A Review on Recent Processing and Bioprocessing Developments in Alternative Proteins: Sources, Modification Methods, Economic Feasibility, and Future Challenges

A lternative proteins (APs) are anticipated to offer a practical approach to tackle the growing need for protein while remaining within environmental limits. Different studies have discussed AP sources; however, a systematic comparison of the extraction, modification, analytical techniques, challenges, and their potential solutions for APs has not been conducted together. A comprehensive perspective is provided by this review, which integrates these aspects. Extracting suitable proteins from plants, insects, and mycoprotein sources is challenging and involves various technical interventions, including protein modification, isolation, product processing, and tracking the modified structure. This review article explores multiple sources of APs, extraction processes, and emerging modification technologies, including non-thermal (high-pressure processing (HPP), pulsed electric field (PEF), extrusion, sonication) and biological (fermentation and enzymatic) methods, along with dual approaches used to alter the structure of APs. These techniques improve the techno-functional attributes (foaming, solubility, emulsification, digestibility) and reduce the allergenicity level of different APs. Various analytical approaches (atomic force microscopy, Fourier-transform infrared, Raman spectroscopy, differential scanning calorimetry, scanning electron microscopy, circular dichroism, and x-ray diffraction) are discussed for tracking AP-modified structure and functionality. The review examines the economic feasibility (initial cost) of each technique for commercialization and industrial scale. The initial installation capital required for HPP was ($0.5 million–$2.5 million). Dual approaches are efficient for improving the yield and functionality of APs, but cost scalability is a major factor limiting the adoption of these approaches. Improvement of flavor changes during these modifications remains an unexplored area. This review, by integrating technological, economic, and regulatory perspectives, provides insights that can help researchers and industry develop more sustainable protein solutions.