Peter Gaberz Kirschnik

Efeito da lavagem e da adição de aditivos sobre a estabilidade de carne mecanicamente separada de tilápia do Nilo (Oreochromis niloticus) durante estocagem a -18 ºC

This study evaluates the influence of washing and adding sodium erythorbate and sodium tripolyphosphate on the stability of minced Nile Tilapia (Oreochromis niloticus) during 6 months of storage under -18 oC. The minced fish was obtained using a meat bone separator and was divided into four treatments (washed minced fish with or without additives and non-washed minced fish with or without additives) and kept at -18 oC for 180 days. The stability of the minced fish was evaluated by microbiological analyses and the following parameters non-proteic nitrogen (NNP), total nitrogen volatile bases (BNV), Thiobarbituric Acid Reactive Substances (TBARS), pH, and Drip (loss of water in thaw process) were evaluated. The washing process caused a reduction of approximately 41, 44, and 66% in total protein, lipid, and ash values, respectively reducing also the initial values of NNP, BNV, and TBARS. During the storage, an increase (p > 0,05) was observed in the NNP, BNV, and pH values for all treatments, except for the non-washed minced with additives which did not show statistic increase in the NNP and pH values. The use of additives in the minced fish caused a decrease of the drip during the storage, but it did not affect (p > 0,05) the TBARS values. Microbiological parameters do not exceed the values allowed by the legislation. the minced fish was maintained at stable and good conditions for use regardless of the addition of additives, so it can be stored for up 180 days at -18 oC.This study evaluates the influence of washing and adding sodium erythorbate and sodium tripolyphosphate on the stability of minced Nile Tilapia (Oreochromis niloticus) during 6 months of storage under -18 oC. The minced fish was obtained using a meat bone separator and was divided into four treatments (washed minced fish with or without additives and non-washed minced fish with or without additives) and kept at -18 oC for 180 days. The stability of the minced fish was evaluated by microbiological analyses and the following parameters non-proteic nitrogen (NNP), total nitrogen volatile bases (BNV), Thiobarbituric Acid Reactive Substances (TBARS), pH, and Drip (loss of water in thaw process) were evaluated. The washing process caused a reduction of approximately 41, 44, and 66% in total protein, lipid, and ash values, respectively reducing also the initial values of NNP, BNV, and TBARS. During the storage, an increase (p > 0,05) was observed in the NNP, BNV, and pH values for all treatments, except for the non-washed minced with additives which did not show statistic increase in the NNP and pH values. The use of additives in the minced fish caused a decrease of the drip during the storage, but it did not affect (p > 0,05) the TBARS values. Microbiological parameters do not exceed the values allowed by the legislation. the minced fish was maintained at stable and good conditions for use regardless of the addition of additives, so it can be stored for up 180 days at -18 oC.

Effect of heat treatment and packaging systems on the stability of fish sausage

The purpose of this study was to evaluate the physicochemical and microbiological stability of sausages produced from mechanically separated fish meat (MSM) obtained from Nile tilapia filleting residues. Different heat treatments (pasteurization or smoking) and packaging systems (conventional or vacuum) were used. The sausages were characterized for chemical composition, weight loss, water activity, instrumental texture and sensorial analysis. Additionally, microbiological analysis, instrumental color, pH, thiobarbituric acid reactive substances (TBARS) and total volatile base nitrogen (TVB-N) were assessed during storage. No presence of Escherichia coli, Salmonella sp. or coagulase-positive Staphylococcus was detected; however, the psychrotrophic count in pasteurized sausages exceeded the limits allowed for consumption. pH and lipid oxidation speed (TBARS) values were reduced when vacuum packaging was used. Volatile nitrogenous bases remained virtually constant during the storage period, and higher values were observed in smoked products. Pasteurized sausages remain stable for 10 and 15 days in conventional and vacuum packages, respectively, and smoked sausages remain stable for 25 and 45 days in conventional and vacuum packages, respectively.