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- Effect of storage conditions on the quality of the bee pollenPublication . Estevinho, Leticia M.; Rocha, Joana; Pascoal, Ananias; Pereira, Ana Paula; Choupina, AltinoBee pollen (BP), is the result of the agglutination of flower pollens, made by worker honey bees, with nectar and salivary substances and collected at the hive entrance. The collection of AP is a relatively recent development, dependent primarily on the basic concept of scraping pollen of the bees' legs as they enter the hive. The objective of this work was to evaluate the effect of storage conditions in the physical-chemical and microbiological parameters of organic bee pollen.
- Effect of the temperature in the honey qualityPublication . Pascoal, Ananias; Lopes, Sara; Estevinho, Leticia M.; Carvalho, MarietaHoney is the natural sweet substance produced by Apis mellifera bees from the nectar of plants, secretions of living parts of plants, or excretions of plant-sucking insects on the living parts of plants, which the bees collect, transform by combining with specific substances of their own, deposit, dehydrate, store and leave in the honeycomb to ripen and mature (Decreto-Lei nº214/2003). This product can suffer alterations if the conditions of conservation and storage are not appropriate. The objective of this work was to evaluate the effect of the temperature in the physical-chemical and microbiological parameters of monofloral honeys stored for 4 months. The evaluated physical-chemical parameters were: moisture, pH, free acidity, electrical conductivity, ashes, reducer’s sugars, apparent sucrose, hydroxymethylfurfural (HMF), diastase activity and color. Relatively to the moisture none of the samples exceeded the legislated limits. The maximum value obtained for the pH were 4.92 for the heather honey maintained to room temperature and the minimum were 3.77 for the rosemary honey in the same storage conditions. Free acidity decreased in all samples, and all storage conditions. Relatively to electrical conductivity and ash, it was found that, for rosemary and cherry honeys, independently of storage conditions, the values obtained were within legal limits. Regarding to heather and chestnut honeys, the values obtained for the mentioned above parameters exceeded the stipulated by law. In all of the analyzed samples an increase of HMF was verified along the time, being this more accentuated to 45ºC. In this case, the obtained values exceeded broadly allowed it by law. Relatively to the reducer’s sugars and the sucrose it was verified, in most of the samples a progressive decrease during storage, however, in all cases, the obtained values located inside of the legislated. In most of the samples, the diastase activity decreased over the time. The storage caused a darkening of the honey, especially for the chestnut honey, stored to 45ºC. Relatively to the microbiological analysis, the aerobics mesophylics were found in some of the analyzed samples; however they never exceeded the limits stipulated by law. The moulds and yeasts just were present in the chestnut tree honey stored in the freezer. The indicators of sanitary quality and the toxigenic species were absent in all of the samples in study.
- Evaluation of the sensory quality of monofloral honeyPublication . Estevinho, Leticia M.; Lopes, Sara; Pascoal, Ananias; Carvalho, MarietaHoney is an alimentary product much appreciated due to his aroma, flavor and nutritional characteristics. The sensorial analysis is important in the evaluation of the quality and authenticity of monofloral honeys. It considers attributes as color, aroma, consistence and flavor, which are interlinked and depend on the volatile compounds related with the fragrance of the flowers where the nectar was collected. The aroma and the flavor are also related directly with honeys’ color. The objective of this work was to evaluate the pollinic profile and the sensorial characteristics of four honeys from biological mode of production. The pollen analysis indicated that all of the analyzed honeys were monofloral,presenting as dominant pollen Lavandula sp. (45.83%), Erica sp. (49.69%), Prunus sp. (61.91%) and Castanea sp. (69.01%). The results obtained in the sensorial analysis performed by the consumer’s panel were treated by the Generalized Procrustes method. It was verified that the attributes that the consumers managed to evaluate more easily and whose contribution for the global appreciation was more accentuated were the color, the flavor and the consistence. The cherry tree honey presented higher values in the scale of preferences in terms of global appreciation, color, flavor, consistence and intermediate values regarding the aroma. Concerning the heather honey, aroma was the most valued attribute. Honeys from chestnut and rosemary were the ones that received lowest punctuation.
