of tortilla chips from 5 millets
as partial fulfillment requirement for
of Technology in Food Technology and Management (FTM)
Department of Food science and Technology (FST)
Associate Professor 413014
Department FTM (2nd sem)
Institute of Food Technology Entrepreneurship and Management
Autonomous Institution under Ministry of Food Processing
Industries, Government of India.
Types of millets in India
Millets and their Indian name
Baking and cooling
Cooling and packaging
Tortilla chip a Mexican snack made from corn tortillas. Tortilla means “flat bread” in Spanish. It is traditionally
made of corn, vegetable oil, salt and water.
Tortillas are high nutritious. Tortilla
was first made in America by Latin Americans .Tortilla chips are rounds,
trianglesnd rectangular chips.
Tortillas are traditionally made
from corn however with the addition of millets it will improve its nutritional
value even more.
India is the largest producer of
millets, having a share of 45% in the world. Millets are
small seeded grass that grows well in dry zones as rain fed crops under
marginal conditions of soil fertility and moisture.
The manufacturing of tortilla chips has been
same since ancient times. Traditionally tortilla are made including cooking
corn, soaking for 8 to 16 hours and grinding from which corn masa is formed. Tortillas
are made from corn masa and baked. With incorporation of millets the
nutritional content of tortillas chips could be increased.
Rebecca Webb Carranza was the one who popularized tortilla
chips. She use the rejected tortillas
from her processing machine and deep fried it after cutting into triangle shape
which made a popular snack and was sold in
a bag at the El Zarape Tortilla Factory. In 1994, Carranza was awarded the
Golden Tortilla award for her contribution to the Mexican food industry.
Tortillas have been made in the same way since it was
started. It is always been served as a table snack. Tortilla chips are very
popular in the processing industry with many variations. However the
incorporation of millets will add in the utilization of the abundant millent
production while enhancing the nutritional quality as well.
Foxtail Millet is
known to be the first domesticated millet. China
cultivation of millet around 8300–6700 BC in which
where found in pits.
Millet spread from China to Black Sea
region of Europeby 5000 BC.
Wild ancestor of Pearl Millets were found in the Sahel region of West Africa. Pearl Millet
were found in Mali in 2500 BC and
found in South Asia by 2300 BC.
Finger Millet is originally from East Africa and was cultivated before the third millennium BC and has spread
to South India by 1800 BC.
TYPES OF MILLETS IN INDIA
Millets the oldest foods known and the first
cereal grain to be used for domestic purposes.
Millets require a short growing
season. Millets can develop from planted seeds and mature
to harvest plants in about 65 days.
MILLETS AND THEIR INDIAN NAME
Nachani, Mundua, Mandika, Marwah
Pearl Millet | Bajra | Kambu
India is largest
producer of pearl millet in the world. Pearl millet is a rich source of
phosphorus which is important for structure of body cells. Consumption of pearl
millets helps in minimizing the risk of type 2 diabetes.
Role of pearl millet in diet:
Pearl millet has high
fibre content it hence digest slowly and glucose is released at a slower rate as
compared to other foods. It helps in maintaining blood sugar levels for long time.
It takes a longer time to digest from the stomach to the intestines because of
high in fibre content.
It contains phyto chemical, called phytic acid believed to increase cholesterol
metabolism hence reduces cholesterol.
also reduces secretion of bile acids and is linked to a lowered risk of
prevent cancer: Bajra has cancer-protecting properties.
study showed that regular intake of bajra protects pre-menopausal women from
developing breast cancer. (Mandwi Singh,
5 health benefits of protein and mineral rich pearl millet or Bajra, IndiaToday.in )
Finger Millet | Nachani | Kezhvaragu
Also known as
African finger millet, red millet, ragi and very popular millet specially in
Southern India. It is rich in calcium and protein and also have good amount of
iron and other minerals. Ragi tops in antioxidant activity among common Indian
foods, Ragi also has some good number of Essential Amino Acids (EAA) which are
essential for human body.
