Nutritional and biochemical profiling of Leucopaxillus candidus (Bres.) singer wild mushroom

The wild mushroom Leucopaxillus candidus (Bres.) Singer was studied for the first time to obtain information about its chemical composition, nutritional value and bioactivity. Free sugars, fatty acids, tocopherols, organic and phenolic acids were analysed by chromatographic techniques coupled to different detectors. L. candidus methanolic extract was tested regarding antioxidant potential (reducing power, radical scavenging activity and lipid peroxidation inhibition). L. candidus was shown to be an interesting species in terms of nutritional value, with high content in proteins and carbohydrates, but low fat levels, with the prevalence of polyunsaturated fatty acids. Mannitol was the most abundant free sugar and β-tocopherol was the main tocopherol isoform. Other compounds detected were oxalic and fumaric acids, p-hydroxybenzoic and cinnamic acids. The methanolic extract revealed antioxidant activity and did not show hepatoxicity in porcine liver primary cells. The present study provides new information about L. candidus.

Extraction, identification, fractionation and isolation of phenolic compounds in plants with hepatoprotective effects

The liver is one of the most important organs of human body, being involved in several vital functions and regulation of physiological processes. Given its pivotal role in the excretion of waste metabolites and drugs detoxification, the liver is often subjected to oxidative stress that leads to lipid peroxidation and severe cellular damage. The conventional treatments of liver diseases such as cirrhosis, fatty liver and chronic hepatitis are frequently inadequate due to side effects caused by hepatotoxic chemical drugs. To overcome this problematic paradox, medicinal plants, owing to their natural richness in phenolic compounds, have been intensively exploited concerning their extracts and fraction composition in order to find bioactive compounds that could be isolated and applied in the treatment of liver ailments. The present review aimed to collect the main results of recent studies carried out in this field and systematize the information for a better understanding of the hepatoprotective capacity of medicinal plants in in vitro and in vivo systems. Generally, the assessed plant extracts revealed good hepatoprotective properties, justifying the fractionation and further isolation of phenolic compounds from different parts of the plant. Twenty-five phenolic compounds, including flavonoids, lignan compounds, phenolic acids and other phenolic compounds, have been isolated and identified, and proved to be effective in the prevention and/or treatment of chemically induced liver damage. In this perspective, the use of medicinal plant extracts, fractions and phenolic compounds seems to be a promising strategy to avoid side effects caused by hepatotoxic chemicals.

Biotechnological, nutritional and therapeutic uses of Pleurotus spp. (Oyster mushroom) related with its chemical composition: A review on the past decade findings

The particular characteristics of growth and development of mushrooms in nature result in the accumulation of a variety of secondary metabolites, several of them with biological activities. The genus Pleurotus is a cosmopolitan group of mushrooms with high nutritional value and therapeutic properties, besides a wide array of biotechnological and environmental applications. Scope and approach: The present report aims to provide a critical review on aspects related to chemical compounds isolated from the genus Pleurotus with possible biotechnological, nutritional and therapeutic uses. Investigations on the genus have immensely accelerated during the last ten years, so that only reports published after 2005 have been considered. Key findings and conclusions: The most important Pleurotus species cultivated in large scale are P. ostreatus and P. pulmonarius. However, more than 200 species have already been investigated to various degrees. Both basidiomata and mycelia of Pleurotus are a great renewable and easily accessible source of functional foods/nutraceuticals and pharmaceuticals with antioxidant, antimicrobial, anti-inflammatory, antitumor and immunomodulatory effects. A series of compounds have already been precisely defined including several polysaccharides, phenolics, terpenes and sterols. However, intensification of structure determination is highly desirable and demands considerable efforts. Further studies including clinical trials need to be carried out to ascertain the safety of these compounds as adequate alternatives to conventional drugs. Not less important is to extend the search for novel bioactives to less explored Pleurotus species.

Non-fermented and fermented jabuticaba (Myrciaria cauliflora Mart.) pomaces as valuable sources of functional ingredients

abuticaba (Myrciaria cauliflora. Mart) is a highly perishable fruit native to Brazil, which is consumed both fresh and industrially processed in the form of juices, jams, wines and distilled liqueurs. This processing generates a large amount of waste by-products, which represent approximately 50% of the fruit weight. The by-products are of interest for obtaining valuable bioactive compounds that could be used as nutraceuticals or functional ingredients. In this study, fermented and non-fermented jabuticaba pomaces were studied regarding their hydrophilic and lipophilic compounds, as well as their antioxidant properties, including: soluble sugars, organic acids and tocopherols (using high performance liquid chromatography coupled to refraction index, diode array and fluorescence detector, respectively); phenolics and anthocyanins, (using liquid chromatography coupled to diode array detection, and mass spectrometry with electrospray ionization); and fatty acids (using gas-liquid chromatography with flame ionization detection). The analytical data demonstrated that jabuticaba pomaces are a rich source of bioactive compounds such as tocopherols, polyunsaturated fatty acids and phenolic compounds (namely hydrolyzable tannins and anthocyanins) with antioxidant potential. Therefore, jabuticaba pomace may have good potential as a functional ingredient in the fabrication of human foods and animal feed.

