (5 °C) for ten days. The nanocellulose extraction was carried out using a combined extraction method (chemical procedures and ultrasound radiation). The characterization of the fibers showed that the maximum degradation temperatures ranged between 300 and 311 °C. The SEM analysis revealed the presence of fibers after the chemical treatment. The removal of lignin and hemicellulose was validated using Fourier Transform Infra Red (FTIR) spectroscopy. The results showed that the fruits treated with pectin and pectin reinforced with nanocellulose at 0.5 % (w/w) had an adequate visual appearance and showed a minor color change (ΔE of 19.04 and 21.04, respectively) and the highest retention of L∗ during storage. Although the addition of nanocellulose at 0.5% presented the lowest respiratory rate (29.60 mgCO2/kg h), the treatment with pectin offered the least weight loss and showed the highest firmness retention at the end of storage. Thus, the edible pectin-coating may be useful for improving the postharvest quality and storage life of fresh P. peruviana fruit. Nanocellulose from P. peruviana calyces can be used under the concept of a circular economy; although, its use as a reinforcement of pectin showed some limitations.

A Pilot-Scale Supercritical Carbon Dioxide Extraction to Valorize Colombian Mango Seed Kernel.

Colombian mango production, which exceeded 261,000 t in 2020, generates about 40% of the whole fruit as solid waste, of which more than 50% are seed kernels (over 52,000 t solid by-product); though none is currently used for commercial purposes. This study reports the results of the supercritical carbon dioxide (scCO2) extraction of an oil rich in essential fatty acids (EFAs) from revalorized mango seed kernels and the optimization of the process by the Response Surface Methodology (RSM). In pilot-scale scCO2 experiments, pressure (23-37 MPa) and temperature (52-73 °C) were varied, using 4.5 kg of CO2. The highest experimental oil extraction yield was 83 g/kg (37 MPa and 63 °C); while RSM predicted that 84 g/kg would be extracted at 35 MPa and 65 °C. Moreover, by fine-tuning pressure and temperature it was possible to obtain an EFA-rich lipid fraction in linoleic (37 g/kg) and α-linolenic (4 g/kg) acids, along with a high oleic acid content (155 g/kg), by using a relatively low extraction pressure (23 MPa), which makes the process a promising approach for the extraction of oil from mango waste on an industrial scale, based on a circular economy model.

Author Correction: Valorization of Colombian fique (Furcraea bedinghausii) for production of cellulose nanofibers and its application in hydrogels.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Valorization of Colombian fique (Furcraea bedinghausii) for production of cellulose nanofibers and its application in hydrogels.

Cellulose nanofibers were obtained from the Colombian fique (Furcraea bedinghausii) and Acrylic hydrogels (H) and reinforced acrylic hydrogels with fique nanofibres (HRFN) were synthesized, using the solution polymerization method. The extraction was carried out using a combined extraction method (chemical procedures and ultrasound radiation). The raw material (NAT-F), bleached fibers (B-F), hydrolyzed fibers and fibers treated with ultrasound (US-F) were characterized by infrared spectroscopy (FTIR) and thermal stability analysis; also, in order to have a comparison criterion, a commercial microcrystalline cellulose sample (CC) was analyzed, which demonstrated the extraction of fique cellulose. The surface morphology of the NAT-F and the B-F was determined by scanning electron microscopy and the average particle size of the nanofibers was made through transmission electron microscopy. In H y HRFN the strain percent and compression resistance (Rc) were measured. The fique nanofibers showed diameter and length averages of 25.2 ± 6.2 nm and 483.8 ± 283.2 nm respectively. Maximum degradation temperature was 317 °C. HRFN presented higher compression resistance (16.39 ± 4.30 kPa) and this resistance was 2.5 greater than the resistance of H (6.49 ± 2.48 kPa). The results indicate that fique lignocellulosic matrix has potential application for obtaining polymeric type composite materials.

Formulation of a fermentation substrate from pineapple and sacha inchi wastes to grow Weissella cibaria.

