Tipos polínicos de las mieles comercializadas de Galicia

Tipos polínicos de las mieles comercializadas de Galicia. Se ha realizado un estudio de las mieles de producción gallega existentes en el mercado. De las 39 muestras analizadas, tres han resultado monoflorales de Castanea, otras tantas monoflorales de Eucalyptus, cinco monoflorales de Rubus y el resto han sido milflorales. La mayoría de las mieles comercializadas proceden de las provincias de A Coruña y Lugo y en relación a sus características palinológicas, no difieren en gran medida de las procedentes de pequeños productores

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

Variaciones intranuales del espectro polínico de miel de Nogueira de Ramuín, Orense

Se ha realizado el análisis polínico de 12 muestras recogidas de forma secuencial durante el periodo de producción de miel en tres colmenas, ubicadas en Nogueira de Ramuin (Orense), comparando los resultados obtenidos con el espectro polínico de la mezcla final. Se observan diferencias importantes entre las muestras parciales, que ponen de manifiesto el pecoreo selectivo de las distintas colonias

El polen de Eucalyptus y su incidencia en la atmósfera de Vigo (NO España)

El polen de Eucalyptus y su incidencia en la atmósfera de Vigo (N.O. España). Eucalyptus globulus Labill. es la especie arbórea de la familia Myrtaceae, más frecuente en los alrededores de la ciudad de Vigo formando abundantes y densas masas forestales. Aunque su polen se considera moderadamente alergénico, en áreas en las que, como consecuencia de repoblación forestal ocupa extensiones importantes, puede llegar a causar problemas alérgicos.Entre los años 1995 y 2000 se ha realizado el estudio aerobiológico en la ciudad de Vigo mediante un captador LANZONI VPPS 2000 situado en la margen derecha de la ría de Vigo (42º14'15''N, 8º43'30''W). La cantidad de granos de polen anual de Myrtaceae varía ampliamente, alternándose años de concentraciones bajas con otros de valores elevados que representan entre un 1 y un 3% del polen total anual. El valor más elevado se detectó en 1997 con 1.147 granos de polen.Se encuentra en la atmósfera de Vigo durante todo el año, aunque las concentraciones más importantes se producen generalmente durante los meses de marzo y abril. Asimismo, a lo largo del día los máximos de concentración tienen lugar entre las 15 y las 17 horas. Finalmente se ha realizado un análisis estadístico para poner de manifiesto la posible correlación existente entre las concentraciones de polen y los principales parámetros meteorológicos. El viento procedente del N-NE fue el parámetro con el que se obtuvo correlación positiva y significativa de forma constante, mientras que esta fue negativa con la humedad relativa

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

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

Características palinológicas de las mieles de castaño de Galicia (NO España)

Características palinológicas de las mieles de castaño de Galicia (NO España). Se han estudiado melisopalinológicamente 83 muestras de miel de Galicia con porcentajes superiores al 70% de polen de Castanea. El 46% de las muestras presenta porcentajes de este tipo polínico comprendidos entre el 70% y el 79%, el 43% valores entre el 80% y el 89% y el 11% restante valores de este polen superiores al 89%. El número medio de tipos polínicos es de 21 y el índice de mielada es nulo o muy bajo para todas las muestras. En cuanto a la riqueza polínica presentan una media de 26.384 granos de polen por gramo de miel. Otros tipos polínicos presentes en estas mieles son: Rubus, Erica, Eucalyptus, Cytisus y Campanula. Este tipo de mieles se producen, principalmente, en las provincias de Lugo y Ourense. En Lugo, la zona centro y las sierras orientales son las de mayor producción. En Ourense lo son las zonas de montaña de las sierras de Manzaneda, Queixa, San Mamede, el valle del Sil y el límite de la provincia con Portugal. En la provincia de Pontevedra la principal zona de producción es la comarca del Deza, mientras que en A Coruña es la zona Norte. Las principales características diferenciadoras de las mieles de castaño gallegas con respecto a otras de producción española son la ausencia de Lavandula stoechas, Cistus ladanifer, Clematis vitalba, Melilotus y la escasa presencia de Calluna vulgaris

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

Factors influencing the airborne sporangia concentration of Phytophthora infestans and its relationship with potato disease severity

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGForecasting systems are widely used to predict the application of fungicides for managing late blight. However, airborne inoculum has rarely been included in these forecasting systems. Monitoring the sporangia in crop environments may offer an opportunity to improve late blight forecast systems by integrating pathogen pressure. Hence, this experiment aiming to analyze relationships between weather based risk systems and sporangia levels in the atmosphere of potato crops. The experiments were conducted during two growing seasons in a potato field. During the study, the concentration of Phytophthora infestans in the air, the weather conditions, the phenology of cultivars and r-AUPDC during the crop cycle were recorded. The weather-based risk of late blight was estimated using infection pressure (IP) and the daily risk value (DRV) based on hourly relative humidity (RH) and temperature (T). The effect of weather parameters on sporangia levels was analyzed. IP and DRV showed a strong positive correlation with sporangia concentration, standing out the pronounced effect of RH on the sporangia levels. Analysis of the hourly sporangia concentration within a day showed an increase in the sporangia concentration from 9 h to 18 h. This increase in sporangia was linked to an increase in T, spore release, and a decrease in RH. Our results identified a T of 10 ◦C and RH of 80% as the minimum threshold for significant sporangia concentration in the air. However, maximum sporangia level was found in the air at 88% (average relative humidity) and 17 ◦C (average temperature). Finally, the effect of weekly P. infestans sporangia was observed on cultivars with different susceptibility to late blight.Ministerio de Educación, Cultura y Deporte | Ref. FPU 17/0026

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