Evaluation of process conditions in the bigels production: a multivariate analysis

The 19th Gums & Stabilisers for the Food Industry Conference: Hydrocolloid MultifunctionalityBigels are complex biphasic gels, composed by the mixture of organogel and hydrogel. These systems have been exploited mainly due to their ability to act as vehicle for hydrophilic and lipophilic simultaneously, being very attractive for food, pharmaceutical and cosmetic applications. However, despite the increasing number of publications concerning the production and use of bigels in recent years, to our knowledge there are no papers evaluating the effects of process conditions on their properties. Thus, the aim of this work was evaluating the influence of the process variables on particle size, mechanical and rheological properties through multivariate analysis. For this purpose, organogelator and hydrocolloid concentration, organogel:hydrogel ratio and mixing speed were evaluated. At first, gellan gum hy drogels (1 % -1,5 % w/w) and glycerol monostearate and high oleic sunflower oil organogels (5 % –15 % w/w) were produced separately by solubilization at 80 ºC during 30 min. After gelation, they were mixed in a mechanica l stirrer at determined speed for 10 min. Bigels produced were evaluated through microscopy, rheological (frequency sweeps) and mechanical properties (spreadability, consistency, adhesiveness and cohesiveness). According to principal component analysis (PCA), the reduction of the analysis to a bivariate dimension was satisfactory. The first component (horizontal axis) explained almost 58 % and the second (vertical axis) 20 % of th e variability found in measured data. From the projection of variables, it was possible to confirm that consistency and spreadability of bigels are well correlated. These variable were mainly responsible for the variability of data along the horizontal axis as well as complex modulus (G*) that was positively correlated to them. On the other hand, tan delta (G ́ ́/G ́) and adhesiveness were negatively correlated with these variables. The second component was explained mainly by cohesiveness and particle size distribution that were oppositely correlated. These correlations were in agreement with structural arrangement of the bigels. In general, small particle size led to more cohesive systems, with higher viscous modulus (higher tan delta values) and consequently adhesiveness. On the other hand, higher complex modulus is related to stronger structures, which means higher consistency and spreadability. From the cases and variable overlapping it was possible to evaluate that the main variables were mixing speed and organogel:hydrogel ratio. Moreover, different groups were distinguished according to organogel:hydrogel ratio. However, it can be observed that there were synergistic effects among the other variables , which also influenced the physicochemical properties of the bigels and were responsible for the other 20% of variability. Thus, different physicochemical properties can be obtained by tuning the parameters involved in the bigels production process. Softer or harder gels, with higher or lower spreadability, bigger or smaller particles size distribution can be produced depending on the desired final product and applicationPortuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE - 01 - 0145 - FEDER - 000004 ) funded by the European Regional Development Fund under the scope of Norte 2020 - Programa Operacional Regional do Norte . This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the Project RECI/BBB-EBI/0179/2012(FCOMP-01-0124-FEDER-027462)info:eu-repo/semantics/publishedVersio

Development of beeswax oleogels and the influence of gelator concentration and oil type on their final properties

[Excerpt] Introduction: Concerns regarding food nutritional value, sensory attributes, and consumer health urge to get a valid and feasible answer. The use of food‐grade materials that guarantee gel‐like behaviour and address consumer needs is currently essential in food industry. Structuring edible oils (i.e. oleogels) can be the response for such challenge, offering a healthier alternative (e.g. replacing saturated and trans fats) with tailored functionalities (e.g. different melting behaviour). This work focused on how different types of oil phase – medium chain triglycerides (MCT) and long chain triglycerides (LCT) – influence the gelation process of beeswax and the properties of the organogels produced thereof. [...]info:eu-repo/semantics/publishedVersio

Structural and mechanical properties of organogels: Role of oil and gelator molecular structure

Supplementary data to this article can be found online at http://dx.doi.org/10.1016/j.foodres.2017.03.021.This work aims at evaluating the influence of oil and gelator structure on organogels' properties through rheological measurements, polarized microscopy and small-angle X-ray scattering (SAXS). Four different food-grade gelators (glyceryl tristearate GT; sorbitan tristearate ST; sorbitan monostearate SM and glyceryl monostearate - GM) were tested in medium-chain triglyceride and high oleic sunflower (MCT and LCT, respectively) oil phases. Organogels were prepared by mixing the oil phase and gelator at different concentrations (5, 10, 15, 20 and 25%) at 80 °C during 30 min. All organogels presented birefringence confirming the formation of a crystalline structure that changed with the increase of the gelator concentration. Through the evaluation of SAXS peaks it has been confirmed that all structures were organized as lamellas but with different d-spacing values. These particularities at micro- and nanoscale level lead to differences in rheological properties of organogels. Results showed that the oil type (i.e. medium- and long-chain triglyceride) and hydrophilic head of gelators (i.e. sorbitan versus glyceryl) exert influence on the organogels physical properties, but the presence of monostearate leads to the formation of stronger organogels. Moreover, gels produced with LCT were stronger and gelled at lower organogelator concentration than MCT.The authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project “BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes”, REF. NORTE-07- 0124-FEDER-000028 co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. The financial support of CAPES/FCT Project “Nanotechnological systems based in biocompatible ingredients: characterization, controlled release and in vitro digestion” (CAPES/FCT n° 348/13) and CNPq (Universal 479459/2012-6) are gratefully acknowledged. The authors also thank the Brazilian Synchrotron Light Laboratory (LNLS) for the opportunity to carry out SAXS measurements.info:eu-repo/semantics/publishedVersio

Emergent food proteins Towards sustainability, health and innovation

There is an increasing demand for alternative and sustainable protein sources, such as vegetables, insects and microorganisms, that can meet the nutritional and sensory pleasantness needs of consumers. This emergent interest for novel protein sources, allied with green and cost-effective processing technologies, such as high hydrostatic pressure, ohmic heating and pulsed electric fields, can be used as strategies to improve the consumption of proteins from sustainable sources without compromising food security. In addition to their nutritional value, these novel proteins present several technological-functional properties that can be used to create various protein systems in different scales (i.e., macro, micro and nano scale), which can be tailored for a specific application in innovative food products. However, in order for these novel protein sources to be broadly used in future food products, their fate in the human gastrointestinal tract (e.g., digestion and bioavailability) must be assessed, as well as their safety for consumers must be clearly demonstrated. In particular, these proteins may become novel allergens triggering adverse reactions and, therefore, a comprehensive allergenicity risk assessment is needed. This review presents an overview of the most promising alternative protein sources, their application in the production of innovative food systems, as well as their potential effects on human health. In addition, new insights on sustainable processing strategies are given.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic fundingof UID/ BIO/04469/2019 and UID/Multi/50016/2019 units and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte 2020-Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio