Physicochemical Properties and Pollen Profile of Oak Honeydew and Evergreen Oak Honeydew Honeys from Spain: A Comparative Study

This work investigates the similarities and differences of oak honeydew (Quercus pyrenaica Willd.) and evergreen honeydew (Quercus ilex L.) honey produced in Spain. For this purpose, the physicochemical characteristics of 17 samples from oak honeydew and 11 samples from evergreen honeydew collected in different geographical regions were analyzed. All the samples accomplished European Union requirements for honey consumption. Both honey types had amber dark color; however, the evergreen oak honey was clearer than oak honey, having higher mean values in a* and b* coordinates of CIELab scale. In general, both honey types exhibited high electrical conductivity, a moderate value of pH, medium to low water content, and high diastase activity. The reducing sugar content was significantly lower and maltose content was significantly higher in evergreen honeydew. In addition, total phenols and total flavonoid contents, the antioxidant activity and the melissopalynological analysis was performed. The oak honeydew honey had a higher abundance of Castanea, Rubus and Erica pollen grains, while the evergreen oak honeydew honey had a higher abundance of Lavandula, Olea europaea or Anthyllis cytisoides. A multivariate analysis using the most representative pollen types and physicochemical components facilitated the differentiation of the honey samples, thus this information can be useful for the honey characterization

Multivariate statistical approach for the discrimination of honey samples from Galicia (NW Spain) using physicochemical and pollen parameters

Raw honey is a food with a close relation to the territory in which it is produced because of factors such as soil conditions, weather patterns, and plant communities living in the area together. Furthermore, beekeeping management affects the properties of honey. Protected Geographical Indication Miel de Galicia protects the honey produced in Galicia (Northwest Spain). Various types of honeys (362 samples) from this geographical area were analyzed using chemometric techniques. Principal component analysis was favorable to analyzing the physicochemical and pollen variables with the greatest weight in the differentiation of honey. The linear discriminant analysis correctly classified 89.8% of the samples according to the botanical origin using main pollen spectra and physicochemical attributes (moisture, pH, electrical conductivity, diastase content, phenols, flavonoids, and color). Regarding unifloral honey, blackberry, eucalyptus, and heather honeys were correctly grouped, while five chestnut honeys and fourteen samples of honeydew honeys were misclassified. The chestnut and honeydew honeys have similar physicochemical properties and frequently similar pollen spectra profiles complicating the differentiation. Experimental evidence suggests the potential of multivariate statistics in the characterization of honey of the same geographical origin. Therefore, the classification results were good, with electrical conductivity, total phenol content, total flavonoid content and dominant pollens Eucalyptus, Erica, Rubus and Castanea sativa as the variables of higher importance in the differentiation of botanical origin of honeys.Xunta de Galicia | Ref. 2014/2020-FEADER 2018/054

Contribution to the chromatic characterization of unifloral honeys from Galicia (NW Spain)

Honey color and other physicochemical characteristics depend mainly on the botanical and geographical origin. The study of these properties could make easier a correct classification of unifloral honey. This work determined the palynological characteristics and some physicochemical properties such as pH, electrical conductivity, and color (Pfund scale and the CIELab coordinates), as well as the total content of the bioactive compounds phenols and flavonoids of ninety-three honey samples. Samples were classified as chestnut, blackberry, heather, eucalyptus, and honeydew honey. The study showed a close relationship between the physicochemical variables and the botanical origin. The five types of honey presented different physicochemical properties among them. A principal component analysis showed that Hue, lightness, b, and Chroma variables were important for the honey types classification, followed by Erica pollen, pH, Cytisus, and Castanea variables. A forward stepwise regression analysis was performed introducing as dependent variables the color (mm Pfund) and the Chroma and the Hue variables. The regression models obtained explained 86%, 74%, and 86% of the variance of the data, respectively. The combination of the chromatic and physicochemical and pollen variables through the use of multivariable methods was optimal to characterize and group the honey samples studied.Xunta de Galicia | Ref. FEADER 2018/054

Rapid estimation of potato quality parameters by a portable near-infrared spectroscopy device

The aim of the present work was to determine the main quality parameters on tuber potato using a portable near-infrared spectroscopy device (MicroNIR). Potato tubers protected by the Protected Geographical Indication (PGI “Patata de Galicia”, Spain) were analyzed both using chemical methods of reference and also using the NIR methodology for the determination of important parameters for tuber commercialization, such as dry matter and reducing sugars. MicroNIR technology allows for the attainment/estimation of dry matter and reducing sugars in the warehouses by directly measuring the tubers without a chemical treatment and destruction of samples. The principal component analysis and modified partial least squares regression method were used to develop the NIR calibration model. The best determination coefficients obtained for dry matter and reducing sugars were of 0.72 and 0.55, respectively, and with acceptable standard errors of cross-validation. Near-infrared spectroscopy was established as an effective tool to obtain prediction equations of these potato quality parameters. At the same time, the efficiency of portable devices for taking instantaneous measurements of crucial quality parameters is useful for potato processors.Xunta de Galicia | Ref. FEADER 2017/045BMinisterio de Educación, Cultura y Deporte | Ref. FPU 17/0026

