Browsing by Author "Iglesias, Antonio"
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- Características de la canal de terneros de la Denominación de Origen Protegida MirandesaPublication . Sousa, Fernando Ruivo de; Lorenzo Rodriguez, Jose Manuel; Iglesias, Antonio; Cantalapiedra, Jesús J.; Franco, DanielEl objetivo de este trabajo fue evaluar las características de la canal de la raza Mirandesa. Para llevar a cabo este estudio, un total de 20 animales de la raza Mirandesa fueron sacrificados a los 315 días. 24 horas tras el sacrificio, se determinó el peso canal y rendimiento canal, se realizaron las medidas morfométricas (longitud de la canal, longitud de la pierna, espesor de la pierna, profundidad interna del pecho y perímetro máximo de la pierna), se calcularon los siguientes índices: índice de compacidad de la canal e índice longitudinal transversal de la pierna y se realizó el despiece de los principales cortes comerciales. Los animales de la raza Mirandesa presentaron un peso vivo de 293,7 kg, un peso canal de 152 kg y un rendimiento canal de 60,5 %. En relación a las medidas morfométricas, la raza Mirandesa mostró una longitud de canal de 110 cm, una longitud de pierna de 69 cm y un perímetro de pierna de 89,8 cm. Los valores para el índice de compacidad de la canal y el índice longitudinal transversal de la pierna fueron de 1,4 y 3,7, respectivamente. Con respecto al quinto cuarto, la piel presentó los mayores porcentajes seguida de la cabeza y pies. Finalmente, la composición de las canales de la raza Mirandesa fue: 74,9 % de carne, 18,1 % de hueso y 7,0 % de grasa.
- Characterization of artisanal honey produced on the Northwest of Portugal by melissopalynological and physico-chemical dataPublication . Feás, Xesús; Pires, José; Iglesias, Antonio; Estevinho, Leticia M.Honey has always been regarded as a food which is advantageous for one’s health and as a product which has healing qualities. For this reason, is necessary to protect consumers from the fraudulent mislabeling of inferior honeys. The purpose of this study was to investigate some properties of artisanal honey samples (n = 45) collected from the Northwest of Portugal by using different honey analysis tests such as moisture, ash, pH, free acidity, electrical conductivity, hydroxymethylfurfural (HMF), apparent sucrose, reducing sugars and diastase activity. 77.8% of the total exceeded the quality parameters and should be labeled as ‘‘virgin” (humidity 618% and HMF 6 25 mg/kg). The present study found a linear correlation (y = 0.551x 0.089; R = 0.995) between the electrical conductivity of honeys and their ash content. All of the samples showed an Erica sp. pollen percentageP15%, and 42% of the total were monofloral Erica sp. In respect to coliforms and Salmonella’s presence, all the honey’s samples shown to be negative. The existence of sulphite-reducing Clostridia was low, and well below the established limit by MERCOSUR. Yeasts, moulds and aerobic mesophiles were detected in low amounts.
- Commercial bee pollen with different geographical origins: a comprehensive approachPublication . Nogueira, Carla; Iglesias, Antonio; Feás, Xesús; Estevinho, Leticia M.Since the primordial of humanity, pollen has been considered a good source of nutrients and energy. Its promising healing properties have also been referred to. The present study aimed to characterize, for the first time, eight commercial pollens from Portugal and Spain available on the market studying the legislation on labeling, pollinic origin, physicochemical and microbiological analyses and identification of yeasts. Eleven botanical families were found amongst the samples. The most abundant family and the most dominant pollen was Cistaceae. The moisture content, ash, aw, pH, reducing sugars, carbohydrates, proteins, lipids and energy were analyzed and the specific parameters were within the specifications required by some countries with legislation regarding these parameters. Microbiologically commercial pollen showed acceptable safety for the commercial quality and hygiene. All samples showed negative results for toxigenic species. The microorganisms studied were aerobic mesophiles, yeasts and moulds, coliforms, Escherichia coli, Staphylococcus aureus, Salmonella and sulfite-reducing Clostridium. During the work, six yeasts species were isolated from pollen, with Rhodotorula mucilaginosa being the most abundant, as it was present in four samples.