Gold honey variety pineapple wastes and sacha inchi sub-products (SIS) were characterized in their elemental, physical, and chemical form in order to formulate a supplemented fermentation substrate (SFS) for the growth Weissella cibaria. The peels and fresh cores of the pineapple (FPP, FPC) were dried and ground (PPP, PPC) and then mixed (MCPP). The following procedures were then undertaken: a physicochemical characterization (moisture, aw, pH, acidity, and soluble solids) of the SIS, FPP, FPC, PPP, and PPC; a proximal characterization of he FPP, FPC, SIS, and SFS; and an elemental analysis (C-N2-H2-O2-S) of the MCPP, SIS, and W. cibaria, which allowed the stoichiometric equation to be defined and the SFS to be formulated. We then evaluated the effect that homogenization and heating to boiling point had on the concentration of reducing sugars in the SFS (g L-1). Finally, W. cibaria´s kinetic fermentation parameters were evaluated in the SFS and in a commercial substrate (control). The results showed FPP and FPC yields of 26.02 ± 0.58 and 14.69 ± 1.13%, respectively; a higher total sugar content in FPC (7.21%) than in FPP (6.65%); a high crude protein content in SIS (56.70%), and a C:N2 ratio of 6.50:1.00. Moreover, the highest concentration of reducing sugars (4.44 ± 0.29 g L-1) in the SFS was obtained with 5 h of hydrolysis under homogenization pre-treatments and heating until boiling. The SFS allowed the adaptation of W. cibaria, and there was a biomass production of 2.93 g L-1 and a viability of 9.88 log CFU mL-1. The formulation of an unconventional fermentation substrate from -Agro-industrial wastes of pineapple and sacha inchi to produce valuable products (such as lactic acid biomass through fermentation), is an excellent perspective for large-scale application.

Evaluación calórica y sensorial de una mezcla para helado formulado con inulina como sustituto parcial de grasa / Sensory and calorie evaluation of an ice cream mix, where inulin is incorporated as a partial substitute for fat

RESUMEN Se evaluó el aporte calórico, el contenido de grasa saturada y la aceptación sensorial de helados de vainilla formulados con inulina, como sustituto parcial de grasa saturada. Se formularon por triplicado cuatro mezclas para helados, en las cuales, se reemplazó parte de la grasa de palma (2, 3 y 4%) por inulina comercial. La grasa del tratamiento control, se formuló con 7% de grasa vegetal saturada. Para el reemplazo, se utilizó una relación 1:0,25 (grasa saturada:inulina). El aporte calórico, se calculó mediante la medición de energía bruta. El análisis sensorial, se realizó con 23 jueces consumidores habituales de helado. Se concluyó que en la formulación de helados de vainilla es posible reemplazar el 57,14% de grasa vegetal saturada por inulina sin que se afecten las propiedades sensoriales en el producto, logrando reducir en un 16%, el contenido calórico y, en 48,6%, el contenido de grasa saturada. Por lo tanto, la sustitución de grasa vegetal por inulina es una alternativa, que permite ofrecer en el mercado helados funcionales, con bajo contenido calórico, sin perder la palatabilidad, que hace a los helados un producto placentero para la gran mayoría de la población mundial.

ABSTRACT The caloric intake, saturated fat content and sensory acceptance of vanilla ice cream formulated with inulin as a partial substitute for saturated fat was evaluated. Ice cream mixtures by triplicate were formulated, and part of the palm fat (2, 3 and 4%) was replaced by commercial inulin. The fat of the control treatment was formulated with 7% vegetable fat. For the replacement of fat, a ratio of 1: 0.25 (fat: inulin) was used. The caloric intake was calculated by measuring gross energy. The sensory analysis was carried out with 23 habitual consumers judges of ice cream. It was concluded that in the formulation of vanilla ice cream is possible to replace 57.14% vegetable fat for inulin without affecting the sensory properties in the product, with this is possible to obtain 16% reduction in the caloric content and 48.6% in the content of saturated fat. Therefore, the replacement of vegetable fat by inulin is an alternative that allows offering functional ice cream with low caloric content, without losing the palatability that makes ice cream pleasant for most of the world population.

Influencia de agentes crioprotectores sobre las cinéticas de congelación de lechuga (Lactuca sativa L.) / Influence of cryoprotective agents on lettuce freezing kinetics (Lactuca sativa L.)

