Soy protein enzymatic hydrolysis and polysaccharides interactions: differential performance on kinetic adsorption at air-water interface

The objective of the work was to study the impact of soy protein hydrolysis on kinetic adsorption to the air-water interface and the effect of polysaccharides addition. Was used soy protein (SP) and theirs hydrolysates of 2% (H1) and 5.4% (H2) degree of hydrolysis. The polysaccharides (PS) used were a surface active one called E4M and a non-surface active one, lamda carrageenan (C). The dynamic surface pressure of interfacial films was evaluated with a drop tensiometer. In this contribution, we have determined the kinetic parameters of adsorption to the air-water interface which determined the penetration (Kp) and rearrangement (Kr) rates of SP, H1, H2 and PS, as well as their mixed systems. It was observed an increase of Kp and Kr when the protein were hydrolyzed (from SP to H1), however, when degree of hydrolysis progresses to H2 the parameters decreased again. In other hand, considerable differences were not found between these two PS studied concerning the Kp to air-water interface at these conditions. In spite of the different surface active nature of the PS, the proteins seem to control the behavior of the protein-PS interactions. However, when Kr of mixed systems was analyzed, the degree of hydrolysis and PS nature started to have a huge importance. Hence, it could be observed synergic or antagonic effects on Kr of biopolymers at liquid interface depending to the degree of hydrolysis of protein analyzed and the type of PS selected.CYTED through project 105PI0274CYCYT through grant AGL2007-60045Junta de Andalucía through grant PO6-AGR-01535Universidad de Buenos Aires, Agencia Nacional de Promoción Científica y Tecnológica (PICT 2008-1901) and Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentin

Development of a clean label mayonnaise using fruit flour

Over the past few years, clean label food has been growing, meaning that consumers are searching for shorter and simpler ingredient lists composed of familiar and natural ingredients. The objective of the present work was to develop a vegan clean label mayonnaise, replacing the additives with fruit flour obtained from fruit reduced commercial value. The mayonnaises were prepared by replacing the egg yolk with 1.5% (w/w) lupin and faba proteins, while fruit flour (apple, nectarine, pear, and peach flour) was incorporated to substitute sugar, preservatives, and colorants. Texture profile analysis and rheology—small amplitude oscillatory measurements were performed to evaluate the impact of the fruit flour on mechanical properties. The mayonnaise antioxidant activity was also analyzed in terms of color, pH, microbiology, and stability measurements. The results showed that mayonnaises produced with fruit flour had better structure parameters in terms of viscosity, and texture, but also improved pH and antioxidant activity (p < 0.05) compared to the standard mayonnaise (mayonnaise without fruit flour). The incorporation of this ingredient into mayonnaise increases the antioxidant potential, though it is in lower concentrations compared to the fruit flours that compose them. Nectarine mayonnaise showed the most promising results in terms of texture and antioxidant capacity (11.30 mg equivalent of gallic acid/100 g).info:eu-repo/semantics/publishedVersio

Effect of temperature on whey protein isolated (WPI) films adsorbed at the water-oil interface.