Changes in the morphological characteristics of potato plants attributed to seasonal variability

The development of a potato crop differs according to the environmental conditions and growing season of an area. Periods of high temperatures and drought have been frequent in recent years, and this has affected crops worldwide. The effect of meteorological factors on the plant morphology of potato cultivars growing in A Limia was analyzed for three consecutive years. The crop cycle with the highest temperatures and least accumulated rainfall (2016) showed plants with a higher number of leaflets, which were shorter in length. The crop cycle (2014) with a lower temperature and more rainfall had the tallest plants, the highest degree of flowering, fewer pairs of leaflets and the highest length of the floral peduncle. Kennebec and Fontane were the varieties that showed the least variability in morphological characteristics during the seasons analyzed. Considering the meteorological and morphological data, a principal component analysis was carried out, which explained 80.1% of the variance of the data. Spearman rank correlations showed higher significant coefficients between the temperature and foliar characteristics. The leaf size of plants was estimated using a multiple linear regression analysis, which included the mean temperature, explaining 64% of the variability of the data.Xunta de Galicia | Ref. 2014/2020-FEADE

Describing the pollen content in the gastrointestinal tract of Vespa velutina larvae

Vespa velutina is an invasive species that exhibits flexible social behavior, which may have contributed to its introduction in several European countries. It is important to understand its behavior in order to combat the effects of its introduction in different areas. This implies knowing the resources that it uses during its biological cycle. Hornets require protein resources taken from insects and organic matter as well as carbohydrates as an energy source to fly and also to forage for food and nest-building materials. The gastrointestinal tract of adults and larvae contains a wide variety of pollen types. The identification of this pollen in larvae collected from nests could offer information about the plant species that V. velutina visits as a foraging place. The main objective of this research was to study the pollen content in the gastrointestinal tract of larvae. Patterns of pollen content and pollen diversity were established according to the nest type, altitude, season, and location in the nest comb. The abundance of pollen types such as Eucalyptus, Castanea, Foeniculum vulgare, Hedera helix, Taraxacum officinale, Echium, or Cytisus pollen type stands out in many of the samples.Simple Summary: The yellow-legged hornet is an invasive species from southeast Asia that has turned the European beekeeping sector upside down. The spread of this species has been advancing in recent years, and today, several European countries are threatened by Vespa velutina. The need to study its behavior is urgent given the increasingly evident economic and environmental impacts. In this regard, there is little information about the feeding habits and the resources it uses during the life cycle. Like other Hymenoptera, hornets require carbohydrates and proteins as their primary nutrients. Sugary secretions such as floral nectar, honeydew, or fruit juices are the main sources of carbohydrates but the protein intake is provided by the consumption of a diverse diet of insects such as the honey bee. There is scarce information on the presence of pollen grains in the gastrointestinal content of larvae other than secondary contamination from hunting. This content could represent the surrounding flora of its habitat that is used as a resource. Therefore, the objective of this study was to describe the main pollen types present in the gastrointestinal system of larvae taken from V. velutina nests.Fundación Centro de Estudos Eurorrexionais Galicia - Norte de Portugal | Ref. EAPA_800/2018-Atlantic-POSitiveXunta de Galicia | Ref. ED481D-2022-02

Next generation sequencing study on RNA viruses of Vespa velutina and Apis mellifera sharing the same foraging area

The predator Asian hornet (Vespa velutina) represents one of the major threats to honeybee survival. Viral spillover from bee to wasp has been supposed in several studies, and this work aims to identify and study the virome of both insect species living simultaneously in the same foraging area. Transcriptomic analysis was performed on V. velutina and Apis mellifera samples, and replicative form of detected viruses was carried out by strand‐specific RT‐PCR. Overall, 6 and 9 different viral types were reported in V. velutina and A. mellifera, respectively, and five of these viruses were recorded in both hosts. Varroa destructor virus‐1 and Cripavirus NB‐1/2011/HUN (now classified as Triato‐like virus) were the most represented viruses detected in both hosts, also in replicative form. In this investigation, Triato‐like virus, as well as Aphis gossypii virus and Nora virus, was detected for the first time in honeybees. Concerning V. velutina, we report for the first time the recently detected honeybee La Jolla virus. A general high homology rate between genomes of shared viruses between V. velutina and A. mellifera suggests the efficient transmission of the virus from bee to wasp. In conclusion, our findings highlight the presence of several known and newly reported RNA viruses infecting A. mellifera and V. velutina. This confirms the environment role as an important source of infection and indicates the possibility of spillover from prey to predator

