Influence of processing techniques on the protein quality of major and minor millet crops: A review

Millets have a distinctive protein composition comprising of high concentrations of essential amino acids with numerous health-promoting characteristics. Through various in vitro and animal research studies, a variety of millet-based bioactive peptides isolated from millets have given significant evidence of their health-improving properties. However, the processing technique significantly impacts the biological activity of these millet peptides. The amount, structure, and function of major and minor millet proteins are influenced by different processing techniques. Studies have demonstrated that germination and fermentation increase bioavailability, in vitro protein digestibility, and protein efficiency. Moreover, the innovative processing techniques viz: microwave, ultrasound, and high-pressure processing had a significant impact on structural and quality attributes of the millet proteins and their fractionation. The non-thermal processing ensured the modification of structure and stability with the enhancement of functionality of the millet protein. The present review has been designed to summarize the major health benefits of millet proteins and the effect of various processing methods on their quality attributes. The information provided in the review would play an important role in further research and development activities at the commercial scale governing the improvement in millet protein efficiency, modification, bioavailability, and in vitro protein digestibility by different processing techniques. Novelty impact statement This review summarized the recent research on the major health benefits of millet proteins and the influence of different processing methods on bioactive peptides from major and minor millets.