En este trabajo se ha estudiado la agregación interfacial inducida por el calor en un aislado proteico del suero bovino (WPI), previamente adsorbido sobre la interfase aceite-agua. Se ha seguido la evolución, durante el tratamiento térmico, de las características dinámicas interfaciales (tensión interfacial y propiedades dilatacionales superficiales), determinadas en un tensiómetro dinámico de gota, en unión de la observación microscópica y posterior análisis de la imagen de una gota que tiene adsorbida a la proteína sobre su superficie. Las variables estudiadas fueron la temperatura (en el intervalo comprendido entre 20 y 80 o C) y la concentración de proteína en el seno de la fase acuosa (en el intervalo comprendido entre 1.10 -1 y 1.10 -5 % en peso). Durante el tratamiento térmico, (a) la película de WPI presenta un comportamiento viscoelástico, con un ángulo de fase distinto de cero, (b) se incrementa el carácter elástico de la interfase, (c) se produce un incremento del módulo dilatacional superficial (E) y (d) una disminución de la tensión interfacial. La variación de E con el tiempo puede cuantificarse mediante ecuaciones de primer orden que pueden relacionarse con dos mecanismos cinéticos, asociados con la gelificación de WPI sobre la interfase aceite-agua. El tratamiento térmico produce cambios irreversibles en la película de WPI adsorbida sobre la interfase. Se han observado cambios significativos en las características interfaciales y en la imagen de la gota a concentraciones de proteína tan bajas como 1.10 -5 % en peso.Heat-induced interfacial aggregation of a whey protein isolate (WPI) with a high content of β -lactoglobulin, previously adsorbed at the oil-water interface, was studied by interfacial dynamic characteristics (interfacial tension and surface dilational properties) performed in an automatic drop tensiometer coupled with microscopic observation and image analysis of the drop after heat-treatment. The temperature, ranging between 20 and 80 o C, and protein concentration in aqueous bulk phase, ranging between 1.10 -1 and 1.10 -5 % wt/wt, were studied as variables. The pH, and ionic strength were maintained constant at 5 and 0.05 M, respectively. During the heat-treatment, WPI films behave typically as viscoelastic with non-zero phase angle, but with increasing elastic characteristics as the heat-treatment progresses. During isothermal treatment the surface dilational modulus, E, increases and the interfacial tension, σ , and phase angle, φ , decrease with time to a plateau value. The time dependence of E can be quantified by a first-order equation according to two kinetic mechanisms. The rate of thermal changes in WPI adsorbed films increases with protein concentration in solution. Heat-treatment produces irreversible changes in WPI adsorbed films because the interfacial characteristics do not return to original values after cooling back to the initial temperature. Significant changes in interfacial characteristics and drop image associated with interfacial WPI gelation were observed at protein concentration as low as 1.10 -5 % wt/wt, even for heat-treatment at 40 o C

Foaming characteristics of β-lactoglobulin as affected by enzymatic hydrolysis and polysaccharide addition: Relationships with the bulk and interfacial properties

The objective of this work was to study the effect of enzymatic hydrolysis and polysaccharide addition on the foaming characteristics of β-lactoglobulin (β-LG). Enzymatic treatment was performed in the hydrolysis degree (HD) range of 0.0–5.0% using bovine α-chymotrypsin II immobilized on agarose microbeads. Anionic non-surface active polysaccharides (PS), sodium alginate (SA) and λ-carrageenan (λ-C) were studied in the concentration range of 0.0–0.5 wt.%. Foaming characteristics were determined by conductimetric and optical methods and were linked to protein diffusion kinetics, film mechanical properties and biopolymer molecular dynamics in solution. Experiments were performed at constant temperature (20 °C), pH 7 and ionic strength 0.05 M. Limited hydrolysis improved the formation and stability of β-LG foam possibly due to an increased protein diffusion rate and film dilatational elasticity. Furthermore, PS addition caused different effects on β-LG foaming characteristics depending on the PS type, their relative concentration and extent of enzymatic treatment (HD). Diffusion rate and interfacial rheological behavior of mixed systems could exert a decisive role in foaming characteristics of β-LG and its hydrolysates in close connection with biopolymer interactions in solution, e.g., macromolecule repulsion, protein segregation/aggregation and soluble complexes formation.Fil: Perez, Adrián Alejandro. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Carrera Sánchez, Cecilio. Universidad de Sevilla; EspañaFil: Rodríguez Patino, Juan M.. Universidad de Sevilla; EspañaFil: Rubiolo, Amelia Catalina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Santiago, Liliana Gabriela. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Caracterització d’emulsions prebiòtiques estabilitzades amb inulina i ß-lactoglobulina

