Chemical Changes After Irradiation and Post‐Irradiation Storage in Tilapia and Spanish Mackerel

Abstract

Influence of gamma irradiation (1.5-10 kGy) and post-irradiation storage up to 20 days at 2 ‫ע‬ 2ЊC on some chemical criteria of tilapia and Spanish mackerel were studied. Total volatile basic nitrogen formation was lower in irradiated fish than in the unirradiated. Irradiation also caused a larger increase in thiobarbituric acid values which continued gradually during storage. Some fatty acids decreased by irradiation treatments at all doses. Thiamin loss was more severe at higher doses (≥4.5 kGy), whereas riboflavin was not affected. Alpha and gamma tocopherols of tilapia and alpha, beta, gamma, and delta tocopherols, in Spanish mackerel, decreased with increased dose and continued to decrease during 20-day post-irradiation storage.

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

“…Yerlikaya et al (2005) studied alterations in the quality of anchovy patties in conventional packaging stored at 4 ºC for 6 days, observing higher TBARS values (10.61 to 27.21 mg of malonaldehyde/kg) when compared with this study. Bilgin et al (2008) Although the Brazilian Legislation does not cite TBARS limit values for fish products, the maximum averages found in this study are similar to values cited by Balogun et al (1984) and Al-Kahtani et al (1996), who considered values below 3.32 mg and 3 mg malonaldehyde/kg of sample, respectively, acceptable.…”

Validade comercial de filés de Tilápia do Nilo (Oreochromis niloticus) resfriados embalados em atmosfera modificada e irradiados

“…Como não há padrão para este parâmetro na legislação nacional, os resultados são comparados com achados de trabalhos anteriores descritos na literatura. AL-KAHTANI et al (1996) afirmaram que peixes, como Tabela 2 -Resultados das análises de pH e número de substâncias reativas ao ácido 2-tiobarbitúrico (TBARS) (expresso em mg de malonaldeído kg -1 de amostra), em filés de tilápia (Oreochromis niloticus) estocados em gelo reciclável durante 20 dias. Em que: T1 = embalagem em aerobiose (controle), T2 = embalagem em atmosfera modificada (40% CO 2 e 60% N 2 ), T3 (irradiação na dose de 1,5kGy) e T4 = embalagem em atmosfera e irradiação (nas mesmas condições de T2 e T3 (2002), que constataram aumento proporcional à concentração de CO 2 , provavelmente, devido à dissolução desse gás no músculo, ocasionando alteração da permeabilidade das membranas celulares interferindo no potencial antioxidante.…”

“…Entretanto, esses valores decresceram continuamente (1,58; 2,06 e 1,27mg de malonaldeído kg -1 ) até apresentarem aspectos sensoriais e bacteriológicos característicos de um produto impróprio para o consumo. AL-KAHTANI et al (1996) relataram uma possível interação covalente do malonaldeído com os grupos aminas livres presentes nas proteínas.…”

Influence of the process parameters on osmotic dehydration of mapara (Hypophthalmus edentatus) fillet

“…muscle in fish captured in the summer when compared to those captured in the winter. The low TBA value (0.18 ± 0.01 mg malondialdehyde/kg fresh fish) observed in the fresh fish muscle showed that the product had excellent preservation regarding lipid oxidation (Al-Kahtani et al 1996).…”