- Comprehensive study of honey with protected denomination of origin and contribution to the enhancement of legal specificationsPublication . Iglesias, Antonio; Feás, Xesús; Rodrigues, Sandra; Seijas, Julio; Vázquez-Tato, Maria PilarIn this study the characterization of a total of 60 honey samples with Protected Denomination of Origin (PDO) collected over three harvests (2009–2011, inclusive), from the Northeast of Portugal was carried out based on the presence of pollen, physicochemical and microbiological characteristics. All samples were found to meet the European Legislation, but some didn’t meet the requirements of the PDO specifications. Concerning the floral origin of honey, our results showed the prevalence of rosemary (Lavandula pedunculata) pollen. The microbiological quality of all the analyzed samples was satisfactory, since fecal coliforms, sulfite-reducing clostridia and Salmonella were absent, and molds and yeasts were detected in low counts. Significant differences between the results were studied using one-way analysis of variance (ANOVA), followed by Tukey’s HSD test. The samples were submitted to discriminant function analysis, in order to determine which variables differentiate between two or more naturally occurring groups (Forward Stepwise Analysis). The variables selected were in this order: diastase activity, pH, reducing sugars, free acidity and HMF. The pollen spectrum has perfect discriminatory power. This is the first study in which a honey with PDO was tested, in order to assess its compliance with the PDO book of specifications.
- Contribution of non-genetic factors to the reproductive performance of mirandesa cowsPublication . Sousa, Fernando Ruivo de; Blanco-Penedo, Isabel; Cantalapiedra, Jesús J.; Sanchez, L.; Iglesias, Antonio; Colaço, A.J.; Payan-Carreira, R.Characterization of reproductive traits in Mirandesa beef cattle is important for breed improvement and conservation, mainly due to its little genetic diversity. Reduced individual and maternal performance is often associated with inbreeding depression, which could be further aggravate the environmental effects. In this study, 7386 herd records for Mirandesa were used to characterize the main reproductive traits, like age at first calving (AFC), pregnancy length (PL), calving interval (CI), yearly calving distribution (CD) and productive lifespan (PLf). The non-genetic effects were tested using non-parametric methods, as the target variables were not normally distributed. The median for AFC in Mirandesa was close to 32 months; AFC was affected by the production system, farm and by the year and season of birth. The mean for PL was 287±8.9 days, being affected by parity and calf gender. The median CI, of 378 days, was only affected by the breeding program, parity, season and year. Calving season was unevenly distributed over the year, showing different patterns after the production system. The mean productive lifespan of Mirandesa was 6.45 years, though 20% of the cows presented a PLf longer than ten years. The main non-genetic effects suggested that farmer´s decision and nutrition may constrain the expression of the reproductive traits in Mirandesa breed. This aspect needs to be addressed when designing any breeding programs which should prioritise for the increase in the number of calves per year along with a careful selection of reproducers to decrease reported inbreeding.
- Developments in the fermentation process and quality improvement strategies for mead productionPublication . Iglesias, Antonio; Pascoal, Ananias; Choupina, Altino; Carvalho, Carlos Alfredo Lopes de; Feás, Xesús; Estevinho, Leticia M.Mead is a traditional alcoholic drink derived from the fermentation of diluted honey in the presence of appropriate yeast. Its modern production, in general terms, involves the addition of nutrients to initial diluted honey, pasteurization, yeast inoculation, fermentation and removal of impurities. Undesirable events along the process have been reported; among them, we highlight: delayed or arrested fermentations, modified and unpleasant sensory and quality parameters of the final product. These problems have been linked to the inability of yeasts to accomplish their role in extreme growth conditions. Emphasis has also been placed on the long fermentation times required, ranging from weeks to months, particularly when traditional procedures are applied and when the honey concentration is low. A series of alterations to the must and technological changes have been proposed in order to optimize the mead production process. In this context, this review examines the evidence that aims to improve meads’ quality and make the production process easier and more efficient, by clarifying the source of unexpected events, describing the implementation of different fermentative microorganisms and using new methodologies.
- Effect of Erica sp honey against microorganisms of clinical importance: study of the factors underlying this biological activityPublication . Feás, Xesús; Iglesias, Antonio; Rodrigues, Sandra; Estevinho, Leticia M.This study aimed to determine the factors (phenolic compounds, flavonoids, sugars or H2O2) that contribute the most to the antimicrobial activity of heather honey samples against four yeasts and four bacteria with medical importance. To discard the effect of H2O2 in the antimicrobial activity, catalase was added. To evaluate the osmotic pressure’s effect, artificial honey was also used. Phenolic compounds and flavonoids were determined and Pearson’s correlation analysis was performed to assess whether these correlated with antimicrobial activity. The amount of phenolic compounds ranged from 630.89 ± 5.21 GAE kg−1 to 718.92 ± 4.41 GAE kg−1, while the flavonoids varied between 450.72 ± 5.67 CAE kg−1 and 673.98 ± 4.33 CAE kg−1. For the bacteria, the minimum inhibitory concentration (MIC) of the honey without catalase ranged from 1.01 ± 0.50% to 10.00 ± 4.72% and was between 2.00 ± 0.94% and 13.27 ± 5.23% for honey with catalase. Concerning the yeasts, the MICs was between 13.16 ± 4.08% and 20.00 ± 5.09% for honey without catalase and between 14.95 ± 4.16% and 25.67 ± 5.50% for honey with catalase. The elucidation of the antimicrobial factors and action mechanisms is essential for the correct use of honey in therapeutic applications.
