Browsing by Author "Pintado, M. M."
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- Acceptability of reengineered Hibiscus drinks by Senegalese consumersPublication . Monteiro, M. J.; Cisse, M.; Fliedel, G.; Bechoff, A.; Bouche, M.; Pallet, D.; Tomlins, K.; Ayessou, A.; Costa, A. I. A.; Pintado, M. M.Bissap is a non-alcoholic drink commonly consumed in African countries, particularly in Senegal. It is made from Hibiscus sabdariffa L. - an herbaceous plant belonging to the Malvaceae, most often from its Ordinary/Kor (Senegal) and/or Vimto (Sudan) varieties. Past research has shown that Hibiscus drinks are generally rich in vitamins, minerals and bioactive compounds. These drinks are amongst the products investigated by AFTER, an EU FP7-funded research project aiming at the production of good quality (nutritional and sanitary) and extended shelf-life products of African tradition for local and European markets. A previous AFTER study on the acceptability of four traditional Hibiscus drinks by a sample of Senegalese consumers uncovered significant effects of plant variety and processing method. This highlighted the importance of harmonizing the sensory profile of these drinks as part of the product re-engineering process, and re-assessing their acceptability amongst the Senegalese population. In view of this, three new Hibiscus (50% Kor and 50% Vinto) drinks – an infusion, a syrup and a vacuum-concentrate – were developed by AFTER researchers. Their sensory quality was evaluated, alongside that of a traditional infusion (baseline), by a sample of 156 Senegalese in Dakar in October-November of 2013. Consumer profiling techniques based on hedonic acceptance, Just-About-Right intensity evaluation of specific descriptors (JAR) and Check-All- That-Apply questions with sensory and emotional descriptors (CATA) were used to establish sensory profiles and preference maps. Descriptors and other relevant evaluative information were obtained through two exploratory focus groups.Results show that the new Hibiscus drinks all had better acceptability than the baseline. Moreover, three distinct types of Senegalese consumers were identified: baseline dislikers, who liked all drinks except traditional one; overall likers; new Infusion dislikers. Finally, multiple factor analysis of overall liking scores, JAR ratings and CATA answers yield highly convergent results for all the drinks evaluated.
- Antimicrobial activity of an anthocyanin rich blueberry extract, purified using SPEPublication . Silva, S.; Costa, E. M.; Morais, R. M.; Pintado, M. M.
- Bacterial nanocellulose membranes loaded with vitamin B-based ionic liquids for dermal care applicationsPublication . Chantereau, G.; Sharma, M.; Abednejad, A.; Vilela, C.; Costa, E. M.; Veiga, M.; Antunes, F.; Pintado, M. M.; Sèbe, G.; Coma, V.; Freire, M. G.; Freire, C. S. R.; Silvestre, A. J. D.The development of innovative bio-based skin care products has received an increase attention in the latter years. In the present work, the synthesis of original active principle ingredients based ionic liquids (ILs) with cholinium cation and vitamins B anions followed by their incorporation in bacterial nanocellulose (BC) membranes for topical applications is reported. Three ILs, namely cholinium nicotinate [Ch][B3], cholinium pantothenate [Ch][B5] and cholinium pyridoxylate [Ch][B6], were synthesized through a metathesis reaction and their structure characterized in detail. Thermal analysis confirmed their denomination as ILs and their high thermal resistance. The solubility of these ILs was higher than their vitamin precursors, especially in the case of [Ch][B3] whose solubility increased 30.6-fold enhancing the bioavailability of this vitamin. The incorporation of ILs in BC led to transparent and homogeneous membranes stable up to 190 °C. ILs acted as plasticizers reducing BC brittleness that facilitated their application on irregular skin regions. Moreover, the re-hydration ability of BC-ILs membranes was improved 2.9 to 4.8-fold in comparison to BC, ensuring adequate hydration for ILs release, while the release of ILs in buffer solutions was more complete and faster than the release of vitamins. Finally, BC-ILs were proven not cytotoxic to skin epithelial cells and thus are suitable materials for skin care applications.