- The Role of Honey and Propolis in the Treatment of Infected WoundsPublication . Pascoal, Ananias; Feás, Xesús; Dias, Teresa; Dias, L.G.; Estevinho, Leticia M.Honey is defined as the natural substance produced by Apis mellifera bees from plant nectar, from secretions of the living parts of plants, or from the excretions of plant sucking insects feeding on the living parts of plants.1,2 Honeybees collect, transform, and combine this with specific substances of their own, and then store it and leave it in the honeycomb to ripen and mature. This natural product is generally composed of a complex mixture of carbohydrates and other less common substances, such as organic acids, amino acids, proteins, minerals, vitamins, lipids, aroma compounds, flavonoids, pigments, waxes, pollen grains, several enzymes and other phytochemicals.3 5 However, the specific composition depends on many factors, such as the nectar composition of the source plant, the species of bee, the climate, environmental and seasonal conditions, agricultural practices and treatment of honey during extraction and storage.6-9 As a natural, unprocessed and easily digested food, honey plays an important role in the human diet, and is also used in pharmaceutical and cosmetic industries.10 Modern science has studied the medical significance of honeys in healing wounds and burns,11 oncology care,12 as well as its antioxidant and antimicrobial properties.
- Microbiological quality and sensory evaluation of new cured products obtained from sheep and goat meatPublication . Tolentino, Georgina Santos; Estevinho, Leticia M.; Pascoal, Ananias; Rodrigues, Sandra; Teixeira, AlfredoThe present work aims to study the effect of species and seasoning time on the physicochemical, microbiological and sensory characteristics of cured legs of sheep and goats. Three cure periods were used: two for sheep and one for goat legs. Legs of lamb were cured for 7 and 8 months whereas legs of goat were cured for 8 months only. Samples were evaluated regarding pH, water activity and indicators of food microbial q uality and safety. A trained panel carried out the sensory analysis, with aroma, texture, appearance and taste being the evaluated parameters. Significant differences were detected between the amount of aerobic mesophiles of the products cured during 7 months and the sheep legs cured during 8 months. Moulds and yeasts were between 1.81 × 106 ± 1.73 × 106 and 3.97 × 106 ± 5.45 × 106 colony-forming units/g, whereas total coliforms varied from 2.80 × 102 ± 4.13 × 102 to 1.31 × 104 ± 2.39 × 104. All samples were negative for toxigenic species. Concerning sensory analysis, hardness and taste persistence were the attributes that presented the highest and the lowest discriminative power, respectively. In general, the panel was able to characterise and distinguish the samples. The cured legs of goats were characterised as harder and as less succulent than those obtained from sheep. Sheep meat with larger time of cure was the brightest, whereas the one with a smaller time of cure was the most succulent. However, goat meat presented higher values of rancid and acid flavour. Sheep meat submitted to longer processing presented the most intense flavour and sheep meat with an inferior cure period presented the lowest intensity in all flavour attributes. This paper describes, for the first time in Portugal, the production and characterisation of cured legs of sheep and goats as a strategy to enhance economic value to good quality products obtained from animals of second category.
