Percorrer por autor "Revilla, Isabel"
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- Determination of Carbohydrate Composition in Lentils Using Near-Infrared SpectroscopyPublication . López-Calabozo, Rocío; Liberal, Ângela; Fernandes, Ângela; Revilla, Isabel; Ferreira, Isabel C.F.R.; Barros, Lillian; Vivar-Quintana, Ana MariaCarbohydrates are the main components of lentils, accounting for more than 60% of their composition. Their content is influenced by genetic factors, with different contents depending on the variety. These compounds have not only been linked to interesting health benefits, but they also have a significant influence on the techno-functional properties of lentil-derived products. In this study, the use of near-infrared spectroscopy (NIRS) to predict the concentration of total carbohydrate, fibre, starch, total sugars, fructose, sucrose and raffinose was investigated. For this purpose, six different cultivars of macrosperm (n = 37) and microsperm (n = 43) lentils have been analysed, the samples were recorded whole and ground and the suitability of both recording methods were compared. Different spectral and mathematical pre-treatments were evaluated before developing the calibration models using the Modified Partial Least Squares regression method, with a cross-validation and an external validation. The predictive models developed show excellent coefficients of determination (RSQ > 0.9) for the total sugars and fructose, sucrose, and raffinose. The recording of ground samples allowed for obtaining better models for the calibration of starch content (R > 0.8), total sugars and sucrose (R > 0.93), and raffinose (R > 0.91). The results obtained confirm that there is sufficient information in the NIRS spectral region for the development of predictive models for the quantification of the carbohydrate content in lentils.
- Effect of melatonin implants on carcass characteristics and meat quality of slow-growing chickensPublication . Nieto, Jaime; Leite, Ana; Vasconcelos, Lia; Plaza, Javier; Abecia, José-Alfonso; Revilla, Isabel; Palacios, Carlos; Teixeira, AlfredoThis study evaluated the effect of melatonin implants on carcass characteristics and meat quality of slow-growing broilers slaughtered at 43 and 97 days (d) of age. A total of 128 one day-old male broilers (Coloryeld) were randomly divided into two groups, which in turn were divided into 8 groups (replicates) of 8 broilers each one. One group (64 animals) was the control group (C) and the other received a melatonin implant (18 mg melatonin per animal) at 8 d of age (M). The animals were reared for 97 d. For the first 42 d they were kept in an enclosed facility and then allowed access to the outside. Two culls were performed: one at 43 d and one at 97 d, randomly selecting 8 chicks from each group at each time (N = 8 × 2 × 2= 32). Carcass traits and meat quality were evaluated on these samples. Chickens slaughtered at older ages had higher dead-plucked, leg and carcass weights (P < 0.05). In terms of meat quality, chickens slaughtered at 97 days had higher L* (P < 0.001), lower a*, b* and chroma values (P < 0.01), as well as lower pH (P = 0.006), higher shear strength (P < 0.001), water holding capacity (P < 0.001) and water activity (P = 0.036). The melatonin implants did not influence carcass characteristics (P>0.05). Luminosity, tone and water activity decreased with melatonin implants at 43 d of age (P <0.001), whereas pH increased (P = 0.004). At 97 d after slaughter, meat yellowness was lower (P = 0.028) and firmness increased (P = 0.029). At both time points, melatonin caused reddening of the meat (P < 0.001). Lipid oxidisability tended to be reduced, extending the shelf life of the meat (P = 0.068). The fatty acid profile was little affected by the placement of the implants. Age and melatonin have different effects on the meat quality of slow-growing chickens. While age affects several factors such as texture and fatty acid profile, melatonin improves colour, water activity and lipid oxidation. Its use could improve preservation and extend the shelf life of meat