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

Abstract

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.

Effects of Protein Components on the Chemical Composition and Sensory Properties of Millet Huangjiu (Chinese Millet Wine)

“…A total of 56 volatile compounds were identified in the millet Huangjiu samples, comprising 22 esters, 13 alcohols, 10 aldehydes, 6 acids, 3 phenolics, and 2 ketones, as shown in Table 3 . These results are generally consistent with previous reports on the volatile composition of other millet Huangjiu samples [ 4 , 10 , 12 ].…”

“…Previous research has suggested that the production of bitter peptides in sake is highly dependent on the glutelin content of rice grains [ 8 ], highlighting the significance of protein metabolism in shaping the flavor profile of fermented beverages. The development of bitterness in Huangjiu is thought to arise from an imbalance in protein hydrolysis and peptide hydrolysis, emphasizing the importance of carefully balancing the glutelin contents in raw materials to optimize wine quality [ 4 , 6 , 9 ]. Taken together, these findings suggest that carefully selecting the appropriate protein type and amount during the fermentation process is essential to achieving the desired taste profile in millet Huangjiu.…”

“…Millet has been used in various products, such as yogurts, breads, and supplementary foods for infants, and its high protein content renders it an optimal choice for Northern Huangjiu fermentation [ 3 ]. The use of millet in Northern Huangjiu production may enhance its nutritional value and provide distinct functional properties in the final product [ 4 ]. Chinese millet Huangjiu is typically characterized by its light color, low alcohol content (11~13%), mellow taste, and smooth mouthfeel.…”

A review: Hydrothermal processing of millets and effect on techno‐functional and nutritional properties

“…The impact of processing on specific varieties of millet starches has also been reviewed by various researchers (Punia et al, 2021; Rathore et al, 2019). Concurrently, changes in specific nutritional properties namely, proteins, and starch, have been reviewed by some authors (Bangar et al, 2022; Mahajan et al, 2021). However, no dedicated comprehensive review on hydrothermal processing of millets for its value addition and development of hydrothermally processed millet‐based products has been published so far.…”

“…Previously published reviews have mostly reported on raw millet grains, their flours, and composite products based on millet flours in combination with other flours and ingredients (Gowda et al, 2022; Hassan et al, 2021; Saleh et al, 2013; Sharma et al, 2021; Yousaf et al, 2021). Most reviews are limited to the characterization of a single nutritional component (Bangar et al, 2022; Mahajan et al, 2021) and single or a few varieties of millets (Punia et al, 2021; Rathore et al, 2019). Considerable gaps exist in the knowledge related to the hydrothermal processing of grain and its relation with the techno‐functional characteristics.…”