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- Antioxidant activities, distribution of phenolics and free amino acids of Erica australis L. leaves and flowers collected in Algarve, PortugalPublication . Nunes, Ricardo; Carvalho, Isabel Saraiva deLeaves and flowers from Erica plant possess nutritional and medicinal properties. We determined the antioxidant activity, phenolic, flavonoid and amino acid profiles of the leaves and flowers of this plant. Total amino acid content varied from 28 to 49 and essential amino acids from 8 to 20mg/g for flowers and leaves, respectively, with different distributions within the plant. From 16 phenolic compounds identified, delphinidin-3-glucoside, caffeic acid and cyanidin-3,5-glucoside in leaves and pelargonidin-3,5-glucoside in flowers were the compounds in highest amount, all with over 500g/g. Although flowers had higher contents of phenolic compounds (4000g/g) than leaves (3400g/g), they showed lower antioxidant activity, indicating that the antioxidant activity depends not only on the content of phenolics, but also on their type. This study shows that this plant has the potential to be used as an extra dietary source of amino acids and phenolic compounds and its consumption may provide health benefits.
- Evaluation of proximate composition, antioxidant properties, and phylogenetic analysis of two edible seaweedsPublication . Rathinam, Raja; Hemaiswarya, Shanmugam; Sridhar, Sekaran; Alagarsamy, Arun; Ganesan, Venkatesan; Elumalai, Sanniyasi; Carvalho, Isabel S.The present study was evaluated for the proximate composition (moisture, carbohydrate, protein, and lipid contents) of two seaweedsGracilaria corticata(Rhodophyceaen) andHalimeda opuntia(Chlorophycean). Phylogenetic analysis based on the SSU (small subunit) rRNA ascertained their molecular identification. The results showed that the carbohydrate (5.72 +/- 0.05 g/100 g), protein (42.38 +/- 0.08 g/100 g), and total lipids (10.09 +/- 0.06 g/100 g) are elevated inG. corticatawhen compared toH. opuntia. H. opuntiahad a protein content of 3.51 +/- 0.072 g/100 g and higher moisture content (95 +/- 0.45 g/100 g). The methanolic extracts ofG. corticataandH. opuntiawere used to examine the antioxidants (viz. TPC, TFC, DPPH, and FRAP) and antidiabetic (alpha-glucosidase) properties. The antioxidant results of the methanolic extract ofG.corticataexhibited a higher amount of phenolic compounds (13.37 +/- 0.01 mg GAE/g dry wt.) compared toH. opuntia. But in the case of flavonoids,H.opuntiacontained a slightly higher amount of quercetin equivalent 9.56 +/- 0.26 mg/g dry wt. In FRAP,H.opuntiashowed an elevated level (62.02 mg TE/g dry wt). DPPH scavenging activity in the seaweed extracts were recorded in the following order:H.opuntiaandG.corticata. The amino acid content ofH.opuntiawas 0.097 +/- 0.56 (mg/g) and 0.086 +/- 0.42 (mg/g) was recorded inG.corticata. [GRAPHICS.]
- Evaluation of oil composition of some crops suitable for human nutritionPublication . Carvalho, Isabel Saraiva de; Miranda, I.; Pereira, H.Interest in Canola, Cannabis, Sunflower, Cardoon and Safflower, was focused on the composition of the fat because of their growing importance for nutritional and pharmaceutical purposes. We have therefore begun the analysis and characterization of their fatty acids (FAs) in different oils extracted from those crops to obtain reliable data on their suitability for both human nutrition and industrial or pharmaceutical purposes. The oil content fluctuated from 243 g/kg for Cardoon, 327 g/kg for Cannabis, 358 g/kg for Safflower, 411 g/kg for Sunflower to 488 g/kg for Canola. The ratio of n-6 to n-3 and total unsaturated to total saturated fatty acids ranged from 1.8 to 78.6 and 4.0 to 12.9, respectively. All five crop oils contained a high concentration of unsaturated fatty acids, namely linoleic acid (LA) and linolenic acid (LNA), which are two of the main representative compounds, known as dietary essential fatty acids (EFA) because they prevent deficiency symptoms and cannot be synthesized by humans. They could be considered, per si, functional foods without any biochemical extra additions. Thus, we conclude that whole crop oils do not differ significantly in their FAs composition; consequently, all seem to be suitable for human nutrition after refined procedure.
