Vol. 12, Issue 1 (2023)

Author(s):
Tejveer Singh, Ansheef Ali, Ranjeet R Kumar, Vinutha T and Suneha Goswami

Abstract:
Pearl millet is a nutritionally dense crop which ensures high production potential under the changing climatic conditions. Inspite of their rich nutritional composition in terms of fats, carbohydrates, proteins, fibre etc., they are not well accepted by the consumers. Higher content of fatty acids and phenolics in pearl millet gets oxidized in the presence of certain enzymes leading to rancidity, browning and off-flavor generation. Mainly, polyphenol oxidase (PPO) and peroxidase (POX) enzyme activities are associated with the browning effect and thus, limiting the widespread popularity and consumption of pearl millet flour. In this study, we have characterized PPO and POX enzymes activities in 22 pearl millet genotypes during 0, 10 and 20 days of their storage period. Also, we have analyzed the effect of gamma irradiation in inhibiting these enzymes for increasing the shelf life of pearl millet associated with its appearance, taste and flavor. During the course of our study, we have analyzed a large variation in the activities of polyphenol oxidase (0.08-0.23 U/mg protein) and peroxidase (47-121 nM DMAP/min/mg protein) enzymes in fresh flour of genotypes under study. Additionally, we found that gamma irradiated grains caused reduction in PPO activity by 13-15% and POX activity by 53-55%. This study is useful for the selection of pearl millet genotypes with less oxidative enzyme activities which may be ideal for the breeding purpose in future. This may also help in selection and optimization of gamma treatment for improving the shelf life and nutritional properties of pearl millet flour.