Lecithin and phytosterols-based mixtures as hybrid structuring agents in different organic phases

In this study the effect of lecithin (L) addition and solvent quality in a well-established oleogel system formed by -sitosterol and -oryzanol (BG) was investigated. Medium chain triglycerides (MCT) and sunflower oil (SFO) were used as triglycerides and hexadecane (HEX) as a model of linear hydrocarbon. Lecithin was proposed due to its natural and versatile properties, showing different functionalities such as emulsifier and co-oleogelator. A study based on hierarchical organization of structured oil was performed applying techniques for bulk, meso and nanoscale. Self-sustained structures could no longer be observed after 40wt% of BG replacement by lecithin. Small-angle X-ray scattering showed that the formed nanostructures (building blocks) were dependent on type of solvent and BG:L ratio in the mixture of oleogelators. Differential scanning calorimetry showed that stability against temperature was improved decreasing the polarity of the oil, and a time-dependent self-assembly of hybrid systems was observed from thermal and rheological measurements. Microscopy images exhibited changes on typical fibril aggregation of BG as lecithin was added, which promoted to a certain extent the suppression of ribbons. Oscillatory shear and uniaxial compression measurements were influenced by BG:L ratio and solvent mainly at higher lecithin amount. The combination of BG and MCT appeared to be the most affected by lecithin incorporation whereas SFO rendered harder oleogels. These results could contribute to understand the role of both lecithin and solvent type influencing the host oleogelator structure. It was hypothesized that intermolecular BG complex formation is hindered by lecithin, besides this phospholipid also might coexist as a different phase, causing structural changes in the gel network. Addressing the role of co-oleogelator it can provide the opportunity to tune soft materials with adjusted properties.Paula Kiyomi Okuro thanks to CNPq (159180/2013-9) and São Paulo Research Foundation (FAPESP) grant #2015/24912-4 and 2016/ 10277-8, for the PhD fellowship; Rosiane Lopes Cunha thanks CNPq (307168/2016-6) for the productivity grant. The authors also thank the Brazilian Synchrotron Light Laboratory (LNLS) for the opportunity to use SAXS1 (proposal number 20160277 and 20170297) beamline and Tsuno Rice Fine Chemicals Co., Ltd. for the donation of gamma oryzanol samples. We thank the access to equipment and assistance provided bytheLaboratory ofProcessEngineering, Department ofFood Engineering, Faculty ofFood Engineering at the University of Campinas co-funded by FAPESP (96/08366-5, 2004/08517-3, 2006/03263-9, 2007/58017-5, 2011/06083-0).info:eu-repo/semantics/publishedVersio

Perspective on oleogelator mixtures, structure design and behaviour towards digestibility of oleogels

The concepts of either multi-component supramolecular gels or structures derived from oleogels have not yet been fully investigated to their respective potentials. The study of hybrid structures might cover technological points such as (i) how to vehiculate hydrosoluble and/or liposoluble bioactive components simultaneously? (ii) How could the framework of an oleogel contribute to a specific structure design strategy? (iii) How does oleogels structure influence bioactivity during digestion? A deeper understanding of these issues widens the range of opportunities foreseen for oleogel applications in food matrices. This paper presents the most relevant developments in the field, including the role of ingredients on structured oil-based systems. The authors perspective towards digestibility of oleogels and oleogel-derived structures is also addressed.Paula Kiyomi Okuro thanks FAPESP (grant #2018/20308-3 São Paulo Research Foundation -FAPESP). Rosiane Lopes Cunha thanks CNPqBrazil (307168/2016-6) for the productivity grant.info:eu-repo/semantics/publishedVersio

Tuning phytosterols-based oleogels properties by soybean lecithin addition in different organic phases

info:eu-repo/semantics/publishedVersio

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

Encapsulation of active pharmaceutical ingredients in lipid micro/nanoparticles for oral administration by spray-cooling

