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- Chemical and Physical Properties of Some Hazelnut Varieties Grown in PortugalPublication . Ferrão, Ana Cristina; Guiné, Raquel P. F.; Ramalhosa, Elsa; Lopes, Arminda; Rodrigues, Cláudia Filipa; Martins, Hugo; Gonçalves, Roberto; Correia, PaulaHazelnuts are one of the most appreciated nuts worldwide due to their unique organoleptic and nutritional characteristics. The present work intended to analyse several physical and chemical properties of different hazelnut varieties grown in Portugal, namely Tonda de Giffoni, Grada de Viseu, Segorbe, Longa de Espanha, Butler, Gunslebert, and Negreta. In general, the results revealed statistically significant differences between the varieties under study. The Gunslebert had more elongated hazelnuts and with heavier shelled fruits, while the kernels of the Grada de Viseu revealed to be heavier. Grada de Viseu was harder in the shell, Gunslebert had a harder core, and Segorbe was more resistant to fracture. Fat was the more representative component for all varieties and in some cases the values of moisture and water activity were over the recommended amount (≥0.62). Tonda de Giffoni was the variety with the highest induction time, indicating the highest oxidation stability. Moreover, discriminant analysis revealed that the variables more important to distinguish the varieties were protein (λ = 0.007) and water activity (λ = 0.010). The results of this study help to better understand the differences between some hazelnut varieties that are cultivated in Portugal, which gives important hints for all players in the hazelnut sector.
- Influence of Temperature and Packaging Materials in Ewe’s Cheeses StoragePublication . Correia, Paula; Guiné, Raquel; Rodrigues, M. C.; Mendes, R.One of the major concerns in cheese production is the shelf life extension, and the use of different conservation methods is extremely important. During commercialization period several problems often appear, like molds or packages that change the characteristics of cheese, which concerns the producers because they can lead to significant economic losses. The objective of this work was to evaluate the quality of the effect of temperature and packaging material in ewe’s cheeses during 120 days of storage. Cheeses were produced by industrial manufacture from raw ewe’s milk produced by animals of breeds Bordaleira Serra da Estrela and Churra Mondegueira, in Seia district, belonging to the PDO (Protected Designation of Origin) of Serra da Estrela cheese region of Portugal. Cheeses were subject to two different storage conditions: control chamber (CC) [16 ± 1 0 C and RH (relative humidity) of 75 ± 2%], packaging in vacuum with a high barrier blade film and polyolefin shrink film; and refrigeration with a mean temperature of 7 0 C and HR 47%, simulating the usual commercial storage. The ewe’s cheeses were analysed in three different moments: at 1, 60 and 120 days. Several physicochemical parameters were evaluated: moisture, water activity, colour, and texture. A hygrometer, at 25 0 C, was used to determine the water activity of cheeses. The colour parameters were measured using a colorimeter, and the Cartesian Coordinates were measured: L*, a* and b* (CIELab colour space). A texturometer TA-XT2 was used for analysis of the textural parameters. A spreadability test was performed. The test consisted in measurement of force under compression with a probe P/1S (1 inch stainless ball). Sensory analysis was also performed, involving a descriptive sensory profile performed by 25 persons which evaluated the appearance, aroma, taste, texture and global appreciation. The cheeses packed in polyolefin film presented molds after 20 days of storage. The moisture content and water activity were high in the initial stage of storage, but they decrease with storage time, and this effect was more evident in the unpacked cheeses. Vacuum packed cheeses stored in CC (CCP) presented similar colour parameters along storage time, with high L* and low b* values. The harder cheeses were the CC cheeses after 120 days (CC120) of storage, and the stickier ones were the CCP120. The refrigerated cheeses were the most appreciated by the panellists, followed by cheeses stored at the CC with vacuum package, and the buttery attribute showed high differences. After 120 days of storage, the biggest differences between the two conservation processes were in the moisture content, stickiness and adhesiveness. Moreover, cheeses packaged with a high barrier blade film Polyethylene Terephthalate/Polyamide/ Ethylene Vinyl alcohol/Polyethylene (PET/PA/EVOH/ PE) preserved their moisture content and the water activity when compared with unpackaged cheeses. During storage cheeses changed their colour in all processes, being the cheeses in the control chamber were less dark and less yellow. In general, cheeses were less hard than the control, independently of storage process and time. The refrigeration process was the one that preserved the best characteristics of stored cheese. In conclusion, the conservation process, the storage time and the packaging material influenced the physical and sensorial properties of the cheeses.