NUTRITIONAL AND AMINO ACID ANALYSIS OF RAW, PARTIALLY FERMENTED AND COMPLETELY FERMENTED LOCUST BEAN ( Parkia biglobosa ) SEEDS

The nutritional and amino acid analysis of raw and fermented seeds of Parkia biglobosa were carried out. Parameters investigated include moisture, crude protein, crude fat, ash, crude fibre and mineral contents; and the effect of the degree of fermentation on these parameters was also investigated. The amino acid compositions of all the samples were evaluated and amino acid quality determined by calculating amino acid scores and the predicted protein efficiency ratio (P-PER). Results showed that the proximate composition was significantly affected by fermentation, although there was little difference between the parameters for the partially fermented and completely fermented samples. Based on dry matter percentage, protein content was in the 39.77 – 43.74 % range while crude fibre ranged between 5.55 – 7.42 %. The ash content was lowest in the raw sample (2.34 %), while the fermented samples had ash contents between 4.27 and 8.33 % for the fully fermented and the partially fermented seeds, respectively. The fat content increased from 8.65 % in the raw seed to 24.4 % and 27.6 % for the partially and completely fermented samples, respectively. Results of the amino acid analysis showed that the partially fermented sample had the lowest quantities of all amino acids determined and had lysine as the limiting amino acid, whereas the raw and completely fermented samples had very similar amino acid profile with amino acid scores of 100, indicating that there are no limiting amino acids. All the samples were rich in essential amino acids. The P-PER also showed that the partially fermented sample had the lowest protein efficiency while the raw seed had the highest. Mineral contents generally increased from the raw, through the partially fermented, to the completely fermented seeds and results showed the samples to be good sources of potassium (K), calcium (Ca), manganese (Mn) and copper (Cu) in addition to being complementary sources of other metals. Locust bean seed does not accumulate lead and is, therefore, safe for consumption without the potential of food poisoning.

Effect of fertilization and type of pruning on quality of fresh and dehydrated Stevia rebaudiana

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia - UL

Natural plant polyphenols for alleviating oxidative damage in man: Current status and future perspectives

The balance between oxidation and reduction is important for maintaining a healthy biological system. Oxidative stress results from an imbalance between excessive formation of reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) and limited endogenous defense systems, and this imbalance can adversely alter lipids, proteins and DNA, causing a number of human diseases. Thus, exogenous antioxidants that can neutralize the effect of free radicals are needed to diminish the cumulative effects of oxidative damage over human life span. Current research reveals that phenolic compounds in plants possess high antioxidant activity and free radical scavenging capacity and can prevent the body from oxidative damage over human life span. This review focuses on the present understanding of free radicals and antioxidants and their importance in human health and disease. Information about the chemical features of free radicals as well as their deleterious effects on cell structures is reviewed. The chemical structure and anti-oxidative mechanisms of essential polyphenols and their potential health benefits are presented. In addition, the limitation of natural antioxidants and a perspective on likely future trends in this field are also discussed.

Study of extraction conditions for phenolic compounds from Strawberry fruits

Strawberries are an important source of phytochemicals, namely vitamins and phenolic compounds such as anthocyanins and tannins with antioxidant properties [1]. The yield and phenolic content of natural extracts are dependent on the conditions used for extraction [2]. In the present work three different types of extracting solutions (methanol, ethanol:water and aceton:water), two times of extraction (15 and 60 min) and three ratios of solid/solvent (5/25, 5/50 and 5/100 g/mL) were tested in order to evaluate the efficiency of the extraction of phenolic compounds. Phenolic compounds were determined by Folin-Ciocalteu method [3]. Each assay was performed in triplicate. Regarding the extraction solution, it was possible to observe a slight tendency towards a higher efficiency of acetone:water (AcO:H2O, 60:40), but the differences mioght not be statistically significant. A longer time of contact, 60 min as opposed to 15 min, did not show advantages in the yield of extraction. Considering the factors under study, the results obtained showed that volume of extraction solution was the parameter that most influenced the values obtained. Using a higher volume lead to an increase in the amount of phenolic compounds extracted, in a more pronounced way for 15 min of extraction. For a volume of 25 mL the amount of phenolic compounds quantified ranged from 2.13-2.41 mg GAE/g, and increased 30-68% when it was used 50 mL of solution. Using 100 mL of solution, it was extracted twice as double of phenolic compounds. In case of 60 min, the amount of phenolic compounds quantified in samples obtained with 25 mL of solution ranged from 2.32-2.97 mg GAE/g, and increased for 2.43-4.27 mg GAE/g and 3.98-4.68 mg GAE/g when was used 50 and 100 mL, respectively.

