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The global production of aquatic organisms has grown steadily in recent decades. This increase in production results in high volumes of by-products and waste, generally considered to be of low commercial value and part of them are consequently discarded in landfills or in the sea, causing serious environmental problems when not used. Currently, a large part of the reused aquaculture waste is destined for the feed industry. This generally undervalued waste presents an important source of bioactive compounds in its composition, such as: amino acids, carotenoids, chitin and its derivatives, fatty acids and minerals. These compounds are capable of offering numerous benefits due to their bioactive properties. However, the applicability of these compounds may be opportune in several other sectors. This review describes studies that seek to obtain and apply bioactive compounds from different sources of aquaculture waste, thus adding commercial value to these underutilized biomasses. Volume of aquaculture industrial waste from crustaceans and mollusks. Quantity and quality of bioactive components in aquaculture waste. Applications of recovered proteins, lipids, chitin, carotenoids and minerals. Future prospects for the destination of aquaculture waste. [ABSTRACT FROM AUTHOR]

Potential of the enzyme peroxidase (PO) from soybean meal to mitigate aflatoxin B1 (AFB1) in fish feed was evaluated. Reaction parameters studied in the wet stage of the feed production process were enzyme activity (0.01–0.1 U/g), temperature (20–36 °C), time (0–8 h) and humidity content (40–70%). Feed was produced in conformity with the National Research Council and spiked with AFB1 at 10 ng/g. Any residual concentration of AFB1 in the diet was extracted by the QuEChERS method and quantified by a liquid chromatograph with a fluorescence detector. AFB1 mitigation of 90% was reached when feed production conditions were 0.035 U/g, 32 °C, 6 h and 70% humidity. Therefore, application of PO to the feed industry may be considered a promising tool for mitigation of AFB1, considering its toxicity and frequent occurrence. In addition, it guarantees safe food for consumers of fish farming products, as AFB1 can bioaccumulate in the food chain. It also provides an alternative use for soybean meal that would previously be discarded. [ABSTRACT FROM AUTHOR]

Bioaccessibility of aflatoxin B1 (AFB1) found in contaminated peanut meal was assessed by an in vitro system that simulated conditions of Nile tilapia (Oreochromis niloticus) intestine. Peanut meal containing 17.1 µg kg−1 AFB1 was used as substrate. Reference assays were carried out with intestinal enzyme extracts from adult tilapia under realistic physiological conditions of enzyme/substrate ratio (0.21 U mg−1), pH (8.2), and temperature (25 °C). Different factors that could potentially affect bioaccessibility of AFB1 were evaluated: total digestion time (3 to 6 h), relative amount of substrate (250 to 750 mg), and amount of rice husk used as adsorbent (1:1 and 1:2, peanut meal/rice husk). AFB1 released after digestive hydrolysis was extracted by QuEChERS and quantified by a multi-reader. Bioaccessibility of AFB1 increased with digestion time (from 36 after 3 h to 100% after 6 h) and with the amount of substrate. In contrast, rice husk reduced bioaccessibility of AFB1 by 28 and 20% in ratios of 1:1 and 1:2, respectively. Therefore, this study suggests not only that in vitro assays may be used as prospective assays to evaluate bioaccessibility of AFB1 under species-specific digestive conditions, but also that inclusion of rice rusk in feed may be a promising tool to reduce mycotoxin bioaccessibility. [ABSTRACT FROM AUTHOR]

This work investigates the effect of adding different sources of organic carbon in biofloc systems on water quality, microorganisms' density and zootechnical performance of juvenile Mugil liza raised in the biofloc system indoors over 45 days. Fish (±7.99 g) were stored at a density of 15 fish per tank and fed a commercial feed of 42% protein. The study was arranged in three treatments according to the carbon source: dextrose—DE, liquid molasses—LM and rice bran—RB, and one control with no bioflocs (clear water—CW), all in triplicate. The treatments had no influence (p > 0.05) on the performance parameters of the animals, survival (over 90%), as well on the productivity (between 0.35 and 0.6 kg/m3). Overall mean of total ammonia was lower (p < 0.05) in the biofloc systems than in clear water (CW). Nitrite average was lower (p < 0.05) in the bioflocs fertilized with LM and RB carbon sources, having a concentration of 1.3 ± 1.9 mg/L and 0.6 ± 0.6 mg/L respectively. RB also had the smallest range in nitrite levels throughout the study, from 0.04 to 2.5 mg/L. The LM and RB provided a greater (p < 0.05) abundance of total adhered and coccus bacteria. Water consumption was higher (p < 0.05) in the CW (1.87 m3 per tank) compared with the biofloc treatments (0.41 and 0.44 m3 per tank). Liquid molasses contributed to maintaining water quality compared with clear water, providing savings of around 80% of water. [ABSTRACT FROM AUTHOR]

This study investigated the effects of the inclusion of Mauritia flexuosa fruit pulp in the diet on the growth performance, economic benefit, muscle composition, total contents of carotenoids and flavonoids, chromaticity parameters, total antioxidant capacity, and lipid peroxidation in the hepatopancreas and muscle of the juvenile shrimp Litopenaeus vannamei (weighing 1.26 ± 0.023 g). Five diets (37% protein, 10% lipid) consisting of 0 (control), 1.25%, 2.50%, 5.00% and 10.00% (w/w) M. flexuosa fruit pulp were formulated and provided to the shrimps (n = 50 per tank, treatments in triplicate) for 31 days. Results showed that there were no significant differences between the treatments in terms of the growth capacity, chromaticity parameters, muscle composition and total flavonoid content of shrimps (p >.05). However, the carotenoid content in the muscle and hepatopancreas of the shrimps was significantly increased due to the dietary carotenoids present in M. flexuosa fruit pulp (p <.05). This increase in the carotenoid content directly favoured the increase in the antioxidant capacity in the hepatopancreas and muscle of the shrimps (R2 = 0.99 and R2 = 0.97 respectively; p <.05). There was also a direct relationship between the carotenoid content and the decrease in lipid peroxidation in the hepatopancreas (R2 = 0.90; p <.05). The feed cost kg−1 in terms of weight gain and protein production decreased with the inclusion of high levels of M. flexuosa fruit pulp, reaching 8.11% and 18.76% of cost reduction, respectively, with the addition of 5.00% of M. flexuosa fruit pulp. Therefore, the inclusion of M. flexuosa fruit pulp in the diets of shrimp can increase the carotenoid content and the antioxidant capacity in the hepatopancreas and muscle, reduce lipid peroxidation in the hepatopancreas, and probably provide economic benefits for the rearing of juvenile shrimps. [ABSTRACT FROM AUTHOR]

Five isonitrogenous and isolipidic diets were prepared with different inclusion levels of Gracilaria domingensis (GD; 0%, 5%, 10%, 15%, and 20%) with the objective to test its effects on growth and mullet immune system. The experimental diets were fed to juvenile mullet (Mugil liza, 0.42 ± 0.03g) for 60 days. The growth and expression of anti-CD3 and anti-CD4 primary antibodies for T lymphocytes were evaluated. Fish growth and feed conversion ratio decreased insignificantly by increasing GD levels up to 10% level, after which fish growth was significantly retarded. On the other hand, no significant difference was observed in granulocytes, lymphocytes, and monocytes values due to GD supplementation. Mullet fed with GD-enriched diets had a higher expression of anti-CD3 and anti-CD4 antibodies than those fed the control diet. It is concluded that a 5% inclusion level of G. domingensis in the diet increases immune competence without compromising fish growth. [ABSTRACT FROM AUTHOR]

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