Browsing by Author "Tenreiro, Marlene"
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- Effect of diferente thistle flowers as milk-clitting in Serra da Estrela cheesePublication . Correia, Paula; Vítor, André; Tenreiro, Marlene; Correia, Paulo; Correia, Ana Cristina; Madanelo, João; Carvalho, Marta; Guiné, RaquelThistle flower (Cynara cardunculus) aqueous extracts, as rich source of milk-clotting peptidases, have been widely used for cheeses marketed under the Registry of the Protected Designation of Origin, as it is the case of Serra da Estrela cheese, manufactured from raw ewes ‘milk and without addition of any commercial starter culture. This work was aimed at studying the influence of six different ecotypes of thistle flowers in cheese properties during the ripening, and at final products. The clotting time, weight and colour of cheeses, as well as texture properties and sensorial characteristics were evaluated. The chemical composition of sheep milk was determined for all cheese batches, and it did not change among them. The clotting time varied from 66 to 21 minutes, the loss of weight decreased slightly with the similar tendency but with quite different values. Generally, there was a little influence of thistle flower ecotype on L* and b*colour parameters, during the ripening process and in final product, but there was a significant influence on a* parameter. Serra da Estrela cheese produced with different extracts of thistle flower presented different sensorial properties, meaning that with a strong knowledge of the properties assigned by these different flower extracts it is possible to produce a specific cheese attending to different consumer targets.
- Effect of different thistle flower ecotypes as milk-clotting in Serra da Estrela cheesePublication . Correia, Paula; Vítor, André; Tenreiro, Marlene; Correia, Ana Cristina; Madanelo, João; Guiné, RaquelPurpose – Thistle flower( Cynara cardunculus) aqueous extracts, as rich source of milk-clotting peptidases, have been widely used for cheeses marketed under the Registry of the Protected Designation of Origin, as it is the case of Serra da Estrela cheese, manufactured from raw ewes’ milk and without addition of any commercial starter culture. This paper aims at studying the influence of six different ecotypes of thistle flowers in cheese properties during the ripening and of final products. Design/methodology/approach – Cheeses were produced with different thistle flower extracts and then the clotting time, weight and colour of cheeses, as well as texture properties and sensorial characteristics, were evaluated. Findings – The clotting time varied from 47 to 66 min, and the weight loss along ripening varied between 32 and 40 per cent. There was some influence of thistle flower ecotype on the colour during ripening and in the final product. The results of texture analysis revealed significant differences between the thistle ecotypes: crust firmness varying from 2.4 to 5.6 N; inner firmness from 0.82 to 1.82 N; stickiness from 0.5 to 1.60 N; adhesiveness from 3.0 to 11.3 N.s; and Ecotype C was particularly distinguishable. Sensorial evaluation revealed differences among the cheeses, with Ecotype C receiving the highest score for global appreciation. Originality/value – The usage of different extracts of thistle flower to produce Serra da Estrela cheese with different properties is a novelty, and it allows the possibility of manipulating this parameter in the future so as to produce cheeses with specific characteristics, addressed to different consumer targets.
- Effect of Thistle Ecotype in the Physical-Chemical and Sensorial Properties of Serra da Estrela CheesePublication . Guiné, Raquel; Tenreiro, Marlene; Correia, Paula; Barracosa, Paulo; Correia, Ana CristinaThe objective of this study was to evaluate the physical and chemical characteristics of Serra da Estrela cheese and compare these results with those of the sensory analysis. For the study were taken six samples of Serra da Estrela cheese produced with 6 different ecotypes of thistle in a dairy situated in Penalva do Castelo. The chemical properties evaluated were moisture content, protein, fat, ash, chloride and pH; the physical properties studied were color and texture; and finally a sensory evaluation was undertaken. The results showed moisture varying in the range 40- 48%, protein in the range 15-20%, fat between 41-45%, ash between 3.9-5.0% and chlorides varying from 1.2 to 3.0%. The pH varied from 4.8 to 5.4. The textural properties revealed that the crust hardness is relatively low (maximum 7.3 N), although greater than flesh firmness (maximum 1.7 N), and also that these cheeses are in fact soft paste type, with measurable stickiness and intense adhesiveness. The color analysis showed that the crust is relatively light (L* over 50), and with a predominant yellow coloration (b* around 20 or over) although with a slight greenish tone (a* negative). The results of the sensory analysis did not show great variability for most of the attributes measured, although some differences were found in attributes such as crust thickness, crust uniformity, and creamy flesh.
