Universidade da Madeira
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Browsing Universidade da Madeira by Field of Science and Technology (FOS) "Ciências Agrárias::Biotecnologia Agrária e Alimentar"
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- Comparative analysis of antioxidant and fatty acid composition in avocado (Persea americana Mill.) fruits: exploring regional and commercial varietiesPublication . Gonçalves, David; Gouveia, Carla S. S.; Ferreira, Maria J.; Ganança, José F. T.; Pinto, Diana C. G.; Carvalho, Miguel A. A. Pinheiro de; Ganança, José Filipehytochemical and biochemical properties. Aiming to evaluate the antioxidant quality and fatty acid composi tion with a commercial avocado, flours were obtained from five varieties (four regional and one commercial Hass) across different tissues (pulp and by-products) and cycles (years and on-tree maturation stages). Results showed that a regional variety with thin purple skin had the highest antioxidant qualities and lipid content, surpassing the other regional and commercial Hass varieties. Oleic acid prevailed in all samples, with regional avocados containing arachidonic acid which is an uncommon occurrence among higher plants. Variations in fatty acid content were influenced by the timing of harvest. These outcomes highlight the promising potential of avocados from Madeira Island.
- Comparative analysis of biochemical and nutritional composition in regional and commercial varieties of avocado fruit (Persea americana Mill.)Publication . Gonçalves, João David Henriques; Carvalho, Miguel Ângelo Almeida Pinheiro de; Gouveia, Carla Susana SilvaAvocado (Persea americana Mill.) is a fruit native to Central America and lately figures as one of the most important and popular tropical fruits in the world due to its nutritional, biochemical and phytochemical characteristics. In order to evaluate the nutritional, antioxidant and fatty acid composition of four regional varieties and compare them to a commercial one, flours were obtained across different tissues (pulp and by-products) and harvest cycles (different years and on-tree maturation stages). The nutritional evaluation was carried out using seven parameters covered by crude protein, crude fiber, ash, soluble sugars, starch, lipids, and dry biomass. Was also performed physico-chemical (pH, TA, and color) and pigments (chlorophylls and carotenoids) parameters, and sensory analysis. Among the variability founded in all varieties, in these nutritional parameters, it was revealed the close association of the pulp with the lipid’s parameter, while the peel and seed associated to both crude fiber and starch, respectively. In general terms, the on-tree maturation (third harvest cycle) improved the quality of the analyzed parameters. In antioxidant analysis (TFC, DPPH, and lipids) the by-product exhibited more antioxidant capacity than the pulp, with “Roxa de Casca Fina” (RCF) surpassing the other regionals and commercial varieties in this analysis, especially in lipid content. The fatty acid profile was obtained by GC-MS, which was observed that oleic acid stands out as the major fatty acid founded in all samples, with regional avocados containing arachidonic acid which is an uncommon occurrence among higher plants. The variability found in these parameters were influenced by the timing of harvest but was notable the major quality of regional avocados in various parameters against the commercial one. This work outcomes highlight the promising potential of avocados from Madeira Island.
