Unveiling the effect of processing on bioactive compounds in millets: Implications for health benefits and risks.

Millets have been a staple food for most of the population since ancient times, serving as their daily meal. Millets are the powerhouse of various nutrients and important bioactive compounds. The major bioactive compounds present in the millet are carotenoids, phenolic acids, flavonoids, lignin, and beta-glucan. The objective of this review is to discuss the effect of processing on potential bioactive compounds, associated health risks, and their benefits. The effect of different processing methods on bioactive composition and their degradation are also discussed. The germination of millets can significantly increase the total phenolic content (TPC) and total flavonoid (TFC) content. The dehulling operation leads to a reduction in the amount of TPC and TFC. Malting increases the phenolic content while fermentation decreases the total phenolic acids. Even though the phenolic content is reduced during extrusion cooking, the phenolic acids can be retained by controlling the process parameter. Novel processing techniques like ultrasound enhance the TPC and cold plasma reduces the TPC. The microwave treatment enhanced the germination rate which in turn enhanced the TPC, TFC, and antioxidant activity in germinated millets. Therefore, millet bioactive compounds have immense potential for shaping functional and nutraceuticals-based products that offer health benefits beyond basic nutrition. These foods can be tailored to specific health needs, such as heart health, digestive wellness, or immune support.