- Physical properties of frozen ewe’s cheesePublication . Correia, Paula; Rodrigues, Melania; Mendes, Rita; Guiné, RaquelThis work evaluates the effect of freezing and storage time in ewe´s cheese. Ewe´s cheeses were subject to two different conservation conditions: frozen at -60 C, with storage at -18 C (Frozen), and refrigeration at 7 C, with a RH (relative humidity) of 47% (Control). The initial values of moisture and water activity (a w ) were high and similar between the analysed samples, 62.2-61.3 % and 0.91-0.92 respectively, with a decrease of moisture during the storage, being lower in the Frozen sample. The cheeses presented an light colour (L* = 69.0 and 74.6), which decreased during storage. The a* and b* coordinates showed negative and positive values, respectively, meaning that the predominant colours were green and yellow, and generally during storage they diminished. The texture of cheeses, in the first day of storage, presented similar values for Control and Frozen cheeses: 9.8 and 9.9 N for crust firmness; 3.6 and 3.9 N for flesh firmness; -2.6 and -2.8 N for stickiness; -22.7 and 24.7 N.sec for adhesiveness. Finally, after 120 days of storage for these cheeses, the crust firmness, the stickiness and the adhesiveness decreased more about three times.
- Development of New Pastry Products and Jams with Shiitake MushroomsPublication . Correia, Paula; Monteiro, Jéssica; Guiné, RaquelThe present study aimed at promoting the Shiitake mushroom through developments of alternative food products in the sector of pastry that may incorporated this type of mushrooms. In this way, several experiments were done and chosen to achieve the fi nal formulations and the production of jams and pies containing Shiitake pieces as ingredients, eliminating successively the less promising sensory attempts. From the developed products, three jams and two pies were selected for their optimal characteristics and these were then evaluated for physical analyses (colour and texture) as well as chemical com- position (pH, water activity, acidity, moisture, sugars, fi bre, protein, fat and ash). Furthermore, in order to check the acceptability of the products by consumers and identify the main organoleptic characteristics of each product, sensory analysis was performed by determining the sensory pro fi les using 25 panellists. The results showed that the pies were soft (hardness about 13 N), easy to chew and elastic (66 – 73%), and with similar textural attributes for both variations of pie (with apple and peach based fi llings). Regarding colour, the pies showed similar results, while differences in the jams were observed. The sample with citrus fruits was darker and with a more intense red coloration. As for the chemical characteristics of the jams, it was found that these had pH values (between 3.1 and 3.6) compliant with a good gel formation to obtain a desired consistency. Furthermore, the incorporation of the Shiitake mushroom turned the products richer in protein and fi bre, with enhanced nutritional bene fi ts.
- Influence of temperatures and packaging materials in ewe´s cheeses storagePublication . Correia, Paula; Rodrigues, Melania; Mendes, Rita; Guiné, RaquelThe use of different conservation methods to increase the shelf life of food has always been a major concern. The objective of this work was to evaluate the effect of temperature and packaging material in ewe´s cheeses during storage time (at 1, 60 and 120 days). Cheeses were subject to two different storage conditions: control chamber (CC) 16±1C and RH (relative humidity) of 75±2%, packaging in vacuum with a high barrier blade film and polyolefin shrink film; and refrigeration with a mean temperature of 7C and HR 47%. The cheeses packed in polyolefin film presented molds after 20 days of storage. The moisture content and water activity were high, decreasing with storage time, and this effect was more evident in the unpacked cheeses. Vacuum packed cheeses stored in CC (CCP) presented similar colour parameters along storage time, with high L* and low b* values. The harder cheeses were the CC cheeses after 120 days (CC120) of storage, and the stickier ones were the CCP120. The refrigerated cheeses were the most appreciated, followed by cheeses stored at the CC with vacuum package, and the buttery attribute showed high differences. The conservation process greatly influenced the physical and sensorial properties of the cheeses.
- Physical properties of frozen ewe’s cheesePublication . Correia, Paula; Rodrigues, Melania; Mendes, Rita; Guiné, RaquelThis work evaluates the effect of freezing and storage time in ewe´s cheese. Ewe´s cheeses were subject to two different conservation conditions: frozen at -60C, with storage at -18C (Frozen), and refrigeration at 7C, with a RH (relative humidity) of 47% (Control). The initial values of moisture and water activity (a w ) were high and similar between the analysed samples, 62.2-61.3% and 0.91-0.92 respectively, with a decrease of moisture during the storage, being lower in the Frozen sample. The cheeses presented a light colour (L* = 69.0 and 74.6), which decreased during storage. The a* and b* coordinates showed negative and positive values, respectively, meaning that the predominant colours were green and yellow, and generally during storage they diminished. The texture of cheeses, in the first day of storage, presented similar values for Control and Frozen cheeses: 9.8 and 9.9 N for crust firmness; 3.6 and 3.9 N for flesh firmness; -2.6 and -2.8 N for stickiness; -22.7 and 24.7 N.sec for adhesiveness. Finally, after 120 days of storage for these cheeses, the crust firmness, the stickiness and the adhesiveness decreased more about three times.