- Enrichment of bioactive compounds in microalgae for aquaculturePublication . Fernandes, Tomásia Micaela Gomez; Cordeiro, Nereida Maria Abano; Andrade, Carlos Alberto PestanaMicroalgae are promising microorganisms for the production of food and fine chemicals. Several species of microalgae are used in aquaculture with the purpose of transfer bioactive compounds up to the aquatic food chain. The main objective of this project was to develop a stress–inducement strategy in order to enhance the biochemical productivity of Nannochloropsis gaditana, Rhodomonas marina and Isochrysis sp. for aquaculture purposes having in account their growth and organizational differences. In this regard, two experiments were design: the first one consisted on the alteration of overall nutrient availabilities in growth medium; and the second one comprised changes in nitrogen and sulfur concentrations maintaining the concentrations of the other nutrients present in a commercial growth medium (Nutribloom plus), which is frequently used in aquaculture. Microalgae dried biomass was characterized biochemically and elemental analysis was also performed for all samples. In first experimental design: linear trends between nutrient availability in growth media and microalgae protein content were obtained; optimum productivities of eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) were attained for both R. marina and N. gaditana in growth media enriched with 1000 L L-1 of nutrient solution whereas for Isochrysis sp. the double of Nutribloom plus was needed; the decrease of glucans and total monosaccharides with nutrient availability for R. marina and Isochrysis sp. showed the occurrence of a possible depletion of carbohydrates towards lipids and proteins biosynthesis. Second experimental desing: N. gaditana exhibited the highest variation in their biochemical composition against the applied perturbation; variations observed for microalgae in their biochemical composition were reflected in their elemental stoichiometry; in N. gaditana the highest nitrogen concentrations lead to overall maximum productivities of the biochemical parameters. The results of the present work show two stress-inducement strategies for microalgae that may constitute a base for further investigations on their biochemical enhancement.
- Estudo da composição e das propriedades bioactivas de plantas produtoras de bagasPublication . Pinto, Joana Carolina Nunes; Castilho, Paula Cristina Machado FerreiraO consumo de frutas e vegetais tem sido associado à prevenção de várias doenças crónicas, nomeadamente doenças cardiovasculares, diabetes, cancro e outras que envolvam processos inflamatórios. As bagas destacam-se pelo seu elevado conteúdo em polifenóis, cujas propriedades antioxidantes contribuem para a manutenção da saúde humana. O presente trabalho teve como alvo de estudo as diferentes partes morfológicas (bagas e folhas) de espécies produtoras de bagas, nomeadamente Elaeagnus umbellata, a Rubus grandofolius, a Sambucus lancolata, a Vaccinium padifolium e a Vaccinium cylindraceum, tendo em vista a sua valorização como produtos alimentares e/ou nutracêuticos. A caracterização físico-química destas espécies permitiu determinar que o teor total de sólidos solúveis (TSS) das bagas varia de 4,4 a 16,5 °Brix. As bagas demonstraram ser a parte morfológica com teor de humidade mais elevado. A análise do perfil fenólico por HPLC-DAD-ESI/MSn, no modo negativo, dos extractos metanólicos mostrou que as folhas apresentam maior conteúdo de compostos fenólicos, comparativamente às bagas. Os ácidos hidroxicinâmicos (derivados dos ácidos cafeicos, cumárico e ferúlico), os ácidos cafeoilquínicos, bem como os flavonóis-O-glicosilados (derivados da quercetina e canferol) predominam nestas espécies. A análise pelo modo positivo permitiu a identificação de antocianinas glicosiladas (delfinidina, cianidina, petunidina, peonidina e malvidina) nas bagas e folhas jovens da espécie Vaccinium padifolium. Os ensaios in vitro de simulação da digestão gastrointestinal permitiram compreender a sua influência na actividade antioxidante dos extractos. Após a digestão, as folhas continuam a apresentar maior capacidade antioxidante do que as bagas. Adicionalmente, concluiu-se que as enzimas presentes neste processo têm menor influência do que o pH e a força iónica dos sucos digestivos. O estudo do efeito inibitório in vitro dos extractos sobre a actividade de enzimas responsáveis pelo metabolismo dos hidratos de carbono permitiu determinar que os viii Joana Pinto (2016) extractos foram mais eficientes na inibição da actividade da α-glucosidase do que na inibição da actividade da α-amilase.
