Kachoris, Samosas, Fafdas, Bhajjis, Vada Pav, Bhaturas, Puris, Mathries and Namkeens… what's the common factor tying all these savories together? Well, they're all deep fried! These fried items have a special place in the hearts of people from the western region states in India, namely Gujarat, Maharashtra, Rajasthan and Madhya Pradesh. Every city in these states is flooded with shops that sell these fried items and the consumption there is sky high.
The conventional frying is done on Diesel Bhatthis, or Gas Kadais. The frying temperatures vary from 140 degrees for besan items to 230-240 degrees centigrade for Bhaturas [made from Maida]. More than 95% of Indian recipes are fried below 190 degrees except for Bhaturas. The purpose of oil is to retain the heat and pass it on to the product being fried. The smoke point of good oils is around 210 degrees. Hence there is no reason for the oil to get burnt and black, as the smoke point is much higher than the required frying temperatures. The other big issue is the generation of smoke while frying, which is harmful for the cook, who does the frying for long hours.
The generation of environmental heat cannot be reduced in the flame based technology, which provides heat efficiency of only 40% and heats the environment by 60%, compared to Induction which is 90% heat efficient. This results in excess heating and perspiration on the cook's body and smoke in his eyes.
Cereals like Chana dal, Moong dal, Wafers etc. require tremendous heat (high flame) as the vapor content is very high in these items (which is why they are soaked in water for 6-7 hours).
If there is a technology by which there is a cut off and restart of the heating at desired temperatures, then we can increase the life of the oils and the number of fries too can be increased without the oil blackening. These issues related to farsan (Namkeen) frying are very well addressed by the advent of a very successful technology known as Induction Heating Technology.
Unlike gas, the generator of heat is the vessel itself. With a PID sensor dipped in to the oil, we can fry at desired temperatures. The temperature of the sensors can be changed within seconds. These sensors will make the unit stop at the desired temperature and start as soon as the temperature falls by 3-5 degrees.
The induction technology is much faster than gas. Hence the products are fried in 20-30 % less time. Hence the oil deposits on the fried products are reduced. For Example: Samosas take minimum 20 minutes to fry at low temperature on a gas stove, while the same quantity of samosa with ideally worked out Kw power are fried in 14 minutes on an Induction Kadai.
Ask any housewife, how much oil a kilo of mathries will consume when you fry during Diwali, in western India and the prompt answer will be 1 liter of oil per 1 kilogram of mathry on the gas in 12 minutes. However, tests on induction have proved beyond doubt that the consumption is reduced to 400 milliliter per 1 kg of Mathry when you fry on induction kadai in 8-9 minutes. So the oil deposits are 50% less on induction frying then in gas. Hence, induction provides more production and less oil deposits.
With gas you can never get uniform heating as the flames are either yellow, blue or Orange in color because of impurities. Only when there are Blue flames, the heat generation is optimum. When flames are yellow or orange, less heat is being generated. This results in errant temperatures during frying. This is the reason why the products we fry with diesel or gas flames have multiple colors like light yellow, dark yellow, light brown, dark brown and sometimes red.
In induction frying, since the generator of heat is the vessel itself [Kadais], there is uniform drop in temperature when the products are dropped in the kadai and there is uniform rise thereafter, till the products are fried. There is a controlled temperature at which the unit will automatically stop. This is the reason why Induction fried products are always uniform in color and have less oil deposits.
Savings in induction: Normal savings compared to LPG is around 30% and against Diesel it is up to 50%.
Bhavnagar farsan fryer installed a 15kw powered induction kadai. After the installation was complete, he called for an electrician to fix a meter to measure the hourly consumption of electricity. It was found that when the besan items were fried at 160 degrees the consumption of electricity was 5 units @ Rs. 8/- per unit i.e. Rs. 40/- per hour compared to diesel consumption of Rs. 150/- per hour. In an 8 hour working day, the savings are approximately Rs. 24,000/- per month. Considering an average capital cost of Rs. 1.5 lakhs, the investments are returned in 6-9 months.
For 80 GMs samosas the fuel cost on gas is paise 64 while on induction is paise 20 per piece. Similarly Sev/Papdi/Ganthya fuel cost may be around Rs 3.50 per kg on gas but in induction it will be around Rs. 1.60 per kg on induction. The ratio of the savings remains the same for all fried products.
Normally the investments done in induction equipment are comparatively five times higher than in gas. However, for a unit working for 10 hours a day, the return on investments are within 8-9 months.
Maintenance: It is important to understand the science of induction to understand its maintenance. Unlike fuel based heating, where the heat flows from the bottom to top, in induction technology, the flow of heat is from top to bottom i.e from the kadai to its base.
In an induction kadai we only have a copper coil and a fan. A ceramic cloth and air curtains are used to stop the heat from reaching the coils, which are to be kept cold. In other words, the copper coils are kept around 80 -100 degrees whereas the oils are around 160-200 degrees in the Kadai. If the balance of generated heat is vented out properly, the maintenance is as good as nil.
The power box containing electronics like, IGBT, Heat Sink, PCB, Capacitors, and Rectifiers etc is mounted on the wall to safeguard from water used for washing in mega kitchens.
• There is no emission of carbon
• There is no emission of oxygen
• The environment remains green
• The temperatures of the working space are comparatively cooler
• The fried products have less oil deposits (they are healthy and taste better)
• The cook does not suffer from the heat, perspiration and smoke
• The fried products look uniform in color
• The exhaust cost is reduced as there is no smoke and environmental heat.
You always have to create space for a gas bank either in the premises or outside. This eats in to your valuable space investments. Moreover, there is always the risk of faulty cylinder that can blast. One cylinder blast can play major havoc, as even the neighboring units are affected.
Over the last 3-4 years there has seen tremendous growth in the induction kadai frying market. There are batch fryer units, where frying is being done with 45-50 all the way up to 100 liters (The frying temperatures are reached in 10 minutes).
The major issues related to induction technology are:
• Awareness, as there are no major players on the national level
• Domestic Inductions are available but companies are not aware of the benefits and hence they have not yet started promoting commercial inductions [A leading domestic player introduced 3.5kw, however they could not sell, only for want of proper knowledge of the technology and the applications].
• The selective players manufacturing inductions are only interested in pushing the sales whereas they fail in after sales service. The calculation of the exact kilowatt power for the designed application is also an important factor and that knowledge is still absent. They do not spend time in the commercial kitchens to understand the needs.
• Only iron and steel of a specific grade will work, other metals will not be suitable for induction.
The market is growing at a fast pace, people have started realizing the importance of providing better environment and quality products. People have also realized the safety issues and are searching for safe alternatives as there are frequent news of blasts, gas leakage and excess heat related issues in a kitchen. We need to realize that a human life is very important and cannot be lost due to negligence and ignorance, especially with the advent of such a unique flameless cooking/frying technology. It is not only beneficial on the individual level, but is also environment friendly.
It is high time we understood and adopted the marvel that is this technology, else we run the risk of losing more lives to flames, than wars.
Author Anil Desai is Induction Specialist