Browsing by Author "Lima, Rui C."
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- Can sardine cooking wastewaters modulate European seabass feed intake?Publication . Resende, Daniela; Pereira, Maria J.; Sá, Tiago; Rocha, Célia; Cunha, Luís M.; Lima, Rui C.; Brazinha, Carla; Pintado, Manuela; Valente, Luísa M. P.; Velasco, CristinaThe goal of this work was to evaluate three extracts from sardine cooking waters, a by-product of the canning industry, as feed intake modulators, when included in highly vegetable diets, which often display low intake by carnivorous species. Sardine cooking waters, supplemented with acorn extract (Aroma 3) were processed, by vacuum condensation (Aroma 1) or liquid/liquid extraction with soybean oil (Aroma 2). Aromas were then included in a low-fishmeal diet (12.5%), achieving equal amounts of 1-penten-3-ol (2 μg/g). Diets were assigned to triplicate groups of 15 European seabasses (initial weight 95.7 ± 13.5 g) fed twice daily until apparent satiation in a recirculating saltwater system. Growth, nutrient utilization and wholebody composition were assessed after 18 weeks, along with both instrumental texture and color measurements and a sensory analysis of fillets. In parallel, a short-term trial was performed, in which fish fed the experimental diets were sampled 2 or 6 hours after the first feeding, for evaluation of neuropeptides involved in intake regulation. No significant differences among diets were found in fish final weight, specific growth rate, whole-body composition, and nutrient gain. Diet with Aroma 2 displayed a significantly higher voluntary feed intake than the Aroma 3, although both remained similar to the non-supplemented control. No differences on organoleptic properties were found by the panelists in the sensory analysis. No differences were found on neuropeptides expression 2h after feeding, but expression of orexigenic agrp2 was increased 6h post-feeding in all supplemented diets, in the telencephalon. Overall, results suggest that the aromas can modulate feed intake, but further optimization of incorporation levels should be performed as to see a clear effect on fish growth.
- Comparative analysis between synthetic vitamin E and natural antioxidant sources from tomato, carrot and coriander in diets for market-sized dicentrarchus labraxPublication . Pereira, Ricardo; Costa, Mónica; Velasco, Cristina; Cunha, Luís M.; Lima, Rui C.; Baião, Luís F.; Batista, Sónia; Marques, Alexandra; Sá, Tiago; Campos, Débora A.; Pereira, Miguel; Jesus, Diva; Fernández-Boo, Sergio; Costas, Benjamin; Pintado, Manuela; Valente, Luisa M.P.Synthetic vitamin E is commonly used in aquafeeds to prevent oxidative stress in fish and delay feed and flesh oxidation during storage, but consumers’ preferences tend towards natural antioxidant sources. The potential of vegetable antioxidants-rich coproducts, dried tomato (TO), carrot (CA) and coriander (CO) was compared to that of synthetic vitamin E included in diets at either a regular (CTRL; 100 mg kg−1) or reinforced dose (VITE; 500 mg kg−1). Natural antioxidants were added at 2% to the CTRL. Mixes were then extruded and dried, generating five experimental diets that were fed to European sea bass juveniles (114 g) over 12 weeks. Vitamin E and carotenoid content of extruded diets showed signs of degradation. The experimental diets had very limited effects on fish growth or body composition, immunomodulatory response, muscle and liver antioxidant potential, organoleptic properties or consumer acceptance. Altogether, experimental findings suggest that neither a heightened inclusion dose of 500 mg kg−1 of vitamin E, nor a 2% inclusion of natural antioxidants provided additional antioxidant protection, compared to fish fed diets including the regular dose of 100 mg kg−1 of vitamin E.