- Chitosan as an effective inhibitor of multidrug resistant Acinetobacter baumanniiPublication . Costa, E. M.; Silva, S.; Vicente, S.; Veiga, M.; Tavaria, F.; Pintado, M. M.Over the last two decades worldwide levels of antibiotic resistance have risen leading to the appearance of multidrug resistant microorganisms. Acinetobacter baumannii is a known skin pathogen which has emerged as a major cause of nosocomial outbreaks due to its capacity to colonize indwelling medical devices and natural antibiotic resistance. With chitosan being an effective antimicrobial agent against antibiotic resistant microorganisms, the aim of this work was to access its potential as an alternative to traditional antimicrobials in the management of A. baumannii growth. What the results showed was that both chitosan MW’s tested were active upon A. baumannii’s planktonic and sessile growth. For planktonic growth MICs and MBCs were obtained at relatively low concentrations (0.5–2 mg/mL) while for sessile growth chitosan proved to be an effective inhibitor of A. baumannii’s adhesion and biofilm formation. Considering these results chitosan shows a high potential for control of A. baumannii infections.
- Chitosan effect upon biofilm formation of multiresistant Staphylococcus aureus strainsPublication . Costa, E. M.; Silva, S.; Tavaria, F. K.; Pintado, M. M.
- Chitosan in oral health: a proof of conceptPublication . Costa, E. M.; Silva, Sara; Cardelle-Cobas, A.; Madureira, A. R.; Ferreira, M. O.; Tavaria, Freni K.; Pintado, M. M.Nowadays chitosan has established itself as a high sought material due to its biocompatibility, reduced toxicity and highpercentage of amino groups that confer it specific functionalities, including antimicrobial activity and acceleration of woundhealing, and studies into chitosan’s applicability have shown chitosan’s potential and feasibility. One of the possible fieldsof application for chitosan based products is the oral cavity, since several of the existing oral health products possesssecondary effects. The aim of this work was to prove that chitosan is a feasible component for oral health productsbiofabrication. As such a chitosan based mouthwash was developed and validated through assessment ofin vitroandin vivoantimicrobial activity, antibiofilm activity and sensory properties. The results obtained showed that it was possible tosuccessfully incorporate chitosan in an oral care product while retaining a considerable antimicrobial activity.In vitrotestingdemonstrated that the chitosan mouthwash possessed a wide range of antimicrobial activity against oral pathogens andwas capable of inhibiting microbial adherence and biofilm formation. Direct comparison with two commercial mouthwashesshowed that the chitosan mouthwash possessed stronger activity than both reference samples.In vivotesting showedthat the chitosan mouthwash was very effective in reducing enterococci and streptococci bacterial counts up to 30 min.after rinsing. Overall, the present shows a successful development of a chitosan-based product and is a tangible proof ofconcept for future utilization of chitosan in oral health.
- Chitosan mouthwash: toxicity and in vivo validationPublication . Costa, E. M.; Silva, S.; Costa, M. R.; Pereira, M.; Campos, D. A.; Odila, J.; Madureira, A. R.; Cardelle-Cobas, A.; Tavaria, F. K.; Rodrigues, A. S.; Pintado, M. M.A previous study showed that a chitosan mouthwash would be a valid alternative to current mouthwashesas it demonstrated, in vitro, significantly higher antibiofilm activity than two commercial mouthwashes.As such, the aim of this work was to verify the safety of the developed product and to validate, in vivo, thebiological activity ascertained in vitro. Chitosan mouthwash safety was evaluated through Ames, MTT andV79 chromosomal aberration assay while antimicrobial activity was evaluated through in vivo assays. Theresults showed that the chitosan mouthwash was safe, presenting lower cytotoxicity than a commercialmouthwash, and that it effectively reduced viable counts of Streptococcus spp. and Enterococcus spp. by ca.5.5 log of CFU. Furthermore, in direct comparison with a commercial mouthwash the chitosan mouthwashpossessed significantly higher antimicrobial activity. The conjunction of these results proves that thechitosan mouthwash is a safe, effective, natural alternative to the existent chemical mouthwashes.
- Chitosan nanoparticles as alternative anti-staphylococci agents: bactericidal, antibiofilm and antiadhesive effectsPublication . Costa, E. M.; Silva, S.; Vicente, S.; Neto, C.; Castro, P. M.; Veiga, M.; Madureira, R.; Tavaria, F.; Pintado, M. M.Chitosan is a biocompatible, bioactive, non-toxic polymer that due to these characteristics has been widely used as a carrier for targeted delivery of bioactive molecules. In recent years, and considering that chitosan has a strong antimicrobial potential, the scientific community's focus has shifted onto the possible antimicrobial activity of chitosan nanoparticles. With this in mind, the aim of this work was to produce low molecular weight chitosan nanoparticles, through the ionic gelation method and characterize their potential biological activity against three staphylococci (MSSA, MRSA and MRSE) in planktonic and sessile environments. The chitosan nanoparticles produced had an average size of 244 ± 12 nm, an average charge of 17.3 ± 1.4 mV and had a MIC of 1.25 mg/mL for all tested microorganisms. Bactericidal activity was only registered for MSSA and MRSA with the time-inhibition curves showing bactericidal activity within 1 h. Assays regarding chitosan nanoparticles' impact upon sessile populations showed that they were effective in preventing MRSE adhesion and highly effective in reducing MRSA and MSSA biofilm formation.
