Extraction and study of soybean soluble polysaccharide and its evaluation on the stability and rheology of soursop juice containing soy protein isolate

Orientador: Rosiane Lopes da CunhaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: As bebidas à base de soja são bastante susceptíveis à sedimentação devido à presença de proteína e baixo pH, sendo necessária a adição de gomas para sua estabilização. As propriedades funcionais dos polissacarídeos solúveis de soja (SSPS) podem variar dependendo da temperatura de extração e forma de secagem (liofilização ou atomização) desta macromolécula. Além disso, a sua utilização como estabilizante de proteínas em suspensões ainda é pouco explorada e não é de completo entendimento. Tendo isso em vista, este trabalho teve como primeiro objetivo caracterizar o SSPS obtido em três condições de extração e avaliar as suas propriedades reológicas em diferentes soluções. A caracterização físico-química mostrou que os polissacarídeos apresentaram valores distintos apenas para a umidade, devido ao método de secagem a que foram submetidos. No entanto, os valores de viscosidade intrínseca mostraram influência do pH no comportamento hidrodinâmico das moléculas, atuando de forma diferente para cada SSPS. Por outro lado, as medidas reológicas mostraram que o SSPS seco em condições mais brandas (liofilizado) apresentou os maiores valores de pseudoplasticidade e viscosidade em altas taxas de deformação quando comparado aos demais. Embora a caracterização dos polissacarídeos não tenha indicado diferença entre os mesmos, esses resultados poderiam ser relacionados a uma diferença estrutural quanto ao grau de esterificação das moléculas de cada SSPS e/ou diferença na massa molecular, explicando a diferença de comportamento observado. Apesar do SSPS liofilizado ter mostrado maior viscosidade, o polissacarídeo extraído a menor temperatura e seco por atomização foi escolhido para a realização da segunda parte deste trabalho em função de sua maior viabilidade de obtenção. Esta etapa teve como objetivo avaliar a influência do SSPS na estabilização de proteínas de soja em suco de graviola, através de análises reológicas e de estabilidade à sedimentação. Através de um planejamento experimental foi avaliada a influência da concentração de SSPS, de cloreto de cálcio e de isolado protéico de soja (IPS) na estabilidade e reologia das bebidas. As bebidas mostraram comportamento pseudoplástico e não foi observada influência de nenhuma variável nos valores de índice de comportamento (n), que se mantiveram em torno de 0,77. No entanto, o SSPS mostrou importante aumento da viscosidade em taxa de deformação próxima a zero (_0), o que levou ao aumento da estabilidade das soluções, diminuindo o índice de sedimentação. No entanto, ao elevar a taxa de deformação para valores próximos às condições de consumo (50s-1) o IPS tornou-se a única variável significativa no aumento desses valores. Os resultados desse trabalho mostram que o SSPS é um polissacarídeo eficaz no que diz respeito à estabilização de proteínas em suspensões sem no entanto alterar as características reológicas do sistema em condições de consumo, tornando-o um interessante ingrediente para utilização em bebidas à base de sojaAbstract: Soy based drinks are quite susceptible to sedimentation due the presence of proteins and low pH, requiring addition of food gums to stabilize them. The functional properties of soybean soluble polysaccharide can vary depending on the temperature of extraction and way of drying (freeze or spray dried) of this macromolecule. Moreover, its use as a protein stabilizer in suspensions is underexplored and is not complete understanding yet. With this in view, this work was characterize as a first objective, the SSPS extracted in three different conditions and evaluated their rheological properties in diverse solutions. Physicalchemical characterization showed different values for only the moisture, because the method of drying they have undergone. However, the intrinsic viscosity values showed influence of pH on the hydrodynamic behavior of molecules, acting differently for each SSPS. In addition, rheological measurements showed that the SSPS dried in soft conditions (freeze dried) showed highest values of shear thinning behavior and viscosity at high strain rates when compared to the others. Although the polysaccharides characterization has not indicated difference between them, these results could be related to a structural difference in the degree of esterification of each SSPS molecules and/or difference in the molecular weight, explaining the difference in behavior observed. Despite the SSPS freeze fried had higher viscosity, the polysaccharide extracted at lowest temperature and spray dried was chosen to carry out the second part of this work due to its higher viability of obtaining. This step was to evaluate the influence of SSPS in the stabilization of soy proteins in soursop juice, through rheological and stability to sedimentation analysis. Through an experimental design was evaluated the influence of SSPS, calcium chloride and soy protein isolate (IPS) concentration in the stability and rheology of drinks. Beverages showed shear thinning behavior and no apparent influence of any variables in the index of behavior (n) values, which remained around 0.77. However, SSPS showed significant increase in the viscosity at rest (_0), which led to increased of the solutions stability, reducing the sedimentation rate. Besides, at strain rate close to the conditions of consumption (50s-1) IPS become the only significant variable in the increase of these values. The results of this study show that SSPS is a polysaccharide effective at stabilizations of proteins in suspensions, but without altering rheological characteristics of the system in terms of consumption, making it an interesting ingredient for use in soy beveragesMestradoMestre em Engenharia de Alimento