- Organic bee pollen: botanical origin, nutritional value, bioactive compounds, antioxidant activity and microbiological qualityPublication . Feás, Xesús; Vázquez-Tato, Maria Pilar; Estevinho, Leticia M.; Seijas, Julio; Iglesias, AntonioOrganic bee pollen (BP, n = 22) harvested from the Douro International Natural Park (DINP, Portugal) was studied. Nine botanical families were found in the mixture of the samples. The water activity and pH ranged 0.21–0.37 and 4.3–5.2, respectively. The BP analyses averaged 67.7% carbohydrates, 21.8% crude protein, 5.2% crude fat and 2.9% ash. The energy ranged from 396.4 to 411.1 kcal/100 g. The principal fatty acid found was linolenic, followed by linoleic acid, palmitic acid and oleic acid. The phenolic and flavonoid contents varied from 12.9 to 19.8 mg of gallic acid equivalents/g of extract and from 4.5 to 7.1 mg of catechin equivalents/g of extract, respectively. The scavenger activity and β-carotene bleaching assays values (EC50) were 3.0 ± 0.7 mg/mL and 4.6 mg/mL ± 0.9 mg/mL, respectively. E. coli, sulphite-reducing Clostridia, Salmonella and S. aureus were not found. Since there are studies indicating appreciable differences among BPs from different regions, the full characterization of BP from diverse origins still appears to be a sound research priority in order to obtain reliable data about this beehive product.
- Palynological and physicochemical data characterisation of honeys produced in the Entre-Douro e Minho region of PortugalPublication . Feás, Xesús; Pires, José; Estevinho, Leticia M.; Iglesias, Antonio; Araújo, José PedroHoney legislation has been addressed to establish the minimum marketing level of the product and the need for consumer protection through correct denominations. Research oriented toward assessment of floral origin and physicochemical properties may increase the commercial value of these products. The characteristics of thirty-one honeys produced in the Entre-Douro e Minho region in Portugal were studied. Pollen features and some physicochemical parameters (moisture, ash, pH, free acidity, electrical conductivity, hydroxymethylfurfural contain, apparent sucrose, reducing sugars and diastase activity) were determined. The samples were found to meet international honey specifications. The present study found a linear regression between the ash content of honeys and their specific conductivity. Five samples are listed as Eucalyptus honey, one sample as Citrus honey, and twenty-five samples as multifloral honeys. Of the total, 87.1% exceeded the quality parameters and should be labelled as ‘virgin’ honey.
- Pollen spectrum and physico-chemical attributes of heather (Erica sp.) honeys of north PortugalPublication . Pires, José; Estevinho, Leticia M.; Feás, Xesús; Cantalapiedra, Jesús J.; Iglesias, AntonioHoney legislation has been addressed to establish the minimum marketing level of the product and the need for consumer protection through correct denominations. Research oriented toward assessment of floral origin and physicochemical properties may increase the commercial value of these products. The characteristics of 23 unifloral honeys of Erica sp., from Portugal, were studied. Pollen features and some physicochemical parameters (moisture, ash, pH, free acidity, electrical conductivity, hydroxymethylfurfural content, apparent sucrose, reducing sugars and diastase activity) were determined. RESULTS: All honey samples can be classified as monofloral Erica sp., they gave a mean value of 56% of Erica pollen type. The families Fabaceae and Rosaceae provided the greatest number of pollen types with 8 and 4 pollen types each respectively. The second most important pollen type is Eucalyptus, present in 69.6% of the samples. All honey samples met the international physicochemical quality standards. The present study found a linear correlation (R = 0.996) between the ash content of honeys and their specific conductivity. CONCLUSION: All honey samples can be classified as monofloral Erica sp. Unifloral honeys are increasingly requested and appreciated, despite their higher prices. The samples were found to meet allmajor international honey specifications.