Multifunctional Role of the Whey Culture Medium in the Spray Drying Microencapsulation of Lactic Acid Bacteria

Svrha je ovoga rada bila ispitati raznovrsnost primjene podloge od sirutke tijekom mikroenkapsulacije bakterije Lactobacillus fermentum K73 tehnikom sušenja raspršivanjem. Podloga od sirutke s mikroorganizmima korištena je za ovlaživanje različitih smjesa (arapske gume, maltodekstrina i sirutke u prahu). Ispitali smo moguću primjenu tih smjesa kao izvora ugljika te njihovu zaštitnu ulogu u simuliranim uvjetima gastrointestinalnog trakta. Optimalna smjesa sušena je raspršivanjem pri različitim temperaturama i tlaku na sapnici, prema metodi odzivnih površina. Pritom su ispitani sljedeći parametri: preživljavanje mikroorganizama, njihova in vitro tolerancija na uvjete gastrointestinalnog trakta, fizikalno-kemijska svojstva, morfološke značajke i stabilnost pri 4, 25 i 37 °C. Lactobacillus fermentum K73 replicirao se u nosaču. Stanični ciklusi bili su: (–1,97±0,16) log CFU/g nakon sušenja, (–0,61±0,08) log CFU/g nakon izlaganja kapsula pH-vrijednosti koja simulira uvjete želuca i (–0,23±0,00) log CFU/g nakon izlaganja žučnim solima. Fizikalno-kemijska svojstva i morfološke značajke bile su u rasponu očekivanih za praškasti proizvod. Prah je bio stabilan pri temperaturi skladištenja od 4 °C. Sušenje podloge od sirutke s dodatkom mikroorganizama raspršivanjem pri optimalnim uvjetima bilo je uspješno. Istraživanje je dokazalo mogućnost primjene podloge od sirutke kao nosača ili komponente nosača, te njezinu zaštitnu ulogu tijekom sušenja, u simuliranim uvjetima gastrointestinalnog trakta i pri različitim temperaturama skladištenja.This study aims to evaluate the multifunctional role of whey culture medium during the spray drying microencapsulation of Lactobacillus fermentum K73. Whey culture medium containing growing microorganisms served to hydrate different mixtures (gum arabic, maltodextrin and whey). We evaluated the use of these mixtures as carbon sources and their protective effects on simulated gastrointestinal conditions. The optimal mixture was spray-dried while varying the outlet temperature and atomizing pressure using a response surface design. These conditions served to evaluate microorganism survival, tolerance to gastrointestinal conditions in vitro, physicochemical properties, morphometric features and stability at 4, 25 and 37 °C. Lactobacillus fermentum K73 replicated in the carrier material. Bacterial change cycles were (–1.97±0.16) log CFU/g after the drying process and (–0.61±0.08) and (–0.23±0.00) log CFU/g after exposure of the capsules to simulated gastric pH and bile salt content, respectively. The physicochemical properties and morphometric features were within the normal ranges for a powder product. The powder was stable at a storage temperature of 4 °C. The spray drying of the whey culture medium with growing microorganisms using the optimized drying conditions was successful. This study demonstrates the use of whey culture medium as a component of carrier material or as the carrier material itself, as well as its protective effects during drying, under simulated gastrointestinal conditions, and at varied storage temperatures