- Microalgal omicas and their applicationsPublication . Hemaiswarya, Shanmugam; Raja, R.; Ravikumar, R.; Yogesh Kumar, A.; Carvalho, Isabel Saraiva deMicroalgae constitute a large and diverse group of unicellular phototrophic and heterotrophic organisms, which comprise the base of the food chain and are evolutionarily distinct from other species. They have emerged as a promising group in the production of bioproducts and biofuel, as well as for the remediation of effluents. Indigenous populations have used microalgae for centuries and the commercial application of microalgae has been extensively reviewed [1–4]. The efficiency of the microalgal production process depends on higher biomass, yield, productivity, and process robustness. These parameters highly depend on the host microorganism. Natural screening, mutagenesis, selection, bioprocess development, genetic engineering, and metabolic engineering strategies have been adopted to increase the metabolic capabilities of the host microorganisms [5]. Nevertheless, problems such as the accumulation of toxic intermediates or metabolic stress resulting in a decreased cellular fitness need to be solved. The lack of knowledge about the regulatory mechanisms of key enzymes and the complex relationships between genotype and phenotype are still barriers to the development of efficient cell factories. The overexpression, deletion, or introduction of heterologous genes in specific metabolic pathways does not always result in the desired phenotype. Recent remarkable innovations in platforms for omics-based research and application development have provided crucial solutions to these problems. A combinatorial approach using multiple omics platforms and the integration of their outcomes is now an effective strategy for clarifying the molecular systems that are integral to improving algal productivity.
- Phenolic composition and antioxidant capacity of six Artemisia speciesPublication . Carvalho, Isabel Saraiva de; Cavaco, Teresa; Brodelius, AnaThe aim of this work was to establish the antioxidant capacities and the polyphenolic profile of six different Artemisia species that could potentially be used in the human diet. A high-performance liquid chromatographic method coupled with photodiode-array detector was used to identify and quantify individual phenolic compounds of the Artemisia leaves. A total of 18 polyphenolic compounds were identified and quantified in Artemisia leaves, including hydroxybenzoic acids (4), hydroxycinnamic acids (5), flavonols (3), and catechins (2). It was observed that total phenolic content of A. annua and A. stelleriana leaves were significantly lower than the other four species. Ferulic and caffeic conjugates acids were the most dominant hydroxycinnamic acid and gallic acid and catechin were the most dominant hydroxycinnamic acid and catechins respectively. According to DPPH assays, the antioxidant capacity of A. arborescens spp., A. ludoviciana spp., A. oleandica spp. and A. princepts spp., were found to be higher (reflecting a 2-fold difference) than that of the other two species. Compared with those of major commercial leafy vegetables, leaves of Artemisia contain a higher content of flavonoids and phenolic acids, which provide significant health benefits and may be used as natural colorants.
- Efficiency of triple emitter source (TES) for irrigation experiments of horticultural cropsPublication . Beltrão, José; Jesus, S. B.; Silva, V.; Sousa, P. B.; Carvalho, Isabel Saraiva de; Trindade, D.; Rodrigues, M. H.; Machado, A.Triple emitter source TES experimental irrigation was designed. Three trickle laterals were connected together in order to form a triple joint lateral. Two of them and their emitters are connected to two tanks of stock solutions. The third lateral contains only fresh water. The emitters of the two solution lines have different and varying discharges to obtain several mixings of the two stock solutions. The third line is necessary to obtain constant water application rates for each trickling point along the lateral. This method was tested for several experiments involving the study of the combined effects of salinity and fertilizers on the yield function of horticultural crops, namely lettuce and cabbage. As concluding remarks, it was shown the high uniformity of the factor to be evaluated, through the use of Christiansen coefficient of uniformity distribution CUC, which value was always larger than 90%. Main advantage of this experimental design is its smaller experimental plots (reducing pollution and research costs).
