Análise da estocagem sob congelamento de carne mecanicamente separada de Tilápia (Oreochromis Niloticus) aplicando polissacarídeos sulfatados da Rodofícea Hypnea Musciformis como aditivo alternativo

Abstract

Fish is one of the most perishable foods and so research into new natural sources of antioxidant compounds is being sought. The antioxidant activit y of sulfated polysaccharides S P s) of H. musciformis applied to th e mechanically separated meat ( MS M ) of tilapia Oreochromis niloticus ) was analyzed. S Ps extracted with water at 80 °C (1.5%; m /v) were quantified for total sugars, sulfate and proteins. The polydispersity of S P s was evalu ated by agarose gel electrophoresis. MS M received different concentrations of S Ps (0, 0.01, 0.02 or 0.03g /100g CMS) or butyl ated hydroxytoluene (BHT: 0.01g /1 00g CMS) and was stocked ( 18 ° C) for 180 days. The centesimal composition of MS M (initial and fina l) was determined by moisture, ash, lipid, protein and carbohydrate contents. To evaluate the antioxidant activity and product quali ty, pH, total volatile bases ( T VB ), lipid oxidation and the growth of psychrotrophic bacteria were monthly analyzed. The sam ples were sent to a laboratory for analysis according to the bacteria present in the legislation. Lyophilized S Ps (20.00 ±13.25%) exhibited 58.77 and 21.54% total sugars and sulfate, respectively, and were absent from proteins. The electrophoresis revealed in the gel p olydispersion of the extracted S P s. S P s did not affect the nutritional quality of MS M . Besides that , addition of 0.02g of SPs /100g of MS M reduced the moisture by 6%. During storage, small increases in pH were observed from the 30th day of stora ge for the treatments, except for the control and the addition of 0.02g of S P s/100g of MS M . At the end of the storage it was possible to observe that the TVB values obtai ned in the added treatments of S P s were significantly lower when compared to the control and positive control treatments (BHT ). Likewise, the addit ion of S P s in the concentration of 0.02g /100g MS M was more efficient in inhibiting or retardin g lipid oxidation than the other treatments, even when compared to the antioxidant treatment used in the industry. The treatments of S P s at concentrations of 0 .01 and 0.02g /100g of MS M showed the smallest difference between the count of psychrotrophic bact eria at the beginning and at the end of storage. All treatments were within the limit established by the legislation for Salmonella sp., Coliforms at 45ºC and coagulase positive staphylococci. Therefore, we can conclude that the addition of S P in tilapia M S M showed an antioxidant behavior, with an optimum concentration of 0.02g/100g MS M , followed by the concentration of 0.01g / 100g of the product.