Desenvolvimento e caracterização de revestimento alimentício formulado a partir do colágeno extraído do resíduo pesqueiro (bexiga natatória) de tambaqui (Colossoma macropomum)

Abstract

The utilization of waste from the fishing industry offers an alternative for obtaining materials with higher added value and for reducing the impacts associated with their disposal. In this study, the swim bladder of the tambaqui (Colossoma macropomum) was used as a raw material for collagen extraction and the development of food films and coatings. Collagen was obtained using an acid-enzymatic method, followed by salt precipitation, dialysis, freeze-drying, and grinding. The material exhibited a yield of 47%, a solubility in acetic acid of 93.0 ± 0.8%, and a pH of 2.83. FTIR-ATR analysis revealed the characteristic bands of amides A, I, II, and III, indicating the preservation of the collagen structure, while thermogravimetric analysis showed behavior consistent with collagen-based materials. Six film-forming formulations were developed containing 1.5%, 2.0%, and 2.5% collagen, with three formulations without a plasticizer and three with the addition of glycerol at 30% relative to the collagen mass. The films were evaluated for film formation, thickness, opacity, structure, and thermal stability. The presence of glycerol mainly influenced the thickness and thermal behavior, without compromising the structural integrity of the collagen in the formulations. The solutions corresponding to films A2 and B1 were applied as coatings to bananas and strawberries. In bananas, the treatments helped maintain shape and apparent firmness for a longer period, although they did not prevent the skin from browning. In strawberries, the coatings numerically reduced mass loss and delayed the onset of visible fungal growth compared to the control. Overall, the results demonstrated the potential of the tambaqui swim bladder as a source of collagen for the development of biodegradable materials that could be applied in post-harvest food preservation.