RESUMEN La lechuga es una hortaliza de hoja que no resiste la congelación. Como una alternativa de conservación de lechuga Lactuca sativa L. "Lollo Bionda", se evaluó el efecto de la aplicación de crioprotectores sobre cada una de las etapas de congelación de lechuga. En cada etapa, se evaluó el tiempo de duración, la velocidad y la temperatura de congelación. Como crioprotectores, se utilizaron soluciones de Aloe (Aloe barbadensis Miller), a concentraciones de 70, 80 y 90%; almidón, a concentraciones de 0,5, 1 y 2% p/p y aceite de oliva. Las muestras, se impregnaron con los diferentes crioprotectores y se ultracongelaron. Las temperaturas del material vegetal, se registraron durante una hora, con intervalos de 5s; se construyeron las cinéticas de congelación y sobre las cinéticas, se identificaron las diferentes etapas de congelación. Se encontró que el tipo y la concentración del crioprotector altera, de manera estadísticamente significativa, la temperatura, el tiempo y la velocidad de cada una de las etapas de congelación. Las mayores concentraciones de solutos presentes en Aloe vera al 90%, almidón al 2% y aceite de oliva influyeron considerablemente en la acción crioprotectora de la lechuga.

ABSTRACT Lettuce is a leafy vegetable that does not resist freezing. As an alternative to the lettuce Lactuca sativa L. "Lollo Bionda" lettuce conservation, the effect of the application of cryoprotectants on each of the freezing stages of lettuce was evaluated. In each stage, duration time, speed and freezing temperature were evaluated. Aloe (Aloe barbadensis Miller) solutions at concentrations of 70, 80 and 90%, starch at concentrations of 0.5, 1 and 2% w / w and olive oil were used as cryoprotectants. The samples were impregnated with the different cryoprotectants and deep-frozen. The temperatures of the plant material were recorded for one hour at intervals of 5 s, the freezing kinetics were built and, on the kinetics, the different stages of freezing were identified. It was found that the type and concentration of the cryoprotectant alters in a statistically significant way the temperature, time and speed of each of the freezing stages. The highest concentrations of solutes present in 90% Aloe vera, 2% starch and olive oil significantly influenced the cryoprotective action of lettuce.

Crude extracts of metabolites from co-cultures of lactic acid bacteria are highly antagonists of Listeria monocytogenes.

Listeria monocytogenes is a pathogen difficult to control, due to its resistance to extreme conditions. The antimicrobial activity of a mixture of metabolites produced by lactic acid bacteria was evaluated against L. monocytogenes. Bacterial combined cultures in 1:1 ratio of Lactobacillus plantarum and Weissella cibaria (treatment LP + WC) and mixtures in ratio 1:1:1 of Lactobacillus brevis, L. plantarum, and W. cibaria, (treatment (LB + LP + WC) were grown by discontinuous fermentation, at 32 °C for 48 h. At 1, 2, 6, 12, 24 and 48 h of fermentation, samples were taken, the biomass was separated from the metabolites, and the antimicrobial activity of the metabolites was measured in vitro against L. monocytogenes. For comparison, experimental data published in the literature corresponding to monocultures of L. brevis (L.B), L. plantarum (LP) and W. cibaria (WC) were used. The antimicrobial activity was measured by a surface diffusion technique using absorbent paper discs impregnated with 60 µl from each metabolite and placed on the TSA agar surface (36 °C, 24 h). The metabolites from the microbial mixtures showed statistical differences with respect to their respective monocultures. With the treatment (LP + WC) an inhibition diameter of 2.54 cm was obtained at 12 h of fermentation, this value was higher than those obtained in the monoculture LP (2.19 cm), and WC (2.44 cm), during the same period. In the mixture (LB + LP + WC) during the first 12 h of fermentation, the antimicrobial activity was higher (2.12-2.28 cm) than the antimicrobial activity of the monoculture LB (1.66-2.23 cm). The use of metabolites from the co-culture of L brevis, L. plantarum and W. cibaria under the evaluated conditions, potentiate the antimicrobial activity of L. brevis against L. monocytogenes, therefore, they are promising in bio-preservation.

Adhesion Capacity of Weissella cibaria to Bovine Mammary Tissue and the Effect of Bio-Sealant Topical Application on Physicochemical Properties of Milk.