Effect of amplitude and pulse in low frequency ultrasound on oil/water emulsions

The application of ultrasound within advanced or emerging technologies requires selecting parameters that depend on the target application. This study evaluated pulse and amplitude parameters of oil/water emulsions (20:80% w/w) using low frequency probe ultrasound equipment (20 KHz). A categorical multilevel factorial design was used with Design Expert® in which the following pulse treatments were defined: continuous, pulse 20:20 (on:off) and pulse 30:30 (on:off), for five minutes. Six amplitudes (30, 36, 42, 48, 54 and 60 μm) were evaluated for the following response variables: separation of phases in emulsion, temperature and accumulated power. The results showed that the best condition to obtain an emulsion with less phase separation was the 20:20 (on:off) treatment with an amplitude of 42 μm. The ultrasound probe application parameters that were obtained will enable the design of stable products from low-fat emulsions.La aplicación de ultrasonido dentro del concepto de tecnologías avanzadas o emergentes, requiere de la selección de parámetros según sea el objetivo de su aplicación. En esta investigación fueron evaluados parámetros de pulsación y amplitud para mezclas aceite/agua (20:80 % p/p), empleando un equipo de ultrasonido de sonda de baja frecuencia (20KHz). Los tratamientos de pulsación utilizados fueron: continuo, pulsación 20:20 (on:off) y pulsación 30:30 (on:off) durante cinco minutos; se evaluaron seis amplitudes (30, 36, 42, 48, 54 y 60 μm) sobre las variables de respuesta: separación de fases en la mezcla, temperatura y potencia acumulada. Los resultados obtenidos analizados por Design Expert® por medio de un diseño factorial multinivel categórico mostraron que la mejor condición para obtener una mezcla con menor separación, fue el tratamiento 20:20 (on:off), con una amplitud de 42 μm.Lo anterior evidencia el uso de ultrasonido de sonda como una metodología potencial para la homogenización de mezclas

Compound distribution, structural analysis and nanomechanical properties of nanofibers loaded with high-oleic palm oil nanoemulsions for packaging application

The effect of the HOPO concentration on the morphology, fiber diameter, oil load and distribution, protein structure, protein-oil colocalization, and nanomechanical properties of the NFs were evaluated. We obtained smooth and defect-free NFs with diameters in range of 77–94 nm. Fourier-transform infrared spectroscopy was used as a reliable method to confirm oil load and protein structure after electrospinning. β-turn, β-sheet, α-helix, and triple helical structures were quantified. Confocal laser scanning microscopy was used to analyze colocalization, and results revealed a high distribution of NE droplets along the NFs and high oil-protein colocalization (overlap coefficient of ~ 0.63). The nanomechanical properties of the NE-loaded NFs demonstrated that at higher HOPO concentrations, the elastic modulus decreased. Likewise, homogeneity and synergy between compounds were observed. The adhesion properties of NE-loaded NFs were associated with their sticky surface, which was attributed to presence of HOPO. The NE-loaded NFs presented suitable physical properties for edible packaging.Fil: Ricaurte, Leidy. Universidad de la Sabana; ColombiaFil: Perea Flores, María de Jesús. INSTITUTO POLITÉCNICO NACIONAL (IPN);Fil: Méndez Méndez, Juan Vicente. INSTITUTO POLITÉCNICO NACIONAL (IPN);Fil: Santagapita, Patricio Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Quintanilla Carvajal, María Ximena. Universidad de la Sabana; Colombi

Bioaccessibility assay, antioxidant activity and consumer-oriented sensory analysis of Beta vulgaris by-product encapsulated in Ca(II)-alginate beads for different foods

