Towards waste meat biorefinery: Extraction of proteins from waste chicken meat with non-thermal pulsed electric fields and mechanical pressing

Meat waste has significant economic and environmental costs in the food supply chain. New approaches for meat waste conversion to products are needed. In this work, we developed a pulsed electric field-based process for functional chemicals extraction from waste chicken breast muscle. We show that a two-step protocol, which consists from high voltage, short pulses followed by low voltage long pulses, with the total invested energy of 38.4 ± 1.2 J g⁻¹, of initial waste meat, enables extraction of 12 ± 2% of the initial waste chicken biomass to the liquid fraction. The protein content of the extract fraction was 78 ± 8 mg mL⁻¹. In silico analysis also suggested that the extracted proteins could have antioxidant properties. This was corroborated experimentally with DPPH and ABTS assays. Process parameters analysis with Taguchi methodology showed that long pulse duration played the most important role in liquid extraction from the waste chicken breast muscle, followed by short pulses duration, number of long and short pulses. Our study suggests that pulsed electric fields combined with mechanical pressing can be used for extraction of functional molecules from the waste meat biomass using non-thermal, chemical-free process. Such a strategy could provide an additional income and thus, stimulate farmers and meat processors to reduce waste and waste-related environmental pollution.