Foxtail Millet | Kangni | Thinai
Foxtail millets are
high in Iron content and these millets are totally pest-free. Foxtail not only
not need any fumigants, but act as anti pest agents to store delicate pulses
such as green gram. They also control blood sugar and cholesterol levels &
increase HDL cholesterol.
Kodo Millet | Kodra | Varagu
Kodo millets contain high amounts of
polyphenols, an antioxidant compound, they also has high on fibre, low on fat.
Kodo millet inhibited glycation and cross-linking of collagen. Kodo millets are
good for diabetes.
Little Millet | Kutki | Saamai
Little Millets seeds are smaller than other millets, like
foxtail millet, little millet also high in Iron content, high in fibre like
Kodo and has high antioxidant activity. It helps in diabetes and diseases
Barnyard Millet | Jhangora |
Barnyard millets are high in fibre content,
phosphorous and calcium. Barnyard has low glycemic index and thus helps in type
2 diabetes, cardiovascular disease with regular intake of this millet.
Millets are highly nutritious, non-glutinous and non acid forming food. They
are easy to digest. They are least allergenic. Millets have lesser percentage
of glucose and lowers the risk of diabetes. Millets are rich source
of vitamin B, potassium, magnesium, calcium, iron, zinc. Millets help lower
type 2diabetes. Millets are high-energy food.They are highly
nutritious, non-glutinous and not acid forming foods. Hence they are soothing
and easy to digest. They are considered to be the least allergenic and most
digestible grains available. Compared to rice, especially polished rice,
millets release lesser percentage of glucose and over a longer period of time.
This lowers the risk of diabetes (More here).
particularly high in minerals like iron, magnesium, phosphorous and potassium.
Finger millet is the richest in calcium content, about 10 times that of rice or
wheat. Click here for the nutrient composition of
millets as compared to wheat and rice.
and wheat that require many inputs in terms of soil fertility and water,
millets grow well in dry regions as rainfed crops. By eating millets, we will
be encouraging farmers in dryland areas to grow crops that are best suited for
those regions. This is a step towards sustainable cropping practices where by
introducing diversity in our diets, we respect the biodiversity in nature
rather than forcefully changing cropping patterns to grow wheat and rice
Preparing the masa (dough)
The first major process in tortilla chip
manufacturing is the production of coarse masa
dough. In a typical mixture, 2.5 to 3.0 liters of water, 1 kilogram of
12 percent moist com, and 0.01 kilogram of food-grade lime (usually
quicklime or hydrated lime) are added together in a large industrial cooker.
The lime is used primarily as an aid in removing the pericarp (hull or
skin) during cooking and steeping. The lime also helps to increase the
product shelf life by controlling microbial activity, and it affects the
flavor, aroma, color, and nutritional value of the chips.
This mixture is then batch-cooked in
either a Hamilton steam kettle or a vertical closed cooker. The Hamilton
kettle is indirectly heated by steam, and the grain contents are
mechanically agitated. It is designed for cooking at or near the boiling
point of the lime-water-corn solution. An elaborate agitation system
ensures the uniform transfer of heat by condensing steam through the
kettle wall and into the limewater-corn solution. The capacity of these
steam-jacketed kettles ranges from 300 to 595 pounds (136 to 270
kilograms). The vertical closed cooker uses direct steam injection to heat
and agitate the lime-water-corn solution in a large tank, which serves for
both cooking and steeping. Additional agitation is accomplished with
compressed air. Because this system is designed for cooking at
temperatures well below the solution boiling point (185 degrees Fahrenheit or 85 degrees Celsius), the cooking time is
longer than in the Hamilton steam kettles. The capacity of the vertical
cookers ranges from 3,000 to 6,000 pounds (1,360 to 2,730 kilograms).
Cooking time can vary greatly from a few minutes to a half hour, depending
upon which system is used. In general, temperatures above 155 degrees
Fahrenheit (68 degrees Celsius) are considered to be the optimum cooking
temperatures. Cooking depends on the characteristics of the corn and the
interaction of time, temperature, lime concentration, cooking vessel size,
and agitation. Nixtamal used for fried products is generally cooked less
than nixtamal used for table tortillas.