Bioaccessibility analysis and antioxidant activity along in vitro digestion and a consumer-oriented sensory analysis were conducted in three potential functional foods based on Ca(II)-alginate beads containing bioactive compounds extracted from beet stems. Ca(II)-alginate beads per se, and two selected products (cookies and turkish delights supplemented with the beads) were prepared. Regarding the beads, among the attributes rated by consumers, visual appreciation predominates, being color in the just-as-right (JAR) category and in the like preference. Instead, both flavor and sweet taste were attributes highly penalized and should be improved in beads to be accepted as food per se. A higher percentage of customers preferred cookies and turkish delights instead of only beads, considering global satisfaction. Regarding in vitro digestion, there was a significant content of phenolic compounds in the products with beads, showing a bioaccessibility greater than 80% (for cookies) and 26% (for turkish delights). Also, the antioxidant capacity measured by ABTS ranged between 50 and 109% for cookies and turkish delights, being lower when measured by FRAP (between 20 and 30%, respectively). Thus, including the beads with beet stem extract in both products leads to a significant increase in the content of phenolic compounds and in the antioxidant capacity compared to their counterparts, protecting the compound during oral and gastric phases. These results allow the generation of improved Ca(II)-alginate systems with promising functional properties for the development of ingredients and functional foods.Fil: Aguirre Calvo, Tatiana Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; ArgentinaFil: Sosa, Natalia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe. Instituto de Ciencia y Tecnologia de Los Alimentos de Entre Rios. - Universidad Nacional de Entre Rios. Instituto de Ciencia y Tecnologia de Los Alimentos de Entre Rios.; Argentina. Universidad Nacional de Entre Ríos. Facultad de Bromatología; ArgentinaFil: López, Tamara Anahí. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe. Instituto de Ciencia y Tecnologia de Los Alimentos de Entre Rios. - Universidad Nacional de Entre Rios. Instituto de Ciencia y Tecnologia de Los Alimentos de Entre Rios.; Argentina. Universidad Nacional de Entre Ríos. Facultad de Bromatología; ArgentinaFil: Quintanilla Carvajal, María Ximena. Universidad de la Sabana; ColombiaFil: Perullini, Ana Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Santagapita, Patricio Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentin

Volatile compounds, sensory quality and ice morphology in falling-film and block freeze concentration of coffee extract

Coffee extract was freeze-concentrated through block and falling-film techniques. Solute retention and concentration efficiency were determined after one stage of these processes. Ice morphology was characterized through image analysis. Preservation of volatile compounds was determined through GC–MS. The effect of coffee extract on flavour was determined after freeze concentration through sensory evaluation. Solute occlusion was higher for falling-film than for block freeze-concentration, with an average distribution coefficient of 0.45 and 0.29, respectively. The ice crystal size was lower for the falling-film technique; this explains the higher solute occlusion. The dewatering capacity was higher for the falling-film technique, as this process is faster than block freeze-concentration. The most abundant volatile compounds of the coffee extracts were preserved after freeze concentration with both techniques. In the same way, no differences were found in most of the sensory attributes of the freeze-concentrated extract obtained using both techniques. Our results confirm the benefits of the block and falling-film freeze concentration techniques in preserving the quality of coffee extracts.Postprint (author's final draft

ESTUDIO SOBRE LA DISTRIBUCIÓN DE α-TOCOFEROL EN MICROCÁPSULAS OBTENIDAS POR SECADO POR ASPERSIÓN

En este trabajo se evaluó la distribución del α-tocoferol (AT) en microcápsulas obtenidas por secado por aspersión a partir de nanoemulsiones generadas por dos técnicas de homogenización diferentes. Inicialmente se estudió el efecto de la atomización en la distribución de tamaño de partícula a emulsiones con 20% de sólidos (maltodextrina, goma arábiga y AT en diferentes proporciones: 3:2:1, 3:2:2, 3:1:1, 2:2:1 y 2:1:1 respectivamente). Se determinó el efecto de la atomización como técnica de homogenización en la cantidad de AT extraíble y encapsulado en polvos obtenidos a partir de dichas emulsiones sometidas a dos pasos por boquilla (atomización fuera del secador y atomización durante el proceso de secado) y en los polvos obtenidos de las emulsiones que pasaron sólo una vez por boquilla (durante el proceso de secado). Esta cuantificación del AT extraíble y encapsulado se hizo a partir de extracciones con cloroformo con el fin de no romper o modificar la cápsula. Los resultados de eficiencia de encapsulación total se compararon con la suma de AT extraíble y encapsulado sin encontrarse diferencias significativas en los dos procesos. Por lo menos en uno de los varios parámetros morfométricos evaluados (área, diámetro de Feret, perímetro máximo, perímetro y factor de forma) se evidenciaron diferencias significativas entre los dos procesos de homogenización (dos pasos por boquilla y un paso por boquilla) antes y después de la extracción del AT. La microestructura de los polvos también se evaluó a través de la dimensión fractal de textura y contorno, evidenciándose también diferencia para los polvos obtenidos de las emulsiones homogenizadas (dos pasos boquilla) y no homogenizadas antes y después de la extracción. En general se determinó que la cantidad inicial de AT controla la cantidad de AT extraíble, pero es el acomodamiento y las relaciones de los materiales de pared, durante el proceso de atomización, los que determinan la cantidad de AT encapsulado. Finalmente, se evaluó el efecto de la microfluidización en la cantidad de AT extraíble y encapsulado en 21 diferentes combinaciones de maltodextrina, goma arábiga y AT determinadas a partir de un diseño de superficie de respuesta de dos factores (concentración de AT: 17, 19, 20 y 25% y ciclos de microfluidización: 0, 1 y 2). Se determinó que la eficiencia máxima de encapsulación depende de la cantidad inicial de AT en la emulsión y variará en una relación de segundo orden según los ciclos de microfluidización que se utilicen. Así mismo se encontró una relación entre el tamaño de la emulsión y la cantidad de AT cuantificado, un mayor número de pasos en el microfluidizador disminuirá el tamaño de la nanoemulsión con concentraciones iníciales bajas (17-20%) de tocoferol. También se estableció el perfil de acomodamiento del AT por microscopia confocal y se correlacionaron las eficiencias de encapsulación de todos los polvos con su respectiva coordenada de color “a” hallando una relación de segundo orden