The ability of a probiotic strain (Weissella cibaria) to adhere on tissue and the effect of its topical application in nipples of lactating cows on physicochemical characteristics of milk were evaluated. An ex vivo model was used to demonstrate the adhesion capacity of W. cibaria. Tissue samples were randomly distributed in three different solutions corresponding to three treatments (a nipple bio-sealant formulation, sterile PBS solution and biomass of W. cibaria, sterile PBS solution without microorganism addition). The number of bacteria adhered in tissue was quantified and observed using electron microscopy. Additionally, a bio-sealant prepared with W. cibaria was topically applied to nipples of dairy cows. Milk samples were taken every 7 days for 60 days. Two controls were used. California mastitis test (CMT), somatic cell count, electrical conductivity, pH, density, and acidity were evaluated. The adhesion capacity of W. cibaria strain to epithelial cells of bovine teat tissue samples was demonstrated. When the strain was added as a bio-sealant, the adhesion capacity of W. cibaria was 80.44%. The response variables did not show significant differences among treatments; these results indicate the safety of the topical application of W. cibaria on the bovine mammary gland. In this study, a new safe way of administering probiotic microorganisms in nipples of lactating cows was demonstrated. W. cibaria adheres to the bovine mammary tissue and can be topically applied in nipples of lactating cows without affecting the physicochemical characteristics of milk.

Double emulsion and complex coacervation in stevia encapsulation / Doble emulsión y coacervacion compleja en la encapsulación de estevia

Background: Stevia leaves a residual flavor at moment of being consumed, and its sweet taste remains little time, whereby, encapsulation is an option to mitigate these problems. Objective: Evaluate the double emulsion system followed by complex coacervation in stevia encapsulation. Methods: The effect of the concentration of the sweetener was determined (3.5; 5; 7.5 and 10% p/p) as well as the concentration of the wall material (2.5 and 5% p/p), on the morphology, capsules size, and encapsulation capacity. The double emulsion was prepared, the coacervate was formed, and then capsules were lyophilized. The morphology and capsule size were measured before and after lyophilization by optical microscopy. From Fourier´s infrared transformed spectrometry, encapsulation capacity was analyzed. Water activity and solubility were measured in lyophilized capsules. Results: Micro and nanocapsules (minimum size of 19.39 ± 0.74µm and 62.33 ± 6.65µm maximum) were obtained. Micrographs showed that the encapsulation technique used, allows obtaining dispersed stevia capsules and those of round and homogeneous morphology. The encapsulation capacity was 84.37 ± 4.04%. The minimum value of water activity was 0.49 ± 0.01 and 17.65 ± 0.91% of solubility. Conclusions: An increased in encapsulation capacity was obtained when the highest concentration of the wall material was used. The capsule diameter increased as the sweetener concentrations increased. The formulation to 5% (p/p) of stevia and 5% (p/p) in wall material was associated with better controlled release of the sweetener, which allows establishing subsequent applications in which the sweet taste is prolonged and the stevia bitter taste concealed.

Antecedentes: La estevia deja sabor residual al ser consumida, y su sabor dulce permanece poco tiempo, por lo cual, la encapsulación es una opción para mitigar estos problemas. Objetivo: Se evaluó el sistema doble emulsión seguido por coacervación compleja en la encapsulación de estevia. Métodos: Se determinó el efecto de la concentración del edulcorante (3.5; 5; 7.5 y 10% p/p) y de la concentración del material de pared (2.5 y 5% p/p), en la morfología, tamaño de cápsulas, y capacidad de encapsulación. Se elaboró la doble emulsión, se formó el coacervado, y posteriormente, las cápsulas se liofilizaron. La morfología y el tamaño de las cápsulas, se midieron antes y después de la liofilización mediante microscopia óptica. A partir de espectrometría infrarroja de transformada de Fourier se analizó capacidad de encapsulación. En las cápsulas liofilizadas se midió actividad de agua y solubilidad. Resultados: Se obtuvieron micro y nanocápsulas (tamaño mínimo de 19.39±0.74µm y máximo 62.33±6.65µm). Las micrografías indicaron que la técnica de encapsulación usada, permite obtener cápsulas de estevia dispersas y de morfología redonda y homogénea. La capacidad de encapsulación fue 84.37±4.04%. El valor mínimo de actividad de agua fue 0.49±0.01, y solubilidad de 17.65±0.91%. Conclusiones: Se obtuvo incremento en la capacidad de encapsulación cuando se utilizó la mayor concentración del material de pared. El diámetro de las cápsulas aumentó a medida que se incrementaron las concentraciones del edulcorante. Se concluyó que la formulación a 5% (p/p) de edulcorante y de 5% (p/p) en material de pared fue el tratamiento que mejor se asocia a una liberación controlada de estevia, lo cual permite establecer posteriores aplicaciones en las que se prolongue el sabor dulce y enmascare el sabor amargo de la estevia.