- Evaluation of the effects of biostimulants on the Madeiran maize variety ‘Milho de Santana’ under drought conditionsPublication . Silva, Patrícia Raquel Abreu; Carvalho, Miguel Ângelo Almeida Pinheiro de; Jiménez Arias, DavidAnthropogenic activities are responsible for the emission of greenhouse gases into the atmosphere, which leads to an increase in their concentration and, therefore, an increase in temperature. Drought is one of the stressors that most disturb crop production. Biostimulants are eco-friendly substances and can be used to enhance stress tolerance. However, weekly treatments are needed to make them effective, which is disadvantageous for larger farms. One solution to overcome this problem is to use nanoencapsulation techniques to prevent degradation or provide controlled release of biostimulants. In this study, the ionotropic gelation technique was used to produce chitosan nanoparticles, which is fast, relatively cheap, and does not require expensive reagents and equipment, or organic solvents. In this study, L-pyroglutamic acid (LPGA) was used as the main biostimulant. The Madeiran maize variety called ‘Milho de Santana’ was subjected to drought. Well-watered (WW) plants with 100 % irrigation were compared to water-deficit (WD) plants under a 50 % irrigation. The following experimental variants were assessed: control (C), empty particle of chitosan (EP), entrapped biostimulant in chitosan particles (EBs), and free biostimulant (Bs). Hoagland’s nutrient solution and the experimental variants were directly applied to the soil. Five assays were performed: the first three to establish the experimental design and the last two to assess biostimulant action. Parameters such as soil water content, size of chitosan particles, peat microbe analysis, whole-plant biomass dry weight, root, aerial-part and whole-plant lengths, root stress index (SI), proline (Pro), total soluble sugars (TSS) in roots and aerial parts (stems and leaves), and correlations between these parameters were analysed. No significant differences (p < 0.05) were detected for most parameters, except for TSS in the roots and aerial parts. Sampling size, maize variability, difficulties in stress and irrigation reproducibility, among other reasons, may explain the obtained results.
- Evolution of staling aldehydes on lager beer stability: impact of maritime transport and storage condidtionsPublication . Aguiar, Dayana Nataly de Menezes; Marques, José Carlos Antunes; Pereira, Ana Cristina RebolaA estabilidade organolética da cerveja engarrafada é atualmente um dos principais desafios da indústria cervejeira. Não obstante à contribuição de inúmeras substâncias, os compostos carbonilos, em particular os aldeídos, são responsáveis por muitas das mudanças desfavoráveis e percetíveis ao consumidor. Estas modificações são favorecidas por temperaturas não refrigeradas, armazenamento durante períodos longos, vibrações induzidas pelo transporte, entre outros fatores. Atualmente, existem ainda poucos dados na literatura científica sobre o impacto das condições reais de transporte, nomeadamente impacto das vibrações e temperaturas não refrigeradas, na estabilidade organolética da cerveja. O presente trabalho teve como objetivo avaliar a evolução de 10 aldeídos em cerveja Lager engarrafada durante exportação por via marítima e armazenamento no destino. Para tal, simulou-se as condições reais que a cerveja produzida localmente é submetida, nomeadamente temperatura (19-30ºC), vibração (1.7 Hz) e tempo (até 120 dias). A análise dos compostos em estudo foi realizada por micro-extração em fase sólida seguida por cromatografia gasosa acoplada a espetrometria de massa. Os resultados obtidos revelaram que as condições de transporte (influência de tempo, temperatura e vibração) e armazenamento (tempo, temperatura) simuladas i) promoveram o aumento médio na concentração dos aldeídos de Strecker, de 65%, ii) enquanto os aldeídos formados a partir oxidação lipídica bem como o acetaldeído, regra geral, não apresentam variações significativas neste período. O aumento descrito em i) apresentou dois padrões: garrafas com abertura tradicional (carica) apresentavam valores médios de 131.6±9.9 e 190.3±9.4 µg/L enquanto garrafas com um sistema de abertura fácil 190.5±10.0 e 180.3±9.5 µg/L, após transporte e armazenamento respetivamente. O fenilacetaldeído foi o composto com maior variação nas condições estudadas, aumentando de 94.7±7.3 (cerveja fresca) para 143.6±8.0 e 168.9±8.9 µg/L, após transporte e considerando um período adicional de armazenamento, respetivamente. Adicionalmente, verificou-se que o procedimento de envelhecimento forçado tipicamente adotado, pode apresentar limitações a reproduzir as condições reais em alguns compostos. Em particular, destaca-se o benzaldeído, que em qualquer período de envelhecimento forçado, 7, 14 e 28 dias, apresentou concentrações, em média, inferiores, de 5.3±0.3 µg/L, 5.4±0.3 µg/L e 5.4±0.3 µg/L, respetivamente, em comparação com o teor real ao fim de 120 dias, de 6.4±0.4 µg/L.