Electrospinning Microencapsulation of <i>Lactobacillus fermentum</i> K73 Using Gelatin as the Main Component of a Food-Grade Matrix

This work aimed to establish the conditions that improve the viability of Lactobacillus fermentum K73 during and after the electrospinning process. A mixture of experimental designs were performed to select the formulation (gelatin and bacterial culture) that improves the probiotic viability after blending and under simulated gastrointestinal conditions. A Box–Behnken design was performed to improve the encapsulation yield and survival during the electrospinning process. For the Box–Behnken design, the factors were soy lecithin and bacteria culture concentration at the blend and collector distance for electrospinning. It was hypothesized that soy lecithin improved the electrospinnability, acting as a surfactant in the mixture and allowing lower voltage to be used during the process. The selected volume ratio of the gelatin (25%)/bacterial culture mixture was 0.66/0.34. The physicochemical parameters of the selected blend were in the recommended range for electrospinning. The conditions that improved the encapsulation yield and survival during electrospinning were 200 g/L of bacterial culture, 2.5% (w/v) soy lecithin, and 7 cm collector distance. The experimental encapsulation yield and survival was 80.7%, with an experimental error of 7.2%. SEM micrographs showed the formation of fibers with gelatin/bacterial culture beads. Encapsulation improved the viability of the probiotic under simulated gastrointestinal conditions compared to free cells

Effect of amplitude and pulse in low frequency ultrasound on oil/water emulsions

The application of ultrasound within advanced or emerging technologies requires selecting parameters that depend on the target application. This study evaluated pulse and amplitude parameters of oil/water emulsions (20:80% w/w) using low frequency probe ultrasound equipment (20 KHz). A categorical multilevel factorial design was used with Design Expert® in which the following pulse treatments were defined: continuous, pulse 20:20 (on:off) and pulse 30:30 (on:off), for five minutes. Six amplitudes (30, 36, 42, 48, 54 and 60 µm) were evaluated for the following response variables: separation of phases in emulsion, temperature and accumulated power. The results showed that the best condition to obtain an emulsion with less phase separation was the 20:20 (on:off) treatment with an amplitude of 42 µm. The ultrasound probe application parameters that were obtained will enable the design of stable products from low-fat emulsions.La aplicación de ultrasonido dentro del concepto de tecnologías avanzadas o emergentes, requiere de la selección de parámetros según sea el objetivo de su aplicación. En esta investigación fueron evaluados parámetros de pulsación y amplitud para mezclas aceite/agua (20:80 % p/p), empleando un equipo de ultrasonido de sonda de baja frecuencia (20KHz). Los tratamientos de pulsación utilizados fueron: continuo, pulsación 20:20 (on:off) y pulsación 30:30 (on:off) durante cinco minutos; se evaluaron seis amplitudes (30, 36, 42, 48, 54 y 60 µm) sobre las variables de respuesta: separación de fases en la mezcla, temperatura y potencia acumulada. Los resultados obtenidos analizados por Design Expert® por medio de un diseño factorial multinivel categórico mostraron que la mejor condición para obtener una mezcla con menor separación, fue el tratamiento 20:20 (on:off), con una amplitud de 42 µm.Lo anterior evidencia el uso de ultrasonido de sonda como una metodología potencial para la homogenización de mezclas

