Alex da Silva de Freitas

Dr. Alex da Silva de Freitas

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 May 2020 in Journal of Apicultural Research
Verified
Journal Article
Closed access
LALigia Bicudo de Almeida-Muradian
Ligia Bicudo de Almeida-Muradian
OBOrtrud Monika Barth
Ortrud Monika Barth
VDVincent Dietemann
Vincent Dietemann
MEMichael Eyer
Michael Eyer
AFAlex da Silva de Freitas
Alex da Silva de Freitas
JSJosé Augusto Gasparotto Sattler
José Augusto Gasparotto Sattler
Honey is an important food for man and has been used as a natural sweetener since ancient times. It is a viscous and aromatic product made by honey bees using the nectar of flowers or honeydew. Honey is composed of a complex mixture of carbohydrates and other substances such as organic acids, amino acids, proteins, minerals, vitamins, lipids, aroma compounds, flavonoids, pigments, waxes, pollen grains, several enzymes, and other phytochemicals. This chapter presents some properties of Apis mellifera honey as well as the main methods of honey analysis. All methods are based on specialized literature, including the Codex Alimentarius, AOAC, and publications of the International Honey Commission. Herein, we describe methods related to honey authenticity, botanical origin, geographical origin, physicochemical analysis, radioentomology, pesticide and antibiotic contamination, chemotherapeutics, and sensory analysis. All methods are described in a step-by-step model in order to facilitate their use. La miel es un alimento importante para el hombre y se ha utilizado como edulcorante natural desde la antigüedad. Es un producto viscoso y aromático hecho por las abejas de la miel usando el néctar de las flores o el rocío de miel. La miel está compuesta por una mezcla compleja de carbohidratos y otras sustancias como ácidos orgánicos, aminoácidos, proteínas, minerales, vitaminas, lípidos, compuestos aromáticos, flavonoides, pigmentos, ceras, granos de polen, varias enzimas y otros fitoquímicos. En este capítulo se presentan algunas propiedades de la miel de Apis mellifera, así como los principales métodos de análisis de la miel. Todos los métodos se basan en literatura especializada, incluido el Codex Alimentarius, AOAC y publicaciones de la Comisión Internacional de la Miel. A continuación, describimos métodos relacionados con la autenticidad de la miel, el origen botánico, el origen geográfico, el análisis fisicoquímico, la radioentomología, la contaminación por pesticidas y antibióticos, la quimioterapia y el análisis sensorial. Todos los métodos se describen en un modelo paso a paso para facilitar su uso.

30 January 2020 in Journal of Apicultural Research
Verified
Journal Article
Closed access
OBOrtrud Monika Barth
Ortrud Monika Barth
AFAlex da Silva de Freitas
Alex da Silva de Freitas
BVBarth Vanderborght
Barth Vanderborght
Rio de Janeiro city presents one of the biggest urban forests today comprising several types of vegetation, highlighting the Atlantic tropical rainforest. Maintenance of these ecosystems requires protection and strong and efficient pollination. The stingless bees are between its main pollinators. The present investigation aims to recognize and to compare the pollen source preference and competition between Melipona rufiventris and Melipona quadrifasciata anthidioides in the Parque Nacional da Tijuca (PNT) urban forest at Rio de Janeiro. Bee pollen pellets were collected and prepared without the use of acetolysis. Evaluation intended the comparison of the taxon percentages of pollen grains collected by the bees in the same morning time. Dominant plant species were of Alchornea, Eucalyptus, Mimosa caesalpiniifolia, Mimosa scabrella, Melastomataceae, Myrcia and Solanum. The favorite sources of the two bee species in collecting pollen in the rainforest of the PNT were partially distinct among them. Therefore, an overlapping of harvesting sources was not so frequent during a year. In this respect, the forest needs several species of bees for pollination and perpetuation.