- Comparison of bioactive compounds in four blueberry cultivars throughout the years: selection of the best cultivars to be used in health promoting foodstuffsPublication . Silva, S.; Costa, E. M.; Coelho, M. C.; Pereira, M. F.; Costa, M. R.; Pintado, M. M.Blueberries are known as rich in phenolics and possessing a considerable antioxidant capacity. In recent decades, Portuguese blueberry production has increased greatly with several new blueberry producers appearing every year and, considering the amount of factors that can affect the overall fruit composition it is important to systematically study each matrix in order to understand the phenolic compounds profile, and therefore allow both the industry and consumers to maximize the potential benefits. Therefore the present work aimed to characterize four blueberry cultivars (representative of Portuguese blueberry production); Duke, Bluecrop, Goldtraube and Ozarkblue throughout a period of 3 years. Antioxidant activity, total phenolic compounds and anthocyanins were assessed. The results obtained illustrated, as could be expected, significant differences throughout the years studied for all parameters assessed, with values ranging from ca. 205 to 770 g of ascorbic acid equivalents per 100 g of fresh fruit for the total antioxidant capacity, ca. 115 to 630 g of gallic acid equivalents per 100 g of fresh fruit for the total phenolics content and ca. 56 to 263 mg of cianidin-3-glucoside equivalents per 100 g of fresh fruit for the total anthocyanin content. Despite the large variations, the cultivar Goldtraube proved to possess systematically higher contents of anthocyanins and antioxidants than all other cultivars though the same cannot be said for the total phenolics were, despite possessing higher values for 2 years, in both Duke and Bluecrop significantly higher content of phenolic compounds were observed. In conclusion, as it stands Goldtraube appears to be the better cultivar to be used in the development of blueberry based matrices and foodstuffs with higher potential health benefits.
- Consumers’ sensory perception and acceptability of Hibiscus drinks: a cross-cultural study in EuropePublication . Monteiro, M. J.; Costa, A. I. A.; Fliedel, G.; Bechoff, A.; Maraval, I.; Pintado, A. I. E.; Cisse, M.; Pallet, D.; Tomlins, K.; Pintado, M. M.Important differences can be observed between consumers from different countries due to the strong impact of culture on food preferences and acceptance, while a less important effect is usually expected in sensory perception. In the present study consumer’s sensory perception, preference and acceptability of Hibiscus drinks (an African functional drink rich in anthocyanins) were evaluated in three European countries: United Kingdom, France and Portugal. The drinks were developed under the scope of AFTER, an EU FP7-funded research project aiming at the production of improved quality and extended shelf-life products of African tradition for local and European markets. Hibiscus drinks are rich in nutrients and their consumption is widespread in Africa and Asia, but they still are quite unknown amongst European consumers. The sensory quality and acceptability of two Hibiscus drinks developed by AFTER researchers, as well as a traditional infusion prepared from Hibiscus flowers (baseline), were evaluated by 3 independent samples of consumers (France n=143; United Kingdom n=126; Portugal n=124) from March to June 2014. All factors concerning consumers’ socio-demographic profiles and materials were maintained as similar as possible. To gather evaluative relevant information and maximize the equivalence between questionnaires, exploratory local focus groups were held. Consumer profiling techniques based on hedonic acceptance, Just-About-Right intensity evaluation of specific descriptors (JAR) and Check-All-That-Apply questions (CATA) were used to establish sensory profiles and preference maps. Additionally, the chemical composition of the drinks was evaluated and a conjoint analysis was held to determine how consumers valued the composition and African origin of the drinks.Similar preference profiles for the Hibiscus drinks were obtained for the three countries but significant differences were observed in relation between consumers’ acceptance, with French consumers being generally the most appreciative. Importantly, these differences in acceptance were significantly correlated with the drinks sensory profiles and chemical composition.
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