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- Nutritional characterization of acorn flour (a traditional component of the Mediterranean gastronomical folklore)Publication . Silva, Sara; Costa, Eduardo M.; Borges, André; Carvalho, Ana Paula; Monteiro, Maria João; Pintado, M. E.Abstract Nowadays, acorns, the fruits of Quercus trees, are mostly associated with animal feed. However they are part of the traditional gastronomical folklore of severalMediterranean countries. Though several uses can be mentioned, one of the most common uses is powdering the acorns in order to produce a flour that can substitute regular corn flour in the manufacture breads and cakes. An example of this is acorn bread, a typical Portuguese loaf.However, to the best of our knowledge, there is no information about the nutritional value of these flours. As such, the main goal of this work was to describe the nutritional value of acorn flours from two different subspecies of Quercus abundant in Portugal (Quercus ilex and Quercus rotundifolia) obtained using two different traditional methods (drying and roasting). The results demonstrated that all flours possessed interesting nutritional properties, namely the absence of gluten and elevated values of both monounsaturated and polyunsaturated fatty acids. Because of these facts and it’s low production cost, acorn flour poses as an interesting alternative to traditional flours particularly for gluten intolerant individuals.
- Consumer acceptance and sensory profiling of reengineered kitoza productsPublication . Pintado, Ana I. E.; Monteiro, Maria João; Talon, Régine; Leroy, Sabine; Scislowski, Valérie; Fliedel, Geneviève; Rakoto, Danielle; Maraval, Isabelle; Costa, Ana I. A.; Silva, Ana P.; Pallet, Dominique; Tomlins, Keith; Pintado, M. E.Kitoza refers to a traditional way of preparing beef and pork in Madagascar. However, in order to improve some drawbacks previous identified, the product was submitted to a reengineering process. The acceptance and sensory profiling of improved Kitoza products among Portuguese consumers was investigated. A local smoked loin sausage was selected as basis for comparison. Firstly, a Focus Group study was performed to identify sensory descriptors for Kitoza products and explore product perception. Subsequently, a Flash Profile and a consumer sensory acceptance study were conducted. Flash Profile's results showed that beef- and pork-based Kitoza products investigated differed considerably in all sensory dimensions. The Portuguese sausage was characterized as having a more intense and lasting after taste, as well as displaying a higher degree of (meat) doneness. The acceptance study yielded higher overall liking ratings for pork- than for beef-based Kitoza, although the Portuguese sausage remained the most appreciated product.
- Study of antioxidant properties and consumer acceptance of sour cherry based jamsPublication . Costa, E.; Silva, S.; Monteiro, M.; Pintado, M.In recent years a major market trend has been the design of more natural foodstuffs with chemical constituents being replaced by natural compounds and ingredients. Sour cherry is a phenolic rich fruit that has already been incorporated into the food chain, namely through a Portuguese traditional liquor (Ginjinha), however other food matrices may be the carrier for this antioxidant fruit, but formulation and processing conditions may affect functionality and acceptability. With that in mind the goal of this work was to expand the incorporation of sour cherry into the food chain via development of novel sour cherry based recipes or foodstuffs, with the most promising one being sour cherry jams with reduced sugar content. From this work two formulations resulted, one with whole cherries and other with cherry pulp? These products where characterized in terms of antioxidant activity, phenolic compounds and anthocyanin profile and consumer acceptance. The results obtained through chemical and sensorial analysis of the two formulations showed that from a chemical standpoint the jams possessed significant antioxidant capacity with a high content of phenolic compounds, namely caffeic acid. Regretfully when considering the anthocyanin content due to the high temperature used during processing they were highly reduced. When considering the sensorial analysis of the two jams through a focus group, results showed that over 77% of the panellists liking both products, with their texture and sweet flavour being remarked as the strong points of both products. Furthermore 72% of the panellists stated their intention to buy the products. In conclusion the results obtained show that the developed products were market ready and that, despite the thermal treatment involved in their processing, both jams validated for consumption still maintained a significant level of biologically active compounds.