Nanoencapsulation via spray cooling (also known as spray chilling and spray congealing) has been used with the aim to improve the functionality, solubility, and protection of drugs; as well as to reduce hygroscopicity; to modify taste and odor to enable oral administration; and many times to achieve a controlled release profile. It is a relatively simple technology, it does not require the use of low-cost solvents (mostly associated to toxicological risk), and it can be applied for lipid raw materials as excipients of oral pharmaceutical formulations. The objective of this work was to revise and discuss the advances of spray cooling technology, with a greater emphasis on the development of lipid micro/nanoparticles to the load of active pharmaceutical ingredients for oral administration.This research was funded by the Portuguese Science and Technology Foundation (FCT/MCT) and European Funds (PRODER/COMPETE), under the project reference UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020, granted to Eliana B. Souto. This work was also supported by the National Science Centre within the MINIATURA 4 for a single research activity carried out by Aleksandra Zieli ´nska (grant no: 2020/04/X/ST5/00789), and by the Institute of Human Genetics, Polish Academy of Sciences by the internal grant for the implementation of a single scientific activity.info:eu-repo/semantics/publishedVersio

Flaxseed gum-biopolymers interactions driving rheological behaviour of oropharyngeal dysphagia-oriented products

Viscosity-modified diet through thickeners is used as a strategy to circumvent swallowing problems by oropharyngeal dysphagia patients. Most commercial products present xanthan and starch in their formulations, but flaxseed gum (FG) is a potential thickener for liquid food that provides additional health benefits. FG was mixed either with modified starch (MS) and/or xanthan gum (XG), varying biopolymersâ concentration according to a central composite rotational design in which rheological and colour properties in water were the evaluated responses. All formulations showed a shear time-independent and shear-thinning behaviour, mainly influenced by XG and MS concentrations. In oscillatory measurements, the formulations presented a prevailing elastic character attributed to MS and mainly to XG, which despite the lower concentration in which it was incorporated, exerted a similar influence on this rheological property. However, the increase of FG concentration was the most significant factor influencing viscosity, but also favoured an increase of both viscoelastic moduli mainly G'. Analysis of the microstructure disclosed different network structures as a result of biopolymers interactions, which was related to rheological behaviour giving insights to design new thickeners for dysphagia management. In addition, the amount of glucose released after in vitro digestion was evaluated and compared to a commercial MS-based thickener. Interestingly, the commercial formulation showed a glucose release significantly higher than the proposed FG/MS/XG-based formulations. These results open the opportunity to tailor the rheological characteristics of food systems by adding and combining natural ingredients, improving technological and nutritional properties.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) (Finance code 001); São Paulo Research Foundation - FAPESP (Process numbers 2016/05448–8; 2011/51707–1; EMU 2009/54137–1; 2007/58017–5; 2006/03263–9; 2004/08517–3) and by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq - Process 307168/2016–6). Okuro and Santos thanks São Paulo Research Foundation (FAPESP) (Grant numbers 2018/20308–3 and 2017/18109–0)info:eu-repo/semantics/publishedVersio

Association of severe hypertension with pneumonia in elderly patients with acute ischemic stroke

Pneumonia is one of the most frequent complications in elderly patients with acute ischemic stroke. Although severe hypertension is often observed in the early phase of acute stroke, there are few studies of acute hypertension as a factor influencing the incidence of stroke-associated pneumonia (SAP) in elderly subjects with acute ischemic stroke. To assess the association of acute phase blood-pressure elevation with the incidence of SAP, we compared 10 elderly patients with acute ischemic stroke complicated with severe hypertension (⩾200/120 mm Hg) with 43 patients with moderate hypertension (160–199/100–119 mm Hg), as well as with 65 control normotensive or mildly hypertensive (<160/100 mm Hg) controls on admission. Data were collected on known risk factors, type of ischemic stroke and underlying chronic conditions. The significance of differences in risk factors was analyzed using univariate and multivariate comparisons of 38 SAP cases and others, 8 SAP death cases and others, and 28 patients with poor outcome associated with in-hospital death or artificial feeding at discharge and others. After adjustment for potential confounding factors, the relative risk estimates for SAP, SAP death and poor outcome were 2.83 (95% confidence interval 1.14–7.05), 5.20 (1.01–26.8) and 6.84 (1.32–35.4), respectively, for severe hypertension relative to normotensive or mildly hypertensive controls. We conclude that severe hypertension on admission is an independent predictive factor for SAP in elderly patients with acute ischemic stroke