Development of a Teat Bio-sealant and Evaluation of its Technological and Functional Properties.

A teat bio-sealant was developed using Weissella cibaria, and the bio-sealant's technological and functional properties were assessed. The development included four experimental phases that were analyzed using independent experimental designs. Initially, sterilized or pasteurized Aloe vera gels were used, and the effect of heat treatment was investigated. In the second phase, the effects of time, storage temperature, and addition of cryopreservatives on the viability of the probiotic were observed. The third phase consisted of evaluating the synergistic effects of the cryopreservatives. The fourth phase involved selecting a material that would provide viscosity to the teat sealant. Technological and functional properties were measured in terms of viability of W. cibaria, and antimicrobial activity against Staphylococcus aureus and Streptococcus agalactiae was also analyzed. A mixture of milk powder and glycerol preserved this antimicrobial activity. Pullulan provided greater viscosity and maintained the technological and functional properties of the bio-sealant for 29 days. This teat bio-sealant can be used as an alternative for the prevention of bovine mastitis.

Infusão intramamária de Weissella confusa afeta a contagem de células somáticas e a contagem diferencial de leucócitos no leite / Intramammary infusion of Weissella confusa affects somatic cell counts and milk differential leukocyte count

A utilização de bactérias do ácido láctico (LAB) como uma alternativa ao uso de antimicrobianos tem sido proposta para o controle da mastite bovina. No entanto, antes dessas aplicações, o efeito in vivo das LAB sobre a glândula deve ser cuidadosamente avaliado. O objetivo deste estudo foi determinar se a infusão intramamária de Weissella confusa e seus metabólitos em vacas afeta a contagem de células somáticas (CCS) e a contagem diferencial de leucócitos no leite. Vinte e quatro tetos de seis vacas Hartón del Valle foram selecionados para a pesquisa. Uma alíquota de 5mL de uma solução aquosa de células de W. confusa (W) (concentração 109u.f.c. mL-1), 5mL de células de W. confusa com seus metabólitos (W + W10b) ou 5mL de metabólitos (W10b) foi aplicada ao acaso em três tetos de cada vaca. O teto restante em cada úbere representou a unidade experimental de controle (C). Nos dias 1, 2, 3, 5, 7, 9, 13 e 15 após infusão (PI), a CCS, o pH, a acidez titulável e a contagem diferencial de leucócitos no leite foram avaliadas. A aplicação das três substâncias biológicas produziu aumentos significativos na CCS, no pH e na contagem de neutrófilos polimorfonucleares. Não foram encontradas diferenças significativas entre W e W+W10b. O W10b mostrou a menor alteração sobre as variáveis avaliadas. Os resultados sugerem que a aplicação de W. confusa e seus metabólitos afeta a CCS e a contagem diferencial de leucócitos no leite.

The use of lactic acid bacteria (LAB) as an alternative to antimicrobial usage has been proposed for the control of bovine mastitis. However, before its application, the in vivo effects of the LAB on mammary gland must be carefully evaluated. The objective of this study was to determine whether the intramammary infusion of Weissella confusa and its metabolites in cows affects the somatic cell counts (SCCs) and milk differential leukocyte count. Twenty-four mammary quarters of six Hartón del Valle cows were selected for the investigation. A 5mL aliquot of an aqueous solution of W. confusa cells (W) (concentration of 109cfu mL-1), 5mL of W. confusa cells with its metabolites (W+W10b) or 5mL of metabolites (W10b) was randomly applied to three mammary quarters of each cow. The remaining teat on each udder represented the experimental control units (C). At 1, 2, 3, 5, 7, 9, 13 and 15 days post-infusion (PI), the SCCs, pH, titrable acidity and milk differential leukocyte count were evaluated. The application of the three biological substances produced significant increases in SCCs, pH and polymorphonuclear neutrophil counts. No significant differences between W and W+W10b infusion were found. W10b resulted in a lesser alteration on the variables evaluated. The results suggest that the intramammary infusion of W. confusa and its metabolites affect the SCCs and milk differential leukocyte count in cows.