- Effect of Thistle Ecotype in the Physical-Chemical and Sensorial Properties of Serra da Estrela CheesePublication . Guiné, Raquel; Tenreiro, Marlene; Correia, Paula; Barracosa, Paulo; Correia, AnaThe objective of this study was to evaluate the physical and chemical characteristics of Serra da Estrela cheese and compare these results with those of the sensory analysis. For the study were taken six samples of Serra da Estrela cheese produced with 6 different ecotypes of thistlein a dairy situated in Penalva do Castelo. The chemical properties evaluated were moisture content, protein, fat, ash, chloride and pH; the physical properties studied were color and texture; and finally a sensory evaluation was undertaken. The results showed moisture varying in the range 40- 48%, protein in the range 15-20%, fat between 41-45%, ash between 3.9-5.0% and chlorides varying from 1.2 to 3.0%. The pH varied from 4.8 to 5.4. The textural properties revealed that the crust hardness is relatively low (maximum 7.3 N), although greater than flesh firmness (maximum 1.7 N), and also that these cheeses are in fact soft paste type, with measurable stickiness and intense adhesiveness. The color analysis showed that the crust is relatively light (L* over 50), and with a predominant yellow coloration (b* around 20 or over) although with a slight greenish tone (a* negative). The results of the sensory analysis did not show great variability for most of the attributes measured, although some differences were found in attributes such as crust thickness, crust uniformity, and creamy flesh.
- Influence of different processing parameters in physical and sensorial properties of Serra da Estrela cheesePublication . Correia, Paula; Vítor, André; Tenreiro, Marlene; Correia, Ana Cristina; Pinto, António; Barracosa, Paulo; Madanelo, João; Vacas, Marta; Guiné, RaquelIntroduction: Cheese is a classical dairy product, which is strongly judged by its appearance, flavour and texture. Processing parameters that could affect cheese structure play a dominant role upon the features exhibited by the final product. Serra da Estrela cheese is a DOP cheese manufactured from raw ewes’ milk and curdled with thistle flowers aqueous extract. The aim of this study was the evaluation of physical and sensorial properties of cheeses, produced with thistle flowers from different ecotypes and added in different quantities to milk from sheep breed. Other variable factors were salt quantity and ripening moisture. Materials and methods: Two dairies were involved in this study: ANCOSE and Quinta das Lameiras. The chemical composition of sheep milk was determined for all cheese batches. The clotting time, the evolution of weight and colour, the texture and sensorial characteristics of cheeses were evaluated. Results: Both dairies presented similar chemical sheep milk composition. The clotting time is independent of the quanties of thistle aquous extracts added to the milk, and it is similar for both dairies, varaing from 36-47 minutes. The loss of weight showed a similar decreasing tendency but with quite different values. Generally, the thistle flower ecotype didn’t influence the L and b*colour parameters during the ripening process and in the final product, but there was a significant influence on a* parameter. The textural analysis results reveal significant differences between the two dairies for the same thistle flower ecotype, considering the crust and inner firmness, stickiness and adhesiveness. Cheeses presented different sensorial properties, considering the different processing parameters studied. Conclusions: Serra da Estrela cheese produced in both dairies presented different physical and sensorial properties, meaning that with a strong knowledge of the properties assigned by these different flower extracts and with the control of some processing parameters it is possible to produce a specific cheese attending to different consumer targets.
