Biomassas microbianas na alimentação de tilápias
Data
2018-08-24
Autores
Grassi, Thiago Luís Magnani [UNESP]
Título da Revista
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Biomassas microbianas produzidas a partir de resíduos e coprodutos industriais podem ser utilizadas como fonte de proteínas e de antioxidantes em dietas de peixes, reduzindo os custos para a indústria com tratamento e descarte e auxiliando na preservação do meio ambiente. O objetivo deste experimento foi avaliar o desempenho produtivo e o status oxidativo de tilápias alimentadas com diferentes biomassas microbianas e a qualidade de sua carne. Juvenis de tilápia-do-Nilo (26,84 ± 1,03 g) foram alimentadas com as dietas experimentais durante 76 dias. Os tratamentos incluíram uma dieta controle negativo (sem biomassa microbiana), uma dieta controle com 0,01% de vitamina E (VE) e as demais contendo três tipos de biomassa microbiana em duas concentrações (0,25 e 0,5%): Rubrivivax gelatinosus (RG25 e RG50), Saccharomyces cerevisiae (SC25 e SC50) e Spirulina platensis (SP25 e SP50). Foram avaliados o desempenho e o status oxidativo dos peixes e os parâmetros físicos, químicos e bromatológicos da qualidade da carne. A inclusão de biomassa microbiana nas dietas reduziu o status oxidante total do plasma, o malonaldeído e a atividade respiratória dos leucócitos, e aumentou o status antioxidante total, sem interferir nos parâmetros bioquímicos. Todos os tratamentos apresentaram resultado similar para os parâmetros de desempenho, exceto pela conversão alimentar aparente do RG50 que foi menor que do grupo controle negativo. No filé, o uso de biomassa microbiana diminuiu as substâncias reativas ao ácido tiobarbitúrico, incrementou a intensidade de vermelho (exceto por SC) e a deposição de carotenoides (exceto por SC25), aumentou a concentração de proteínas e melhorou a relação n-6/n-3, sem interferir na textura. Os tratamentos RG25, SC25 e SP50 aumentaram a concentração do ácido eicosapentaenoico dos filés e o RG50 apresentou efeito positivo sobre desempenho dos animais. Com isso, pôde-se concluir que o uso de biomassa microbiana provocou um efeito antioxidante no plasma e melhorou a conversão alimentar dos animais, reduziu a oxidação lipídica e aumentou o teor de proteínas, a intensidade de vermelho e a concentração de carotenoides dos filés, sem influenciar negativamente na saúde dos animais.
Microbial biomass produced with industrial residues can be used as sources of proteins and antioxidants in fish feeds. The practice results in reduced amounts of waste to treat and discard and so brings benefits to the industry and to the environment. The aim of this experiment was to evaluate the growth and the oxidative status of tilapia fed microbial biomass and the quality of its flesh. Nile tilapia (26.84 ± 1.03 g) were fed one of experimental diets for 76 days. Treatments included a negative control diet (without microbial biomass), a control diet supplemented with 0.01% vitamin E (VE), and diets containing three types of microbial biomass in two concentrations (0.25 and 0.5%): R. gelatinosus (RG25 and RG50), S. cerevisiae (SC25 and SC50), and S. platensis (SP25 and SP50). The growth and the oxidative status of the animals and the physical, chemical and bromatological parameters of the flesh quality were evaluated. Adding microbial biomass to diets decreased plasma total oxidant status, malonaldehyde and leukocyte respiratory burst, increased the total antioxidant status and did not affect the blood biochemical parameters. All treatments had similar growth parameters, except feed conversion ratio that was lower for RG50 than for negative control group. In the flesh, the use of the microbial biomass lowered the thiobarbituric acid reactive substances and increased redness (except for S. cerevisiae), carotenoid deposition (except SC25) and protein content and improved the n-6/n-3 ratio of the fillets without interfering with the texture. RG25, SC25 and SP50 increased eicosapentaenoic acid on the fillets and RG50 had a positive effect on the animals’ growth. So, it was concluded that the use of the microbial biomass provided an antioxidant effect in blood plasma and improved the feed conversion ratio of the animals, decreased the lipid oxidation and increased protein content, pigmentation and carotenoid deposition in the fish flesh, without imparting a negative impact on the animals` health.
Microbial biomass produced with industrial residues can be used as sources of proteins and antioxidants in fish feeds. The practice results in reduced amounts of waste to treat and discard and so brings benefits to the industry and to the environment. The aim of this experiment was to evaluate the growth and the oxidative status of tilapia fed microbial biomass and the quality of its flesh. Nile tilapia (26.84 ± 1.03 g) were fed one of experimental diets for 76 days. Treatments included a negative control diet (without microbial biomass), a control diet supplemented with 0.01% vitamin E (VE), and diets containing three types of microbial biomass in two concentrations (0.25 and 0.5%): R. gelatinosus (RG25 and RG50), S. cerevisiae (SC25 and SC50), and S. platensis (SP25 and SP50). The growth and the oxidative status of the animals and the physical, chemical and bromatological parameters of the flesh quality were evaluated. Adding microbial biomass to diets decreased plasma total oxidant status, malonaldehyde and leukocyte respiratory burst, increased the total antioxidant status and did not affect the blood biochemical parameters. All treatments had similar growth parameters, except feed conversion ratio that was lower for RG50 than for negative control group. In the flesh, the use of the microbial biomass lowered the thiobarbituric acid reactive substances and increased redness (except for S. cerevisiae), carotenoid deposition (except SC25) and protein content and improved the n-6/n-3 ratio of the fillets without interfering with the texture. RG25, SC25 and SP50 increased eicosapentaenoic acid on the fillets and RG50 had a positive effect on the animals’ growth. So, it was concluded that the use of the microbial biomass provided an antioxidant effect in blood plasma and improved the feed conversion ratio of the animals, decreased the lipid oxidation and increased protein content, pigmentation and carotenoid deposition in the fish flesh, without imparting a negative impact on the animals` health.
Descrição
Palavras-chave
Oreochromis niloticus, Rubrivivax, Saccharomyces, Spirulina