Efeito da embalagem, do músculo e do tempo de estocagem sobre a estabilidade físico-química da carne bovina

• Autor(a) principal: Wanderley Junior, Marcus Andrade
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2842
• topic: Embalagem; Carne bovina; Qualidade; Packaging; Beef; Quality; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS

Effectiveness of plastic films incorporated with UV light absorber on color stability, and it s physical-chemical indicators, of beef Psoas major (PM), Semitendinosus inner region (IST) and Semitendinosus outer region (OST) were evaluated. The contribution of the physical-chemical indicators to beef color stability was also evaluated. Plastic films, control and with added UV absorber, were developed and analyzed for their mechanical properties as well as oxygen and light transmission permeability. Incorporation of UV absorber to the polyethylene resin reduced plastic film UV light transmisson from 61% to 12% and did not (P > 0.05) affect its oxygen permeability and mechanical properties. Film incorporation with UV absorber did not affect (P > 0.05) any of the analyzed properties indicative of color stability. For all muscles it was observed, during the storage period, an increase in metmyoglobin (MMb) level, lipid oxidation rate (TBARs) and pH. It was also observed a reduction of redness (a*), oxymyoglobin (MbO2) levels, yellowness (b*), oxygen consumption rate (OCR) and metmyoglobin reductase activity (MRA). Except for the OST muscle, which became lighter (P < 0.05), lightness (L*) of the PM and IST muscles did not vary (P > 0.05) during storage. Oxidation reduction potential (ORP) varied (P < 0.05) during storage, increasing its values up to the fourth day followed by reduction thereafter. Based on MMb development, PM muscle was characterized as the least color stable (P < 0.05) and IST and OST muscles did not differ (P > 0.05). PM muscle presented (P < 0.05) higher pH, OCR and TBARs and intermediate MRA. IST muscle presented (P < 0.05) intermediate pH, OCR and TBARs and higher MRA. OST muscle presented (P < 0.05) lower pH, OCR, TBARs and MRA. Muscles ORP did differ (P > 0.05). Results suggests that despite the relative light blocking action of the UV absorber, its incorporation into the plastic film was not effective in extending beef shelf life probably by not completely eliminating absorption of the UV light generated by the fluorescent lamp. In addition, it seems reasonable to conclude that muscles in which the processes inducing meat pigment oxidation such as high OCR and lipid oxidation rate are superior to their reducing capacity (MRA), such as the PM muscle, accumulation of MMb is very fast making it of low color stability. On the other hand muscles, such as the IST, having sufficient reducing action (high MRA) to compensate the oxidative stress imposed by OCR and lipid oxidation, or muscles, such as the OST, were oxidative processes are not pronounced, MMb accumulation is retarded leading to a greater color stability.