- From Citrus Waste to a Promising Biopesticide: Hesperidin Extraction, Nanoformulation, and Bioactivity EvaluationPublication . Pereira, Verónica Raquel Sousa; Castilho, Paula Cristina Machado FerreiraBotanical pesticides have gained attention as potential biopesticides and complements to traditional pesticides. Flavonoids have been extensively studied for this purpose because of their involvement in plant defense responses. In particular, hesperidin (HES) is a glycosylated flavanone abundant in citrus waste, whose bactericidal and insecticidal activities have been reported. Despite its potential as a biopesticide, its extraction is usually time-consuming and nonselective, coupled with the use of organic solvents. Moreover, botanical pesticides have some limitations such as rapid biodegradability and low efficiency. The present master’s dissertation addresses these issues by proposing an innovative consecutive extraction scheme for pectin and HES from citrus albedo waste. This process describes a new HES extraction method using a basified hydroethanolic mixture, as well as a less time-consuming precipitation method. The efficiency, selectivity, and environmental impact of this method were compared with those of the conventional methanolic HES extraction. The proof of concept for assessing HES purity with quantitative nuclear magnetic resonance technique (qNMR), using benzoic acid as an internal standard, was addressed, along with the attempted HES encapsulation in polysaccharides. The developed consecutive extraction method allowed the extraction and isolation of two highly valued bioactive compounds from citrus waste with high reproducibility and efficiency, with HES extraction yields and purity reaching approximately 0.68% and 84% (determined by HPLC-PDA), respectively, under the best conditions tested (30 minutes, 70 °C, and 1:10 (w/v)). qNMR showed great potential for use in determining HES purity, but further optimization of the method is needed. Pectin-hesperidin nanoparticles formulated with a HES concentration of 0.5 mg/mL (HES-PecNPs 0.5) revealed satisfactory physicochemical properties (452.8 ± 22.1 nm and -16.9 ± 0.7 mV), an encapsulation efficiency of 85.0 ± 1.5%, and a controlled release of HES over 26h.
- Gelatin-based ballistic gel formulated with phytosynthesized nanocellulose from Arundo donax for alpha-amylase enzyme inhibition activityPublication . Jeevanandam, Jaison; Castro, Rita; Rodrigues, João; Castro, Rita; Rodrigues, JoãoArundo donax, an indigenous plant in the Mediterranean region, has affected the growth of native vegetation as an invasive plant, ultimately reducing soil quality and affecting the food chain in several areas of the world. Thus, the present work aims to obtain cellulose from the A. donax leaf extract via organosolv fractionation and bleaching method, followed by centrifugal fractionation to yield nanocellulose of moderately monodispersed (0.428 PDI) 91.2 nm in size and a zeta potential of -35.5 mV of high stability in aqueous medium (water). In addition, the resultant nanocellulose was formulated in ballistic gelatin hydrogel, and their antidiabetic effect via alpha-amylase enzyme inhibition activity was also investigated. Systematic characterization of the hydrogel samples (different volume ratios of gelatin and nanocellulose) revealed that the sample with 18:2 (v/v) gelatin: nanocellulose content is thermally stable until 152 ◦C, releasing nanocellulose for three days from hydrogel until 45 ◦C. This study confirms the feasibility and potential of utilizing invasive plant species to extract nanocellulose for medical purposes. Furthermore, the gelatin-formulated nanocellulose, with its demonstrated alpha-amylase inhibition activity at a dosage of 80 µg/mL, holds the promise of being a potential revolutionary medical gummy for sustained reduction of blood glucose levels.