Diseño de nanoemulsiones de aceite de palma alto oleico aptas para secado en refractance window™

40 páginasNanoencapsulation is a technique in which high-interest lipids are protected. Refractance Window™ is a novel drying technique designed mainly to convert fruit puree into powder, flakes, or concentrates. Thus, in this work we study the effect of wall materials on the moisture content and break distance of flakes obtained by RW from emulsions of high-oleic palm oil, also, we study the physical properties of the optimal nanoemulsions. High whey concentrations originate flakes with low moisture content and high break distance. Microfluidization pressure significantly affected droplet size, polydispersity index, zeta potential, and surface tension of the optimal nanoemulsions. In this sense, increasing the pressure decreased size and PdI, and increased ζ and ST. To obtain nanoemulsions suitable for drying in RW, high whey concentrations and high microfluidization pressures should be used to promote the stability of nanoemulsions in order to obtain flakes with high break distance and low moisture contentsLa nanoencapsulación es una técnica en la que se protegen los lípidos de alto interés. Refractance Window™ es una nueva técnica de secado diseñada principalmente para convertir puré de frutas en polvo, copos o concentrados. Así, en este trabajo estudiamos el efecto de los materiales de pared sobre el contenido de humedad y la distancia de rotura de las hojuelas obtenidas por RW a partir de emulsiones de aceite de palma alto oleico, además, estudiamos las propiedades físicas de las nanoemulsiones óptimas. Las altas concentraciones de suero originan copos con un bajo contenido de humedad y una gran distancia de rotura. La presión de microfluidización afectó significativamente el tamaño de las gotas, el índice de polidispersidad, el potencial zeta y la tensión superficial de las nanoemulsiones óptimas. En este sentido, al aumentar la presión disminuyó el tamaño y PdI, y aumentó ζ y ST. Para obtener nanoemulsiones aptas para el secado en RW, se deben utilizar altas concentraciones de suero y altas presiones de microfluidización para promover la estabilidad de las nanoemulsiones con el fin de obtener copos con una alta distancia de ruptura y bajos contenidos de humedad

Hydrolysed Gelatin-Derived, Solvent-Free, Electrospun Nanofibres for Edible Applications: Physical, Chemical and Thermal Behaviour

12 páginasElectrospinning is a novel technique which has been used recently in the food field. Electrospun nanofibres (NF) have often been produced from non-edible compounds. Biopolymer solutions were developed from gelatin hydrolysed by bromelain in slightly acid medium (pH 4.5). The effects of gelatin concentration, bromelain activity and tip-collector distance on NF morphology and diameter (Df) were studied. Defect-free NF were produced (no beads or droplets), having a 109.5 to 229.3 nm Df. A Box-Behnken design was optimised for studying acetic acid’s effect on gelatin NF thermal behaviour and residual solvent concentration. Gelatin ionisation by acetic acid improved the solutions’ electrospinnability. NF denaturing temperature (Td) was 98.4 °C and gelatin powder Td 102.3 °C. These values were associated with smaller amorphous structure in NF than in gelatin powder. Total acetic acid became evaporated during electrospinning; solvent-free NF were thus produced in line with international food regulations