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Preliminary characterization of a Moroccan honey with a predominance of Bupleurum spinosum pollen

Publication . Elamine, Youssef; Aazza, Smail; Lyoussi, Badiâa; Antunes, Maria Dulce; Estevinho, Leticia M.; Anjos, Ofélia; Resende, Mafalda; Faleiro, Maria Leonor; Miguel, Maria da Graça

Honey with Bupleurum spinosum (zandaz) as a main pollen source has not been the subject of previous detailed study. Therefore, twelve Moroccan samples of this honey were subjected to melissopalynological, physicochemical and microbiological quality characterization, as well as antioxidant activity assessment. From a quality point of view, almost all samples were within the limits established by Codex Alimentarius, and/or the European legislation. All samples presented predominance of B. spinosum pollen (more than 48%). Relatively high levels of trehalose (1.3–4.0 g/100 g) and melezitose (1.5–2.8 g/100 g) were detected. Those sugars, not common in monofloral honeys, could be used as an important factor to discriminate zandaz honey. Flavonoid content correlated positively with the honey color, melanoidin and polyphenol content, and negatively with the IC50values of scavenging ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radicals, while proline amount correlated negatively with IC50values of nitric oxide scavenging activity and chelating power. This correlation supports the use of anti-oxidant activities as important variables for PCA (principal component analysis). Both components explained 70% from the given data, and showed certain homogeneity upon analyzed samples independent of the region, suggesting the importance of B. spinosum nectar in the resulting honey characteristics.

2018Journal article

Open access

Seed origin drives differences in survival and growth traits of cork oak (Quercus suber L.) populations

Publication . Sampaio, Teresa; Gonçalves, Elsa; Patrício, Maria Sameiro; Cota, Tânia M.; Almeida, Maria Helena

Cork oak (Quercus suber L.) has a high ecological and social value and supplies raw materials for the cork industry, a relevant contributor to the economies of Mediterranean countries. Understanding the adaptation potential of cork oak populations to cope with different environmental conditions is a key issue of forest management, particularly for selecting the most adapted genetic material for (re)forestation and assuring the long-term sustainability of the cork industry. Intraspecific variation in fitness surrogate traits (survival, height and stem diameter) was investigated in thirty-five cork oak populations sampled from the entire range of the natural distribution of the species. The study was conducted in two provenance field trials, established in Portugal under different edaphoclimatic conditions. Each trial was surveyed at four tree ages (two ages, 11 and 14 years, were sampled simultaneously in both trials). The trial located at a lower altitude, which had higher mean winter and annual temperatures, exhibited higher growth and survival rates. In both trials, significant genetic variation among cork oak populations was observed for the analyzed traits and evaluated ages. Moroccan populations displayed a higher probability of survival and higher growth rates, while local populations exhibited an intermediate performance. Low to moderate correlations were found between the analyzed traits and the environmental variables of seed origin, suggesting that factors other than climate are likely to be relevant for cork oak adaptation. Moderate to high values of population mean-basis broad-sense heritability (H2≥0.44) and high genetic correlations between traits (0.88–0.95) were found for growth traits. This information is crucial for the establishment of a breeding program for the species. With this study, we have improved the knowledge regarding how cork oak performs for fitness surrogate traits in different environments.

2019Journal article

Open access

Physicochemical characterization and antioxidant activity of honey with Eragrostis spp. pollen predominance

Publication . Aazza, Smail; Elamine, Youssef; El-Guendouz, Soukaïna; Lyoussi, Badiâa; Antunes, Maria Dulce; Estevinho, Leticia M.; Anjos, Ofélia; Carlier, Jorge D.; Costa, Maria Clara; Miguel, Maria da Graça

This study aimed to characterize the pollen and physicochemical profiles, and to evaluate the antioxidant capacity of six samples of Moroccan honey. The pollen grains of Eragrostis spp. were predominant in all samples (from a minimum of 46.58 ± 1.59% to 72.72 ± 2.43% as a maximum), exceeding the minimum (generally 45%) required for the monoflorality nomination of a honey sample, and suggestion a case of newly reported honey. The analyzed samples had low diastase activity and hydroxymethylfurfural (HMF) content. Potassium was the dominant element in practically all samples, except the sample with the highest Eragrostis spp. pollen percentage, which showed sodium predominance. The honey color ranged from water white to light amber, and positively correlated the concentrations of phenols, proline and the capacity for scavenging free radicals. However, great variability observed in all the analyzed parameters, and could not be explained by the variability of the Eragrostis spp. pollen percentage, which suggests a hypothesis of low concentrated nectar. Practical applications: The melissopalynological profile of honey is an important parameter for determining the type of honey (multifloral, monofloral, blossom, honeydew) and its relationship to the botanical and geographical provenance. There is generally a relationship between the pollen profile of honey and the biological properties. The physicochemical characterization, antioxidant activity and melissopalynological profile of Eragrostis honey was reported for the first time in this study. These data intend to contribute for the introduction of a new type of honey labeled as Eragrostis honey. At the same time, the evaluation of the antioxidant activity may also trigger the search of other biological properties with medicinal attributes for the new Eragrostis ssp. honey.

2018Journal article

Open access

Insight into the sensing mechanism of an impedance based electronic tongue for honey botanic origin discrimination

Publication . Elamine, Youssef; Inácio, Pedro M.C.; Lyoussi, Badiâa; Anjos, Ofélia; Estevinho, Leticia M.; Miguel, Maria da Graça; Gomes, Henrique L.

Animpedance based electronictongue was developed and used to discriminate honey of diﬀerent botanic origin. The e-tongue presented here is based on the small-signal frequency response of the electrical double-layer established between the honey solution and an array of four diﬀerent sensing units composed by gold, carbon, indium-tin-oxide, and doped silicon. The ability of the e-tongue to discriminate honey of diﬀerent ﬂoral origins was demonstrated by distinguishing honey from Bupleurum and Lavandula pollen prevalence. The honey ﬁngerprint obtained with the e-tongue was validated by parallel melissopalenogical analysis and physico-chemical methods. It is demonstrated that the e-tongue is very sensitive to changes on the honey electrical conductivity. Small diﬀerences in electrical conductivity are introduced by the presence of ionisable organic acids and mineral salts. Moreover, we propose that the sensitivity of the tongue to changes in electrical conductivity can be explored to probe other complex liquid substances.

2019Journal article

Open access

Physicochemical characterization of Lavandula spp. honey with FT-Raman spectroscopy

Publication . Anjos, Ofélia; Santos, António J.A.; Paixão, Vasco; Estevinho, Leticia M.

This study aimed to evaluate the potential of FT-Raman spectroscopy in the prediction of the chemical composition of Lavandula spp. monofloral honey. Partial Least Squares (PLS) regression models were performed for the quantitative estimation and the results were correlated with those obtained using reference methods. Good calibration models were obtained for electrical conductivity, ash, total acidity, pH, reducing sugars, hydroxymethylfurfural (HMF), proline, diastase index, apparent sucrose, total flavonoids content and total phenol content. On the other hand, the model was less accurate for pH determination. The calibration models had high r 2 (ranging between 92.8% and 99.9%), high residual prediction deviation - RPD (ranging between 4.2 and 26.8) and low root mean square errors. These results confirm the hypothesis that FT-Raman is a useful technique for the quality control and chemical properties’ evaluation of Lavandula spp honey. Its application may allow improving the efficiency, speed and cost of the current laboratory analysis.

2018Journal article

Open access