Bigels as a vehicle for bioactives compounds: assessment of in vitro digestion behavior

Bigels are novel complex biphasic systems composed by organic and aqueous gelled phases that can act as texture modifiers, and vehicle for topical and gastrointestinal delivery of hydrophilic/lipophilic bioactives. However, its behavior through digestion has still not been assessed. Moreover, process conditions can change their structure and consequently the bioactive stability and release. Thus, the aim of this work was to evaluate the influence of the process on bigels structure and behavior through gastrointestinal tract. Bigels were produced with gellan gum hydrogel (1.25% w/w) and high oleic sunflower oil+glycerol monostearate (10% w/w) organogel loaded with 0.1% curcumin. Gelling agents were solubilized separately (80 °C, 30 min) and then mixed by cold or hot-emulsification method. Cold-set was carried out mixing gelled systems by mechanical stirring (50 °C, 1,000 min-1, 10 min). Hot-emulsification was performed with addition of 2% (w/w) Tween 80 by mechanical stirring (same conditions) or rotor-stator device (50 °C, 14,000 min-1, 2 min). Bigels were submitted to an in vitro gastrointestinal digestion using the harmonized digestion method, and changes were assessed through fluorescent microscopy. At the end of digestion, free fatty acids (FFA) released and bioaccessibility and stability of curcumin were determined. Cold-set bigels showed W/O structure while hot-emulsification led to W/O bigels with smaller droplets when rotor-stator was used. The results from the in vitro digestion indicated that all bigels were stable after stomach conditions, however, they destabilized during intestinal conditions. Besides, O/W bigels showed higher stability with less droplets coalescence, due to the surfactant presence. FFA and curcumin stability followed the same tendency, with higher values for O/W bigels. However, despite the higher stability, the effective bioavailability was similar for all bigels produced. Thus, independent of the structure and physical properties, bigels could be used for protection and oral delivery of hydrophobic bioactives and are promising systems for concomitant hydrophilic/hydrophobic loading.FCTCOMPETE 2020NORTE 2020This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Production of olive oil organogels: influence of beeswax concentration on physicochemical properties

This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.The author Pedro Silva is the recipient of a fellowship (SFRD/BD/130247/2017) supported by Fundação para a Ciência e a Tecnologia, (FCT, Portugal). Artur Martins is the recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Modulation and characterization of wax-based olive oil organogels in view of their application in the food industry

Olive oil has recognized health benefits but lacks structural resilience to act in a similar fashion as do the typically used triglycerides (TAGs) when applied in food manufacturing. Therefore, olive oil structuring is critical to widening its use as a healthier alternative in spreadable products. Foreseeing the development of an application for the food industry, three types of natural waxes were used as organogelators, generating olive oil organogels with distinct properties. Retail-simulated storage conditions were used to mimic real-life industrial and commercial use. Organogel systems were evaluated according to their oxidation stability and textural and rheological properties. Textural and rheological parameters increased in response to increasing gelator concentration, while oxidation values (below 1.5 meq O2·kg−1) remained within legal limits. Organogels displayed similar textural properties to those of commercially available spreadable products, while displaying a low critical gelation concentration. In short, it was shown that tailoring the physicochemical properties of organogels towards specific applications is possible. The produced organogels showed similar properties to the ones of commercially available spreadable products, revealing favourable oxidative profiles. Therefore, an industrial application can be easily foreseen, building on the natural characteristics of olive oil as a healthier alternative to current spreadable products.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte. The author Pedro Silva is the recipient of a fellowship (SFRD/BD/130247/2017) supported by Fundação para a Ciência e a Tecnologia, (FCT, Portugal). Artur Martins is the recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020—Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Production of olive oil organogels: Influence of candelilla wax concentration on physicochemical properties

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Digestibility of organogels produced with medium- and large- chain triacylglycerols

