Potencial nutricional, tecnológico e bioativo das farinhas de resíduos do abate de rãs-touro (Lithobates catesbeainus)

Abstract

Bullfrog meat is still considered an exotic raw material, and consequently, the byproducts generated from the slaughter of these animals—primarily consisting of heads, leg tips, and viscera—are often neglected and occasionally discarded into the environment. However, the literature suggests that these by-products may exhibit nutritional, bioactive, and technological properties that could add value within the frog farming production chain. In this context, the present study aimed to evaluate the nutritional, technological, and bioactive potential of flours produced from bullfrog heads, leg tips, and viscera. The by-products were subjected to a drying process at 60 °C for 10 hours and subsequently ground into flour. The resulting flours were analyzed for their chemical composition, antioxidant capacity, and technological properties. Leg tip flour exhibited the highest protein content (59.1%), which was significantly higher than that observed in head (54.5%) and viscera (53.06%) flours. Viscera flour stood out due to its higher lipid content (24.3%), while head and leg tip flours showed higher ash content (23.9%). The lipid fraction of the flours presented a profile rich in unsaturated fatty acids, and quality indices such as the Atherogenicity Index and Thrombogenicity Index indicated potential beneficial effects in the prevention of cardiovascular diseases. Head flour demonstrated the most prominent bioactive properties, particularly regarding iron-chelating ability. In addition, its proteins exhibited higher solubility across different pH levels. Viscera flour showed greater water absorption capacity and emulsifying properties, whereas leg tip flour presented high oil absorption capacity. Overall, all flours derived from bullfrog slaughter by-products exhibited notable nutritional, bioactive, or technological potential, highlighting their applicability in the food industry and encouraging further research on this type of protein source.