Inulin is a prebiotic polysaccharide that is being increasingly used in food emulsions as fat replacer, due to its thickening effect. In the present work, oil in water (O/W) emulsions (5/95) have been prepared by means of a pressure homogenizer, using β-lactoglobulin as an emulsifier (0.5 %), and varying the polysaccharide content up to 10 %. The zeta potential measurements suggest that there are no significant protein-polysaccharide interactions in the continuous phase. An increase in viscoelastic properties and viscosity of these pseudoplastic systems is observed as inulin content increases. Although inulin has no surface activity, its presence seems to favor protein adsorption kinetics at the interface. Likewise, the distribution of droplet sizes study for emulsions throughout the storage time points out how bimodal distributions obtained remain constant, indicating their stability, which is reinforced by backscattering results. These prebiotic emulsions may enjoy a great demand by the food industry.La inulina es un polisacárido prebiótico que se utiliza cada vez más en emulsiones alimentarias como sustituyente de grasa, al tener un efecto espesante sobre las mismas. En el presente trabajo, se han preparado emulsiones aceite/agua (5/95) mediante un homogeneizador de presión, utilizando b-lactoglobulina como emulsionante a una concentración fija de 0,5 % (p/p), y variando el contenido en polisacárido desde 0 al 10 % (p/p). Las medidas de popotencial zeta sugieren que no existen interacciones importantes entre la proteína y el polisacárido en la fase continua, al tiempo que se observa un aumento de las propiedades viscoelásticas y viscosidad de estos sistemas pseudopláticos. Aunque la inulina no presenta actividad superficial, su presencia parece favorecer la cinética de adsorción de la proteína en la interfase. Asimismo, el estudio de la distribución de tamaños de gota de las emulsiones a lo largo del tiempo de almacenamiento permite observar cómo las distribuciones bimodales obtenidas permanecen constantes, indicando la estabilidad de las mismas. Esto queda reforzado por los resultados obtenidos por medio de un analizador óptico de emulsiones con detectores de luz transmitida y retrodispersa. Emulsiones con ingredientes prebióticos como las estudiadas tiene un gran potencial en la industria alimentaria.La inulina és un polisacàrid prebiòtic que s’utilitza cada vegada més en emulsions alimentàries com substituent del greix, en tenir un efecte espessidor sobre les mateixes. En el present treball, s’han preparat emulsions oli / aigua (5/95) mitjançant un homogeneïtzador de pressió, utilitzant β-lactoglobulina com emulsionant a una concentració fixa de 0,5% (p/p), i variant el contingut en polisacàrid des de 0 al 10% (p/p). Les mesures de potencial zeta suggereixen que no hi ha interaccions importants entre la proteïna i el polisacàrid a la fase contínua, alhora que s’observa un augment de les propietats viscoelàstiques i de la viscositat d’aquests sistemes pseudoplàstics. Tot i que la inulina no presenta activitat superficial, la seva presència sembla afavorir la cinètica d’adsorció de la proteïna a la interfase. Així mateix, l’estudi de la distribució de mides de gota de les emulsions al llarg del temps d’emmagatzematge permet observar com les distribucions bimodals obtingudes romanen constants, indicant l’estabilitat de les mateixes. Això queda reforçat pels resultats obtinguts per mitjà d’un analitzador òptic de emulsions amb detectors de llum transmesa i retrodispersa. Emulsions amb ingredients prebiòtics com les estudiades tenen un gran potencial en la indústria alimentària.Universidad de Sevilla (España) III Plan Propio de Docenci

Interfacial/foaming properties and antioxidant activity of a silkworm (Bombyx mori) pupae protein concentrate