Bioactive Phenols in Small Fruits and Berries

Bioactive compounds are extra nutritional constituents occurring naturally in plant foods in small amounts, however in quantities enough to produce bioactive effects. Among bioactive compounds the phenolic compounds are a very large set of molecules, which include several groups such as for example flavonoids, phenolic acids or tannins. Small fruits and berries include a wide diversity of fruits, like grapes, strawberries, blackberries, blueberries, raspberries, cherries, hardi kiwi, gooseberries, cranberries, currants (black, white, red), physalis, crowberries, açaí, elderberries, dates or goji berries, and these frequently have been reported as having particularly high concentrations of phenolic compounds with antioxidant activity. Hence, the objective of this chapter is to review the literature about the type and contents of different phenolic compounds present in small fruits and berries, as well as their bioactive properties, including antioxidant capacity. All the fruits and berries investigated in this chapter were particularly rich in bioactive compounds, including phenolic compounds that provide the fruits with high antioxidant properties. The most relevant health promoting effects include anti-cancer, anti-inflamatory, neuro protective, cardio protective or anti-diabetes, thus indicating that these foods are a valuable resource to prevent and treat diseases.

Impact of biohybrid magnetite nanoparticles and moroccan propolis on adherence of methicillin resistant strains of staphylococcus aureus

Biofilm bacteria are more resistant to antibiotics than planktonic cells. Propolis possesses antimicrobial activity. Generally, nanoparticles containing heavy metals possess antimicrobial and antibiofilm properties. In this study, the ability of adherence of Methicillin Resistant Strains of Staphylococcus aureus (MRSA) to catheters treated with magnetite nanoparticles (MNPs), produced by three methods and functionalized with oleic acid and a hydro-alcoholic extract of propolis from Morocco, was evaluated. The chemical composition of propolis was established by gas chromatography mass spectrometry (GC-MS), and the fabricated nanostructures characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Mossbauer spectroscopy and Fourrier transform infrared spectroscopy (FTIR). The capacity for impairing biofilm formation was dependent on the strain, as well as on the mode of production of MNPs. The co-precipitation method of MNPs fabrication using Fe(3+) and Na₂SO₃ solution and functionalized with oleic acid and propolis was the most effective in the impairment of adherence of all MRSA strains to catheters (p < 0.001). The adherence of the strain MRSA16 was also significantly lower (p < 0.001) when the catheters were treated with the hybrid MNPs with oleic acid produced by a hydrothermal method. The anti-MRSA observed can be attributed to the presence of benzyl caffeate, pinocembrin, galangin, and isocupressic acid in propolis extract, along with MNPs. However, for MRSA16, the impairment of its adherence on catheters may only be attributed to the hybrid MNPs with oleic acid, since very small amount, if any at all of propolis compounds were added to the MNPs.

The influence of nitrogen fertilization on growth, yield, nitrate and oxalic acid concentration in purslane ( Portulaca oleracea )

Purslane (Portulaca oleracea) is widely used for culinary purposes throughout Mediterranean region, and the interest in this plant increased due to it being a source of bio-protective compounds, such as fatty acids and antioxidants. However, the use of purslane could be limited by accumulation of high levels of compounds harmful to human health, such as nitrate and oxalic acid. The main objective of present study was to evaluate the influence of nitrogen fertilization on growth and yield parameters and on nitrate and oxalic acid concentrations in leaves and stems. Plants of golden-leafed purslane of sativa subspecies were grown in styro-foam boxes with substrate and fertilized two times per week during four weeks with ammonium-nitrate solution (16.9% NO3--N and 17.6% NH4+-N), for testing of four nitrogen levels (0, 30, 60 and 90 kg N ha-1). Plant growth, yield, nitrate and oxalic acid concentrations were significantly affected by nitrogen application. The best quantity/quality ratio was achieved at fertilization level of 60 kg N ha-1, which gave a yield of 5.1 kg m-2 FW, while nitrate concentration was 48.98 and 43.90 mg g-1 DW in leaf and stem, respectively, and oxalic acid concentration was 1.27 and 0.55 mg g-1 DW, in leaf and stem, respectively: values which are not harmful for consumer health.

Pharmacological and Toxicological Studies of Essential Oil of Lavandula stoechas subsp. luisieri.

