Browsing by Author "Henriques, Marta H.F."
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- Comparative evaluation of oranges available for consumption in PortugalPublication . Fajardo, Ana S.; Serra, Valéria; Peres, António M.; Veloso, Ana C.A.; Henriques, Marta H.F.Citrus production in Portugal, particularly in Algarve, plays a significant role in the national and European markets. Oranges from this region are highly regarded for their exceptional quality, due to unique climatic and geographical conditions. Many of these oranges hold the Protected Geographical Indication (PGI) "Citrinos do Algarve" certification, ensuring their authenticity and superior characteristics. While Algarve oranges dominate the market, other varieties also reach consumers, warranting a broader comparative analysis. This study aimed to compare 5 orange varieties, Baía, Dalmau, Navelate, Lane Late, and Salustiana, sourced from different regions, cultivation methods, and market sources. A versatile approach was used, combining physicochemical and sensory analyses, to determine their quality attributes. External properties (appearance, dimensions, and color) were measured along juice parameters such as total solids (TS), density, total soluble solids (SS) (°Brix), titratable acidity (TA), SS/TA ratio, and color. Sensory perception was assessed by an untrained panel evaluating aspects like appearance, taste, sweetness, and acidity. Additionally, an electronic tongue (E-tongue) was employed to detect and analyze chemical patterns associated with sweetness perception, ensuring precise and consistent results. Results showed all varieties except Dalmau had over 70% sensory acceptance, with scores exceeding 4.2 on a 7-point scale. Lane Late variety was the most favored among consumers, excelling in both external attributes and taste. Lane Late physicochemical analysis supported these preferences: pH of 3.53 ± 0.12, TA of 0.50 ± 0.12 g citric acid/100 g, SS of 12.14 ± 0.66 °Brix, and the highest SS/TA ratio of 22.99 ± 3.27, reinforcing its perceived sweetness. E-tongue analysis successfully distinguished flavor profiles. A classification model using 40 lipid sensor membranes achieved a 94.4% correct classification rate. The linear discriminant analysis (LDA) model, enhanced by the simulated annealing (SA) variable selection algorithm, efficiently separated the 5 orange cultivars. Two discriminant functions (DF1 accounting for 99.8% variability and DF2 for 0.10%) effectively differentiated the samples. The E-tongue's ability to detect and classify sweet and acidic sensations contributed to its strong predictive performance. This integrated analytical approach provided a comprehensive comparison of the sweetness profiles of oranges available in Portugal, blending objective and subjective evaluations. The study reaffirmed the superior qualities of Algarve oranges, with the PGI-certified Lane Late standing out. With an average diameter of 87.41 ± 3.76 mm, second only to Baía (92.14 ± 5.40 mm), and an intermediate peel thickness of 5.27 ± 0.58 mm, Lane Late demonstrated notable physical attributes. Its TS content (12.01 ± 0.72%) was close to Navelate (12.62 ± 1.49%), while it had the lowest ash content (0.38 ± 1.13%), reinforcing its distinctiveness.
- Comprehensive analysis of oranges available for consumption in Portugal: A comparative studyPublication . Fajardo, Ana S.; Serra, Valéria; Peres, António M.; Veloso, Ana C.A.; Henriques, Marta H.F.Citrus production in Portugal's Algarve region is a major economic activity, contributing to both local and national markets with exports primarily to Europe.
- Effect of extraction method on the bioactive composition, antimicrobial activity and phytotoxicity of pomegranate by-productsPublication . Campos, Lara; Seixas, Luana; Dias, Susana; Peres, António M.; Veloso, Ana C.A.; Henriques, Marta H.F.Pomegranate by-products can be an asset to the food industry due to the richness in bioactive and antimicrobial compounds. This work studied the influence of conventional solvent and sonication-assisted extraction methods on the bioactive profile, antimicrobial properties, and phytotoxicity effect of the peels and seeds extracts from Acco, Big Full, and Wonderful pomegranate cultivars. The bioactive composition of the extracts was evaluated for the content of total phenolics, total flavonoids, and antioxidant activity (expressed as the half-maximal inhibitory concentration— IC50) by spectrophotometric methods, while the tannins were determined by titration and the anthocyanins were estimated by the pH-differential method. For the evaluation of the antimicrobial activity, the disk diffusion method of Kirby-Bauer was adapted through inhibition halos against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and Yarrowia lipolytica. The extracts’ phytotoxicity was evaluated in vitro on garden-cress seeds. Extracts from conventional extraction were richer in total phenolics, expressed as gallic acid equivalents (0.16–0.73 mg GAE/mg extract), while those from sonication-assisted extraction had higher contents of total flavonoids, expressed as catechin equivalents (0.019–0.068 mg CATE/mg extract); anthocyanins, expressed as cyanidin-3-glucoside (0.06–0.60 g C3G/mg, dry basis); and antioxidant activity (IC50, 0.01–0.20 mg/mL). All extracts were more effective against Gram-positive bacteria and yeasts than Gram-negative bacteria. In general, the sonication-assisted extracts led to higher inhibition halos (8.7 to 11.4 mm). All extracts presented phytotoxicity against garden-cress seeds in the tested concentrations. Only the lowest concentration (0.003 mg/mL) enabled the germination of seeds and root growth, and the sonication-assisted extracts showed the highest Munoo-Liisa vitality index (51.3%). Overall, sonication-assisted extraction obtained extracts with greater bioactive and antimicrobial potential and less phytotoxicity.
