Criação de valor com os resíduos e subprodutos alimentares

info:eu-repo/semantics/publishedVersio

Chitosan nanoparticles production: optimization of physical parameters, biochemical characterization, and stability upon storage

Ionic gelation is among the simplest processes for the development of chitosan nanoparticles reported so far in the literature. Its one‑shot synthesis process in conjunction with the mild reaction conditions required are among the main causes for its success. In this work, we sought to optimize a set of physical parameters associated with the ionic gelation process at two different pH values. Following that, the NPs’ freeze‑drying and long‑term storage stability were assayed, and their biocompatibility with HaCat cells was evaluated. The results show that NPs were more homogenously produced at pH 5, and that at this pH value, it was possible to obtain a set of optimum production conditions. Furthermore, of the assayed parameters, TPP addition time and overall reaction time were the parameters which had a significant impact on the produced NPs. Nanoparticle freeze‑drying led to particle aggregation, and, of the cryoprotectants, assayed mannitol at 10% (w/v) presented the best performance, as the NPs were stable to freeze‑drying and maintained their size and charge in the long‑term stability assay. Lastly, the chitosan NPs presented no toxicity towards the HaCat cell line.info:eu-repo/semantics/publishedVersio

Does the nature of added bioactive lipids affect the biological properties of yogurts? — Case study coconut and avocado oils

Bioactive lipids play an important role in human health and their benefits are linked to their chemical nature; for example, medium-chain fatty acids can have an important contribution to body weight management. This work aimed to test a strategy to enhance the quality profile and gastrointestinal tract resistance of previously developed vegetable oil-functionalized yogurts and further probe the biological potential of functionalized yogurts. Fortification with coconut and avocado vegetable oils led to increased nutritional value through an increase in essential fatty acids content, particularly in yogurts with vegetable oil bigels. One of the main problems with bioactive fatty acids fortification is their poor stability during in vitro digestion and consequently poor bioavailability. Despite this, the digested samples decreased lipid accumulation in Hep G2 and 3T3-L1 cells Functionalized yogurts were also responsible for high improvements in adiponectin secretion (35% for COY, 46% for CBY, 53% for AOY, and 48% ABY) compared with control yogurt. Moreover, in the inflammatory model, a reduction between 30% (for control yogurt) and 70% (for CBY) was observed for IL-6 secretion in LPS-stimulated cells. Considering these results, yogurt’s fortification with vegetable oils can be a viable alternative strategy to be scaled up for obesity management.info:eu-repo/semantics/publishedVersio

Insights into the antimicrobial potential of acorn extracts (Quercus ilex and Quercus suber)

Acorns, frequently left uncollected in the fields, have been a part of the traditional medicine of different cultures. Among the different properties associated with them, their antimicrobial potential is of particular importance. However, this characterization has long been superficial and has not ventured into other topics such as biofilm inhibition. Thus, the current work aimed to characterize the antimicrobial and antibiofilm potential of an array of phenolic rich extracts attained from acorns, two different acorn varieties Q. ilex and Q. suber, considering the fruit and shell separately, fresh and after heat-treating the acorns to aid in the shelling process. To accomplish this, the extracts’ capacity to inhibit an array of different microorganisms was evaluated, the minimum bactericidal concentration (MBC) was determined, time-death curves were drawn whenever an MBC was found and the antibiofilm potential of the most effective extracts was drawn. The overall results showed that Gram-positive microorganisms were the most susceptible out of all the microorganisms tested, with the shell extracts being the most effective overall, exhibiting bactericidal effect against S. aureus, B. cereus and L. monocytogenes as well as being capable of inhibiting biofilm formation via the two S. aureus strains. The attained results demonstrated that acorn extracts, particularly shell extracts, pose an interesting antimicrobial activity which could be exploited in an array of food, cosmetic and pharmaceutical applications.info:eu-repo/semantics/publishedVersio

Selective activity of an anthocyanin-rich, purified blueberry extract upon pathogenic and probiotic bacteria

Blueberry extracts have been widely recognized as possessing antimicrobial activity against several potential pathogens. However, the contextualization of the interaction of these extracts with beneficial bacteria (i.e., probiotics), particularly when considering the food applications of these products, may be of importance, not only because their presence is important in the regular gut microbiota, but also because they are important constituents of regular and functional foodstuffs. Therefore, the present work first sought to demonstrate the inhibitory effect of a blueberry extract upon four potential food pathogens and, after identifying the active concentrations, evaluated their impact upon the growth and metabolic activity (organic acid production and sugar consumption) of five potential probiotic microorganisms. Results showed that the extract, at a concentration that inhibited L. monocytogenes, B. cereus, E. coli and S. enteritidis (1000 μg mL−1), had no inhibitory effect on the growth of the potential probiotic stains used. However, the results demonstrated, for the first time, that the extract had a significant impact on the metabolic activity of all probiotic strains, resulting in higher amounts of organic acid production (acetic, citric and lactic acids) and an earlier production of propionic acid.info:eu-repo/semantics/publishedVersio

Anti-obesity potential of a yogurt functionalized with a CLNA-rich pomegranate oil

