Makhana (Euryale ferox) seed, commonly known as gorgon nut or fox nut, is an aquatic crop cultivated in stagnant water bodies like ponds, land depressions, lakes, swamps, and ditches. It belongs to water lily family, Nymphaeaceae, which has cultivation history exceeding more than 2000 years in Asia. This black seed is round in shape with a diameter ranging from 4.5 to 14.5 mm and having hard shell as an outer most structure (Jha & Prasad, 1993). The edible part of the seed is the starchy kernel, which cannot be separated easily from its hard shell. Therefore, the raw makhana seeds are generally processed (popping) to obtain popped makhana for edible use. The consumption of popped makhana has been increased worldwide in the past few years due to its health benefits, lightness, and crispiness (APEDA, 2017). Popped makhana is highly nutritious due to its negligible fat content, high quality protein, and presence of various health promoting bioactive compounds. The high amino acid index (89%-93%) and better arginine + lysine/proline ratio (4.7-7.6) make it superior in comparison to other cereals for achieving the amino acid requirements of the human body (Jha, Barat, & Jha, 1991). The popping is done by initial roasting (270-280°C), tempering (48 hr), final roasting (260-270°C) and breaking of the hard shell for expansion of seed in hot condition (Jha & Prasad, 1996). In the initial roasting of raw seeds, the gelatinization, and retrogradation of starch molecules take place. The initial roasting brings characteristic changes and results in expansion of kernels (popping) during the second roasting. Popping process of makhana seeds is entirely different from rice and cocoa beans. The hull of paddy is removed after parboiling and then puffing is done through roasting (Mir, Bosco, Shah, & Mir, 2016). In cocoa beans, roasting and puffing is done in a single operation (Hu
