Otimização do processo de extração de compostos fenólicos antioxidantes da casca do pinhão (Araucaria angustifolia) e potencial aplicação no preparo de mortadelas de frango

Abstract

The pinhão, seed of Araucaria angustifolia, is a valuable resource not only for its nutritional properties but also for the bioactive compounds found in its peel, with potential applications in the food and pharmaceutical industries. Due to the limited number of studies on these compounds, this work aimed to extract and characterize the phenolic compounds from pinhão peel and identify optimal extraction conditions. A third-order factorial experimental design was employed, with two independent variables (ethanol concentration and extraction time), and the responses evaluated were total phenolic content (TPC) and antioxidant activity (ABTS, DPPH, and FRAP). The extract obtained under optimized conditions (85% ethanol for 15 minutes) showed the best results for all responses analyzed. Three phenolic compounds were identified by HPLC-PDA: catechin (the major compound), epicatechin, and quercetin. However, ultrasound-assisted extraction demonstrated limited yield, while exhaustive extraction proved more effective in recovering bioactive compounds. The extract was incorporated into chicken mortadella, stored under refrigeration (4 ± 1 °C) for 56 days, to assess its effectiveness as a natural antioxidant and colorant. The practical application of the pinhão peel extract in chicken mortadella showed promising results. The addition of the extract positively influenced the physicochemical stability of the product during refrigerated storage. Formulation F2 (0.5% extract) showed the greatest protection against lipid oxidation, maintaining the lowest TBARS values up to day 42. In contrast, formulation F3 (0.75% extract) was more effective in preventing acidification (pH) and controlling TVB-N, remaining within acceptable limits throughout the storage period. While F2 showed better short- and mid-term antioxidant performance, its lower final stability in terms of pH and TVB-N suggests that higher extract concentrations (as in F3) may offer broader benefits, balancing antioxidant activity and microbiological stability. Thus, the pinhão peel extract appears to be a viable and promising alternative for the partial replacement of synthetic antioxidants such as BHT. Moreover, extract incorporation significantly affected the color of the chicken mortadella. Formulation F3 exhibited greater darkening (lower L*), more reddish coloration (higher a*), increased chroma (C*), and a hue angle (h*) tending toward red. This more stable coloration over time (with lower ΔE* values) suggests that pigmented phenolic compounds in the extract also act as natural colorants, adding both functional and sensory value to the meat product. The findings indicate that natural extract from pinhão peel has strong potential for use as a natural antioxidant and colorant in meat products, offering a sustainable and functional alternative to conventional synthetic additives.