- Quality and distribution of assimilates within the whole plant of lupines (L. albus And L. mutabilis) influenced by water stressPublication . Carvalho, Isabel Saraiva de; Ricardo, C. P.; Chaves, Maria ManuelaLupine crops (Lupinus albus and L. mutabilis) often experience water deficits during grain filling, thereby altering partitioning of assimilates. Water deficit, imposed at the beginning of seed production (15 days after anthesis, daa), brought about differences in assimilate partitioning and chemical composition within the whole plant. In both species, water stress (ws) was responsible for a significant decrease in plant water status and gas exchange. In spite of little effect on total biomass, leaf area was reduced for approximately half of the control treatment. The main effects of ws on chemical composition of different organs were a decrease in total oil and an increase in total soluble sugar content in leaves; an increase in both oil and soluble sugars in stems; and a decrease in total oil and total soluble sugar content in seeds. The data suggest that under ws conditions, imposed at flowering, lupine assimilates are stored in stems and pods and later retranslocated to the developing seeds.
- Antioxidant and free radical scavenging activities of different plant parts from two Erica speciesPublication . Nunes, Ricardo; Anastácio, Ana; Carvalho, Isabel Saraiva deAqueous extractions from two species of Erica consumed as infusions in several countries to heal ailments were investigated for their phenolic and flavonoid contents, along with antioxidant capacity and radical scavenging capacity using total antioxidant activity, ferric-reducing antioxidant power, reducing power, 1,1-diphenyl-2-picrylhydrazyl and 2-2'-azino-bis(3 ethylbenzothiazoline-6-sulfonic acid) radicals, respectively. Antioxidant properties and total phenolic content differed significantly among these plants. Aqueous extracts of leaves possessed, on average, the highest antioxidant capacity and phenolic content (34.09 ± 10.81 mg ascorbic acid equivalent/g dry weight and 30.59 ± 10.19 mg gallic acid equivalent/g dry weight, respectively) of all three plant parts. A significant correlation (r2 = 0.952) between antioxidant capacity and total phenolic content was found, indicating that phenolic compounds are the major contributors to the antioxidant properties of these plants. Upon application of hierarchical cluster analysis to the results obtained, leaves with flowers were grouped in one cluster, whereas branches remained in another cluster, showing little interference from the collection site or species factors.
- Mechanism of action of probioticsPublication . Hemaiswarya, Shanmugam; Raja, R.; Ravikumar, R.; Carvalho, Isabel Saraiva deThe modern diet doesn't provide the required amount of beneficial bacteria. Maintenance of a proper microbial ecology in the host is the main criteria to be met for a healthy growth. Probiotics are one such alternative that are supplemented to the host where by and large species of Lactobacillus, Bifidobacterium and Saccharomyces are considered as main probiotics. The field of probiotics has made stupendous strides though there is no major break through in the identification of their mechanism of action. They exert their activity primarily by strengthening the intestinal barrier and immunomodulation. The main objective of the study was to provide a deep insight into the effect of probiotics against the diseases, their applications and proposed mechanism of action.
- A realistic scenario on microalgae based biodiesel production: third generation biofuelPublication . Ananthi, V.; Raja, Rathinam; Carvalho, Isabel Saraiva de; Brindhadevi, Kathirvel; Pugazhendhi, Arivalagan; Arun, A.Microalgae are the widely employed sources of third generation biofuels, which attracted huge attention by the researchers of the present decade because of their great productivity with lipid content. But to date, the utilization of microalgae for renewable biofuel production is not considered economically viable. The various growth modes employed for microalgal cultivation, such as phototrophic, heterotrophic, mixotrophic, photo-heterotrophic has been compared and conferred in the current investigation. A wide variety of microalgal harvesting techniques that balance energy and economic sustainability is being carried out nowadays. Based on the culture employed, mode and conditions of microalgal cultivation, the choice of bioreactor differs like an open system or closed system bioreactor. This review discusses the basis, key challenges and the future perspective of present-day microalgal cultivation conditions regarding biomass and lipid production. Concurrently the impacts of cultivation mode, bioreactor used for lipid productivity to improve profitable microalgal biodiesel have also been summarized.