Browsing by Author "Basto, Ana"
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- Inclusion of pineapple by-products as natural antioxidant sources in diets for European sea bass (Dicentrarchus labrax)Publication . Pereira, Ricardo; Basto, Ana; Pintado, Manuela; Valente, Luisa M. P.; Velasco, CristinaThis study investigates the effects of pineapple by-products on feed preservation during storage at two different temperatures (25 °C and 4 °C) and on European sea bass (Dicentrarchus labrax) stress resistance. Four isoproteic, isolipidic, and isoenergetic diets were manufactured: CTRL—negative control, commercial diet without added antioxidants; VITE—positive control, CTRL diet with 100 mg kg−1 of vitamin E; and P2 and S2—VITE diet with 2% pineapple peel or stem flour, respectively. The fish (13.5 ± 0.8 g) were split into four replicate groups per diet and fed ad libitum for 12 weeks, after which they were subjected to a stress challenge of air exposure (1 min) followed by confinement (5 min, 100 kg m−3). Despite storage time lowering the antioxidant properties of all diets, P2 and S2 showed increased antioxidant capacity (DPPH•, ABTS•+, and ORAC) before and after storage. The diets were well accepted by the fish, and the VITE-fed fish showed significantly lower lipid peroxidation values in the liver and muscle compared to all remaining diets. However, pineapple by-product inclusion did not result in increased fish stress resistance. Further optimization is required for the successful use of pineapple by-products as natural antioxidants in aquafeeds.
- Locally-sourced animal protein hydrolysates in high-plant-protein diets can promote European seabass growth and nutrient utilization, reducing reliance on fishmealPublication . Rodrigues-dos-Santos, Luciano; Basto, Ana; Monteiro, Marta; António, Carla; Rodrigues, Ana M.; Sá, Tiago; Velasco, Cristina; Martins, Rui; Rosa, Ana; Pintado, Manuela; Almeida, André; Valente, Luisa M. P.Upcycling meat and fish by-products into bioactive protein hydrolysates promotes zero-waste practices within the circular bioeconomy and provides locally-sourced alternatives to replace fishmeal (FM) in aquafeeds. In this study, novel hydrolysates were developed from blue shark skin, fish by-products, and swine processed animal protein, aiming to reduce the high-quality FM inclusion in European seabass (Dicentrarchus labrax) diets. Four isoproteic (53%) and isolipidic (18%) plant-based diets were formulated: a control (CTRL) diet containing 12.5% FM was compared to three experimental diets, including 3% of each hydrolysate at the expense of FM-protein: SHARK, FISH, and SWINE. Seabass juveniles (13 g) stocked in 160 L tanks (3.9 kg/m3) were fed the diets in triplicate, three times daily until satiety, for 89 days. All diets were equally well accepted, promoting similar feed intake, daily growth index (1.6), and efficient feed conversion ratio (1.0–1.1). All fish at least quadrupled their initial size, but those fed the SWINE diet showed the highest body weight (55 g) and significantly higher condition factor (1.22), hepatosomatic index (HSI) (1.6), and viscerosomatic index (VSI) (8.4). Intestinal integrity remained similar across treatments, and apparent digestibility coefficients (ADCs) of protein and fat were above 96%. Iron (Fe) ADC was at least doubled with hydrolysates inclusion. Whole-body and muscle composition were similar across groups. However, the muscle metabolome of the SHARK-fed fish exhibited higher levels of glycolytic intermediates and lower levels of glucogenic amino acids (AAs) and fumarate, suggesting an increased catabolic activity. However, these changes were not reflected in fish growth performance or muscle flesh quality, which remained similar among treatments.