- Impact of fining agents on the volatile composition of sparkling meadPublication . Pascoal, Ananias; Anjos, Ofélia; Feás, Xesús; Oliveira, José M.; Estevinho, Leticia M.Sparkling mead is obtained by secondary fermentation of the mead involving the addition of starter yeast culture, sucrose, nutrients and fining agents. The aim of this study was to evaluate the effect of different fining agents (tannins vs combined fining agents) on the volatile composition of sparkling mead. Sparkling mead was produced from a base mead using a commercial yeast strain (Saccharomyces bayanus) and the volatile compounds were determined by gas chromatography–flame ionisation detection and gas chromatography–mass spectrometry. Thirty six volatile compounds were quantified and the major groups were alcohols (73.2%), acetates (19.1%), carbonyl compounds (5.5%) and ethyl esters (1.2%), represented by 3-methyl-1-butanol, ethyl acetate, acetaldehyde and monoethyl succinate, respectively. The remaining compounds were present at <1%. Eleven volatile compounds exhibited odour activity values >1, with ethyl octanoate and ethyl hexanoate contributing to the aroma of sparkling mead, with fruity, strawberry and sweet notes. The combined fining agents caused a marked decrease in the concentration of volatile compounds compared with tannins. In general, 3-ethoxy-1-propanol, ethyl lactate, ethyl octanoate, diethyl succinate, diethyl malate, monoethyl succinate, 2-methylpropanoic acid, hexanoic acid, octanoic acid, acetaldehyde, acetoin, furfural, benzaldehyde, 5-hydroxymethylfurfural, trans-furan linalool oxide, cis-furan linalool oxide and 4-oxo-isophorone decreased in concentration. Conversely, 1-propanol and 2-methylpropanoic acid (tannins) and ethyl butyrate (combined fining agents) increased in concentration. The remaining volatile compounds were not affected. Significant differences (p < 0.05) were found for 19 volatile compounds independently of the type of fining agents used.
- Effect of temperature on the bioactive properties of bee pollenPublication . Pascoal, Ananias; Rocha, Joana; Choupina, Altino; Pereira, Ana Paula; Santos, Luís; Estevinho, Leticia M.Bee pollen is flower pollen collected by the honey bee, Apis mellifera, for the purpose of feeding its larvae in the early stages of development. lt is recognized to be a valuable apitherapeutic product with potential for medical, health and nutritional applications. The objective of this work was to compares the effect of different storage conditions in the bioactive compounds and biological properties of bee pollen.
- 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.
- Review: Novel sources and functions of microbial lipases and their role in the infection mechanismsPublication . Pascoal, Ananias; Estevinho, Leticia M.; Martins, Ivone; Choupina, AltinoLipases belong to the family of serine hydrolases, which in turn include various esterase enzymes (E.C.3.1.1.1). They are involved in the cleavage of triacylglycerols to free fatty acids and glycerol in many important biological processes, as for instance routine metabolism of dietary triglycerides to cell signalling and inflammation. Lipases constitute a ubiquitous group of enzymes able to catalyse a number of different reactions, many of them of industrial interest. Particularly, microbial lipases exhibit a wide range of industrial applications, namely in pharmaceutical, food and detergents industry. The aim of this review is to summarize the recent achievements illustrating the importance and the versatility of microbial lipases, including their involvement in infection mechanisms.
- Effect of processing conditions on the bioactive compounds and biological properties of bee pollenPublication . Dias, L.G.; Tolentino, Georgina Santos; Pascoal, Ananias; Estevinho, Leticia M.Bee pollen has had a valued place in traditional medicine for centuries, even though its use in modern medicine is still limited by the lack of scientific evidence. In this study, we characterized and compared nine types of bee pollen, submitted to two preservation methods (lyophilization and drying), in relation to the content of phenolic compound and total flavonoids. The biological properties were also evaluated and compared. Pollen analysis allowed us to classify two samples as heterofloral, whilst the remaining were monofloral. The concentrations of flavonoid and phenolic compounds were greater in the lyophilized samples. Even though all samples presented antimicrobial activity, the lyophilized ones induced stronger inhibition against both Gram-negative and Gram-positive bacteria. For the yeasts studied, the difference between the two preservation procedures was not so relevant. The antioxidant activity was also greater in the lyophilized samples. Antimutagenic capacity was observed in all samples, independently of the preservation method, even though some bee pollen types decreased the number of gene conversion and mutant colonies more efficiently. In conclusion, the results suggest that lyophilization is better to preserve the bioactive compounds and biological properties of this natural product.