- Dietary inclusion of sardine cooking waters: impact on appetite regulation, growth and sensory properties of European seabassPublication . Resende, Daniela; Velasco, Cristina; Pereira, Maria J.; Sá, Tiago; Rocha, Célia; Cunha, Luís M.; Lima, Rui C.; Brazinha, Carla; Pintado, Manuela; Valente, Luísa M. P.Introduction Plant-based ingredients have been considered suitable options for replacing marinebased ones in aquafeeds (Naylor et al., 2021), but this may compromise diet palatability (Geurden et al., 2013), potentially affecting fish growth and flesh quality. To overcome this, feed attractants have been suggested. These compounds, like alcohols, aldehydes, and organic acids, were reported to stimulate intake in mammals (Chen et al., 2017; Takács et al., 2018). They can be obtained from agri-food by-products, within a circular economy framework. One example is the 9 m3 liquid waste generated by the canning industry per tonne of canned fish (Ferraro et al., 2013). The objective of this work was to extract aromas from the effluent waters of a canning industry and incorporate them in plant-based diets for European seabass. The aim was to evaluate their potential to modulate intake, growth and fillet organoleptic characteristics. Materials and methods Sardine cooking wastewaters were collected and either used directly (CW-A) or after processing by vacuum distillation (VD-A) or liquid/liquid extraction with soybean oil (LLE-A). Although the resulting extracts had different chemical profiles, the most abundant compound in all fractions was the 1-penten-3-ol. This was hence selected as marker and extracts containing 2 μg/g of this compound were incorporated in isolipidic and isoproteic diets (CW, VD and LLE) for European seabass. A non-supplemented diet was used as control (CTRL). Each diet was assigned to triplicate fish groups (initial weight 95.7 ± 13.5 g), hand-fed twice daily until apparent satiation in a recirculating saltwater system at 21 °C. After 18 weeks, growth performance and nutrient utilisation were evaluated. Flesh colour and texture were assessed instrumentally and by sensory analysis using a consumer panel. Moreover, the expression of neuropeptides involved in feed intake regulation (neuropeptide y – npy, agouti-related peptide – agrp2, cocaine and amphetamine-related transcript – carpt2 and pro-opiomelanocortin – pomca) in the brain was analysed. Metabolites in plasma and liver of fish were also quantified. Results and Conclusions Fish fed LLE displayed a significantly higher voluntary feed intake than those fed the CW diet, although neither differed from CTRL. LLE also resulted in increased feed conversion ratio. Final weight, whole-body composition, and nutrient gain were similar among diets. The expression of intake-regulating neuropeptides was not significantly affected by diets, but a slight upregulation of the orexigenic npy was observed for the LLE diet. In addition, fish fed this diet displayed the lowest plasmatic glucose and highest hepatic glucose and triglycerides values, although the remaining metabolites (lactate, non-esterified fatty acids, cholesterol and glycogen) were unaffected. Thus, the changes in feed intake are probably due to a combined effect of the homeostatic (nutrient-driven) and hedonic (pleasure-driven) regulation. No differences were found in skin or muscle colour among treatments. Despite a lower hardness in fillets of fish fed LLE when compared to those fed CTRL, no significant differences were perceived by the sensory panel; global liking of samples was similar among treatments, being all generally well accepted. Additionally, the samples’ taste and odour were characterized as “characteristic fish” and “soft” for all treatments. Overall, results suggest that aromas from sardine cooking wastewaters can modulate feed intake, but further optimization of either the processing and/or incorporation levels seems required to maximize their effectiveness as feed intake stimulants for application in aquafeeds.
