Potencial de aplicação de embalagem biodegradável para conservação de pescado congelado

Abstract

The fish stands out as a food with great nutritional importance, however this richness in its composition makes it highly perishable, which ends up compromising its availability and, therefore, consumption. Brazil is a country defined by the low consumption of fish,although there is an intention to consume it. The lack of habit caused by the unavailability of fish in non-coastal regions or with low production is one of the relevant factors for low consumption. To supply the entire population, the strategic solution is an offer of frozen fish in order to prevent deterioration and increase the shelf-life. Equivalent to the need to offer frozen fish to the entire population, the importance of ethical concern in the use of environmentally friendly packaging also stands out. Mixtures of thermoplastic starch and biodegradable polyester are interesting options due to the low cost of the starch and properties of resulting products, in addition to provide natural decomposition in a short time. Therefore, the present work had the general objective of verifying thepotential of applying biodegradable packaging for fish conservation combined with the replacement of polyethylene packaging. At first, the objective was to evaluate variations in the lipid content of pacu fish captured for over a year. And in a second stage of the work, the objectives were to monitor the stability of the biodegradable packaging during frozen storage and to compare the quality of frozen pacu fish fillets in biodegradable and polyethylene packaging, during the 360 days under freezing. The results of the pacu lipid content classified it as a fat fish in all the seasons of capture throughout the year. In addition, significant differences between the capture of warmer (14.7-16.4%) and cold (20.7-21.5%) periods were recorded. Biodegradable films stored for 360 days under freezing showed stability in their chemical and mechanical structure, with tensile strength greater than 3.5MPa and characteristic bands of PBAT and starch in the wavelength 1710 cm-1, 1270 cm-1 and 1018 cm-1. In relation to the quality evaluation of fish fillets packed with LDPE and biodegradable film, the effect of the type of packaging was not verified, but the time of storage. The freshness parameters showed within the tolerance limits during the 360 days,with values below 30 mg.100g-1 for TVB-N and 6.8 pH, with 90 days there was a significant difference for the WHC parameters (reduction around 8-10%) and TBARS (increased to 0.53-0.57 mg of MDA.kg-1) and with 45 days, total color difference (> 3.0) can be noticed with the naked eye. According to the results, it was verified that there is a potential application of biodegradable films in frozen fish fillets for a long period of time, since the film remained stable and guaranteed the same quality in meat as the standard packaging widely used, besides reducing environmental impact and, therefore, also presenting favorable appeal to the consumer.