Immediately after cooking, the
solution is quenched (rapidly cooled) to about 154 to 162 degrees
Fahrenheit (68-72 degrees Celsius). This lower temperature decreases water
absorption during the steeping process and the cooking time of the
nixtamal. The 11
result is a more consistent masa, which absorbs less oil
The grain is then steeped for 8 to 16
hours in the cooking vat (if a vertical cooker was used) or transferred to
a holding vat (if a Hamilton steam kettle was used). The steeping process
allows water to be absorbed, which helps to disintegrate the hull and
soften the kernel. During the steeping process, the temperature is dropped
to 104 degrees Fahrenheit (40 degrees Celsius).
steeping, the solution is pumped into the washers. The cooking liquor is
drained off, and the resulting nixtamal is washed with pressurized water
or spraying systems. Most of the pericarp and excess lime is removed
during this step. Washing in commercial processes is done in two types of
equipment: the drum washer and the “lowboy”
system. A drum washer consists of a conveyor that transports the nixtamal
into a rotating perforated cylinder with internal flights and water
sprayers located within the drum. After spraying, the nixtamal passes into
a drain conveyor, where the excess water is removed. The lowboy system
consists of a receptacle equipped with internal screens and sprayers. The
washed nixtamal is continuously removed from the bottom of the receptacle
by an inclined belt conveyor. In both systems, a conveyor transports the
washed, drained nixtamal into a hopper, which then feeds the stone
grinder. The end result, using the typical corn and lime mixture, will be
54 ounces (1.53 kilograms) of 47 percent moist nixtamal.
The washed nixtamal is then ground using
two matched carved stones, one stationary and the other rotating at about
500 to 700 rpm. The stones are usually composed of lava or volcanic materials,
although they can also consist of synthetic materials made of
oxide (Ak203). For optimum efficiency, the lava stones must be frequently
recarved; the synthetic stones last longer and require less recarving. A
typical stone is10 centimeters thick and 40 centimeters in diameter and
has radial grooves. The grooves become more shallow as they approach the
perimeter of the stone. The number, design, and depth of the grooves in
the stones vary with the intended product: stones carved for the
production of table tortillas have more shallow grooves to produce a finer
masa, whereas coarser masa for tortilla chips comes from deeper-grooved
The grinding or milling starts when a screw conveyor at the
base of the hopper forces the nixtamal through a center opening and into the
gap between the stones, where shearing occurs. The material travels outward
from the center to the perimeter of the stones. Water added during milling
cools the stones, prevents excessive wear, and reduces the masa temperature.
For a grinder with a capacity of 600 kg/hr, about 0.6 to 1.2 liters of water
per minute (0.16-0.32 gpm) is added. This amount of water increases the masa
moisture content to the optimum for sheeting. Like the grinding stones, the
moisture content depends upon the resulting product. The masa particle size is
the result of several interacting factors: degree of nixtamal cooking; size and
depth of the grooves in the grinding stones; gap or pressure between the
grinding stones; amount of water used. During milling; and the type of corn
used. The grinding breaks up the kernel structure and promotes “plastic” and
cohesive properties in the masa. Once the masa is produced, it is important to
use it immediately or to protect it against moisture loss. After grinding, the
resulting mixture will be 1.65 kilograms of 51 percent moist coarse masa.
1. A chips are produced using the
coarse masa, which is kneaded and mixed into plastic masa by mixers and
extruders and then fed to sheeter rolls. The plastic masa is sheeted 13
into a thin layer, which is then cut
or forced into a specific configuration; the thickness of the sheet determines
the final product weight. The sheeting starts when the masa is fed onto a pair
of smooth rollers, usually coated with Teflon, one rotating
counter-clockwise and the other clockwise. The gap between the rollers is
adjustable, so that products of different thicknesses can be produced. The masa
is forced between the rolls and separated by wires located on the front and
back rolls. The back wire cleans the sheeted masa from the back roll and allows
it to adhere to the front roll, and the front wire or wires strip the masa
pieces from the roll.
cutter rotates underneath the front roll. Different cutter configurations
(triangular, circular, rectangular, etc.) are used for various products. Copper
or plastic bands surround the end of the first roll and help to recycle excess
masa. The masa pieces leave the front roller on a discharge belt, which feeds
directly into the oven.