2 October 2015 in Grana
Verified
Journal Article
Closed access
AFAlex da Silva de Freitas
Alex da Silva de Freitas
JSJosé Augusto Gasparotto Sattler
José Augusto Gasparotto Sattler
BSBianca Rodrigues de Souza
Bianca Rodrigues de Souza
LALigia Bicudo Almeida-Muradian
Ligia Bicudo Almeida-Muradian
ASAroni Sattler
Aroni Sattler
OBOrtrud Monika Barth
Ortrud Monika Barth
Sixty-one samples of dried bee pollen collected from various apiaries in the southern Brazilian macro-region were examined to detect the botanical origin of the pollen and to enable more accurate product certification. The palynological analysis of the samples followed the standard methodology and was conducted without the use of acetolysis. The samples were washed once or twice with ethanol and then with water. The sediment obtained was homogenised in a water/glycerine solution for microscopic observation. The target number of pollen grains to be counted was 500 pollen grains or more per sample. The results demonstrated that 35 samples consisted of a unique pollen type representing more than 90% of the pollen sum (or more than 60% if no accessory pollen was present). These samples were considered monofloral. Several pollen types grouped in a sample were related to heterofloral pollen batches. The most frequent pollen types were of Mimosa scabrella, Eucalyptus, Andira, Machaerium, Myrcia and Piptocarpha. The results of the current study were related to the surrounding vegetation of the apiaries and reflected the resources available to the bees. Furthermore, these results are relevant to apicultural activities and are commercially significant.

18 September 2017 in Palynology
Verified
Journal Article
Closed access
AFAlex da Silva de Freitas
Alex da Silva de Freitas
BVBart Vanderborght
Bart Vanderborght
OBOrtrud Monika Barth
Ortrud Monika Barth
Pollen loads collected by Melipona quadrifasciata anthidioides were examined in order to detect the botanical origin of pollen and to recognise the pollination action of these bees in an urban Atlantic secondary forest. Pollen analysis followed standard methodology and without the use of acetolysis. The results revealed a great contribution of monofloral (more than 90% of a single pollen type or more than 60% if no accessory pollen was present). Quantitatively, Myrtaceae pollen samples followed Melastomataceae ones. Bifloral or heterofloral samples combine several pollen types. Besides Myrcia and Eucalyptus, the most frequent pollen types were Solanum, Mimosa caesalpiniifolia and Alchornea. The current study was related to the apiaries' surrounding vegetation and reflected both the resources available and the preference for native plant species by the bees. Furthermore, these results are relevant to the management of primary and secondary forests in order to preserve the environments.

26 April 2023 in Journal of Trace Elements and Minerals
Verified
Journal Article
Open access
AFAlex da Silva de Freitas
Alex da Silva de Freitas
LPLara Luiza de Oliveira Pompermayer
Lara Luiza de Oliveira Pompermayer
ASAna Dalva de Oliveira Santos
Ana Dalva de Oliveira Santos
MNMarília Teresa Lima Do Nascimento
Marília Teresa Lima Do Nascimento
TSTatiana Dillenburg Saint'PIerre
Tatiana Dillenburg Saint'PIerre
EFEstefan Monteiro da Fonseca
Estefan Monteiro da Fonseca

1 September 2014 in Pesquisa Agropecuária Tropical
Verified
Journal Article
Open access
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ADAdriane Alexandre Machado De-Melo
Adriane Alexandre Machado De-Melo
AMAdriana Hitomi Matsuda
Adriana Hitomi Matsuda
AFAlex da Silva de Freitas
Alex da Silva de Freitas
OBOrtrud Monika Barth
Ortrud Monika Barth
LALigia Bicudo de Almeida-Muradian
Ligia Bicudo de Almeida-Muradian
A própolis é uma substância resinosa coletada de diversas partes das plantas por abelhas e misturada à cera, pólen e secreções salivares. Sua composição é complexa e está relacionada, principalmente, às características da vegetação de cada região. Trinta e três amostras de própolis foram coletadas em quatro regiões brasileiras (Nordeste, Sudeste, Sul e Centro-Oeste) e analisadas quanto à sua capacidade antioxidante, pela oxidação acoplada do sistema β-caroteno/ácido linoleico. Variação significativa na capacidade antioxidante (51,33-92,70%) foi observada de acordo com a região onde a amostra foi coletada. A capacidade antioxidante das amostras de própolis da região Nordeste foi menor que a das amostras das regiões Centro-Oeste, Sul e Sudeste, respectivamente.