Deontologia, ética e valores na educação: revisitar a história da educação: professora Cândida Florinda Ferreira

A deontologia, a ética e os Valores na Educação, são hoje um motivo de preocupação e de profunda reflexão de toda a comunidade educativa. Numa época em que o acesso à formação contínua é facilitada, devemos revisitar autores e pedagogos da nossa história da Educação mantendo um diálogo constante com o passado para melhor entender esta temática actual, quer através da visita às políticas educativas legisladas e praticadas, quer no diálogo com os pedagogos e agentes da educação

A study of the characteristics of chestnut and honeydew honey produced in Galicia

La capacidad de diferenciar los distintos tipos de miel, especialmente para los que presentan características similares, tiene un gran interés comercial y por ello es objeto de atención por parte de la comunidad científica. La diferenciación entre las mieles monoflorales de castaño y la miel de mielada es muy compleja y hasta la actualidad ningún trabajo de investigación se ha centrado en la diferenciación de estos tipos de miel producidos en nuestra comunidad autónoma. A la miel de mielada se le atribuyen propiedades saludables que han incrementado su mercado en muchos países de Europa. Este tipo de miel puede proceder de distintas plantas, principalmente árboles pero en la Península Ibérica, la más reconocida es la de encina (Quercus ilex) . Otras fagáceas producen mielada sin embargo, en el noroeste de España, Q. pyrenaica es la principal fuente de mielada. Además, cabe destacar, el desconocimiento sobre las propiedades fisicoquímicas y nutricionales de este tipo de miel de mielada. De ahí el interés de su caracterización. Las características sensoriales y fisicoquímicos que se le atribuyen presentan patrones muy similares a la miel de castaño y por ello en esta Tesis Doctoral se han buscado elementos que puedan contribuir a su diferenciación y tipificación. Para ello, se utilizaron varios procedimientos analíticos, tales como; análisis melisopalinológicos y físico-químicos y metodologías que permitieron obtener información para una diferenciación más detallada, como es el caso de el espectro de azúcares y la utilización de métodos espectroscópicos infrarrojos, especialmente en el infrarrojo medio (MIR) e infrarrojo cercano (NIR). La información obtenida puede ser relevante para los consumidores, los apicultores, la administración y la industria alimentaria que demandan la caracterización de ambos tipos de miel.A capacidade de diferenciar os distintos tipos de mel, especialmente para os que presentan características similares, teñen un grande interese comercial e por elo é obxecto de atención por parte da comunidade científica. A diferenciación entre as meles monoflorais de castaño e a mel de mielada é moi complexa xa que comparten diversas características sensoriais e físico-químicas. Ata a actualidade ningún traballo de investigación se centrou na diferenciación destes tipos de mel producidos na nosa comunidade autónoma. Por elo é interesante profundizar na súa diferenciacion. Utilizaranse varios procedementos analíticos, tales como : análise melisopalinolóxicos e físico químicos e metodoloxías que permiten obter información para unha diferenciación mías detallada, como é o caso do espectro de azúcares e a utlización de métodos espectroscópicos infrarroxos, especialmente no infrarroxo medio (MIR) e infrarroxo cercano (NIR). A información obtida utilizarase para tipificar e diferenciar ambos tipos de meles

Physicochemical Properties and Pollen Profile of Oak Honeydew and Evergreen Oak Honeydew Honeys from Spain: A Comparative Study

This work investigates the similarities and differences of oak honeydew (Quercus pyrenaica Willd.) and evergreen honeydew (Quercus ilex L.) honey produced in Spain. For this purpose, the physicochemical characteristics of 17 samples from oak honeydew and 11 samples from evergreen honeydew collected in different geographical regions were analyzed. All the samples accomplished European Union requirements for honey consumption. Both honey types had amber dark color; however, the evergreen oak honey was clearer than oak honey, having higher mean values in a* and b* coordinates of CIELab scale. In general, both honey types exhibited high electrical conductivity, a moderate value of pH, medium to low water content, and high diastase activity. The reducing sugar content was significantly lower and maltose content was significantly higher in evergreen honeydew. In addition, total phenols and total flavonoid contents, the antioxidant activity and the melissopalynological analysis was performed. The oak honeydew honey had a higher abundance of Castanea, Rubus and Erica pollen grains, while the evergreen oak honeydew honey had a higher abundance of Lavandula, Olea europaea or Anthyllis cytisoides. A multivariate analysis using the most representative pollen types and physicochemical components facilitated the differentiation of the honey samples, thus this information can be useful for the honey characterization