- Influence of different processing parameters in physical and sensorial properties of Serra de Estrela cheesePublication . Correia, Paula; Vítor, André; Tenreiro, Marlene; Correia, Ana Cristina; Pinto, António; Correia, Paulo; Madanelo, João; Vacas, Marta; Guiné, RaquelCheese is a classical dairy product, which is strongly judged by its appearance, flavour and texture. Processing parameters that could affect cheese structure play a dominant role upon the features exhibited by the final product. Serra da Estrela cheese is a Protected Denomination of Origin (PDO) cheese manufactured from raw ewes ‘milk and curdled with thistle flowers. The study aimed to evaluate cheeses physicochemical, microbiological and sensorial properties, produced with two thistle flowers ecotypes added in different quantities to milk, sheep bread, salt quantity and ripening moisture. Two dairies were involved in this study, named as A and B, both with certification. The sheep milk chemical composition (moisture, protein, fat, solids-non-fat, lactose, solids, density, freezing point), and microbial analysis (coliforms and total enumeration of microorganism at 30ºC) were determined, using respectively a Lactoscan equipment and norms ISO 4832:2006 and 4833-1:2013. The clotting time, the evolution of weight loss and color, the texture (texturometer TA-XT Plus) and sensorial characteristics of cheeses were evaluated. Both dairies presented similar chemical sheep milk composition and clotting time for the same thistles flower, varying from 36-47 minutes. The loss of weight showed similar decreasing and tendency. Generally, the thistle flower ecotype didn’t influence the L, a* and b* color parameters, during the ripening process and in the final product there was a significant influence on a* parameter. The textural analysis revealed significant differences between the two dairies for the same thistle flower ecotype, considering the inner firmness, stickiness and adhesiveness. Cheeses presented similar sensorial properties, considering the different processing parameters studied. Serra da Estrela cheese produced in both dairies presented different physical and sensorial properties, meaning that with a strong knowledge of the properties assign by processing parameters it is possible to produce a specific cheese attending to different consumer targets.
- Serra da Estrela Cheese: evaluation of the thistle ecotype on the physical, chemical and sensorial propertiesPublication . Tenreiro, Marlene; Guiné, Raquel; Barracosa, Paulo; Correia, Paula; Correia, Ana CristinaSerra da Estrela cheese is the most famous variety of farm cheese manufactured in Portugal. Its manufacture is artisanal, from raw ewe's milk of a native breed (Bordaleira da Serra da Estrela), which is coagulated using an aqueous extract of the wild thistle (Cynara cardunculus), without deliberate addition of any starter culture [1-2]. The study of microstructure in specialty cheeses is relevant to sensory features and to fundamental explanation of the changes observed throughout cheese ripening [3]. The objective of this study was to evaluate the physical, chemical and sensorial characteristics of Serra da Estrela cheese produced with different thistle ecotypes. In this study 29 samples of Serra da Estrela cheese produced with 6 different thistle ecotypes in various dairies in the area demarcated for the production of Serra da Estrela cheese were analysed. The chemical properties assessed were moisture content, pH, chloride, ash and proteins; the physical properties evaluated were colour and texture; and finally a sensory evaluation was undertaken. The results obtained showed values for moisture between 34.9% and 49.8%, for ashes varying from 3.4% to 5.5%, and for proteins varying from 21.9% to 13.0%. The chlorides ranged between 1.1% and 3.0% and pH between 4.8 and 5.7. It was further observed that for longer ripening, and therefore lower humidity, the samples exhibited higher firmness and lower stickiness and adhesiveness. The values of hardness of the skin and flesh varied in the ranges 1.56-9.40 N and 0.4-3.4 N, respectively. The stickiness was quite high (-26.29 to -2.21 N.sec), which reflects the creamy character of these soft paste cheeses. The colour coordinates were evaluated on the skin and the values obtained were 53.57 to 64.34 for L*, -4.53 to 1.29 for a* and 15.56 to 29.03 for b*, showing a clear yellowish colour. The results of the sensory analysis did not show a noticeable variability between the different ecotypes, and it was further observed that, in general, the instrumental analyses eventually confirm the perception of panellists.