The present study was carried out to evaluate the chemical and pharmacological properties of essential oil (EO) of Lavandula stoechas L. subsp. luisieri that is a spontaneous shrub widespread in Alentejo (Portugal). Oxygenated monoterpenes, as 1,8-cineole, lavandulol and necrodane derivatives are the main components of essential oil. It revealed important antioxidant activity with high ability to inhibit the lipid peroxidation and showed an outstanding effect against a wide spectrum of microorganisms, such as Gram-positive and Gram-negative bacteria and pathogenic yeasts. The analgesic effect studied in rats was dose dependent, reaching a maximum of 67 % at 60 min. with the dose of 200 mg/kg and the anti-inflammatory activity with this dose caused an inhibition in carrageenan-induced rat paw oedema (83 %) that is higher than dexamethasone 1 mg/Kg (69 %). Besides, animals exhibited a normal behaviour after EO administration revealing low toxicity. Essential oil of L. luisieri from Alentejo that presents important pharmacological properties and low toxicity is a promised candidate to be used as food supplement or in pharmaceutical applications.

Antioxidant and anti-inflammatory potential of Lavandula spp.

Lavenders have been used in folk medicine as disinfectant, expectorant, analgesic, anti-spasmodic, laxative and stimulant. Some species are endemic of Iberian Peninsula and often found in the Portuguese montado, including Lavandula stoechas subsp. luisieri and Lavandula pedunculata. The investigation of the antioxidant and anti-inflammatory potential of the Portuguese montado flora is very poor and restricted to a few botanical families, and their biological activities are mainly attributed to the essential oils. So, it is crucial to know the properties of Lavandula EOs, contributing for animal health and the valorisation of Portuguese montado flora. The aim of this study was to evaluate chemical composition, antioxidant properties and screening anti-inflammatory potential of EOs and extracts of Lavandula stoechas L. subsps. luisieri Rozeira, Lavandula pedunculata (Mill.) Cav. subsp. pedunculata and Lavandula viridis L’Hér, wild grown in the south of Portugal.

Spondias tuberosa trees grown in tropical, wet environments are more susceptible to drought than those grown in arid environments.

In this study, we investigated the different responses of Spondias tuberosa (umbu) trees, which grow in two different ecological life zones in northeast Brazil: tropical wet and tropical arid ecosystems. We evaluated the responses of plants grown under humid and dry conditions by measuring the photosynthesis, water status, fluorescence parameters, carbon isotopes and antioxidant system activity. The higher net photosynthesis values were recorded contemporaneously with the lower VPD values. The highest internal-to-ambient CO2 concentration and the absence of typical changes in the fluorescence parameters suggested an onset of a nonstomatal limitation in the photosynthesis. Our results showed that umbu plants can adjust their antioxidant activity during the dry season as a defensive strategy against the deleterious effects of water stress. This evidence is supported by the observed modifications in the pigment concentrations, increased accumulation of hydrogen peroxide and malondialdehyde, high levels of electrolyte leakage, increased antioxidant activity, and decreased carbon isotope discrimination in the umbu trees during the dry season. Supported by multivariate analysis of variance, significantly effect of interaction between categorical months of collect and location predicts a strong ?dry season effect? on our dataset. Taken together, our data show that umbu trees grown in a wet tropical environment are more susceptible to drought, as compared with their tropical arid counterparts.

Messa a punto delle condizioni ottime di infusione di foglie di Ilex guayusa mediante disegno sperimentale Box-Behnken

Ilex guayusa, a tree native from the Amazon Rainforest, represents an important part of the culinary traditions and folk medicine of the indigenous tribes. In fact, infusions of different parts of the tree have been used as natural remedies. Particularly, the infusion obtained by the dry leaves of guayusa is a source of phenolic compounds, which are considered as antioxidant substances and have been associated with numerous benefits for human health. Currently, the growing interest of consumers towards healthy food and drinks has led to the rapid spread of this drink. However, the scientific literature about the content of polar compounds in infusion of guayusa leaves is scarce. Therefore, the aims of the present work were to enhance the extraction conditions of phenolic compounds from guayusa leaves by infusion and to characterize them via HPLC-ESI-TOF-MS. To reach these objectives, a Box-Behnken design (BBD) was applied to test the effect of different extraction conditions (time 2, 8 and 14 min), temperature (25, 62.5 and 100 °C) and solid ratio (0.25, 0.375 and 0.50 g) on the sum of phenolic content. On the one hand, the optimal conditions were 1 min infusion, 100 °C and 0.370 g of dry leaves. On the other hand, the 99% of the nine phenolic compounds identified were phenolic acids derivatives from hydroxycinnamic acid and the 1% belonged to the flavonoid family. The major compound was dicaffeoylquinic acid (68%). The difference between the results obtained and those of other researches is probably due to the stochastic nature of the vegetable matrix samples, since their chemical composition is susceptible to multiple factors. To sum up, the use of experimental design provided greater quantity of phenolic compounds than other extraction techniques such as blanching, or only to the oxidation process. Besides, the high resolution of the TOF spectrometer allowed the characterization of new isomers of the compounds previously described.