Baking and cooling
three-tiered gas-fired oven is used to bake the formed masa. Generally, the
chips are baked at temperatures ranging from 500 to 554 degrees Fahrenheit
(260-290 degrees Celsius), with the baking time varying from 35 to 50 seconds.
Baking enhances the alkaline flavor and reduces moisture
and oil absorption during frying.
The tortilla chips are then cooled by moving
through a series of open tiers or cooling racks. The chips are sometimes cooled
for up to 20 minutes before frying to produce a more uniform consistency and to
reduce blistering during frying. During this cooling process, the chips lose
additional moisture (up to 3 percent), and the moisture within each chip
becomes more evenly distributed.
Frying and seasoning
1. The next step involves frying the
chips using oil temperatures ranging from 338 to 374 14
2. degrees Fahrenheit (170-190 degrees Celsius)
for 50 to 80 seconds. The frying temperature and time depend on the type of
product. Tortilla chips made from yellow corn require a lower frying
temperature and a longer time than chips made from white or blended white and
yellow corn. For example, corn chips made from yellow corn are fried at 320
degrees Fahrenheit (160 degrees Celsius), while those made from blended white
and yellow corn are fried at temperatures up to 410 degrees Fahrenheit (210
degrees Celsius) for 60 to 90 seconds. Most of the commercial fryers used are
the continuous type with direct or indirect heating elements. Indirect-fired
fryers are more expensive but more efficient, with lower operational costs.
Modern fryers are designed to filter out fines (very small pieces) continuously
and be easy to clean. These commercial fryers are available in sizes that can
process from 160 to 1,360 kg/hr (353-3,000 lbs/hr). The process yield, using
the typical corn/lime mixture, will be 0.96 kilograms (2.1 pounds) of tortilla
chips, with 22 to 24 percent oil and less than 2 percent moisture.
3. The salt and seasonings are applied
immediately after frying while the chips are still hot. The hot chips are
conveyed into an inclined rotating cylinder, where a liquid seasoning mix is
sprayed on them. Generally, the liquid mix consists of hot oil, salt,
seasonings, and flavoring and coloring agents. Upon cooling, the oil
crystallizes, forming the seasoning coat. Salt can also be deposited on the
chips as a liquid spray or by a granulated salt dispenser positioned over the conveying
belts after the tumbling operation. The amount of salt usually added to
tortilla chips is about 1 to 1.5 percent by weight.
Cooling and packaging
1. The tortilla chips are then cooled
to ambient temperature and immediately packaged in moisture proof bags. Because
fried products are very hygroscopic (they readily absorb 15
retain moisture), delayed packaging can cause a loss of crispness. The cooled
tortilla chips, with about 1.5 percent moisture, are conveyed into a bagging
machine. This machine automatically weighs and deposits them in a bag, which is
The food Processing industry is continuously improving to
bring new product in the market. Convenience food is the market call as in the
busy life. However fast food is affecting the health on daily basis. Hence
there is a need for nutritional alternative.
Utilization of the millets in the
demand for the fast food market will add the nutritional value as well as the
proper incorporation of the abundant crop. Preparation of tortilla chips from
the millets will enhance the sensory attributes of the product as will add the
fibre content in the chips. Potato chips could be replaced from the tortilla
This method will increase the
entrepreneurial spirit in the farmers as these millets are not quite utilized.
The proper processing method of the chips could increase the formation of small
Tortilla chips made with millets
would enhance the shelf life and reduce the food spoilage. India being the
largest producer of millets however the proper utilization of millets is still
to be done.
Tortilla chips made from the
incorporation of various millets would reflect the traditional food product
like bhakri from Maharashtra and a global approach like tortilla chips.
“Bhoole Bisre Anaj – The Forgotten Foods”, Navdanya
of Pearl Millet
R.K. Jain, S. Bal -Journal of Agricultural Engineering Research
Volume 66, Issue 2, February 1997, Pages 85-91