Physicochemical properties and biological activities of bracatinga honeydew honey from different geographical locations.

Bracatinga (Mimosa scabrella Bentham) honeydew honey is a Brazilian dark honey in increasing international appreciation. In this sense, the knowledge of its composition and potential biological properties becomes indispensable. In the present study, the physicochemical characteristics, including mineral and phenolic composition, and the scavenging, reducing, and antimicrobial proprieties of bracatinga honeydew honey (bhh) from five different geographical locations, were investigated. Bhh proved to be a potential functional food due to its high content of minerals (up to 6395 mg kg-1) and phenolic compounds (up to 2393 µg 100 g-1) and high scavenging and reducing activities. High antimicrobial activity against four bacterial strains, with minimum inhibitory concentration values ranging from 10 to 60%, were also found. Additionally, through principal component analysis, partial discrimination of bhh was observed according to the geographical location, which favored the separation of samples from Lages, and mainly due to the presence of nectar in this honey, which was proposed for the samples from Bom Retiro. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s13197-020-04937-x) contains supplementary material, which is available to authorized users.

Phenolic composition and biological activities of stingless bee honey: An overview based on its aglycone and glycoside compounds.

Stingless bees are native to tropical and subtropical countries, such as Brazil. The wide variety of species, the sources of food collection (nectar and pollen), and the climate conditions strongly affect the chemical composition of the honey, making this a unique product with peculiar characteristics. Stingless bee honey presents higher water content, higher acidity, and a lower sugar concentration when compared to Apis mellifera honey. Moreover, there is a wide variety of microorganisms in stingless bees' environment, which leads their honey to go through a natural fermentative process during its production in the hive. Besides, fermentation and hydrolysis are effective ways to convert glycosides into aglycones, thus increasing the bioavailability of compounds. In this sense, stingless bee honey may possess a greater concentration of phenolic compounds aglycones than glycosides, which would increase its potential benefits. Therefore, this review aims to compile the most recent studies of stingless bee honey phenolic profile and its biological potential (antioxidant, antimicrobial, and anti-inflammatory activities) and a possible connection to its natural fermentation process.

Quantification of pyrrolizidine alkaloids in Senecio brasiliensis, beehive pollen, and honey by LC-MS/MS.

This article presents the determination of eight pyrrolizidine alkaloids (PAs) by LC-MS/MS in honeys, pollen, and Senecio brasiliensis (Asteraceae) samples, all from Santa Catarina state, Brazil. In addition, the Box-Behnken design was used to perform an optimized sample preparation on pollens and S. brasiliensis parts. Senecionine and its N-oxide, besides retrorsine N-oxide, were determined in six of the seven honeys samples. Pollen from species of the Asteraceae, Fabaceae, and Boraginaceae families were found with greater predominance in three of the seven honeys samples. In these three honeys samples were also found the highest PAs levels. In beehive pollen, flower, and leaf of S. brasiliensis, the total levels of PAs and their N-oxides reached 221, 14.1 × 104, and 14.8 × 104 mg kg-1, respectively. In honeys, these compounds are chemical contaminants and therefore undesirable when the sum exceeds 71 µg kg-1, according to EFSA. On the other hand, although PAs are naturally present in plant and pollen of some species (Senecio, Crotalaria, Bacharis, Ecchium, Mimosa scabrella, Vernonia), it is important to monitor their levels in plants but also in honeys, and other beehive products since these compounds are transferred to the final product.

Pyrrolizidine alkaloids and beehive products: A review.

Pyrrolizidine alkaloids (PA) are secondary metabolites of plants, which are mostly found in the genus Senecio, Echium, Crotalaria, and Eupatorium. The presence of 1,2-unsaturated PA in foods is a concern to food regulators around the world because these compounds have been associated to acute and chronic toxicity, mainly in the liver. The intake foods with PA/PANO usually occur through accidental ingestion of plants and their derivatives, besides to products of vegetal-animal origin, such as honey. PA/PANO are transferred to honey by their presence in nectar, honeydew, and pollen, which are collected from the flora by bees. In addition to honey, other beekeeping products, such as pollen, royal jelly, propolis, and beeswax, are also vulnerable to PA contamination. In this context, this review provides information about chemical characteristics, regulation, and toxicity, as well as summarizes and critically discusses scientific publications that evaluated PA in honeys, pollens, royal jelly, and propolis.

Blackberry (Rubus ulmifolius Schott): Chemical composition, phenolic compounds and antioxidant capacity in two edible stages.

The berries of the genus Rubus has been highlighted as important source of bioactive and health promoting constituents, however, information about chemical composition and antioxidant potential of the specie Rubus ulmifolius are still scarce. In this regard, this study aimed to assess the physicochemical characteristics, total monomeric anthocyanins (TMA), individual phenolics, minerals, sugars, and antioxidant properties of mature and fully mature R. ulmifolius. With the advance of maturation, changes in the physicochemical composition suggest pleasant characteristics for consumption especially in the fully mature stage. High levels of TMA and sugars (fructose and glucose) were also verified in the fully mature stage, as well as, expressive antioxidant potential, with values of 241.06 µM Fe+2 g-1 for ferric reducing antioxidant power and 28.22 mg gallic acid equivalent g-1 for Folin-Ciocalteu reducing capacity (all expressed in dry matter, DM). In contrast, minerals (potassium, calcium, sodium) and most of the studied phenolic compounds showed the highest concentrations in mature fruits. Among the phenolics investigated, 26 compounds were identified and quercetin and isoquercitrin were the predominant phenolic compounds in the fruit. The results reinforce the nutritive and antioxidant potential of Rubus ulmifolius in both maturation stages studied.