- Antimicrobial effects of chitosans and chitooligosaccharides, upon Staphylococcus aureus and Escherichia coli, in food model systemsPublication . Fernandes, João C.; Tavaria, Freni K.; Soares, José C.; Ramos, Óscar S.; Monteiro, M. João; Pintado, Manuela E.; Malcata, F. XavierThe objective of this study was to elucidate the controversial relationship between the molecular weight (MW) of chitosans and their antibacterial activity (upon different inoculum levels, at several concentrations). The influence of food components on the activity was also ascertained, as well as acceptance by a sensory panel. All the compounds tested exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli. This activity was shown to be closely dependent on the inoculum level, MW and concentration used. Within 4 h at 10³ cells/mL, all five compounds, at every concentration (0.5%, 0.25% and 0.1%, w/v), proved to be bactericidal; for higher inocula, 0.1% (w/v) was only bacteriostatic; at 107 or 105 cells/mL, and independently of the inoculum level, 0.25% (w/v) of any chitooligosaccharide (COS) mixture was sufficient to reduce the E. coli initial population by at least 3 log cycles; COS never exhibited bactericidal action over S. aureus, unlike high and medium MW chitosans—which, at 0.5% (w/v), presented a bactericidal effect even against 107 cells/mL. When incorporated in liquid food matrices, medium and high MW chitosans maintained their activity, for both matrices and bacteria, although a slower activity was noticeable in milk; however, COS lost their activity upon both bacteria in milk after 4–8 h. Furthermore, addition of chitosans to apple juice led to several unpleasant off-flavors, such as astringency and after taste—which increased in magnitude with MW.
- Validação de métodos para determinação de mercúrio e selenio em amostras alimentares e ambientais usando um sistema de fluxo multicomutado com detecção por EAAPublication . Silva, M. Fátima M. B.; Albino, Costa; Monteiro, Maria João; Tóth, Ildikó; Rangel, António O.S.S.
- Chemical and microbiological characterization of alheira: A typical Portuguese fermented sausage with particular reference to factors relating to food safetyPublication . Ferreira, Vânia; Barbosa, Joana; Vendeiro, Sandra; Mota, Ana; Silva, Fátima; Monteiro, Maria João; Hogg, Tim; Gibbs, Paul; Teixeira, P.Alheiras are traditional smoked naturally fermented meat sausages produced in the north of Portugal. They have not previously been characterized as to their chemical and microbiological status. pH and salt levels are insufficient to assure microbiological safety, there is ample opportunity for post-cooking contamination; the products require chill storage and cooking before consumption. Heavy metals and biogenic amines were, in general, within accepted limits for meat products. Lactic acid bacteria comprised the major microflora (ca. 7–8log cfu/g) with substantial counts of micrococci and enterococci (up to 7log cfu/g). Escherichia coli, Staphylococcus aureus and Listeria spp. were detected in several samples.
- Impact of whey protein coating incorporated with Bifidobacterium and Lactobacillus on sliced ham propertiesPublication . Pereira, Joana Odila; Soares, José; Monteiro, Maria João P.; Gomes, Ana; Pintado, ManuelaEdible coatings/films with functional ingredients may be a solution to consumers' demands for high-quality food products and an extended shelf-life. The aim of this work was to evaluate the antimicrobial efficiency of edible coatings incorporated with probiotics on sliced ham preservation. Coatings was developed based on whey protein isolates with incorporation of Bifidobacterium animalis Bb-12® or Lactobacillus casei-01. The physicochemical analyses showed that coating decreased water and weight loss on the ham. Furthermore, color analysis showed that coated sliced ham, exhibited no color change, comparatively to uncoated slices. The edible coatings incorporating the probiotic strains inhibited detectable growth of Staphylococcus spp., Pseudomonas spp., Enterobacteriaceae and yeasts/molds, at least, for 45 days of storage at 4 °C. The sensory evaluation demonstrated that there was a preference for the sliced coated ham. Probiotic bacteria viable cell numbers were maintained at ca. 108 CFU/g throughout storage time, enabling the slice of ham to act as a suitable carrier for the beneficial bacteria.