- Pomegranate peels and seeds as a source of phenolic compounds: effect of cultivar, by-product, and extraction solventPublication . Campos, Lara; Seixas, Luana; Henriques, Marta H.F.; Peres, António M.; Veloso, Ana C.A.The nutraceutical properties of Punica granatum L. are not restricted to the edible portion of the fruit but also to the peels and seeds, flowers, leaves, and tree bark. The recovery and valorization of the peel and seeds (ca. 50% of the whole fruit), besides the positive environmental impact, can be viewed as a source of natural bioactive compounds. Thus, the bioactive properties of extracts of pomegranate peel and seeds from Acco and Wonderful known cultivars, as well as of the novel Big Full cultivar, were evaluated. The dried and ground pomegranate by-products were submitted to a conventional solid/liquid extraction with ethanol/water mixtures (0%, 25%, 50%, and 75% of EtOH, v/v). The obtained extracts were characterized in terms of total phenolic compounds (TPC), total flavonoids (TF), and antioxidant activity (AA), determined by the DPPH radical scavenging activity and expressed as IC50 (half maximum inhibitory concentration). With the exception of the Acco cultivar, the extraction yield (EY) was higher for peels, whose extracts showed higher TPC, TF, and IC50 (lower AA). The extracts obtained from the by-products of the Big Full cultivar had a statistically higher overall bioactive potential (TPC: 0.36 mg GAE/mg extract; TF: 0.031 mg CATE/mg extract; IC50: 0.51 mg/mL) compared to the other two studied cultivars. Furthermore, the EY was enhanced by solvents richer in ethanol (50-75%), allowing obtaining extracts richer in TPC and TF with higher AA. Finally, it was shown that EY combined with bioactive data allowed a satisfactory principal component unsupervised differentiation of the pomegranate extracts according to the type of by-product used.
- Pterospartum tridentatum liqueur using spirits aged with almond shells: chemical characterization and phenolic profilePublication . Garcia, Catia; Dias, Maria Inês; Henriques, Marta H.F.; Barros, Lillian; Ramos, FernandoWith great cultural significance, spirits and distillate beverages constitute an important niche market in Europe. The development of new food products, particularly for the functionalization of these beverages, is increasing exponentially. The present work aimed to develop a new wine spirit beverage aged with almond shells and flowers of P. tridentatum for further characterization of bioactive and phenolic compounds, coupled with a sensorial study to evaluate the acceptance of this new product by the market. Twenty-one phenolic compounds were identified, mainly isoflavonoids and O- and C-glycosylated flavonoids, especially in P. tridentatum flowers, indicating that it is a highly aromatizing agent. The developed liqueur and wine spirits (almonds and flowers) showed distinct physicochemical properties, with the last two samples showing greater appreciation and purchase intention by consumers due to their sweetness and smoothness. The most promising results were found for the carqueja flower, which should be further investigated in an industrial context to contribute to its valorization in its regions of origin, such as Beira Interior and Tras-os-Montes (Portugal).
- Valorisation of frozen chestnut by-products: technological challenges for the production of gluten-free flourPublication . Borges, Ana; Fonseca, Catarina; Carreira, Filipa; Rodrigues, Ivo; Henriques, Marta H.F.; Veloso, Ana C.A.; Peres, António M.The industrial process of freezing chestnuts generates 55–60% of by-products. This study aimed to valorise these low-value by-products by producing high-value chestnut flour. Two flour production processes were evaluated, using raw (RCF) and cooked (CCF10, CCF30, CCF50) chestnut by-products during 10, 30 and 50 min. The highest production yield was obtained for RCF (43.6 ± 1.0%) followed by CCF10 (38.0 ± 1.0%). Regarding flour composition, CCF50 presented the smaller protein, fat, fibre and ash contents (P < 0.05). For colour, aw, pH and sedimentation index, no significant differences were observed namely between RCF and CCF10 (P > 0.05). The CCF10 flour also presented the smallest particle size. The highest peroxide index was found in CCF50 penalizing its acceptance by consumers due to the evidence of rancidity, emphasizing that long time-periods of cooking must be avoided. Finally, up to 129 days of storage, under no temperature or lighting controlled conditions, all chestnut flours showed to be stable overtime.