Field of invention:
This invention relates to development of a system for mechanization of roasting and popping
methods of gorgon nut, also called fox nut {Euryale ferox) seeds, and their decortications. The
system consists of mainly roasting and popping units attached to each other for roasting, popping
and decortications of gorgon nu.
Prior art/back ground of invention.
Gorgon nut {Euryale ferox) is seed of an aquatic plant that is roasted and popped manually. The
popped kernel is called makhana. The Gorgon nuts are mainly grown in Bihar, Eastern UP,
Assam, West Bengal, Tripura and J&K. Recently cultivation of gorgon nut has also been started
in Odisha. Makhana is being marketed throughout the country as dry fruit and it is also exported
substantially to various countries.
At present gorgon nut seeds (Fig la) are cleaned, sim dried, graded (according to size), roasted in
the traditional earthen pot or cast-iron pan over fire for 4-5 minutes (hereafter it is called first
roasting) and then roasted seeds are kept for tempering to about 45-60 hour. Thereafter the
tempered seeds are again roasted in similar cast iron/earthen pan for specified time. After
roasting, individual hot roasted seeds are immediately hit by wooden mallet to break the hard
seed coat. Breaking of seed coat results in sudden pressure drop and, therefore, kernel expands
to form makhana (Fig lb). The existing practice of producing makhana is explained in a flow
chart (Fig. 2). The whole process of producing makhana is tedious, time consuming and
operations involve lot of drudgery. The quality of popped makhana also varies and the popping
capacity of individual is limited to a maximum of 20 kg/day.
Makhana is a nutritious dry fiiiit and is, therefore, in demand almost in all religious rituals for
preparation of value added products such as ready-to-constitute kheer mix, namkeen/bhujia,
sweetened/salted makhana etc. Its high demand but tedious/ drudgery-full popping processes
urgently necessitate the requirement of machine/systems to mechanize the roasting and breaking
operation to reduce the drudgery of manual methods. Various kinds of dryers and size graders
are already available in the market and can also be used for drying and size grading of makhana
seeds. Suitable roaster and popping unit however are not available. There is no concept of
decortications of gorgon nut, because hitherto decortications are not possible. An attempt is,
therefore, made to mechanize the roasting and popping operations by developing a power

We claim:
1. A mechanized system (Fig. 5) for popping and/or decorticating makhana seeds (called
gorgon nut or fox nut in English and Euryaleferox in Scientific literature) comprising of:
i. a screw conveyor type detachable roaster (Fig. 3) mounted with a hopper (14), a driving
mechanism for power transmission and heating system (1, 2, 3, 4, 5, 6, 7, 11, 12) for
heating the nut;
ii. a centrifiigal type popping and/or decorticating unit (Fig. 4) comprising of an impeller
(21) mounted on a vertical shaft (26) driven by a motor, a hard rough/indented casing
(22) around the impeller for striking the hot roasted nut fed directly from the roster or pan
(without any delay) to the impeller and popped/decorticated kernels are collected through
a discharge chute (24);
iii. and means for mounting the roaster of (i) and decorating imit of (ii) machine.
2. The system as claimed in claim 1 wherein, the heating system maintains the temperature
between 200°C to 350°C.
3. The system as claimed in claim 1 wherein, the roasting time for heating system ranges
between 1 to 5 minutes, less or/and more depending upon size and feed rate.
4. The system as claimed in claim 1 wherein, a holding bin is optionally attached to the
roaster for automation of the tempering process.
5. The system as claimed in claim 1 wherein, the system is turned into a purely
decorticating machine, by omission of the 2"'' roasting step.
6. The system as claimed in claim 1 wherein, the popping and decorations efficiencies of
the developed system is up to 95%, less or/and more depending upon condition of seed.
7. The system as claimed in claim 1 wherein, the time taken for popping of makhana seeds
is reduced from 45 - 60 hrs in the traditional method to about 20 hrs.
8. The system as claimed in claim 1 wherein, the time taken for decortications of makhana
seeds is reduced to about 1 hrs.
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