- Evaluation of drying and storage conditions on nutritional and sensory properties of dried galega kale (Brassica oleracea L. var. Acephala)Publication . Araújo, Ana C.; Oliveira, Sara M.; Ramos, Inês N.; Brandão, Teresa R. S.; Monteiro, Maria J.; Silva, Cristina L. M.This work evaluated the effect of the air-drying temperature and vacuum packaging on quality and nutritional compounds of dehydrated galega kale, previously steam blanched, during 5 months of storage. When compared with the vacuum packaged kale, the packaging without vacuum yielded improved nutritional features, in general. This approach combined with a drying temperature of 40°C resulted in retention percentages of 62, 38, 92, and 48% for vitamin C, total phenolic content, total antioxidant capacity, and chlorophylls, respectively. The acceptance of the dried product by the consumer was assessed through a focus group. The participants classified the product as a practical and convenient alternative to cook healthier dishes. The appearance of dried galega kale was described as being fragile and being with nice smell, natural colour, and flavour similar to the fresh product. In conclusion, the herein presented product was addressed as an innovation with multiple possible applications in several recipes.
- Chemical-sensory properties and consumer preference of hibiscus beverages produced by improved industrial processesPublication . Monteiro, Maria João P.; Costa, Ana Isabel A.; Fliedel, Geneviève; Cissé, Mady; Bechoff, Aurélie; Pallet, Dominique; Tomlins, Keith; Pintado, Maria Manuela E.The need to increase sustainability and add value to traditional foods claiming health benefits led to the introduction of key improvements in the production of hibiscus beverages in Senegal. The physicochemical and sensory properties of three resulting products (an under-vacuum concentrate, a dilute-to-taste syrup and a ready-to-drink infusion) were assessed, vis-à-vis those of conventionally manufactured beverages, and their impact on local consumer preference determined (n=146). New beverages had more intense, redder colour and higher monomeric anthocyanin content, total phenolic content and antioxidant capacity. Moreover, their colour evaluations by trained panellists were mainly linked to colour density and anthocyanin/polyphenol content, while flavour assessments were associated to titratable acidity and sugar-to-acid ratio. Consumer evaluations, in turn, were driven by the beverages' red colour intensity, aroma strength and balance between sweetness and acidity. This explained why they overwhelmingly preferred the under-vacuum concentrate, regardless of their age, gender or frequency of hibiscus beverage consumption.
- Functional characterisation and sensory evaluation of a novel symbiotic okara beveragePublication . Voss, Glenise B.; Monteiro, Maria João P.; Jauregi, Paula; Valente, Luísa M.P.; Pintado, Manuela E.This study aimed to produce four different beverages from okara (soybean by-product) previously hydrolyzed by Cynara cardunculus enzymes and fermented by probiotic bacteria or unfermented beverage. The probiotic viable cells, the isoflavones profile and organic acids were evaluated in the okara beverage. In addition, total phenolic content, antioxidant and ACE inhibitory activities were evaluated at storage time and during in vitro gastrointestinal digestion of all beverages. The probiotic was viable throughout storage in all fermented beverages. The significant bioconversion of the isoflavone glycosides into their corresponding bioactive aglycones was observed in fermented beverage. Furthermore, the beverages showed a good ACE inhibitory activity. After gastrointestinal tract, all beverages showed an increase in the antioxidant and ACE inhibitory activities. In conclusion, this study shows that the application of okara for a multifunctional beverage could be a promising strategy in the disease prevention and contribution to a zero waste approach in food industry.
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