Embalagem inteligente adicionada de betalaínas extraídas de beterraba (Beta vulgaris L.) como indicador de frescor em peixe

Abstract

Fish is an important food in the human diet, due to its profile in essential polyunsaturated fatty acids. However, this characteristic makes it very susceptible to undesirable sensory and physicochemical changes caused by lipid oxidation. These limiting factors, combined with the high level of demand from the consumer market, require the development of mechanisms to ensure greater stability and quality monitoring for this raw material, such as intelligent packaging. Thus, the objective was to develop a smart packaging added with beet extract (Beta vulgaris L.) by headspace in the tilapia fillet, and evaluate the colorimetric changes of the film and quality parameters of the tilapia. In addition, the extract was characterized and the thermal, mechanical, morphological and colorimetric characteristics of the packaging were evaluated. Three treatments were evaluated: C (control), T2.5% (addition of 2.5% extract) and T5.0% (addition of 5.0% extract). Beetroot extract showed significant content of betalains (644.85 mg/L), total phenolic compounds (540.60 mg EAG/100g), antioxidant activity by DPPH (0.95 μmol ETrolox/mL), FRAP (3.62 μmol ETrolox/mL) and ABTS (2.92 μmol ETrolox/mL), in addition to desirable color parameters that are perceptible to the human eye. The physicochemical characteristics, pH, volatile bases (NBVT) and lipid oxidation (TBA) of tilapia were in accordance with the standards required by current Brazilian legislation for fish and fish. The scanning electron microscopy images of the C and T2.5% treatments mostly showed a homogeneous surface and cross-section, without the presence of grooves or any other empty space. The films were applied by headspace to the tilapia fillet and analyzed over the course of four days at room temperature, showing color changes in the packaging, with a decrease in red color values (a*) and a consequent increase in yellow color (b*). The pH, total bacterial count and NBVT values were high on the last day of monitoring, however, the TBA values had no significant changes with a maximum value of 0.4 mg MDA/Kg. Therefore, the application of intelligent headspace packaging added with beet extract (Beta vulgaris L.) to tilapia fillet was efficient in indicating the quality of the fish through colorimetric modifications of the films, as well as increasing stability against NBVT and total bacteria count.