The structure of organogels depends on the organogelator and the type of oil used, exerting influence on the release profiles of bioactives in the gastrointestinal system. So, the aim of this work was to produce gels using medium-chain triacylglycerols (OMCT) or high oleic sunflower oil (large-chain triacylglycerols – OLCT), glycerol monostearate as organogelator and β-carotene as bioactive compound and evaluate its stability in the digestion in vitro. The static digestion of the organogels was performed and during the digestion, the gel structure, free-fatty acids (FFA) content and bioaccessibility of β-carotene were evaluated by fluorescent microscopy, NaOH titration and spectrophotometry methods, respectively. In the gastric step the gel structure remains almost intact without bioactive release, but some fluid incorporation was visually observed. In the duoden the bile salts in conjunction with lipase interacted with the organogel, destroying the structure and forming micelles. A great number of small micelles was observed for OLCT, while for OMCT systems fewer and bigger droplets were observed due to the coalescence of the droplets that could indicate loss of structure. This is corroborated by the higher amount of FFA and almost all bioactive bioaccessibility of OMCT systems. In the jejun step the OMCT structure was completely destroyed, while for OLCT the number of micelles decreased but no coalescence was observed. Moreover, for OLCT the FFA content remains the same and decreased for OMCT. At the end (ileum), the OLCT droplets began to coalesce increasing their diameter. Thus, stronger organogel and more resistant to the gastrointestinal system was produced with LCT. However, this resistance did not allow the complete bioaccessibility of the bioactive that was observed for MCT. Results showed that it is possible to use organogels as vehicles for bioactives and the release can be controlled by the modification of the structure

Formation and evaluation of chitosan nanoparticles with antibacterial and emulsifying properties for food application

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Self-organizing structures of phosphatidylcholine in nonaqueous solvents: tailoring gel-like systems

In this paper, we investigated the role played by solvent type and additives (water [W] and citric acid [CA]) on the self-assembly of phosphatidylcholine (PtdCho) into gels. Soybean lecithin (L) served as the PtdCho source used in this study. Lecithin was combined with different oils: hexadecane (HEX), sunflower oil, and medium-chain triacylglycerol to explore its ability to form organogels. Among the solvents, only HEX was able to form a translucent self-sustainable gel with lecithin. It was found that the lower water solubility and viscosity of HEX favored gel formation. Small-angle X-ray scattering revealed different structures arisen from lecithin organization depending on the organic medium type. In addition, the gel properties of the L-HEX binary system were also tailored through inclusion of the primers W or CA. Oscillatory rheological behavior of organogels was effectively described by a single relaxation-time Maxwell model, with good fitting at low and intermediate frequencies and with deviations at higher frequencies, indicating the presence of reverse wormlike micelles. Organogels were thermoreversible and, upon CA addition, a substantial increase in zero-shear viscosity was observed. Incorporation of W led to a similar microstructure to that obtained only with L, whereas CA promoted a different ordering of PtdCho assemblies. Formation and properties of PtdCho-based organogels were dictated by using different oil types or by changing the polarity of the medium with the incorporation of primers. A better understanding of phospholipid-based nonlamellar mesophases in organic solvent offers the prospect of adapting the gel properties to the desired application and functionality.Paula Kiyomi Okuro thanks to grant#2015/24912-4; 2016/10277-8 and 2018/20308-3, S~ao PauloResearch Foundation (FAPESP) and CNPq (159180/2013-9);Rosiane Lopes Cunha thanks CNPq (307168/2016-6) for the productivitygrant. Authors want to thank Dr. Ashok R. Patel for his scientific inputsand Dra. Ana Paula Badan Ribeiro for the fatty acid composition analysis.The authors thank the Brazilian Synchrotron Light Laboratory (LNLS) forthe opportunity to use SAXS 1 (Proposal: 19015) beamline. We thank theaccess to equipment and assistance provided by the Laboratory of ProcessEngineering, Department of Food Engineering, Faculty of Food Engineer-ing at the University of Campinas co-funded by FAPESP (96/08366-5,2004/08517-3, 2006/03263-9, 2007/58017-5, 2011/06083-0). This studywas alsofinanced in part by the Coordenaç~ao de Aperfeiçoamento dePessoal de Nível Superior—Brasil (CAPES)—Finance Code 001.info:eu-repo/semantics/publishedVersio

Modelling whey protein gelation under ohmic heating - effects of electric field strength, frequency and heating kinetics

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