Neuroprotective effect of juçara (Euterpe edulis Martius) fruits extracts against glutamate-induced oxytosis in HT22 hippocampal cells.

This study investigated the neuroprotective effect of juçara fruit extracts against glutamate-induced oxytosis in HT22 cells. Potential relationships between the extracts' polyphenolic composition and their protective/antioxidant capacities were also investigated. Experiments with the addition of either the crude methanolic extract or hexane, dichloromethane, ethyl acetate and butanol fractions 24 h before glutamate (pretreatment) and together with glutamate (co-treatment) were performed. At the concentration of 10 µg ml-1, the hexane and dichloromethane fractions were able to protect cells, both in pretreatment and co-treatment. These fractions presented the highest number of quantified polyphenolics (24 and 21, respectively) although the total levels were 63-fold higher in the dichloromethane fraction. Syringaldehyde, vanillin and 4-aminobenzoic, cinnamic, salicylic and syringic acids were found only in these fractions. The dichloromethane fraction presented higher 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, while the butanol and ethyl acetate fractions showed higher ferric reducing antioxidant power. These results suggest juçara fruits extracts as promising for the reduction of the risk of neurodegenerative diseases.

5-HMF and carbohydrates content in stingless bee honey by CE before and after thermal treatment.

This study aimed to assess 5-hydroximethylfurfural and carbohydrates (fructose, glucose, and sucrose) in 13 stingless bee honey samples before and after thermal treatment using a capillary electrophoresis method. The methods were validated for the parameters of linearity, matrix effects, precision, and accuracy. A factorial design was implemented to determine optimal thermal treatment conditions and then verify the postprocedural 5-HMF formation, but once 5-HMF were

Increasing the instrumental throughput of gas chromatography method using multiple injections in a single experimental run: application in determination of friedelan-3-ol and friedelin in Maytenus ilicifolia.

The aim of this study was to develop a separation method using multiple injections in a single experimental run (MISER) employing gas chromatography with flame ionization detection (GC-FID) for the first time, without instrument modification, to increase the instrumental throughput. The method was applied to the determination of the triterpenes friedelan-3-ol and friedelin in a plant extract obtained from Maytenus ilicifolia leaves. The column used in the chromatography system was a ZB-50 (30 m × 0.25 mm × 0.15 µm) with 50% phenyl-50% methyl-polysiloxane. The samples (1.0 µL) were injected using the split mode (1:90), with the injector at 280 °C and FID detector at 320 °C. The column temperature was programmed to isothermal mode at 300°C. Helium was used as the carrier gas with a constant flow of 1.5 mL min(-1). It was possible to perform three injections in the same run using the MISER method. An increase in the instrumental throughput by a factor of around 2.6 was observed when the use of multiple injections was compared with the single injection method. This method showed good linearity for both analytes with R(2)>0.99 and the values for the limit of detection were 0.24 mg L(-1) and 0.44 mg L(-1), for friedelan-3-ol and friedelin, respectively. Furthermore, the values for the limits of quantification were 0.79 mg L(-1) for friedelan-3-ol and 1.16 mg L(-1) for friedelin. The proposed method has potential for other GC applications, allowing an increase in the instrumental throughput of the methods by applying this separation technique.

Optimisation of a capillary zone electrophoresis methodology for simultaneous analysis of organic aliphatic acids in extracts of Brachiaria brizantha.

INTRODUCTION: Aluminum toxicity is commonly verified in acidic soils, and poses a severe limitation to plant growth and development. Therefore, Al complexation by the root system mucilage, Al complexation by organic compounds that are exuded by the roots and internal metabolic processes must be monitored by organic acids (OA), since they play a central role in these aluminum tolerance mechanisms. OBJECTIVE: To optimise a capillary zone electrophoresis method able to perform simultaneous separation of acetic, citric, formic, lactic, malic, oxalic, pyruvic, succinic, tartaric and aspartic acid in plant extract solutions. METHODOLOGY: Method optimisation was achieved by a chemometric approach through experimental designs. The optimal condition found was: 20 mmol/L phthalic acid buffer; 0.8 mmol/L cetyltrimethyl-ammonium bromide; pH 3.4 adjusted with tris(hydroxymethyl)aminomethane (around 16 mmol/L); -15 kV of voltage; 25 °C of cartridge temperature; indirect ultraviolet detection at 240 nm; and 25 mbar injection for 2 s, within an analysis time of 4 min. RESULTS: As a repeatability test of the optimal condition, 30 replicates were carried out with the same working electrolyte, where the relative standard deviation of each peak ranged from 0.081 to 0.36% (for migration time) and from 2.4 to 4.6% (for peak area). CONCLUSION: The methodology was successfully applied to simultaneously determine citric, malic and aspartic acid in roots and leaves extract solutions of Brachiaria brizantha, demonstrating its usefulness to study aluminum tolerance.