Pomegranate oil is rich in conjugated linolenic acids, compounds which have attracted attention due to their potential applicability in obesity management as they are capable of modulating leptin and adiponectin secretion and regulate fatty acids storage and glucose metabolism. Among the possible bioactive foodstuffs capable of delivering these bioactive compounds yogurts have shown potential. Thus, the purpose of this work was to develop functional yogurts through the addition of pomegranate oil either in its free or encapsulated (used as a protective strategy against oxidation and gastrointestinal tract passage) forms. To that end, the pomegranate oil (free and encapsulated) was incorporated in yogurt and the functional yogurt capacity to modulate hepatic lipid accumulation, adipocyte metabolism (in terms of lipolysis, and adipokines secretion) and immune response was evaluated. The results obtained showed that the pomegranate oil's incorporation led to an improvement in the yogurts' nutritional values, with a reduction in its atherogenic and thrombogenic indexes (more than 78% for atherogenic and 76% for thrombogenic index) and an enhancement of its hypocholesterolemic/hypercholesterolemic ratio (more than 62%) when compared to the control yogurt. Furthermore, data also showed for the first time how these functional yogurts promoted modulation of metabolic processes post GIT as they were capable of reducing by 40% triglycerides accumulation in steatosis-induced Hep G2 cells and by 30 % in differentiated adipocytes. Moreover, samples also showed a capacity to modulate the leptin and adiponectin secretion (56 % of increase in adiponectin) and reduce the IL-6 secretion (ca 44%) and TNF-α (ca 12%) in LPS-stimulated cells. Thus, the CLNA-rich yogurt here developed showed potential as a viable nutraceutical alternative for obesity management.info:eu-repo/semantics/publishedVersio

Antiadhesive and antibiofilm effect of malvidin-3-glucoside and malvidin-3-glucoside/neochlorogenic acid mixtures upon staphylococcus

Several reports on the biological activity of anthocyanin-rich extracts have been made. However, despite the association of said activity with their anthocyanin content, to the best of our knowledge, there are no previous works regarding the antimicrobial, antibiofilm and/or antiadhesive properties of anthocyanins alone. Therefore, the present work aimed to determine the effects of malvidin-3-glucoside, a major component of a previously reported extract, and the impact of its association with neochlorogenic acid (the only non-anthocyanin phenolic present in said extract), upon several Staphylococcus strains with varying resistance profiles. Results show that, while malvidin- 3-glucoside and malvidin-3-glucoside/neochlorogenic acid mixtures were unable to considerably inhibit bacterial growth after 24 h, they still possessed an interesting antibiofilm activity (with reductions of biofilm entrapped cells up to 2.5 log cycles, metabolic inhibition rates up to 81% and up to 51% of biomass inhibition). When considering the bacteria’s capacity to adhere to plain polystyrene surfaces, the inhibition ranges were considerably lower (21% maximum value). However, when considering polystyrene surfaces coated with plasmatic proteins this value was considerably higher (45% for adhesion in the presence of extract and 39% for adhesion after the surface was exposed to extract). Overall, the studied anthocyanins showed potential as future alternatives to traditional antimicrobials in adhesion and biofilm formation prevention.info:eu-repo/semantics/publishedVersio

Recovery of valuable aromas from sardine cooking wastewaters by pervaporation with fractionated condensation: matrix effect and model validation

Due to the lack of studies addressing the influence of real food matrices on integrated organophilic pervaporation/fractionated condensation processes, the present work analyses the impact of the real matrix of sardine cooking wastewaters on the fractionation of aromas. In a previous study, a thermodynamic/material balance model was developed to describe the integrated pervaporation—a fractionated condensation process of aroma recovery from model solutions that emulate seafood industry aqueous effluents, aiming to define the best conditions for off-flavour removal. This work assesses whether the previously developed mathematical model, validated only with model solutions, is also applicable in predicting the fractionation of aromas of different chemical families from real effluents (sardine cooking wastewaters), aiming for off-flavour removals. It was found that the food matrix does not influence substantial detrimental consequences on the model simulations, which validates and extends the applicability of the model.info:eu-repo/semantics/publishedVersio

Impact of vegetable oils on lacticaseibacillus rhamnosus and bifidobacterium animalis subsp. lactis growth

Introduction: Studies on bioactive lipids have been increasing in the last years due to their proven health benefits: positive impact on the prevention of cardiovascular disorders, on the development of cognitive function, and more recently on the control of body weight and diabetes. Consequently, the feasibility of their incorporation in new functional products has gained a greater interest in the food industry. Alongside the technological challenges, the antimicrobial activity of some of these oils may constitute a potential barrier for their incorporation, for example in fermented foods. Objective: Taking this into consideration, the aim of this work is the evaluation of the impact of different pomegranate, coconut, and avocado vegetable oils on Lacticaseibacillus rhamnosus and Bifidobacterium animal is subsp. lactis Bb12 growth. Methods: For this purpose, both bacteria were grown in MRS (normal growth media), and in MRS supplemented with each of the vegetable oils at 1.5 % (v/v). The impact on growth, organic acids production, and glucose consumption was evaluated. Results: The presence of either of the three vegetable oils did not affect the bacterial growth. Viable cell numbers reached 9.2 log CFU/mL and 8.1 log CFU/mL upon 24h of incubation for L. rhamnosus and B. animalis Bb12 respectively. For both bacteria, the presence of avocado and coconut oil appears to improve microbial growth. Acknowledgments: This work was supported by National Funds from FCT - Fundação para a Ciência e a Tecnologia through project UIDB/50016/2020. Manuela Machado is grateful for the financial support from FCT through the Doctoral grant reference SFRH/BD/136701/2018.info:eu-repo/semantics/publishedVersio