The current consumer demand for healthier diets, the growing interest in the search for new sources of protein, and the desire to reduce the negative effects on the environment have increased interest in the study of insect proteins. The present study focused on the technofunctional characteristics (interfacial and foaming properties) and the in-vitro antioxidant activity of a protein concentrate obtained from silkworm (Bombyx mori) pupae (SPC). The isoelectric point of the SPC was close to pH 4.0–5.0 as determined by protein solubility and z potential analysis. Given that the SPC had solubilities of ~50% and z potentials of ~20 mV at pH 2.0 and 8.0, it was decided to further study SPC properties at these pH values. The supernatant obtained after adjustment of SPC to pH 8.0 showed higher (p < 0.05) antioxidant activity than that at pH 2.0 when analysed by the ferric reducing antioxidant power (FRAP) assay (168.0 ± 3.0 V. 43.5 ± 8.1 μmol Trolox Eq. ·g−1 protein). However, no significant differences in antioxidant activity were found between pH 2.0 and 8.0 when using the oxygen radical absorbance capacity (ORAC) assay (1826.0 ± 131.9 vs. 1659.2 ± 46.8 μmol Trolox Eq. g−1 protein). The interfacial properties of SPC were determined at pH 2.0 and 8.0 during protein adsorption and after reaching the pseudo equilibrium state by means of dilatational and interfacial shear rheology following by foaming capacity and stability analyses. Faster adsorption kinetic values were obtained at pH 8 ( Vs. at pH 2.0). However, lower kinetic values at pH 2.0 increased the elastic behaviour of the viscoelastic interfacial film formed (E's ⁓ 30 mN/m at pH 2.0 V. E's ⁓ 20 mN/m at pH 8.0), which can be related with the higher protein sizes found at pH 2.0. These rearrangements of the SPC components appeared to increase its foaming capacity, whereas the foaming capacity of SPC adjusted to pH 8.0 was minimal.University of Seville for the VPPI-US grant (Ref.-II.5)Ministerio de Ciencia, Innovación y Universidades (España) / FEDER RTI2018-097100-B-C2

Antihypertensive and Antioxidant Activity of Chia Protein Techno-Functional Extensive Hydrolysates

Twelve high-quality chia protein hydrolysates (CPHs) were produced from chia protein isolate (CPI) in a pilot plant of vegetable proteins. To obtain functional hydrolysate, four CPHs were hydrolyzed by the action of Alcalase, an endoprotease, and the other eight CPHs were hydrolyzed by the action of Flavourzyme, an exoprotease. Alcalase-obtained CPHs showed significant antihypertensive properties particularly, the CPH obtained after 15 min of hydrolysis with Alcalase (CPH15A), which showed a 36.2% hydrolysis degree. In addition, CPH15A increased the antioxidant capacity compared to CPI. The CPH15A physicochemical composition was characterized and compared to chia defatted flour (CDF) and CPI, and its techno-functional properties were determined by in vitro experiments through the analysis of its oil absorption capacity, as well as the capacity and stability of foaming and emulsifying, resulting in an emulsifier and stabilizer better than the intact protein. Therefore, the present study revealed that CPH15A has potent antihypertensive and antioxidant properties and can constitute an effective alternative to other plant protein ingredients sources that are being used in the food industry.Spanish Ministry of Science, Innovation, and Universities grant CYTED-2019/119RT056

Morphological characteristics of European common spadefoot toad Pelobates fuscus (Laurenti, 1768) (Amphibia, Anura) in Posavina region

Češnjača, Pelobates fuscus je jedini predstavnik porodice Pelobatidae na prostoru Hrvatske. Vrsta je široko rasprostranjena u Evropi, ali unatoč tome procjenjeno je da postoji veliki pad populacija diljem zemalja koje naseljavaju. Prema Crvenoj knjizi vodozemaca i gmazova Hrvatske češnjača je smještena u DD kategoriju s nedovoljno podataka. Ona naseljava ravničarska područja uz sporije tokove i stajaće vode s malo predatora te rahlim tlom (prirodna ili antropogenizirana staništa). Istraživano područje obuhvaća stajaće tijelo u selu Lijeva Luka, Sisačko-moslovačka županija. Pronađene su dvije vrpce s jajima koje su tretirane u kontroliranim uvjetima u cilju: 1) detaljnog morfološkog opisa punoglavaca i njihovog oralnog diska kroz stadije razvoja, 2) postojanja morfoloških prilagodbi vrsta P. fuscus i Rana temporaria u eksperimentu kompeticije, 3) postojanja morfoloških prilagodbi vrste P. fuscus u prisustvu predatora Umbra krameri. Punoglavci su tretirani podjednako te prilikom uzorkovanja odvajani u 3 % formaldehid. Punoglavci su skenirani i podvrgnuti mjerenjima pomoću programa ImageJ i digitalne pomične mjerke. Determinirani su razvojni stadiji punoglavaca od 23 do 41 stadija prema Gosner (1960) sa najvećim punoglavacem ukupne dužine tijela 99,04 mm. Detaljno su ilustrirane i opisane morfološke značajke oralnog diska s pratećim formulama. Punoglavci češnjače nisu pokazali značajne morfološke promjene unutar eksperimenta kompeticije.European common spadefoot toad, Pelobates fuscus, is the only representative species of Pelobatidae family in Croatia. Despite the species is widespread all over the Europe, there are many data concerning the global population is in decline. According to the Red List of Amphibians and Reptiles of Croatia, common spadefoot toad is categorized as DD (data deficient). It inhabits lowland areas and flatlands near slow moving or stagnant waterbodies with little or no predator and loose soil (natural or anthropogenic habitats). Researched area includes stagnant waterbody in the village Lijeva Luka, Sisak – Moslavina Country. There were two egg clutches found and kept under controlled conditions with the aims of: 1) detailed morphological description of tadpoles and their oral disc through developmental stages, 2) the existence of morphological adaptations of P. fuscus and R. temporaria in the competition experiment, 3) the existence of morphological adaptations of P. fuscus in the presence of predator fish Umbra krameri. Tadpoles were treated equally and sampled in 3 % formaldehyde. Tadpoles were scanned and measured using the ImageJ programme and digital caliper. Developmental stages from 23 to 41 were determined with the highest value of total body length of 99,04 mm. All morphological features of oral disc with accompanying formulas were illustrated and described in detail. Spadefoot toad tadpoles did not show significant morphological changes within the competition experiment

Estructura, estabilidad, morfología, y características reológicas de películas de emulsionantes alimentarios (lípidos y proteínas) esparcidas sobre la interfase aire-agua

Tradicionalmente, la formulación de productos alimenticios ha sido más un arte que una ciencia. Esto se debe a que muchos de los alimentos que se consumen habitualmente son el resultado de una larga y compleja historia. Sin embargo, la industrialización

Ultrasound as a Method to Control Protein-Polysaccharide Foam Stability by Microscopic Parameter Alteration

The objective of this work was to determine the effect of ultrasound application on the stability of foams of mixed systems of soy protein isolate and a hydroxypropyl methylcellulose called E4M at pH 7 and 3. It was used a soluble fraction of soy protein which is the responsible of functional properties in food applications. The pHs selected were used according to normally range in food meals. The samples were sonicated for 20 min using an ultrasonic processor Vibra Cell Sonics model VCX 750 at a frequency of 20 kHz and an amplitude of 20%. The foams were produced using a foaming instrument with a second CCD camera. The relative foam conductance (Cf%) and complementary parameters: half-life time, t½; relaxation times corresponding to the kinetics of liquid drainage, td; and disproportionation and collapse, tdc, were obtained. Significant differences were found for the relaxation times td and tdc at pH 7 as a consequence of the ultrasound treatment. It could be seen that ultrasound promoted a great increment of these relaxation times in these conditions, attributed to quantity of proteins at different pH.Fil: Martínez, Karina Dafne. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Carrera Sánchez, Cecilio. Universidad de Sevilla; Españ