- Madeira wine vinification process: analysis and controlPublication . Rodrigues, Pedro Marcelo Silva; Marques, José Carlos Antunes; Pereira, Ana Cristina RebolaThe present study was done in collaboration with J. Faria e Filhos company, a Madeira wine producer, and its main goal was to fully characterize three wines produced during 2014 harvest and identify possible improving points in the winemaking process. The winemaking process was followed during 4 weeks, being registered the amounts of grapes received, the fermentation temperatures, the time at which fermentation was stopped and evolution of must densities until the fortification time. The characterization of musts and wines was done in terms of density, total and volatile acidity, alcohol content, pH, total of polyphenol, organic acids composition, sugars concentration and the volatile profile. Also, it was developed and validated an analytical methodology to quantify the volatile fatty acids, namely using SPME-GC-MS. Briefly, the following key features were obtained for the latter methodology: linearity (R2=0.999) e high sensitivity (LOD =0.026-0.068 mg/L), suitable precision (repeatability and reproducibility lower than 8,5%) and good recoveries (103,11-119,46%). The results reveal that fermentation temperatures should be controlled in a more strictly manner, in order to ensure a better balance in proportion of some volatile compounds, namely the esters and higher alcohols and to minimize the concentration of some volatiles, namely hexanoic, octanoic and decanoic acids, that when above their odours threshold are not positive for the wine aroma. Also, regarding the moment to stop the fermentation, it was verified that it can be introduced changes which can also be benefit to guarantee the tipicity of Madeira wine bouquet.
- Multifaceted biological activities of culinary herbs and spices extracts on alzheimer´s disease prevention, focusing on in vitro and in silico molecular docking simulationsPublication . Gonçalves, Nance Carina Hontman; Gouveia, Rosa Maria de Sá Perestrelo; Câmara, José de SousaCulinary herbs and spices are commonly used worldwide, valued not only for flavor and odor but also for their medicinal and therapeutic benefits. These ingredients are composed of a broad spectrum of secondary bioactive metabolites, including polyphenols, terpenoids, and phytosterols, among others, which are involved in plant defenses against biotic or abiotic stresses, and also exhibit health-protecting or disease preventing effects associated to anticarcinogenic, anti-inflammatory, antioxidant, and cognitive-enhancing properties. This study aimed to establish the volatile fingerprint of culinary herbs (lemon verbena, chives, basil, sage, coriander, and parsley) and spices (curcuma, nutmeg, cumin, black pepper, Jamaica pepper, and juniper berry) using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS). The predominant volatile organic metabolites (VOMs) identified were subjected to in silico molecular docking simulations of anti Alzheimer (e.g., acetylcholinesterase (AChE), butyrylcholinesterase (BChE)), antioxidants (e.g., monoamine oxidase B (MAO-B), inducible nitric oxide synthase (iNOS)), and anti-inflammatory receptors (e.g., 5-lipoxygenase (5-LOX), cyclooxygenase-2 (COX-2)). The culinary herb and spice extracts were also subjected to in vitro assays to evaluate their potential as antioxidant (DPPH, ABTS, and ORAC) and anti-inflammatory (% protein denaturation) agents. A total of 121 VOMs were identified in the culinary herbs and spices, with the predominant chemical families being monoterpenoids (48.3%), sesquiterpenoids (14.0%), esters (11.9%), and carbonyl compounds (8.8%). In silico molecular docking simulations revealed that cuminaldehyde, β-caryophyllene, γ-curcumene, germacrene D, and τ-cadinol exhibited the strongest inhibitory activities against the selected receptors (AChE, BChE, MAO-B, 5-LOX, and COX-2). Among the extracts, Jamaica pepper showed the highest antioxidant and anti inflammatory activities, while lemon verbena exhibited the lowest antioxidant and anti inflammatory activities