- Evaluation of sardine cooking wastewaters as feed intake modulators for European seabass dietsPublication . Resende, Daniela; Velasco, Cristina; Pereira, Maria J.; Sá, Tiago; Rocha, Célia; Cunha, Luís M.; Lima, Rui C.; Brazinha, Carla; Pintado, Manuela; Valente, Luísa M.P.There has been a tendency to replace marine ingredients in aquafeeds, namely fishmeal, with more sustainable vegetable protein sources. However, this replacement often reduces diet palatability, with a subsequent decrease in feed intake and growth and/or alteration of flesh quality. The goal of this work was to evaluate the effectiveness of aromatic mixtures extracted from sardine cooking wastewaters, a by-product of the canning industry, as feed intake stimulants in highly vegetable diets for European seabass (Dicentrarchus labrax). Sardine cooking wastewaters were either used directly (CW) or after processing by vacuum condensation (VC) or liquid/liquid extraction with soybean oil (LLE). The chemical profile of the extracts differed, but the most abundant compound identified in all extracts was the 1-penten-3-ol, hence selected as marker and included at 2 μg/g in plant protein-based diets. Thus, four isolipidic and isoproteic diets (one for each aroma sample and a non-supplemented control) were produced. Diets were assigned to triplicate groups of fish (initial weight 95.7 ± 13.5 g) that were hand-fed twice daily until apparent satiation in a recirculating saltwater system at 21 °C. After 18 weeks, fish growth performance and nutrient utilisation were evaluated. Flesh colour and textural properties were assessed instrumentally and by sensory analysis using a consumer panel. Fish fed LLE displayed a significantly higher voluntary feed intake than those fed diet CW, although neither differed from the control. LLE diet also resulted in increased feed conversion ratio, but final weight, daily growth rate, whole-body composition, and nutrient gain remained similar among diets. No differences were also found in fish skin or muscle colour. Despite a lower hardness in fillets of fish fed LLE when compared to those fed the control, no significant differences could be perceived by the sensory panel; global liking of samples was similar among treatments, being all generally well accepted. Additionally, the taste and odour of all samples was similar with a “characteristic fish” and “soft” odour/taste. Overall, results suggest that the aromas from sardine cooking wastewaters can modulate feed intake, but further optimization of either the processing and/or incorporation levels seems required to potentiate their effectiveness on fish growth. The physiological mechanisms underlying the modulation of appetite also merits further evaluation.
- Incorporating sardine cooking water aromas into plant-based diets for european seabass: effects on appetite regulation, growth and sensory properties of fish fleshPublication . Resende, Daniela; Velasco, Cristina; Pereira, Maria J.; Sá, Tiago; Rocha, Célia; Cunha, Luís M.; Lima, Rui C.; Brazinha, Carla; Pintado, Manuela; Valente, Luisa M. P.Sardine cooking wastewaters are by-products of the canning industry with great potential for valorisation. We have hypothesized that they can be a source of aromas to enhance appetite when added to plant-based diets. The poor palatability of such diets often described in carnivorous species poses a recurring problem in fish farming, with harsh consequences on fish growth performance and flesh quality. Aromas from sardine cooking wastewaters were collected without processing (CW-A), processed through vacuum distillation (VD-A), or processed through liquid/liquid extraction with soybean oil (LLE-A) into plant-based diets. Each aroma was added to a plant-protein based diet for European seabass, at a concentration of 2 μg of 1-penten-3-ol/g diet, resulting in 3 experimental diets (CW, VD and LLE). A non-supplemented diet was used as a control. Each diet was assigned to triplicate fish groups (initial weight 95.7 g), that were hand-fed twice daily until apparent satiation in a recirculating saltwater system at 21 °C. After 18 weeks, fish growth performance and nutrient utilisation were evaluated. The expression in the brain of neuropeptides involved in feed intake regulation was also analysed. Moreover, flesh colour and texture were assessed instrumentally and by sensory analysis using a consumer panel. Fish fed LLE displayed a significantly higher feed intake than those fed CW which was correlated with an increased neuropeptide Y expression in the hypothalamus. However, LLE slightly hindered lipid metabolism, leading to lower available glucose and resulting in statistically similar final weights among diets. Despite variations in fillet hardness, the sensory panel revealed similar overall liking across all treatments. The findings indicate that aromas from sardine cooking wastewaters can modulate feed intake, but further refinement in processing or incorporation levels is required to potentiate their efficacy.
- Repurposing sardine cooking wastewaters as ingredients for European seabass dietsPublication . Resende, Daniela; Velasco, Cristina; Pereira, Maria J.; Sá, Tiago; Rocha, Célia; Cunha, Luís M.; Lima, Rui C.; Brazinha, Carla; Pintado, Manuela; Valente, Luísa M. P.